Download Laboratory Manual for Human Anatomy and Physiology I

Laboratory Manual
for
BSC 2093C
Human Anatomy and Physiology I
Laboratory Manual
for
BSC 2093C
Human Anatomy and Physiology I
Compiled by the Faculty of Lake-Sumter Community College
Fall 2011
Table of Contents
Laboratory Rules
Page 3
Exercise One The Human Skull
5
Exercise Two The Human Skeleton
11
Exercise Three Human Muscles
19
Exercise Four Special Senses
29
Exercise Five The Human Brain
37
1
2
LABORATORY RULES
A science laboratory is not a risk-free environment. All students must take
responsibility for knowing and following a few simple rules and guidelines to
maintain their own safety, and the safety of others working in the lab.
1.
Please do not bring food or beverages into the laboratory.
When working in a science or medical laboratory it is best to assume that
every surface - every table, chair, or piece of equipment - is a potential
source of contamination. Even surfaces that look clean may have dried
chemical or biological residue on them, which will transfer easily to hands
and clothing. Anything you put in your mouth, nose or eyes while in the
laboratory may contain noxious or dangerous substances, so eating,
drinking and the application of cosmetics should not occur in the lab.
(Sneaking while the teacher isn't looking doesn't make it safer!)
2. Appropriate clothing must be worn while working in a science laboratory.
Students are required to wear closed-toe shoes before being allowed
entrance into the laboratory. Students wearing sandals, flip-flops, peeptoes, sling-backs, slides, clogs, crocs or other footwear with openings in
the sides will be denied access to the lab. Students should avoid wearing
to lab short shorts, tube and tank tops, short skirts or other clothing that
leaves a lot of skin exposed. Long hair should be tied back off the face.
Dangling jewelry should be removed.
3. Students are expected to behave in a mature and self-controlled manner.
There is no running, jumping, shouting, or throwing things allowed in the
laboratory. Students should keep their hands to themselves; even
"playful" hitting, slapping or punching is strictly forbidden. Laboratory
materials are for laboratory study and use only. Hazardous mis-use of
laboratory materials is cause for immediate ejection from the room.
4. Report any injuries or other health problems immediately.
A small first-aid kit is supplied to each laboratory. Simple injuries such as
cuts or small burns can be treated on-site. Each lab room meets or
exceeds federal standards for ventilation. Students with allergies or
chemical sensitivities should report such problems to their instructor
before entering the lab. Student should familiarize themselves with the
location of the safety shower, eyewash stations, and emergency exits.
3
5. Keep the laboratory room clean and tidy.
Please store personal possessions out of the way of foot traffic. Care
should be taken with the wheeled laboratory chairs to avoid slipping and
falling (for example, do not attempt to sit with one leg curled up on the
seat cushion). Return laboratory materials to their place. Dispose of
trash in the trash container. Wipe up any spilled liquids immediately. If
necessary your instructor will provide additional instruction on clean-up or
decontamination procedures.
6. Wash your hands with soap and water before leaving the laboratory.
Hand sanitizers do not remove dirt, oils, dyes, biological fluids or other
potential contaminants. In fact, the alcohol in most sanitizers may drive
some chemicals deeper into the skin, making later removal more difficult
and increasing their potential damage.
7. PAY ATIENTION!
Your instructor is more knowledgeable and better informed on potential
safety hazards in the laboratory than you. Listen carefully to instructions
on the proper use and handling of all laboratory equipment, solutions,
materials and supplies. In the event of an accident or other emergency,
follow your instructor's directions immediately and without argument.
4
EXERCISE ONE: The Human Skull
Objective: Students will learn to identify and correctly name the bones and
various features of the human skull.
Materials: Life-size medical-quality skulls or skull models, blunt probes, textbook
and/or human anatomy atlases.
Students may work individually or in groups
Before you begin
Most parts of the human body visible to the naked eye were identified and
named thousands of years ago by ancient Greek and Roman physicians. So
most anatomical names are either in Greek or Latin, or are latinized. You will
find it useful to familiarize yourself with the more common Latin and Greek roots
of the names, and with the modern language meanings of words that appear
frequently in anatomical studies. Below is a short list of words you will
encounter in your study of the skull and, later, the skeleton. Take a few minutes
to look them up in your text, or other sources, and write their meanings next to
them:
condyleepicondyle -
foramen-
laminameatus-
5
ramussuturetrochanter tubercletuberosity -
Structures to identify:
The following list is organized by position or viewing aspect. It is important that
students be able to identify a bone or structure regardless of the skull's position
or orientation. Therefore, the list tends to be redundant, listing the same bones,
structures and features several times.
Frontal or Anterior View
(skull is looking back at you)
bones:
structures or features:
frontal
lacrimal
ethmoid
nasal
sphenoid
zygomatic
maxilla
vomer
inferior nasal concha
perpendicular plate of the ethmoid
infraorbital foramen
mental foramen
supraorbital foramen
middle nasal concha
optic foramen (also called optic canals)
zygomatic arch
orbital foramen
Warning- watch your spelling! Foramen are NOT the same as "foremen."
6
Superior View
(looking down on the top of the skull)
bones:
structures or features:
frontal
parietal
temporal
occipital
nasal
coronal suture
sagittal suture
lambdoidal suture
zygomatic arch
Lateral View
(side)
bones:
structures or features:
frontal
temporal
zygomatic
parietal
sphenoid
nasal
lacrimal
ethmoid
maxilla
mandible
occipital
coronal suture
lambdoidal suture
squamousal suture
external auditory (acoustic) meatus
mastoid process
styloid process
zygomatic process of the temporal bone
temporal process of the zygomatic bone
zygomatic arch
mandibular condyle
coronoid process
7
Inferior View
(looking at the bottom)
For some features you may find it useful to temporarily remove (if possible) the
mandible.
bones:
structures or features:
occipital
temporal
zygomatic
sphenoid
vomer
palatine
maxilla
mandible
mastoid process
styloid process
external auditory meatus
foramen magnum
foramen ovale
foramen lacerum
palatine process of the maxilla
horizontal plate of the palatine bone
hard palate
occipital condyles
medial pterygoid lamina of the sphenoid
lateral pterygoid lamina of the sphenoid
zygomatic arch
mandibular fossa
incisive foramen
jugular foramen
Posterior View
(back of the head)
bones:
structures or features:
parietal
occipital
mandible
temporal
sagittal suture
lambdoidal suture
squamousal suture
mandibular foramen
mastoid process
styloid process
mandibular condyle
8
Cranial Cavity
(remove the top of the skull and look inside)
bones:
structures and features:
frontal
ethmoid
sphenoid
temporal
occipital
parietal
foramen magnum
crista galli in latin, a rooster's comb
cribiform plate
olfactory foramina
sella turcica in latin, a Turkish saddle
petrous portion or petrous ridge of the temporal bone
internal auditory (acoustic) meatus
foramen rotundum
foramen ovale
foramen lacerum
Your instructor will explain the specifics of your exam on the skull. In general
the exam is "practical" in nature, meaning that skulls will be tagged with stickers
and you will be asked to correctly identify the bones or structures indicated; your
instructor may prefer to point to the features and prompt you orally.
Spelling counts! Many anatomical names are very similar in spelling, and even
small mistakes can alter the meaning of the words. Sloppy spelling can lead to
serious misunderstandings, so do not expect your instructor to "know what you
mean." They won't, and you wi/llose points!
9
10
EXERCISE TWO: The Human Skeleton
Objectives: Students will learn the names and locations of the bones of the
human skeleton and various identifying structures and features.
Materials: Disarticulated human skeletons or skeleton models, textbooks and
skeleton atlases, blunt probes.
Students will work in groups.
Before you begin
Your instructor will allow several weeks for the study of the skeleton and
preparation for the laboratory practical exam. It is important that you use this
time wisely and not wait until the last moment to try to learn all of the bones and
structures. One way of organizing your time is:
First week- work to identify just the bones. Set the skeleton out on the lab
bench in approximate anatomical position. Identify superior and inferior
positions, left and right bones (where possible) and numbers of bones.
Second week - review the names and positions of the entire skeleton, then focus
on the bones of the axial skeleton. Identify and be able to name the specific
bones and their characteristic structures and features.
Third week - review material from the first two weeks, then focus on the bones
of the appendicular skeleton. Be able to name the specific bones and their
identifying features and structures.
The Learning Center has a skeleton for additional review at times the lab is not
available to you.
Your instructor will give you more information on the laboratory exam on the
skeleton. In general it is a "practical" exam with the bones tagged with
numbered stickers at stations around the room; you will move from station to
station and identify the tagged features. Spelling counts! Many of the bones
and structures have similar names and even minor spelling errors can make a
word unrecognizable. Your instructor will not know what you mean and will not
give you the benefit of the doubt.
11
Be able to identify:
Axial Skeleton
Vertebrae
Atlas (Cl) From the Greek myth of the god who carried the globe of the wor1d on his
shoulders
vertebral foramen
transverse foramen
transverse process
fovea dentis
Axis (C2)
vertebral foramen
dens (also called the odontoid process) Greek for "tooth"
spinous process
transverse process
transverse foramen
Typical cervical vertebrae (C3-C7)
vertebral foramen
body
spinous process Notice that the spinous process is often "bifid," or forked
transverse process
lamina
C7 onlyvertebra prominens
Typical thoracic vertebrae (T1-T12)
vertebral foramen
body
spinous process
transverse process
superior articular process
inferior articular process
pedicle Latin for "little foot"
lamina Latin for "thin layer"
articular facet for the ribs Latin for "little face." This feature may be more
visible on real bone vertebrae
12
Tyoical lumbar vertebrae (L1-L5)
vertebral foramen
spinous process
transverse process
body
superior articular process
inferior articular process
lamina
pedicle
If you were shown just one vertebra, could you identify it as cervical, thoracic or
lumbar? What features can you use to distinguish between the types?
How many of each type of vertebrae are found in the human skeleton?
Additional axial bones
Body greater and lesser horns / cornu
Sacrum
tubercles of medial sacral crest
auricular surface Latin for "ear-like"
sacral promontory
superior articular process
sacral foramen Many texts identify these holes as "anterior sacral foramen"
and "posterior sacral foramen" depending on which side you are viewing. They
are the same holes, passages for neiVes and blood vessels.
Coccyx Greek for "cuckoo;" similar in shape to bird's beak
Sternum
The sternum is formed by the fusion of three bones, the
manu bri urn Latin for "pot handle"
body
xiphoid process Greek for "sword"
costal cartilages Watch the spelling - costal, not coastal
head
neck
shaft
sternal (anterior) end
tubercle Latin for "small swelling"
Costal Groove
13
How many pairs of ribs are typically found in the human body?
What is the definition of a true rib?
What is the definition of a false rib?
How do you tell the difference between a floating rib and other types of ribs?
How many pairs of true ribs, false ribs and floating ribs are in a human body?
You will not be asked to identify individual ribs by position or number. However,
you may be asked to differentiate between attached and floating ribs, or explain
the difference between true and false ribs.
Appendicular Skeleton
Pectoral girdle
Clavicle Latin for "little key"
sternal end
acromial end
Conoid Tubercle
Scapula
axillary border
vertebral border
Be able to distinguish between
superior border
right and left scapula bones
ventral (costal) surface
dorsal surface
acromion process
coracoid process Greek for "crew's beak"
glenoid cavity Greek for "shallow form"
scapular notch (also called the suprascapular notch)
spine
14
Arm and hand
Humerus
head
anatomical neck
surgical neck
greater tubercle
lesser tubercle
Be able to distinguish between
intertubercular groove
right and left humerus bones
shaft
deltoid tuberosity Named for the Greek letter delta A. Where the deltoid
muscle attaches
lateral epicondyle
medial epicondyle
trochlea Latin for "spool" or "pulley"
capitulum Latin for "little head"
coronoid fossa
olecranon fossa
nutrient foramen (more easily seen on real bones)
Note - nutrient foramen, the holes left by blood vessels and nerves, are
seen on many bones, not just the humerus.
trochlear notch
coronoid process
olecranon process
radial notch
head
styloid process A stylus is a pointed tool for marking clay or wax
Radius
head
radial tuberosity
styloid process
ulnar notch
Carpals Be able to identify the group or type of bones. The individual
bones are sometimes used for extra credit questions.
trapezium Greek for "small table"
trapezoid
capitate Latin for "head"
scaphoid Greek for "boat-like"
pisiform Greek for "pea-shaped"
15
triquetrum Latin for "three-cornered"
hamate Latin, a hook
lunate Latin, moon- or crescent-shaped
Metacarpals
Phalanges
Pelvic girdle
Os coxae (pelvic bones) The coxal bones are formed from the fusion of
three bones, the ilium, the ischium and the pubis. Be able to identify the
regions of each of the three on the larger os coxa. You should also be
able to distinguish between right and left pelvic bones.
iliac crest
obturator foramen Latin for "closed up." Same root as "obtuse."
acetabulum In Roman times vinegar-based sauces were served in a cup called
an acetabulum (acetic acid has the same root)
spine of ischium
ischial tuberosity
greater sciatic notch
superior ramus of the pubis
inferior ramus of the pubis
ramus of the ischium
symphysis pubis
Leg and foot
Femur
greater trochanter Greek for "runner"
lesser trochanter
intertrochanteric crest
Be able to distinguish between
head
right and left femur bones
neck
lateral condyle
medial condyle
intercondylar fossa
shaft
linea aspera Latin for "rough line"
Patella
16
Tibia In Roman times a tibia was a flute-like musical instrument
medial condyle
lateral condyle
Be able to distinguish between
tibial tuberosity
right and left tibia bones
medial malleolus Latin for "little hammer"
Intercondyler Eminence
Fibula Latin for clasp or brooch
head
lateral malleolus
Watch your spelling - there is no such bone as a "fibia" or "tibula!"
Tarsals Be able to identify the group or type of bones. The individual
bones are sometimes used for extra credit questions.
calcaneus
talus
cuboid
navicular Latin for "boat-shaped;" the word "navy" has the same root
lateral cuneiform Latin for "wedge-shaped"
intermediate cuneiform
medial cuneiform
Metatarsals
Phalanges
Notice that the big toe has only two phalanges, while the other
toes have three. Was there a similar arrangement in the phalanges
of the hand?
Review activities:
1. Close your eyes and have a lab partner place a bone in your hands. Try to
identify the bone by touch alone. Don't peek!
2. Call out the name of a bone or structure and have your partner point to it.
Point to a bone or structure and have your partner name it. Mix up the
sequence so they can't use the order as a clue.
17
18
EXERCISE 3: Human Muscles
Objective: Students should learn the names, locations and functions of selected
muscles and muscle groups of the human body.
Materials: Students will use anatomical models of arms, legs and torsos.
Before you begin: During the lab periods assigned for this exercise students may
work individually or in groups. Additional study material is available at the
Learning Center (Leesburg campus) and the college libraries (South Lake and
Sumter campuses).
In general a skeletal muscle is attached to two individual bones. When the
muscle contracts, one bone remains relatively stationary. The site of attachment
of the muscle to the stationary bone is called the origin. When the muscle
contracts the other bone is forced to move. The site of attachment to the
moving bone is called the insertion.
You will not be asked to memorize the origins and insertions of the individual
muscles, but knowing where and how muscles are attached to bones will help
you understand their functions.
It is also useful to know the definitions of terms that are used to describe muscle
and joint actions. Use your text or other information source to learn the
definitions of the following terms (usually found in the chapter on joints and
articulations):
FlexionExtensionPlantar flexion Dorsiflexion AbductionAdduction-
19
ElevationDepression Supination PronationCircumduction or rotation -
Procedure:
Be able to identify the following muscles by name (correct spelling) and
function. Keep in mind that functions are described starting from the anatomical
position. "T" means the muscle can be seen on the anatomical torsos. "A"
means it is visible on the arm models, and "L" means it is visible on the leg
models. Some muscles are displayed on more than one model, or at more than
one location on the same model.
1. Frontalis (T) - raises eyebrows and wrinkles forehead
2. Temporalis (T) - elevates mandible
3. Orbicularis oculi (T)- closes eyelids
4. Orbicularis oris (T) - closes lips, protrudes lips
5. Masseter (T) - elevates mandible
6. Zygomaticus major and minor (T)- elevates corners of mouth and upper lip
20
7. Mentalis (T)- moves lower lip forward
8. Buccinator (T) - tenses cheeks
9. Platysma (T) - draws lower lip and corner of mouth downward as when
pouting, depresses mandible
10. Occipitalis (T) -retracts scalp, raises eyebrows
11. Sternocleidomastoid (T)- flexes and rotates neck; or elevates sternum
12. Trapezius (T) - rotates scapula, extends and rotates neck
13. Latissimus dorsi (T) - adducts, extends and medially rotates shoulder (pulls
shoulder downward and back)
14. Infraspinatus (T)- rotates arm and shoulder laterally
15. Pectoralis major (T) - adducts, flexes and medially rotates arm at shoulder
16. Pectoralis minor (T) - depresses scapula, elevates ribs
17. Serratus anterior (T)- rotates scapula, elevates ribs
18. External (abdominal) oblique (T)- flexes and rotates vertebral column,
depresses ribs, compresses abdomen
19. Internal (abdominal) oblique (T)- flexes and rotates vertebral column,
depresses ribs, compresses abdomen
20. Transverse abdominis (T) - compresses abdomen
21
21. Rectus abdominis (T) - compresses abdomen, depresses ribs, flexes
vertebral column
22. Linea alba (T) -this structure, made of dense proper connective tissue, is
an unusual type of tendon called an aponeurosis. Most tendons connect a
muscle to a bone; an aponeurosis connects a muscle to another muscle. The
linea alba (Latin for "white line") connects the right and left rectus abdominis
muscles to each other and is a major surgical landmark.
23. Deltoid (T, A) - abducts, extends and flexes the arm at the shoulder
24. Subscapularis (T, A) - rotates arm medially
25. Biceps brachii (T, A) -flexes forearm at elbow and rotates hand laterally
26. Triceps brachii (T, A) - extends forearm at elbow
27. Teres major (T, A)- extends, adducts and rotates arm medially
28. Teres minor (T, A) - rotates arm laterally
29. Brachialis (A)- flexes forearm at elbow
30. Brachioradialis (A) - flexes forearm at elbow
31. Extensor carpi radialis longus (A)- extends hand at the wrist
32. Extensor carpi radialis brevis (A) - extends hand at the wrist
33. Flexor carpi ulnaris (A) - flexes hand at wrist
22
34. Extensor carpi ulnaris (A)- extends hand at the wrist
35. Extensor digitorum (A) - extends wrist and fingers, spreads fingers apart
36. Pronator teres (A) - rotates forearm medially
37. Flexor carpi radialis (A) - flexes hand at wrist anteriorly
38. Palmaris longus (A) - flexes hand at wrist
39. Gluteus maximus (T, L)- extends thigh at hip, abducts thigh, elevates trunk
from stooping position
40. Gluteus medius (T, L) - abducts and medially rotates thigh
41. Tensor fascia latae (T, L)- flexes and medially rotates hip, stabilizes pelvis
and thigh during standing
42. Sartorius (T, L) - flexes and laterally rotates hip
Quadriceps group
43. Rectus femoris (T, L) - extends leg at knee
44. Vastus medialis (L) - extends leg at knee
45. Vastus lateralis (L) - extends leg at knee
46. Vastus intermedius (L) - extends leg at knee
23
47. Adductor longus (T, L)- adducts, flexes and medially rotates leg at hip
48. Adductor magnus (L)- adducts, extends and rotates thigh laterally
49. Gracilis (L)- adducts thigh and flexes leg at the knee
Hamstrings group
50. Semitendinosus (L) - flexes knee, extends and medially rotates leg at
hip
51. Semimembranosus (L) - flexes knee, extends and medially rotates
leg at hip
52. Biceps femoris (L) - flexes knee, extends and laterally rotates leg at
hip
53. Tibialis anterior (L) - dorsiflexion and inversion of foot
54. Extensor digitorum longus (L) - dorsiflexion and eversion of foot, extends
toes 2-5
55. Fibularis (previously Peroneus) longus (L) - plantar flexion and eversion of
foot
56. Fibularis (Peroneus) brevis (L)- plantar flexion and eversion of foot
57. Gastrocnemius (L)- flexes leg at knee, plantar flexion of foot
58. Soleus (L) - plantar flexion of foot
24
59. Achilles tendon (L)- also called the calcaneal tendon; connects several
muscles of the lower leg to the calcaneus bone of the heel, permitting plantar
flexion of the foot and flexion of the lower leg.
(How did the Achilles tendon get its name?)
Ask your instructor or consult your syllabus about the scheduling and operation
of the exam concerning muscle names and functions. In general the exam is a
"practical" or "tag test." For written exams it is very important that you be able
to spell the names of the muscles correctly and completely. Even small errors
can cause big confusion. For example, there is a muscle called "biceps brachii,"
and another called "biceps femoris." If a students supplies the answer "biceps,"
it is NOT clear which muscle is being identified, and the student will lose points.
25
Key to Muscles of the Arm
A. Muscles, Ligaments, and Tendons
1.
2.
3.
4.
5.
6.
7.
8.
9. ·
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22. ·
23.
24.
25.
2"6.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
39.
40.
41.
42.
43.
44.
Supraspinatus muscle
Infraspinatus muscle
Teres major muscle
Teres minor muscle
Latissimus dorsi muscle
Subscapularis muscle
Deltoid muscle
Pectoralis major muscle
Biceps (brachii)
Brachialis muscle
Triceps muscle
Pronator teres muscle
Flexor carpi radialis
Palmaris longus muscle
Flexor carpi ulnaris
Extensor carpi ulnaris muscle
Extensor digitorum muscle
Extensor carpi radialis brevis muscle
Extensor carpi radialis longus muscle
Brachio-radialis muscle
Tendon of the Extensor pollicis longus muscle
Extensor pollicis brevis muscle
Abductor pollicis longus muscle
Flexor digitorum sublimis
Supinator muscle
Volar fascia
Extensor retinaculum
Flexor pollicis brevis
Abductor pollicis brevis muscle
Adductor pollicis muscle
Opponens pollicis muscle
Opponens digiti minimi muscle
Flexor digiti minimi
Abductor digiti minimi muscle
Lumbrical muscles
Dorsal interosseous muscles of the hand
Flexor retinaculum ofupp'er limb
Tendon sheath
Crucial strings of the tendon sheath
Annular strings of the tendon sheath
Tendon of the flexor pollicis longus
Tendons of the flexor digitorum sublimis
Tendons of the flexor digitorum profundus
Chiasma tendinum
26
B. Arteries
45.
46.
47.
48.
49.
50.
51.
52.
53.
54.
55.
56.
57.
58.
59.
60.
Axillary artery
Subscapular artery
Circumflex scapular artery
Posterior circumflex humeral artery
Brachial artery
Profunda brachii artery
Ramus deltoideus
Medial collateral artery
Radial collateral artery
Superior ulnar collateral artery
Radial artery
Ramus palmaris superficialis
Ramus carpeus dorsalis
A. metacarpea dorsalis I
Ulnar artery
Common interosseous artery
Key to Muscles of the Leg with Base of Pelvis
A. Muscles
1.
Psoas major muscle
2.
Jliacus muscle
3.
Gluteus maximus muscle
4.
Gluteus medius muscle
5.
Piriformis muscle
6.
Obturator intemus muscle
7.
a) Superior gemellus muscle
7.
b) Inferior gemellus muscle
8.
Quadratus femoris muscle
9.
Tensor fasciae latae muscle
10.
Satorius
muscle
Sartorius
M
11.
a-b-c-d) Quadriceps femoris muscle
a) rectus femoris muscle
b) vastus medialis muscle
c) vastus lateralis muscle
d) vastus intermedius muscle
e) common tendon of the muscles
12.
Pectineus muscle
13.
Adductor longus muscle
14.
Adductor magntis muscle
15.
Gracilis muscle
16.
Semitendinosus muscle
17.
Semimembranosus muscle
18.
a-b) Biceps femoris
19.
Tibialis anterior muscle
20.
Extensor hallucis longus muscle
21.
Extensor digitorum longus muscle
27
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
Preoneus longus muscle
Peroneus brevis muscle
-b-e) Triceps surae muscle
and b) Gastrocnemius muscle
(a:Caput mediale, b:Caput laterale)
c) Soleus muscle
d) Achilles tendon
Plantaris muscle
Popliteus muscle
Flexor digitorurn longus
Tibialis posterior muscle
Flexor hallucis longus
Extensor hallucis brevis muscle
Extensor digitorurn brevis muscle
Abductor hallucis muscle
Flexor hallucis brevis
Abductor digiti minimi muscle
Flexor digiti minimi brevis
Flexor digitorum brevis
Lumbrical muscles
Dorsal interosseous muscles of the foot
28
EXERCISE FOUR: Special Senses
Objective: To familiarize students with the structures and functions of the eye
and ear.
Materials: Anatomical models of eye and ear, text books and/or atlases,
otoscopes and opthalmoscopes
Students will work individually or in groups.
Background:
If you ask most people "how many senses do humans have?" the usual
answer is "five." Sometime in childhood we learn the five senses of sight,
hearing, taste, touch and smell. Humans really have many more senses than
just five, including, heat, cold, pain, balance and motion. In addition we have a
number of internal, subconscious senses such as blood pressure and inflation of
the lungs. The traditional senses of sight, hearing, taste and smell, plus
equilibrium, are sometimes referred to as the special senses because of the
complex structures through which we perceive these sensations.
In this laboratory exercise you will become familiar with the structures of
the eye and ear, and gain some understanding of how those structures produce
the sensations of sight, sound, balance and motion. Use the models available in
the laboratory, plus a close examination of the illustrations and explanations in
your text book.
The Eye
External anatomy:
Use a lab partner, or a mirror, and look carefully at the human eye. Consult
illustrations of eye anatomy in your text or other sources. Notice the
1. eyebrows -superior to the eye on the supraorbital ridge. These patches of
short, coarse hair protect the eye from sunlight and block trickling sweat.
2. eyelids -two sheets of connective tissue covered by thin skin, one "upper" lid
and one "lower" lid per eye. Small muscles are attached to the lids to produce
blinking.
29
3. eyelashes - short, coarse hairs along the free edges of the eyelids. The
follicles of these hairs have many touch receptors, so that even the lightest touch
of the eyelash produces reflex blinking.
4. conjunctiva - transparent mucous membranes that line the eyelids and cover
the whites of the eye. Numerous small glands produce a lubricating secretion
that allows the eyelids to move smoothly and moisturizes the eye surface. When
we sleep these secretions may accumulate in the corners of the eye and dry,
producing the "sandman" crystals of childhood myth.
5. lacrimal gland - superior to the eye and slightly lateral of the midline. (Not
visible in an intact face) This gland produces the dilute saline lacrimal solution
also called "tears." Lacrimal solution is secreted through numerous small ducts
onto the conjunctiva of the upper eyelids. Blinking distributes the solution across
the eye. Lacrimal solution contains water and salts, plus antibodies and antibacterial enzymes.
6. lacrimal canals - look for two tiny red spots on the medial margin of the
eyelid. These are the openings for the lacrimal canals, which collect and drain
lacrimal solution after it has washed across the eye surface. The fluid drains
through a series of passages, eventually reaching the nasolacrimal ducts in the
lacrimal bones. From there the fluid drains into the nasal cavities and into the
nose and throat. This is why your nose runs when you cry.
7. extrinsic eye muscles- are attached to the outer surface of the eye (within
the orbit or eye socket, and therefore not visible in an intact face). Six long
skeletal muscles control the movement of the eye within the orbit. They are also
essential for coordinating the focus between the two eyes. Excessive use of
alcohol may cause these muscles to relax or temporarily weaken, producing the
"double vision" of intoxication.
30
Internal anatomy:
Now use the eye model and illustrations in the text or other sources to find and
identify the
B. fibrous tunic - name for the covering or outer surface of the eye. The fibrous
tunic is divided into two regions
9. sclera- the white of the eye
10. cornea -the transparent covering over the iris and pupil. Some of
the models have a cornea and some don't. Look at your lab partner's eye
from the side and you will see a structure bulging slightly from the
anterior surface, forming a clear dome over the front of the eye.
11. anterior chamber - the space between the cornea and the iris & pupil
12. iris- the visibly colored portion of the eye. The iris is made of two layers of
smooth muscle and bundles of elastic fibers, which function to open and close
the pupil.
13. pupil - the central opening of the eye. Light passes through the pupil into
the interior portions of the eye.
14. lens- a clear disc of tightly packed crystallin proteins. As light passes
through the lens the light waves are bent and tightly focused.
15. suspensory ligaments - on the inner surface of the iris you will see thin,
radiating lines. These represent the ligaments that attach the lens to the ciliary
muscles.
16. ciliary muscles - smooth muscles of the iris. By contracting and relaxing the
muscles pull on the suspensory ligaments and change the shape of the lens.
This in turn changes how light passes through the lens and alters the focus.
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17. posterior cavity- the large space inside the eyeball behind the iris.
18. retina - also called the sensory tunic, this is the inside surface lining the
posterior cavity. The retina contains hundreds of millions of photoreceotors,
cells that are sensitive to and respond to light. These are microscopic and are
not represented on most eye models.
19. cones- photoreceptors for bright light and color vision. Each cone
cell contains a colored compound called a visual pigment or iodopsin. We
have three types of cones, with three different iodopsins; one responds to
blue light (420 nm wavelength), one responds to green light (530 nm)
and the third type responds to red light (560 nm).
20. rods - photoreceptors for dim light. Each rod cell contains a pigment
called rhodopsin which is purple in color. Rods are active in dim light but
provide no sense of color, which is why your night vision tends to be in
shades of gray.
21. macula lutea- Latin for "yellow spot," this is an extremely small region on
the posterior portion of the retina. This region contains a dense concentration of
cones, and very few rods.
22. fovea centralis - a tiny depression or pit in the middle of the macula lutea,
packed with cone photoreceptors. Light passing through the lens is focused to
fall mostly on the fovea centralis. Further away from the macula lutea the
concentration of cones decreases and the concentration of rods increases. In
dim light you can see more detail with your peripheral vision than you can when
looking directly at something.
When light falls on a photoreceptor, chemical changes in the visual pigments
generate graded potentials in the cell membrane. These graded potentials affect
nearby neural cells in the retina, which then generate and propagate action
potentials along axons in the retina.
23. optic disc -the "blind spot" of the eye. Here there are no photoreceptors.
Axons of the neural cells merge and collect in this area, forming bundles that exit·
the eye as the optic nerve.
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24. optic nerve - on the rear of the eye model you can see the optic nerve
emerging. Sensory action potentials will be taken to the brain along this nerve.
The Ear
External anatomy:
A. auricle or pinna -the fleshy outer portion of the ear. The auricle is
composed of elastic cartilage and covered with thin skin.
B. helix -the shell-shaped rim of the auricle.
C. lobule -the dangling "ear lobe" of the auricle.
Many animals have the ability to alter the position of their auricles using
extrinsic ear muscles attached to the skull. Humans have the same
muscles, but with a few exceptions, most adults cannot alter the position
of their auricles.
D. external auditory canal or external auditory meatus- the passage from the
outside of the body to the internal structures. Sound waves will pass through
this canal toward the tympanic membrane and the middle ear structures.
You can use the otoscope to look into the external auditory canal.
E. ceruminous glands -the skin of the external auditory canal contains modified
sweat glands. These produce a waxy secretion called cerumen or "earwax." In
most people cerumen is a yellowish-brown color, but in some Asians it is gray.
Fresh cerumen is sticky and traps dust and other particles. It also contains some
insect-repellent chemicals. As cerumen dries, it separates from the skin and,
usually, is slowly worked to the outside by motions of chewing, talking and
swallowing. In some people, most often children, cerumen may become
compacted and collects in the external auditory canal, blocking sound waves and
impairing hearing.
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F. tympanic membrane- a thin connective tissue membrane dividing the outer
ear from the middle ear. The "eardrum." Sound waves passing down the
external auditory canal hit the tympanic membrane and cause it to flex and
vibrate.
Internal anatomy:
You should now turn your attention to the ear models, as well as the illustrations
in your text or other sources.
Middle Ear
G. tympanic cavity - another name for the middle ear
H. ossicles- the three bones of the middle ear. Closest to the tympanic
membrane is the
I. malleus (Latin for "hammer'') - when sound waves hit the
tympanic membrane, the membrane flexes inward and presses on
the malleus.
J. incus (Latin for "anvil'') - when the malleus moves, it strikes the
second ossicle bone, the incus.
K. stapes (Latin for "stirrup'') - when the incus moves, it in turn
strikes the stapes bone. In this way the sound wave is transmitted
through the middle ear to the inner ear.
L. eustachian tube - also called the auditory tube or the
pharyngotympanic tube. This passage allows air to pass between the
middle ear and the oral cavity, keeping air pressure equal on both sides of
the tympanic membrane. Sometimes when you swallow one or both of
your ears will "pop" as the air pressure changes and the tympanic
membrane flexes.
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Inner ear:
The inner ear is also called the labyrinth because of its
complicated and confusing three-dimensional shape. In
most models the entire inner ear lifts out as a single piece.
There are three areas or sections to the inner ear, the
cochlea, the vestibule, and the semicircular canals.
M. cochlea- the organ for the perception of sound. This
spiral-shaped bony structure is named for its resemblance to
a snail (conch) shell. On some models the cochlea can be
opened to show the three parallel chambers inside. Inside
the cochlea is a fluid, called perilymoh, or cochlear fluid,
which flows around the spiral chambers.
N. oval window - the stapes bone is attached to the opening
into the inner ear called the oval window, also called the
vestibular window. On the models the opening is completely
covered by the stapes. When the stapes is struck by the
incus (struck by the malleus, pressed by the tympanic
membrane) the stapes pushes in onto the oval window and
sets the perilymph in motion. As the perilymph moves it
flows across tiny hair cells lining the cochlear chambers.
The stiff cilia projecting from these cells are bent by the
moving perilymph. When the cilia are bent, they either
depolarize or hyperpolarize, depending on the direction of
motion. Enough depolarization causes action potentials,
which are sent along axons in the cochlear chambers to the
cochlear nerve.
0. round window- also called the cochlear window. This
tiny opening is covered with a thin connective tissue
membrane. When the stapes presses on the perilymph at
the oval window, the fluid will flow around the spiral
cochlear chambers toward the round window. The
membrane over the round window bulges outward, relieving
the pressure in the cochlea.
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P. vestibulocochlear nerve - also called the auditory nerve.
This nerve is composed partly of the cochlear nerve, carrying
action potentials from the cochlea, and the vestibular nerve,
carrying action potentials from the other portions of the
inner ear.
Q. vestibule - contains the structures for the perception of
static equilibrium, the ability to sense up and down. Inside
the vestibule is a compartment called the utricle. Like the
cochlea, the vestibule and utricle are lined with hair cells and
filled with perilymph fluid. In addition the utricle contains a
thick sheet of jelly-like material called the otolithic
membrane. Embedded in the otolithic membrane are many
tiny stone-like calcium deposits called otoliths. These make
the otolithic membrane very heavy, so it will slide and settle
to the bottom of the utricle. The membrane presses on the
hair cells, which generate a steady stream of action
potentials. If you tip your head to the side, the otolithic
membrane slides onto the new 'down' position, and presses
on another set of hair cells. These then generate action
potentials and signal the new up and down orientation.
R. semicircular canals - these round structures connect to
the vestibule and produce the sensation of dynamic
equilibrium. This is what we think of as "balance," as well as
the perception of motion, in particular the angular and
rotational motions of the head. Although they are called
semicircular, notice that each canal actually forms about 2/3
of a circle. When your head moves, the perilymph fluid
inside the semicircular canals moves also. As the fluid flows
around the canal, it brushes against the cilia of the hair cells,
and the cells produce action potentials. The semicircular
canals are most sensitive to rotational motion, such as when
you twirl around in a circle. When you stop twirling, the
fluid is still in motion, producing the sensation that you are
still moving, or that the world is spinning around you.
Action potentials from the semicircular canals and the utricle
pass through axons that merge to become the vestibular
nerve, which in turn merges with the cochlear nerve to
become the vestibulocochlear nerve or auditory nerve.
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EXERCISE FIVE: The Human Brain
Objective: To learn the names, locations and some functions of selected parts of
the human brain.
Materials: Human brain models and illustrations from textbook.
Students will work individually or in groups.
Procedure
Use the materials provided to learn the names, locations and brief descriptions of
functions of the parts of the brain listed below. The numbers in parentheses
refer to the Denoyer-Geppert Giant Brain models. The colors and numbers will
assist you in locating some of the specific regions or areas, but please do not
memorize them - real brains don't have bright colors or numbers on them!
I. Definitions. Knowing the definitions of the following terms will help in your
study:
a. gyrus - a convoluted ridge on the cerebral cortex from the Greek for "twisted." A
gyro sandwich is twisted in the bread.
b. sulcus- a shallow groove between two gyri.
c. hemisphere - one half of a spherical structure, such as one half of the
cerebrum or one half of the cerebellum.
d. ventricle -a fluid-filled cavity
e. gray matter- portions of the central nervous system composed primarily of
cell bodies and unmyelinated axons. In life this tissue is a dingey gray
in appearance.
f. white matter - portions of the central nervous system composed primarily
of myelinated axons. In life this tissue is a glossy white in appearance.
g. commisure - white matter fibers that connect hemispheres.
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II. Structures to Identify
Observe the intact brain model. Gento/ lift the model and turn it so it is in an
upright (anatomical) position. Most of what you are seeing is the cerebrum,
the largest part of the human brain. The cerebrum is divided into right and left
cerebral hemispheres by the deep longitudinal fissure running down the
mid-line of the brain.
1. Cerebrum
2. cerebral hemisphere
3. longitudinal fissure
4. cerebral cortex- the outer layer of gray matter of the cerebrum.
Remove the front piece of the right cerebral hemisphere to see the
division between gray matter of the cortex (painted a bright color on the
model) and the deeper white matter (white) of the cerebrum.
The surface of the cerebral cortex is thrown into numerous ridges and
valleys, the gyri and sulci. The folds form five lobes of the cerebral
cortex:
5. frontal lobe (2) - reason, speech, abstract thinking, voluntary
motor activity and perception of odor
6. parietal lobe (4)- body imaging, taste and understanding
speech
7. temporal lobe (3)- perception of sound and odors, memory
and emotion
8. occipital lobe (5) - sight, memory
9. insula (86) buried beneath the temporal lobe - plays a role in
taste and understanding speech
The gyri and sulci of the cortex can be useful landmarks for locating
functional regions of the brain.
10. central sulcus (20)- divides the frontal lobe from the parietal
lobe
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11. anterior central gyrus or pre-central gyrus (10)- primary
motor area of the cortex, controls voluntary movement of most
skeletal muscle
12. posterior central gyrus or post-central gyrus (11)- primary
somatosensory area of the cortex, integrates information about
touch, pressure and position
13. lateral sulcus or Sylvian fissure (28) - divides temporal lobe
from parietal and frontal lobes
The central nervous system begins in the embryo as a hollow, fluid-filled
tube. Remnants of that embryonic structure persist as cavities in the
brain and spinal cord filled with cerebrospinal fluid.
14. lateral ventricles (88 & 89)- ventricles one and two, one in
each cerebral hemisphere. The structures curve out and down
from the midline and are difficult to represent in models. Gently
remove the brainstem from the right hemisphere to see the cavity
more clearly
15. third ventricle (113) - a shallow depression around the
thalamus in the midbrain
16. cerebral aqueduct or Sylvian aqueduct (57) - a passage for
cerebrospinal fluid between the third and fourth ventricle
Aqueducts were large stone and brick systems built by the Romans to bring
water from the mountains to the city.
17. fourth ventricle (59)- a wedge-shaped space between the
cerebellum and the brain stem. At the inferior end the fourth
ventricle connects to the central canal of the spinal cord
18. corpus callosum (41, 42, 43)- a large commisure connecting the
right and left cerebral hemispheres
19. fornix (45)- a smaller commisure connecting regions of the limbic
system The limbic system is a group of structures, some in the cerebrum and some in
the thalamus and hypothalamus. These areas produce emotion and control the physical
expression of emotion, such as facial expressions.
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20. Diencephalon structures
21. thalamus (47, 49, 109)- two egg-shaped masses of gray matter
virtually in the center of the brain, held together by the intermediate mass
of the thalamus. The thalamus processes and integrates sensory
information, sorts and edits what is sent to the cerebral cortex for
conscious perception
22. hypothalamus (not numbered)- this triangular region is inferior and
somewhat anterior to the thalamus. Find #52 and #68- the
hypothalamus is the region between the numbers. The hypothalamus
controls autonomic motor functions, regulates body temperature, and
regulates many primitive drives and emotions such as thirst, hunger,
sleep, pleasure, pain, fear and rage.
23. mammilary bodies (69) -two "breast-shaped" bulges on the inferior
surface of the hypothalamus. These integrate olfactory (smell) sensory
information
24. infundibulum (72)- the stalk of the hypothalamus that connects to
the pituitary gland
25. pituitary gland (115) also called the hypophysis - a major gland of
the endocrine system, secretes several hormones including growth
hormone and oxytocin
26. pineal gland or pineal body (54) - participates in regulation of sleepwake cycle by secreting melatonin (makes you sleepy)
27. Midbrain structures
28. corpora quadrigemina (56, 100, 101, 107, 108)- four ("quad")
rounded protrusions on the posterior of the midbrain
29. superior quadrigeminal bodies (100, 107)- coordinate visual
reflex movements of the eyes when tracking or following a moving
object
30. inferior quadrigeminal bodies (101, 108)- coordinate auditory
reflexes, such as tilting the head toward an unexpected sound
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31. Cerebellum (6) - Once considered mostly a processing center for
unconscious or subconscious motor activity, recent studies indicate the
cerebellum also participates in cognitive functions such as language and problem
solving, in particular predicting sequences or patterns.
32. cerebellar hemisphere (6)
33. vermis (62 & 130) - connects the two cerebellar hemispheres. This
structure may be easier to see on life-size models. Vermis is Latin for "worm." Vermicelli
is pasta that looks like a plate of worms.
34. arbor vitae (61)- the white matter of the cerebellum. Arbor vitae is
Latin for "tree of life.'' Notice the highly branched arrangement of the white matter.
35. Pons (65) - this area integrates and coordinates activity of the cerebral
motor areas and the cerebellum. With the medulla oblongata the pons also
regulates respiration
36. Medulla oblongata (63)- also called just the "medulla." Contains regulatory
centers for respiration and cardiac function, as well as vomiting, hiccupping,
swallowing, coughing and sneezing reflex centers. Coordinates activity with the
hypothalamus
The medulla ends and the true spinal cord begins as the brain stem narrows and
passes through the foramen magnum of the skull.
Nerves are bundles of axons in the peripheral nervous system. Spinal nerves
are connected to the spinal cord. Cranial nerves are connected to the brain.
Sensory nerves contain only the axons of sensory, or afferent, neurons.
Motor nerves contain only the axons of motor, or efferent, neurons. Mixed
nerves contain axons of both sensory and motor neurons. All spinal nerves are
mixed nerves, but some of the cranial nerves are more specialized.
41
Cranial nerves are designated by Roman numerals from the anterior to the most
posterior. They all originate/terminate on the inferior surface of the brain.
Notice that each is actually a pair of nerves, one on each side of the midline of
the brain.
I. olfactory nerve (92 & I) - sensory nerve, carries information about
sense of smell Remember the olfactory foramina in the skull?
II. optic (112 & II)- sensory nerve, carries impulses from the retinas of
the eyes to the visual areas of the occipital lobe.
Notice that the optic nerves branch and cross at the optic chiasma (53).
The optic chiasma is a major landmark of the brain, and functionally
allows both sides of the brain to receive visual information from both
eyes. Chiasm is Greek for crossed lines
III. oculomotor (114 & III)- motor nerve that controls four muscle
groups of the eyeball in its socket, and some of the muscles inside the eye
attached to the lens and pupil
IV. trochlear (116 & IV) - motor nerve that controls some of the muscles
of the eye socket. Trochlea in Latin means spool or pulley. See the illustrations of
the eye muscles in your text to see the connection.
V. trigeminal (117 & V)- mixed nerve. Sensory components for forehead
and eyelids, teeth, palate and gums. Motor components for chewing
VI. abducens (118 & VI)- motor nerve that controls lateral movements
of the eyeball in the socket
VII. facial (119 & VII)- a mixed nerve. Sensory components for taste.
Motor components for some facial muscles and expressions, and tear and
salivary gland secretions
VIII. auditory or vestibulocochlear (120 & VIII) - also called the acoustic
nerve, a sensory nerve that carries information from the semicircular
canals of the inner ear for balance, and the cochlea of the inner ear for
hearing
IX. glossopharyngeal (121 & IX) - a mixed nerve. Sensory components
for tongue and lining of pharynx. Motor component for muscles in
pharynx involved in swallowing
X. vagus (122 & X) - a mixed nerve. Sensory information for pharynx,
larynx, esophagus and organs of the thorax. Motor functions on muscles
of speech, swallowing and the heart.
42
XI. spinal accessory or accessory (123 & XI) - motor nerve, controls
some of the muscles of the neck
XII. hypoglossal (124 & XII) - motor nerve, stimulates muscles of the
tongue for speech, chewing and swallowing
Over the years anatomy students have developed a number of mnemonic
devices to remember the cranial nerves. Here's a few:
(Read down)
on
old
olympus'
towering
tops
a
finn
and
german
viewed
some
hops
on
occasion
our
trusty
truck
acts
funny
very
good
vehicle
any
how
oh
oh
oh
to
touch
and
feel
a
genuine
virgin/vagina
such (ah)
heaven
43
44