Download Anatomical Terminology

Anatomical Terminology
BACKGROUND –
I.
Reading Assignment: Moore, Dalley, and Agur, Clinically Oriented Anatomy, 6th ed., pp. 1-35.
ANATOMY TERMINOLOGY
A. Anatomical position
1. By convention, the relationships of anatomical structures are described as if the person is in anatomical position--standing
upright with the head, eyes and toes directed forward (anteriorly), upper limbs by the sides with the palms of the hand
facing anteriorly, and the lower limbs close together with the feet parallel (directed anteriorly)
2. All anatomical descriptions are always expressed in reference to the anatomical position, regardless of the actual position
of the body
B. Anatomical (cardinal) planes
1. Four imaginary planes that pass through the body in the anatomical position
a. Median plane is the vertical plane that passes longitudinally through the body
 Divides body into equal right and left halves
 Sometimes called the midsagittal plane
b. Sagittal planes are vertical planes that pass through the body parallel to the median plane
 Divides body into unequal right and left halves
 Sometimes referred to as parasagittal planes
c. Coronal (frontal) planes are vertical planes that pass through the body at right angles to the median plane
 Divides body into anterior (front) and posterior (back) portions
d. Horizontal (transverse) planes pass through the body at right angles to the median and coronal planes
 Divides body into superior (upper) and inferior (lower) portions
 Radiologists refer to transverse planes as transaxial or axial planes
C. Terms of relationship and comparison (expressed as pairs of opposites)
1. All are described in reference to the anatomical position
a. Superficial indicates that structures are closer to the surface; deep indicates farther from the surface
b. Medial indicates that structures are closer to the median plane; lateral indicates farther from the median plane
c. Anterior (ventral) indicates that structures are closer to the front; posterior (dorsal) indicates closer to the back
d. Superior (cranial) indicates that structures are closer to the head; inferior (caudal) indicates closer to the feet
e. Proximal indicates that structures are closer to the point of origin or the trunk; distal indicates farther from the point of
origin or the trunk
f. External (outer) indicates that structures are toward or part of the surface; internal (inner) indicates toward or part of
the interior
g. Central indicates that structures are close to the center; peripheral indicates away from the center
h. Parietal indicates structures pertaining to the wall of a cavity; visceral pertains to the covering of an organ
i. Ipsilateral indicates structures on the same side of the body; contralateral indicates on the opposite side of the body
D. Terms of movement (expressed as pairs of opposites)
1. All are described in reference to the anatomical position
a. Flexion indicates bending or decreasing the angle between body parts; extension indicates straightening or increasing
the angle between body parts
b. Abduction indicates moving away from the median plane; adduction indicates moving towards the median plane
 In the hand and foot, abduction and adduction of the digits is in reference to the third (middle) finger and the
second toe, respectively
c. Rotation involves turning or revolving a part of the body about its longitudinal axis
 Medial (internal) rotation brings anterior surface of a limb closer to the median plane
 Lateral (external) rotation takes anterior surface away from the median plane
d. Circumduction is circular movement combining flexion, extension, abduction, and adduction
e. Supination involves rotating the hand and forearm about its longitudinal axis so that the palm faces anteriorly;
pronation involves rotation of the hand and forearm so that the palm faces posteriorly
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
When the elbow is flexed, the palm faces superiorly in supination (like carrying soup) and the palm faces inferiorly
in pronation
f. Eversion moves the sole of the foot away from the midline (raising the lateral side of the foot); inversion moves the sole of
the foot towards the midline (raising the medial side of the foot)
g. Protrusion (protraction) moves a structure anteriorly (like sticking out your jaw); retrusion (retraction) moves a
structure posteriorly
II. SKELETAL SYSTEM DIVISIONS
A. The skeleton can be divided into two parts, the axial skeleton and the appendicular skeleton
1. Axial skeleton consists of the:
a. Skull
b. Hyoid bone
c. Vertebrae
d. 12 pairs of ribs
e. Sternum
2. Appendicular skeleton consists of the:
a. Limb girdles
 Scapula and clavicle for the upper extremity
 Coxal (hip) bone (formed by the ilium, ischium and pubis) for the lower extremity
a. Upper and lower limbs (extremities)
III. CARTILAGE
A. Cartilage is a specialized connective tissue which allows the tissue to bear mechanical stresses without permanent distortion
1. Consists of chondrocytes and an extensive extracellular matrix
B. Types of cartilage
1. Hyaline cartilage
a. Most common type of cartilage
b. Located on articular surfaces of moveable joints, larynx, trachea and bronchi, costal cartilages and epiphyseal plates
of developing bones
2. Elastic cartilage
a. Very similar to hyaline cartilage, contains elastin fibers in matrix
b. Located in auricle of ear, external auditory canal, auditory tubes, epiglottis and cuneiform cartilage of larynx
3. Fibrocartilage
a. Described as being between hyaline cartilage and dense connective tissue
b. Contains abundant quantities of Type I collagen in dense bundles
c. Located in pubic symphysis and annulus fibrosus portion of intervertebral discs
IV. BONE CLASSIFICATION
A. Classification by shape
1. Long bones
a. Tubular
b. Length is greater than the width
c. Long bones have a body (shaft or diaphysis) with a marrow cavity and two ends
2. Short bones
a. Cuboidal
b. Found only in the wrist (carpal) and ankle (tarsal)
1. Flat bones
a. Also called squamous bones
b. Consist of two plates of compact bone with spongy bone and marrow in-between
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c. Function to protect and reinforce structures
d. Found in the skull, and also include the ribs, sternum, and scapula
2. Irregular bones
a. Various shapes other than long, short, or flat
b. Include all skull bones that are not flat bones, vertebrae, and hip bones
3. Sesamoid bones
a. Develop in tendons
b. Found where tendons cross the ends of long bones in the limbs (e.g. patella)
c. Protect tendons from excessive wear and often change the angle of the tendons as they pass to their attachments
4. Accessory (supernumery) bones
a. Extra bones that develop from additional ossification centers
 Many bones develop from several ossification centers and eventually fuse
 Sometimes one of these centers fails to fuse with the main bone, giving the appearance of an extra bone
b. Accessory bones called sutural or wormian bones are commonly seen in skull sutures
B. Features of bone
1. Bone markings appear wherever tendons, ligaments, and fascia are attached, or where arteries lie adjacent to or enter
bones
2. Elevations or prominences
a. Linear elevations are referred to as lines or ridges
 If the elevation is prominent, it is called a crest
b. Elevations are called various names, depending on their size
 Condyles are rounded articular areas
c. Relatively large elevations are called processes, tuberosities, or trochanters
d. Smaller elevations are called protuberances, tubercles, or spines
e. A projecting spine-like part is called a spinous process
3. Depressed areas are referred to as fossae, cavities, antra or foveae
a. An elongated furrow or depression is called a groove or sulcus
b. An indentation is called a notch; if a ligament bridges a notch, it is called a foramen
4. Facets are small, smooth flat areas of bone, usually found where two bones come together
a. They are often covered with articular (hyaline) cartilage
5. A foramen is a hole or passage through a bone
6. A meatus is an opening that does not have an exit; a canal is an opening that has an exit
V.
MUSCLE STRUCTURE
A.
B.
C.
D.
Skeletal muscle fibers arranged in grossly visible bundles - fascicles surrounded by perimysium
Some muscles are fleshy throughout, having direct attachments to bone (without any tendon)
Force of muscle is proportional to cross-sectional area
Most muscles attach to bone via non-contractile tendons
1. When referring to the length of a muscle, both the fleshy belly and tendons are included
a. Length is equal to the distance between attachments
E. Muscle architecture is the arrangement of fascicles relative to tendons or attachments. There are three basic architectures—
parallel-fibered, pennate and fan-like
1. Parallel-fibered muscles
a. Forms vary from flat, short and quadrilateral muscles (e.g. thyrohyoid) to long, strap-like muscles (e.g. sternohyoid,
sartorius)
b. Fascicles run parallel to the line of pull
2. Pennate muscles (pinnate, penniform, pinniform)
a. Fascicles arranged in a feather-like pattern, oblique to the line of pull
b. Permits a muscle to have more fibers and exert more force than parallel-fibered muscle
c. Pennate variations
 Unipennate (e.g. flexor pollicis longus)
 Bipennate (e.g. rectus femoris)
 Multi-pennate (e.g. deltoid)
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3. Fan-like architecture
a. Similarities to both parallel-fibered and pennate (e.g. latissimus dorsi)
F. Muscle nomenclature
1. Names of individual muscles are usually descriptive, based on muscle :
a. Shape
b. Size
c. Number of heads or bellies
d. Position
e. Depth
f. Attachments
g. Actions
 Note that terms are often combined and if the name is based on an action, the action may be overly simplified and
not all the true actions of the muscle may not be apparent
VI.
MUSCLE FUNCTION
A. Principles of muscle function
1. A muscle must cross a joint in order to produce an action at that joint
2. If a muscle crosses more than one joint, its actions and range of motion at one may be affected by the positions of the
others
3. Muscle contractions produce movement by pulling (never pushing) the movable attachment (usually the insertion) toward
the fixed attachment (usually the origin)
4. The force a muscle exerts is proportional to its cross-sectional area. A muscle’s range of contraction is proportional to the
resting length of its fibers
B. Muscle contractions are classified by their effect on muscle fiber length and role in producing particular actions
1. Isotonic contractions
a. Muscle length changes in relation to movement
b. Length may decrease or increase
c. Concentric contractions
 Active muscle decreases in length; typical of an agonist (prime mover)
d. Eccentric contraction
 Active muscle increases in length; typical of an antagonist
2. Isometric contraction
a. Active muscle maintains length; typical of a fixator
C. Functional definitions
1. Prime mover (agonist)
a. Main muscle responsible for producing a specific movement
2. Antagonist
a. Muscle that opposes the action of another muscle
 1° antagonist will oppose the 1° agonist
 As 1° agonist concentrically contracts, the 1° antagonist will eccentrically contract (acting as a brake during rapid or
forceful movements), resulting in a smooth movement
3. Fixator
a. Muscle that steadies the proximal limb through isometric contractions
4. Synergist
a. Compliments function of prime mover
b. Usually weaker or less advantageous mover than prime mover
VII.
FASCIA
A. Masses of connective tissue that can be seen with the naked eye
1. Structure varies from a dense connective tissue to a loose areolar connective tissue
2. Functions as wrapping, packing and insulation to deep structures in the body
3. Two types
a. Superficial
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b. Deep
B. Superficial fascia
1. Also referred to as subcutaneous tissue
a. Deep to skin, superficial to deep fascia
b. Thickness is highly variable
2. Consists primarily of loose connective tissue, stored fat, sweat glands and neurovascular structures
a. Amount of fat varies with location
 Partly under hormonal control
 Also varies with the amount of food eaten
B. Deep fascia
1. Dense connective tissue deep to superficial fascia
a. Devoid of fat
2. Forms a membranous layer that covers muscles and skeletal structures
3. Sometimes referred to as investing deep fascia
4. May be part of epimysium on surface of muscle (e.g. trapezius)
5. Extensions to bone (septa) help delineate fascial compartments in the limbs
Lecture 7: Axial skeleton
I.
Two divisions of Skeleton
Axial
a.
80 total bones
2. Appendicular
a.
126 total bones
II.
Vertebral Column
1. 33 vertebrae and various components that unite them
2. 5 groups
a. 7 cervical
b. 12 thoracic
c. 5 lumbar
d. 5 sacral
e. 4 coccygeal
3. Vertebrae consist of 3 parts:
a. Body
i.
More massive, roughly cylindrical
b. Vertebral Arch
iii. Consists of 2 pedicles and two laminae to create vertebral foramen (vertebral canal)
c. Vertebral processes
iii. Two functions: (1) levers for muscle attachment – transverse and spinous processes and (2)
restriction of movement – articular processes
iv. Thoracic vertebrae: good rotation, poor F/E
v. Lumbar vertebrae: poor rotation, good F/E
B. Cervical Vertebrae
a. Most distinct identifying feature of cv: transverse foramen
b. Superior C3-C7 resembles sculpted seat
a. Inferior part of body reciprocates this form
c. Spinous processes of c3-c7 are bifid and short
a. Spinous process of C7 (vertebra prominens) is long
d. Atlas (c1) and axis(c2) are atypical cervical vertebrae
a. Atlast (c1) supports skull
1. Unique because it has neither a body nor a spinous processs
2. It has paired lateral masses that substitute for a body, and bear the weight of
the skull
1.
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3. Concave superior articular facets on lateral masses articulate with occipital
condyles of the skull
b. Axis (c2) interacts with atlas
1. Strongest of the cervical vertebrae
2. Distinguishing feature is dens, the pivot around which the atlas rotates
3. Two large superior articular facets with interact with C1
C. Thoracic Vertebrae
ii.
Provides attachment for ribs
iii.
Primary structural feature are costal facets
i. Superior and inferior costal facets on body
ii. Transverse costal facets on transverse processes
iv.
Thoracic vertebrae feature long spinous processes
v.
T1
i. T1-T4 share some characteristics of cervical vertebrae
ii. T1, in particular, has a very long, nearly horizontal spinous process
vi.
T12
i. Most of the transition in the form from thoracic to lumbar vertebrae occurs over a single vertebra (t12)
ii. Transitional stress make this the most commonly fractured vertebrae
D. Lumbar Vertebrae
ii.
Very large bodies that occupy a good portion of the median plane
iii.
Nearly horizontal, quadrangular spinous processes
iv.
Two additional processes for muscle attachment
i. Accessory processes at base of transverse processes
ii. Mammillary processes on posterior surface of superior articular processes
E. Sacrum
ii.
Wedge shaped bone consisting of 5 fused vertebrae
iii.
Sacrum transmits body weight to lower limbs
iv.
Features anterior and posterior foramina
i. Site of exit of spinal nerves
v.
Laterally, the sacrum has features associated with the sacroiliac joints
i. Auricular surfaces
ii. Tuberosities
vi.
Potential site for injections: sacral hiatus
i. Inferior opening to sacral canal
ii. Covered by membranous sacrococcygeal ligament
iii. Possible site for caudal epidural anesthesia
A. Palpate 4th spinous process and cornua
F. Coccyx
ii.
Small triangular bone formed by the fusion of 4 rudimentary vertebrae
III. Thoracic Skeleton
A. Ribs
a. All ribs articulate with thoracic vertebrae posteriorly
b. Anterior attachment of the ribs differ(this helps determine naming)
c. Anterior attachment
a. True ribs (1-7)
1. Direct attachment to sternum through own costal cartilage
b. False ribs (8-12)
1. Indirect attachment to sternum through own costal cartilage
2. 11 and 12 have no anterior attachment (free or floating ribs)
d. All ribs have a head, some degree of angle, and a shaft (body)
e. Ribs 3-9 have the following:
a. Head
b. Neck
c. Tubercle
d. Body (note costal groove)
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f.
Atypical ribs
a. Upper ribs (1-2)
1. Broader, shorter
2. Rib 1 articulate with single vertebra
3. Lot of surface markings
4. Have grooves for vessels, arteritis, tuberosities
b. Lower ribs (10-12)
1. No neck or tubercle
2. 12 articulates with single vertebra
B. Sternum
a. Manubrium
a. Contains jugular notch
b. Body
a. Note sternal angle
1. 2nd rib, base of aorta, t4-t5
c. Xiphoid process
a. Inferior border of heart; superior border of liver
d. Palpatable at jugular notch and sternal angle: junction where second rib, top of heart, part of
trachea attach.
C. Cranium
a. 22 bones (excluding ossicles of the ear)
b. Two parts:
a. Neurocranium (cranial vault)
1. 8 bonds
i. 4 singular bones centered on midline (frontal, ethmoidal,
sphenoidal, occipital)
b. Two sets of bones occurring as bilateral pairs (temporal, parietal)
c. Bregma: Craniometric point formed by the intersection of sagittal and coronal sutures
d. Pterion: Craniometric point on lateral aspect of skull. Thin bone overlying middle meningeal
artery. Injuries here are bad and make skull swell.
e. Glabella: Smooth prominence on frontal bone, above nose
a. Two parts of neurocranium:
i. Calvaria: Upper dome shaped portion of skull
ii. floor
b. Viscerocranium (facial skeleton)
1. 15 bones
2. Three singular bones centered on midline: mandible, ethmoid, and vomer
a. Ethmoid makes contributions to both neuro and viscerocranium
3. Six sets of bones occurring as bilateral pairs
D. Surface landmarks
a. Zygomatic arch
b. Tmj (see slide 93)
c. External occipital protuberance (important for muscle attachment – see slide 94)
d. Parietal eminence (demi moores head)
e. Fronatal eminences (where id have horns haha)
f. Supraorbital ridge (gorilla)
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Typical cervical vertebrae
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calvaria on top
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Lecture 8 – Appendicular Skeleton
1. Organized into girdles and limbs
a. Girdles
i. Pectoral
ii. Pelvic
b. Limbs
i. Upper
ii. Lower
2. Shared limb characteristics
a. Both upper and lower arms have proximal anchoring to axial skeleton and distal elaboration for contact with
environment
3. Pectoral Girdle and Upper Limb
a. Pectoral Girdle
i. Incomplete ring consisting of 4 bones:
1. Two clavicles
2.
ii.
Ac
S
1.
Cl
iii.
Two scapulae
The ring is completed anteriorly by the manubrium
Posterior gap allows mobility
Clavicle
Appearance of italic letter f
1.
2. Curvatures increase resilience
3. PALPABLE
4. Transmits shock from upper limb to axial skeleton (makes it be fractured frequently)
5. In a fracture of the clavicle, the distal end drops (due to weight of limb), while proximal end rises
iv. Scapula
1. Overlies ribs 2-7
2. Structural/functional requirements
a. Liberal amount of movement and smooth anterior surface
b. Ability to be acted upon by many muscles
i. Presence of several crests, angles, protrusions
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3. Know subcapsular fossa, spine of scapula, acromion, muscles attach in supraspinous fossa
4. Humerus attaches at glenoid fosa
5. coracoid process is PALPABLE
4. Upper Limb
a. Humerus, radius and ulna, bones of wrist and hand
b. Arm
i. Humerus is the bone of the arm
1. Has proximal end (part spheroid, part platform) and distal end (flat, specialized for strong hinge-like
articulation)
2. Most likely that fracture will occur at surgical neck
3. Anatomical neck is edge of hyaline cartilage
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4. Condyle: articular end of long bone
a. Two parts: trochlea (capitulates with ulna) and capitula (articulation of head of radius)
c.
Forearm
i. Ulna and radius
ii. Ulna
1. Longer, medial, stabilizing bone of the forearm
2. Large, proximal end of ulna is specialized to articulate with the humerus
3. Distal end does not articulate with wrist
iii. Radius
1. Laterally-positioned and is more robust than ulna (for application of force)
2. Allows for versatility of hand
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d. Hand
i. Carpus, metacarpus, phalanges
ii. Carpus
1. Consists of eight carpal bones
arranged in two rows of four
2. The scaphoid and lunate are in contact
the radius
Phalang
es
with
Metacar
pus
Carp
us
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3. Scaphoid bone and radial styloid process are for fracture PALPATION
iii. Metacarpus
1. 5 bones
2. Palm of hand
3. Thumb is the first metacarpal
iv. Phalanges
1. Each digit has 3 phalanges
a. Thumb only has 2
2. Size decreases from proximal to distal
3. Tips of distal phalanges are flattened and
expanded
a. Accommodate nails
5. Pelvic Girdle and lower limb
a. Pelvic girdle
i. 3 bones
ii. Right and left hip bones
1. Known as coxal bones, os coxae, pelvic
bones, or hip bones
iii. Sacrum
iv. Hip bones
1. Each hip bone arises from the fusion of
three bones after puberty (ilium, ischium,
pubis)
2. All three bones contribute to acetabulum
3. You sit on ischium
4. You can PALPATE posterior superior iliac
spine
Iliu
m
Ischiu
m
Acetabul
um
Pub
isLATERAL
VIEW
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b. Thigh
i. Femur : longest and heaviest in body
ii. Identical in concept to the humerus, but with more exaggerated end
1. Trochanters vs tubercles
2. Two large condyles vs smaller single condyle
c.
Patella
i.
ii.
d. Leg
i.
ii.
iii.
Sesamoid bone is embedded in quadriceps tendon
Patella serves to increase leverage in the extending knee and lengthens lever arm
Anatomical leg features tibia and fibula
Mobility is sacrified for weight bearing stability (tibia is 2nd biggest bone)
Both tibia and fibula contribute to ankle (malleoli)
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iv. Tibia
1.
2.
3.
v. Fibula
1.
2.
Dominant both proximally and distally (compare to forearm)
It has a triangular shape in cross section, medial surface represents shin
Proximally, the medial and lateral condyles form a tibial plateau
Positioned posterolaterally to the tibia
It has no weight bearing function nor does it articulate with the femur
a. Role in ankle stability
3. Provides multiple points of muscle attachment
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vi. Can PALPATE head of fibula and tibial tuberosity
e. Foot
Toe flexion/extension
Anatomical division
Foot eversion/inversion
i. Tarsus
1. There are 7 bones organized into proximal and distal rows
2. Only the talus articulates with the leg bones
a. Receives weight of the body via the tibia
3. The term tarsus is synonymous with ankle, however, the ankle is generally considered to include the
malleoli
ii. Metatarsals and Phalanges
1. Numbered 1-5 starting on the medial side
2. Metatarsal 1 is the shortest and the thickest
3. Each digit only has three phalanges
a. Hallux only has 2
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4. Calcaneal tuberosity (back of hill)
a. Can palpate
b. Where Achilles, calcaneal tendon inserts
Lecture 9 – Joints
I.
Types of joints
a. Cartilaginous: held together by hyaline or fibrocartilage
i. Primary – temporary joints found in long bones
during growth; “epiphyses”
ii. Secondary – “symphyses”; strong, slightly
movable joints such as intravertebral disks
b. Fibrous – bones joined by fibrous sheet
i. Sutures of skull
ii. Syndesmosos – long bones joined by a fibrous
sheet or ligament- interosseus membranes of
forearm and leg; clinically important!
iii. Get compartment syndrome
1. pressure within a closed space thus
compromising the circulation and
function of tissues in that space
2. This leads to tissue death from lack of
oxygenation due to the blood vessels
being compressed by the raised pressure within the compartment.
c.
iv. Gomphosis – dentoalveolar joint that holds your teeth in sockets
Synovial Joints
i. Most mobile
ii. Have articular surfaces lined with cartilage
iii. Contained in a fibrous “joint capsule”
iv. Produce lubricant – synovial fluid – that permits smooth movement of bones and cartilage across each other
v. Ex: meniscus inside is additional layer of cartilage, see synovial fluid in knees
vi. Cartilage lines articular surface of bones making up the joint, all other surfaces inside capsule lined with
synovial membrane
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vii. Synovial joint types
1. Plane – acromioclavicular
a. permits gliding movement across
joint
2. Hinge – elbow
a. Permit flexion and extension
across joint
b. Collateral ligaments part of joint
capsule (ex: join humerus and
ulna)
3. Saddle – Biaxial – carpometacarpal joints
a. Permit ab and adduction; flexion
and extension, some
circumduction
4. Condyloid – metacarpophalangeal
a. Permits same motions as
saddle joints except motion in
one axis is greater
than the other
5.
Ball and socket
a. See hip
b. Permits motion in many axes
c. Broad contact surface
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II.
III.
IV.
V.
6. Pivot – atlantoaxial
a. Permits rotation around a central axis
b. Tough ligaments!!!
c. Only one true pivot joint: atlanto-axial joint between c1 and c2
d. Bone will break before ligament tears
viii. What makes a synovial joint work?
1. Tough joint capsules holds articulating surfaces in close opposition
2. Flexible joint capsule allows movement
a. Most stable joint with least movement: sutures of skull
3. Ligaments support joint by connecting bones together
d. Joint ligaments
i. Intrinsic ligaments are part of the fibrous joint capsule. They are essentially thickened bands of the capsule –
medial or tibial collateral ligament of the knee
ii. Extrinsic ligaments are separate from the joint capsule – lateral or fibular collateral ligament of the knee
iii. In many cases, ligaments are stronger than bone
1. This can lead to “avulsion” injuries, in which a joint is forced to move beyond its normal range – this
causes the ligament to reach its limit of stretch – and rather than tearing It rips its attachment point
away from the bone
Vascular supply
a. Arterial supply to joints is via branches from nearby arteries – “articular branches”
b. Form ‘”anastomoses” or interconnected networks around joints
c. Veins – “venae comitantes”
i. The veins that accompany
d. Parallel arteries – often multiple small veins with each artery
e. Usually found in synovial sheath
f. Innervation
i. Joints have a lot
ii. Pain is not a primary modality for joint nerves
iii. “proprioception” is probably most important sensation arising from joints
iv. Awareness of place and movement in space
v. Joints don’t hurt, tissues surrounding them hurt.
vi. “Hilton’s law””, 1806s – John Hilton was a British surgeon and anatomist
1. Law states that joints are innervated by branches of nerves that supply muscles that cross and move
that joint
Bursae
a. Fluid-filled sacs that are found between muscles, bones, tendons and ligaments that surround and cross the joints
b. Often communicate with synovial cavity
c. Allow structures to slide over and around each other
d. Clinically significant if irritated or inflamed
Special Joints of the skull
a. Base of the skull develops by ossification of cartilaginous precursos
b. The vault of the skull, or calvarium, arises from intermembranous (direct) ossification centers in the mesenchyme of
developing head
c. There are gaps between bones as it develops
d. Spaces between bones =sutures, wide gaps in developing skull = fontanelles
The shoulder
a. It is actually made of several joints acting synergistically
b. Anatomically referred to as the “pectoral girdle”
c. Glenohumeral, acromioclavicular, sternoclavicular, and scapulothoracic joints all play a part
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d.
e. Sternoclavicular joint
i. Bony elements – proximal clavicle and manubrium of sternum permits many movements including limited
circumduction
ii. Very strong joint capsule – bears the load from arm to axial skeleton
iii. Complete articular disk
iv. Anterior and posterior sternoclavicular ligaments and interclavicular ligament – this also attaches to
manubrium
v. Blood supply – internal thoracic and suprascapular arteries
vi. Innervation – supraclavicular nerves and nerve to subclavius
vii. Venous drainage parallels artery supply
f. Acromio-clavicular joint
i. Permits rotation of scapula
ii. Bony elements – acromion process of
scapula, clavicle
iii. Weak joint capsule, helped by trapezius m.
iv. Partial articular disk
v. Acromioclavicular ligament and
coroclavicular, conoic and trapezoid
ligaments support joitn capsule
vi. Arterial supply – suprascapular and
thoracoacromial arteries
vii. Innervation – lateral pectoral, axillary and
lateral supraclavicular nerves
viii. Vena comitantes
g. Gleno- Humeral Joint
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i.
ii.
iii.
iv.
v.
vi.
vii.
viii.
ix.
x.
Permits movement in many planes including true circumduction
Bony elements – head of humerus and glenoid fossa (cavity) of scapula
Very flexible
Openings in joint capsule for tendon of long head of biceps, subscapular bursa
Very shallow ball and socket joint
Deepened by glenoid labrum – fibrocartilage attached to lip of glenoid fossa
Joint capsule supported by tendons of muscles of rotator cuff
Arterial supply – circumflex humeral and suprascapular arteries
Innervation – suprascapular, axillary and lateral pectoral nerves
Venae comitantes
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Block 1 – 2012-13