Download 10th Martini, Chapter 11: An Introduction to the Muscular System

2/28/2015
BIOL 241, Winter 2015
Handout for February 28, 2015
Today’s agenda:
• Lecture test on Chapters 1 thru 10 (mostly 7 thru 10)
• Laboratory Exercise 13 (Gross Anatomy of the Muscular System)
• Laboratory Exercise 19 (The Spinal Cord and Spinal Nerves)
Since we have not yet gotten to the textbook chapters corresponding
to these two laboratory exercises, I will provide a mini-lecture as an
introduction to each. Please take notes, which will count as your “inclass activity” for today.
10th Martini, Chapter 11:
An Introduction to the Muscular System
Basically, a whole lot of anatomy …
with a few notes on muscle architecture and levers.
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Muscle fascicles
are arranged in
different ways
PARALLEL
CONVERGENT
CIRCULAR
PENNATE
contracted
relaxed
10th Martini, Figure 11-1
Muscle Attachments to Other Tissues
• Origins and Insertions
•
•
•
•
Origin: fixed point of attachment
Insertion: moving point of attachment
Most muscles originate or insert on the skeleton
Origin is usually proximal to insertion
“Knowing which end is the origin and which is the insertion is
ultimately less important than knowing where the two ends attach
and what the muscle accomplishes when it contracts.”
© 2015 Pearson Education, Inc.
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Muscle Attachments to Other Tissues
• Remember the movement terms from the previous
chapter/lab? (abduction/adduction, pronation/supination, etc.)
• Now we can see how muscles achieve these movements!
10th Martini, Figure 11-3
Muscle Attachments to Other Tissues
• Muscle Terminology Based on Function
• Agonist (or prime mover)
• Antagonist
• Synergist
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Naming Skeletal Muscles
• Names can indicate any of the following:
•
•
•
•
•
1. Location in the body – e.g., temporalis
2. Origin and insertion – e.g., sternocleidomastoid
3. Fascicle organization – e.g., rectus abdominis
4. Relative position – e.g., vastus lateralis
5. Structural characteristics
• Nature of origin – e.g., biceps femoris, triceps brachii
• Shape – e.g., deltoid, orbicularis oris
• Other striking features – e.g., pectoralis major
• 6. Action – e.g., abductor pollicis longus
Guidelines for Laboratory Exercise 13
• Main objective: study a few
muscles in detail (learn their
origins, insertions, actions at
joints).
• Muscles to study:
• Facial expression muscles:
• occipitofrontalis (frontalis)
•
•
•
•
orbicularis oculi
orbicularis oris
levator labii
zygomaticus
• Chewing muscles:
• masseter
• Temporalis
• Shoulder muscles:
• deltoid
• pectoralis major
• trapezius
• Muscles to study (continued):
• Upper limb muscles:
• biceps brachii
• flexor digitorum superficialis
• triceps brachii
• Hip and lower limb muscles:
• gastrocnemius
• gluteus maximus
• “hamstrings”
• biceps femoris
• semimembranosus
• semitendinosus
• “quadriceps”
• rectus femoris
• vastus intermedius
• vastus lateralis
• vastus medialis
• sartorius
• soleus
• tibialis anterior
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Guidelines for Laboratory Exercise 13
• Complete Activities 1 through 4, focusing mostly on the
“muscles to study” listed above but performing all
listed “Demonstrating Operations” exercises.
• Complete the Group Challenge (Name That Muscle).
• Skip Activities 5 and 6.
• In your lab notebook:
• Answer the pre-lab quiz questions.
• Answer the Group Challenge questions.
• Make a large table of information for the “muscles to study”
listed above. This will probably cover several pages. The
columns should be: (1) Muscle, (2) Origin, (3) Insertion, (4)
Action, and (5) Innervation. Leave the last column empty for
now; fill in the other columns for each muscle. For the Action
column, you only need to include the actions in blue font
listed in Tables 13.1 to 13.9.
10th Martini Fig. 12-1: A Functional Overview of the Nervous System (& the rest of the course!)
Ch. 14, 13
Ch. 15
Voluntary
Ch. 16
Automatic
Ch. 15
“rest & digest” / “flight or fight”
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10th Martini, Chapter 13:
The Spinal Cord, Spinal Nerves, and
Spinal Reflexes
• Basic anatomy/organization of spinal cord & nerves
• Neural circuits
• Reflexes
• Clinical issues
• Anaesthesia
• Paraplegia/quadriplegia
• Nerve problems
Terminology: nerve, nerve cell, neuron
10th Martini, Figure 13-6
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The spinal cord itself: gray matter & white matter
10th Martini, Figure 13-2b
White matter is organized into
tracts to/from the brain Image: Wikipedia
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Example:
corticospinal
tracts
10th Martini, Figure 15-9
Branches into and out of the spinal cord
http://www.dartmouth.edu/~humananatomy/figures/chapter_3/3-2.HTM
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Plexuses:
interconnected
networks of
nerves
Cervical plexus
C1 – C5
Brachial plexus
C5 – T1
Cervical
enlargement
Intercostal
nerves
Cervical
nerves
C1 – C8
Thoracic
nerves
T1 – T12
Lumbar
enlargement
Lumbar plexus
L1 – L4
Sacral plexus
L4 – S 4
Cauda equina
Lab manual, Figure 19-5
Lumbar
nerves
L1 – L5
Sacral
nerves
S 1 – S5
Coccygeal
nerve
Co1
10th Martini,
Figure 13-11a
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Guidelines for Laboratory Exercise 19
• Main objective: understand the general organization of the
spinal cord itself and the nerves that enter and exit it.
• Complete Activities 1, 2 (skip the dissection), and 3.
• Do the Group Challenge (Fix the Sequence).
• In your lab notebook:
• Answer the group challenge questions.
• Answer the following Review Sheet questions: 1, 2, 3, 4, 5, 6, 8,
9, 10, 11, 12, 13.
• Go back to the table you created for Lab Exercise 13 and fill in
the innervation column with ventral rami and nerve names!
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