Exam 2 Flashcards
is the sternum a long, short, flat, or irregular bone and is it in the axial or appendicular skeleton?
flat
axial
is the radius a long, short, flat, or irregular bone and is it in the axial or appendicular skeleton?
long
appendicular
is the calcaneus (tarsal bone) a long, short, flat, or irregular bone and is it in the axial or appendicular skeleton?
short
appendicular
is the parietal bone (cranial bone) a long, short, flat, or irregular bone and is it in the axial or appendicular skeleton?
flat
axial
is the phalanx (single bone of a digit) a long, short, flat, or irregular bone and is it in the axial or appendicular skeleton?
long
appendicular
is the vertebra a long, short, flat, or irregular bone and is it in the axial or appendicular skeleton?
irregular
axial
a sharp, slender process
spine
a small rounded projection
tubercle
a narrow ridge of a bone
crest
a large rounded projection
tuberosity
a structure supported on the neck
head
an armlike projection
ramus
rounded, convex projection
condyle
a narrow slitlike opening
fissure
a canal like structure
meatus
a round or oval opening through a bone
foramen
a shallow depression
fossa
an air filled cavity
sinus
large, irregularly shaped projection
trochanter
raised area on or above a condyle
epicondyle
a bony projection
process
a smooth, nearly flat articular surface
facet
1
epiphysis
2
diaphysis
3
articular cartilage
4
spongy bone
5
epiphyseal line
6
compact bone
7
medullary cavity
8
spongy bone
9
articular cartilage
10
compact bone
11
yellow bone marrow
12
compact bone
13
periosteum
14
nutrient artery
end portion of a long bone
epiphysis
helps reduce friction at joints
articular cartilage
site of blood cell formation
red bone marrow
two major sub membranous sites of osteoprogenitor cells
endosteum
periosteum
scientific term for bone shaft
diaphysis
contains yellow bone marrow in adult bones
medullary cavity
growth plate remnant
epiphyseal line
what is the function of the organic matrix in bone?
flexibility and strength
name the important organic bone components
collagen fibers
osteocytes
calcium salts form the bulk of the inorganic material in bone. what is the function of the calcium salts?
makes the bone hard and give it strength
baking a bone removes the _____
soaking bone in acid removes _____
organic part
minerals
2
3
4
1
which cartilage supports the external ear?
elastic cartilage
which cartilage is between the vertebrae?
fibrocartilage
which cartilage forms the walls of the voice box (larynx)?
hyaline
which cartilage is the epiglottis?
elastic
which cartilage is articular cartilages?
hyaline
which cartilage is the meniscus in a knee joint?
fibrocartilage
which cartilage connects the ribs to the sternum?
hyaline
which cartilage is most effective at resisting compression?
fibrocartilage
which cartilage is most springy and flexible?
elastic
which cartilage is most abundant?
hyaline
forms the anterior cranium
frontal bone
cheekbone
zygomatic bone
lower jaw
mandible
bridge of the nose
nasal bone
posterior bones of the hard palate
palatine
much of the lateral and superior cranium
parietal
single, irregular, bat-shaped bone forming part of the cranial base
sphenoid
most posterior part of the cranium
occipital
tiny bones bearing tear ducts
lacrimal
anterior part of the hard palate
maxilla
superior and middle nasal concha form from its projections
ethmoid
site of mastoid process
temporal
site of sella turcica
occipital
site of cribriform plate
ethmoid
site of mental foramen
mandible
site of styloid process
temporal
4 bones containing paranasal sinuses
ethmoid
frontal
maxilla
sphenoid
has condyles that articulate with the atlas
occipital
foramen magnum contained here
occipital
small U-shaped bone in neck, where many tongue muscles attach
hyoid
organ of hearing found here
temporal
2 bones that form the nasal septum
vomer, ethmoid
contains sockets that bear teeth
maxilla
mandible
forms the most inferior turbinate
mandible
1
frontal bone
2
parietal bone
3
supraorbital foramen
4
superior orbital fissure
5
ethmoid bone (perpendicular plate)
6
inferior orbital fissure
7
infraorbital foramen
8
vomer
9
alveolar process
10
mandible
11
mandibular symphysis
12
incisive fossa
13
maxilla
14
styloid process
15
foramen ovale
16
sphenoid bone
17
carotid canal
18
temporal bone
19
stylomastoid process
20
occipital condyle
21
foramen magnum
22
external occipital protuberance
23
occipital bone
24
mastoid process
25
jugular foramen
26
foramen lacerum
27
mandibular fossa
28
zygomatic process
29
vomer
30
palatine bone
31
32
mental foramen
33
maxilla
34
inferior nasal concha
35
zygomatic bone
36
lacrimal bone
37
sphenoid bone
38
nasal bone
39
glabella
name the 8 bones of the cranium (include left and right)
frontal
left parietal
right parietal
left temporal
right temporal
occipital
sphenoid
ethmoid
what bones have sinuses?
maxilla
sphenoid
ethmoid
frontal
2 functions of the sinuses
lighten the facial bones
act as resonance chambers for speech
what is the bony orbit? what 7 bones contribute to the formation of the orbit?
7 bones that surround the eye
frontal
sphenoid
ethmoid
lacrimal
maxilla
palatine
zygomatic
why can the sphenoid bone be called the keystone bone of the cranium?
it is in contact with all other cranial bones
vertebra type containing forming in the transverse process, through which the vertebral arteries ascend to reach the brain
cervical vertebra - typical
dens here provides a pivot for rotation of the first cervical vertebra
axis
transverse processes faceted for articulation with ribs; spinous process pointing sharply downward
thoracic vertebra
composite bone; articulates with the hip bone laterally
sacrum
massive vertebra; weight-sustaining
lumbar vertebra
“tailbone”; vestigial fused vertebra
coccyx
supports the head; allows for a rocking motion in conjunction with the occipital condyles
atlas
cavity enclosing the spinal cord
vertebral foramen
weight-bearing portion of the vertebra
body
provide levers against which muscles pull
spinous process
transverse process
provide an articulation point for the ribs
body
transverse process
openings providing for exit of spinal nerves
intervertebral foramina
structures that form an enclosure for the spinal cord
vertebral arch
1
spinous process
2
transverse process
3
superior articular facet
4
body
5
vertebral foramen
6
pedicle
7
lamina
8
vertebral arch
describe how a spinal nerve exits from the vertebral column
via the ventral root where they synapse on motor neuron ganglia
then go through the ventral horn
name 2 factors that permit flexibility of the vertebral column
intervertebral disc
curvatures
what kind of tissue makes up the intervertebral discs?
fibrocartilage
what is a herniated disc? what problems might it cause?
a ruptured disc that protrudes outward
could compress a nerve leading to pain or paralysis
which 2 spinal curvatures are obvious at birth?
thoracic and sacral
under what conditions do the secondary curvatures develop?
cervical forms when the baby begins to raise its head independently
lumbar forms when baby begins to walk
1
intervertebral discs
2
thoracic vertebrae
3
intervertebral foramina
4
transverse process
5
spinous process
the major components of the thorax are
the sternum and the ribs
differentiate a true rib from a false rib
true ribs attack to the sternum by their own cottage cartilage
false ribs have costal cartilage that attaches to other rib cartilage before attaching to the sternum
what is the general shape of the thoracic cage?
cone/barrel shaped
1
jugular notch
2
clavicle notch
3
manubrium
4
sternal angle
5
body
6
xiphisternal joint
7
xiphoid process
8
costal cartilage
9
floating ribs
10
false ribs
11
true ribs
12
sternum
are the same skull bones seen in the adult also found in the fetal skull?
yes
how does the size of the fetal face compare to the fetal cranium?
large cranium and shorted face, smaller maxilla and mandible
what are the outward conical projections on some of the fetal cranial bones?
ossification centers
what is a fontanelle?
a fibrous membrane connecting fetal skull bones
what is a fate?
progressively ossified and replaced by suture
what is the function of the fontanelles in the fetal skull
allows the skull to be compressed during birth and leave room for brain growth
1
sphenoidal fontanelle
2
anterior fontanelle
3
posterior fontanelle
4
mastoid fontanelle
what type of cartilage is in the ear?
elastic
what type of cartilage is in the nose
hyaline
what type of cartilage is in the joints?
hyaline
what time of cartilage is in the costal ribs?
hyaline
what type of cartilage is in the intervertebral discs?
fibro
what type of cartilage is in the pubic symphysis?
fibro
what type of cartilage is the articular cartilage of a joint?
fibro
what type of cartilage is the meniscus (knee)
fibro
describe the function of hyaline cartilage
- gelatinous ground substance holds a lot of water so resists compression well
- provides support through flexibility and resilience
what cartilage makes up the articular cartilage that covers the ends of adjoining bones in movable joints?
hyaline
what cartilage forms the cartilaginous attachments of the ribs to the sternum and accounts for most of the cartilage found in the respiratory structures
hyaline
compare hyaline and elastic cartilage matrix
elastic has more elastic fibers along with collagen
hyaline only has collagen
what cartilage is able to tolerate repeated bending
elastic
which cartilage can resist both strong compression and strong tension
fibro
what fibers does fibrocartilage contain?
collagen
how does cartilage grow?
2 ways
1) appositional - growth from outside, cartilage forming cells (chondroblasts) in the surrounding perichondrium produce new cartilage tissue by actively secreting matrix
2) interstitial - growth from within, the chondrocytes within the cartilage divide and secrete new matrix
when does cartilage start and stop growing?
grows rapidly in embryonic development, childhood, and adolescent
stops growing in teens when the skeleton stops growing
what is a sign of aging in adults by looking at cartilage?
crystals of calcium phosphate precipitate in the matrix
6 functions of bones
1) support - hard framework that supports the weight of the body
2) movement - skeletal muscles attach to the bones by tendons and use the bones as levers to move the body and its parts
3) protection - the bones of the skull form a protective case for the brain
4) mineral storage - bones serve as a reservoir for minerals, the most important of which are calcium and phosphate
5) blood cell formation and energy storage - contain red and yellow bone marrow
6) energy metabolism - bone-producing cells, osteoblasts, secrete a hormone that influences blood sugar regulation and energy metabolism
function of bone tissue? (organic and inorganic)
organic - cells, fibers, ground substance
- contribute to bone flexibility and tensile strength that allow bone to resist stretching and twisting
inorganic - mineral salts
- provide the bone with hardness which allows it to resist compression
describe a long bone
what are the 5 general structures?
has a shaft plus 2 distinct ends
most bones of the limbs
named for elongated shape, not size
1) diaphysis
2) epiphysis
3) blood vessels
4) the medullary cavity
5) membranes
describe a flat bone
thin, flattened, and usually somewhat curved
most cranial bones of the skull
ribs, sternum, scapula
describe how bones resist compression or tension
- the strong, compact bone tissue occurs in the external portion of the bone
- internal to this region, tension and compression forces tend to cancel each other out, resulting in less overall stress
- compact bone is not found in the bones interiors, spongy bone is sufficient
- because no stress occurs at the bones center, the lack of bone tissue in the central medullary cavity does not impair the strength of the long bones
- bone markings
describe histology of compact bone
- riddled with passageways for blood vessels and nerves
- osteon: long, cylindrical structures oriented parallel to the long axis of the bone and to the main compression stresses - weight bearing pillars - groups of tubes
- lamella - each tube of osteons - a layer of bone matrix in which collagen fibers and mineral crystals of adjacent lamellae always run in roughly opposite directions - inhibit crack propagation
- central canal: through the core of each osteon - contains blood vessels which supply nutrients to the bone cells and its own nerve fibers
- perforating canals: lie at right angles to the central canals and connect the blood and nerve supply of the periosteum to that of the central canals and the marrow cavity
- canaliculi: bodies of osteocytes occupy small cavities in the solid matrix called lacunae and their “spider legs” occupy these thin tubes - run through the matrix, connecting neighboring lacunae to one another and to the nearest capillaries
describe the histology of spongy bone
- each trabecula contains several layers of lamellae and osteocytes but is too small to contain osteons or vessels of its own
- osteocytes receive nutrients from capillaries in the endosteum surrounding the trabecular via connections through the canaliculi
what is inframembrous ossification?
compare to endochrondral ossification
inframembrous
1) ossification centers develop in the fibrous connective tissue membrane
2) osteoid is secrete and calcifies
3) woven bone and periosteum
4) compact bone replaces woven bone, just deep to the periosteum. red bone marrow develops
- the clavicle is the only bone not in the skull formed by this
endochrondal
1) bone collar forms around the diaphysis of the hyaline cartilage model
2) cartilage in the center of the diaphysis calcifies and then develops cavities
3) the periostea bud invades the internal cavities and spongy bones form
4) the diaphysis elongates and a medullary cavity forms. secondary ossification centers appear in the epiphysis
5) the epiphysis ossify. when completed, hyaline cartilage remains only in the epiphyseal plates and articular cartilages
describe how endochondral bones grow at their epiphyseal plates
- the cartilage cells nearest the epiphysis are relatively small and inactive - resting zone
- below the resting zone, cartilage cells form large columns with condroblasts at the top in the “proliferation zone” divide quickly, pushing the epiphysis away from the diaphysis and causing the long bone to lengthen
- the older chondrocytes in the stack at the hypertrophic zone enlarge and signal the surrounding matrix to calcify
discuss how bone tissue is remodeled within the skeleton
- the spongy bone in the skeleton is entirely replaced every 3-4 years
- remodeling in compact bone occurs at the endosteum lining the central canals of the osteons
- remodeling is coordinated by cohorts of adjacent osteoblasts and osteoclasts
BONE RESORPTION: accomplished by osteoclasts that crawl alone the bone surfaces digging pits as they break down the bone tissue. the expanded membrane forms a tight seal against the bone and secretes concentrated hydrochloric acid which dissolves the mineral part
BONE DEPOSITION: accomplished by osteoblasts which lay down organic osteoid on bone surfaces and calcium salts crystalize within this osteoid
explain the 4 steps in the healing of bone fractures
1) hematoma formation - blood vessels break in the periosteum and inside the bone, releasing blood that clots to form a hematoma
2) fibrocartilaginous callus formation - new blood vessels grow into the clot
3) bony callus formation - trabeculae of new woven bone begin to form in the callus, mostly by endochondral ossification
4) bone remodeling - the excess bone material is removed from both the exterior of the bone shaft and the inferior of the medullary cavity
what are the 3 evolutionary domains of the vertebral skull?
splanchnocranium
neurocranium
dermatocranium
what is the primary function of the splanchnocranium?
endochrondral bone supporting the pharyngeal arches (branchiomeric muscles)
- works with chondrocranium, hyoid, elements of jaw, middle ear
what is the primary function of the neurocranium?
endochrondral bone encasing the brain (floor and walls)
(chondrocranium and endocranium)
what is the primary function of the dermatocranium?
dermal armor surrounding entire head
4 major elements of the chondrocranium?
ethmoid region
basal plate - sphenoid
occipital arch
sensory capsules - contained by and formed within bones of skull
6 series in the dermatocranium?
1) facial
2) orbital
3) temporal
4) vault
5) palatal
6) mandibular
provide an example of a bone within the skull that undergoes endochondral development. intramembranous development.
??????
using the temporal bone as an example, discuss the concept of compound skull bones
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compare the functions of the cranial and facial bones
cranial
- form the brain’s protective shell
- allows the bones to be thin, egg-shell like, and strong for its weight
facial
- anchors the teeth and lower/raises the jaw
- idk?
function of frontal bone?
- form forehead
- form orbits
- contain sinuses
function of parietal bones?
- forms most superior and lateral aspects of skull
function of occipital bone?
forms posterior aspect and most of the base of the skull
function of temporal bones?
- forms inferolateral aspects of the skull
- contributes to middle cranial fossa
function of sphenoid bone?
- contributes to middle cranial fossa and orbits
function of ethmoid bone?
- forms part of nasal septum and lateral walls and roof of nasal cavity
- contributes to medial wall of orbit
function of nasal bone?
- forms the bridge of the nose
function of the lacrimal bones?
- form part of the medial orbit wall
function of the zygomatic bones?
form the cheek and part of the orbit
function of the inferior nasal concha bones?
form part of the lateral walls of the nasal cavity
function of the mandible?
raise and lower the jaw
function of the maxilla bones?
- keystone bones of the face
- form the upper jaw and parts of the hard palate, orbits, and nasal cavity walls
function of the palatine bones?
form posterior part of the hard palate and a small part of nasal cavity and orbit walls
function of the vomer?
inferior part of the nasal septum
function of the auditory ossicles?
involved in sound transmission
what are the bony boundaries of the nasal cavity?
roof: ethmoid cribriform plates
floor: palatine processes of the maxillae and horizontal plates of palatine bones
lateral walls: nasal bones, superior and middle conchae of the ethmoid, inferior nasal concha, frontal process of maxilla, perpendicular plates of palatine bones
what are the bony boundaries of the paranasal sinuses?
hollow spaces inside of the frontal, ethmoid, sphenoid, and both maxillary bones
what are the bony boundaries of the orbit?
walls formed by parts of the
- frontal
- sphenoid
- zygomatic
- maxillary
- palatine
- lacrimal
- and ethmoid bones
name a function performed by both the spinal curvatures and the intervertebral discs
increase the resilience of the spine, allowing it to act as a spring rather than a rigid rod
- absorb compressive stress and act as shock absorbers
describe the general structure of the vertebral column, and list its components
1) cervical curvature (7 vertebrae, concave)
2) thoracic curvature (12 vertebrae, convex)
3) lumbar curvature (5 vertebrae, concave)
4) sacral curvature (5 fused vertebrae, concave)
5) coccyx (4 fused vertebrae)
what are true ribs?
attach directly to the sternum by their costal cartilages
what are false ribs?
attach to the sternum indirectly through costal cartilage or not at all
what are floating ribs?
have no anterior attachments
describe how a typical rib attaches to the vertebral column
- the wedge-shaped head has 2 facets: one facet joins the body of the thoracic vertebrae of the same number and the other joins the body of the vertebrae immediately superior
name the bones that form the pectoral girdle
clavicle
scapula
explain how bones of the pectoral girdle articulate with each other
anteriorly the medial end of each clavicle joints to the sternum and first rib
- lateral ends of clavicles join to the scapula and shoulder
explain the functions of the pectoral girdle
- attaches upper limbs to the trunk
- provides attachment for many muscles that move the limb
- only the clavicle attaches to the axial skeleton so the scapula can move freely across the thorax allowing the arm to move
- the socket of the shoulder (scapula glenoid cavity) is shallow so it does not restrict movement of the humerus
what is the largest bone in the arm?
humerus
the humerus articulates with _____ at the ______ and with the _____ and ______ at the ______
scapula at the shoulder
radius and ulna at the elbow
at the proximal head of the humerus is the hemispherical _____
head
just inferior to the humerus head is a slight constriction, the __________
anatomical neck
inferior to the humerus anatomical neck, the lateral _____ and the more medial _____ are separated by the intertubercular sulcus
greater tubercle
lesser tubercle
the _____ of the humerus is inferior to the tubercles
surgical neck
about midway down the shaft of the humerus, on the lateral side, is the _____
deltoid tuberosity
near the deltoid tuberosity on the humerus along the posterior surface of the shaft, the _____ descends obliquely
radial groove
at the distal end of the humerus are 2 condyles, a medial _____ that articulates with the ulna, and a lateral _____ that articulates with the radius
trochlea
capitulum
the trochlea and capitulum of the humerus are flanked by the _______, which are attachment sites for muscles of the forearm
medial and lateral epicondyles
directly above the lateral and medial epicondyles on the humerus are the _____
medial and lateral supracondylar ridges
the _____ and _____ form the forearm
radius and ulna
the radius and ulna articulate with the _____ proximally and ______ distally
humerus
bones of the wrist
the radius and ulna articulate with each other proximally and distally at the ligament called ________
interosseous membrane
at the proximal end of the ulna are 2 prominent projections, the ______ and _____ processes, separated by a deep concavity, the trochlear notch
olecranon
coronoid
on the lateral side of the ulna coronoid process is a smooth depression, the ______, where the head of the radius articulates with the ulna
radial notch
distally, the shaft of the ulna narrows and ends in a _____ that articulates with the radius.
medial to this is the ______, from which a ligament runs to the wrist
head
ulnar styloid process
the superior end of the radius articulates with ______ of the humerus
capitulum
medially, the head of the radius articulates with the ______ of the ulna, forming the proximal radioulnar joint
radial notch
just distal to the head of the radius, on the anterior surface in anatomical position, is a rough bump, the _______, a site of attachment of the biceps muscles
radial tuberosity
on the distal end of the radius, the medial ______ articulates wit the head of the ulna, the ______ articulates with the head of the ulna, forming the distal radioulnar joint
ulnar notch
radial styloid process
the true wrist, or _____, is the proximal region of the hand, just distal to the wrist joint
carpus
the carpus of the hand contains eight marble-sized short bones, or ______, closely united by ligaments
carpals
in the proximal row in the hand, from lateral to medial, are the _____, ______, ______, and ______ bones
scaphoid
lunate
triquetrum
pisiform
the carpals of the distal row, from lateral to medial, are the _____, _____, _____, and _____ bones
trapezium
trapezoid
capitate
hamate
five ______ in the hand radiate distally from the wrist to form the metacarpus, or palm of the hand
metacarpals
the digits, or fingers, are numbered I-V beginning with the thumb, the fingers contain minature long bones called ______
phalanges
radius articulates with ______
carpals
carpals articulates with _______
metacarpals
metacarpals articulate with _______
phalanges
name the bones that form the pelvic girdle
hip bones
sacrum
where the glenoid cavity of the scapula is shallow, the corresponding socket in the pelvic girdle is a deep cut that firmly secures the ____________
head of the femur
each hip bone unites with its partner anteriorly and with the ______ posteriorly
sacrum
compare and contrast child-birthing and non-child-birthing pelves
female: wider, shallower, lighter, provide more room in the true pelvis
male: narrower pubic arch
the _____ is the single bone of the thigh
femur
the ball-like head of the femur has a small central pit called the _____
fovea capitis
at the junction of the shaft and neck of the femur are the lateral _____ and the posteromedial _____, sites of muscle attachment
greater trochanter
lesser trochanter
the 2 trochanters of the femur are interconnected by the _____ anteriorly and by the prominent _____ posteriorly
intertrochanteric line
intertrochanteric cet
inferior to the interterochanteric crest on the femur on the posterior surface of the shaft is the _____
gluteal tuberosity
the inferior part of the gluteal tuberosity (femur) blends into a long vertical ridge, the _____
linea aspera
distally, the femur broadens to end in _______ and _______ _______ shaped like wide wheels
medial and lateral condyles
the _____ is a bump on the upper part of the medial epicondyle of the femur
adductor tubercle
anteriorly, the 2 condyles (femur) are separated by a smooth ______, which articulates with the kneecap, or patella
patellar surface
posteriorly, the condyles (femur) are separated by a deep _____
intercondylar fossa
ending superior from the respective condyles (femur) to the linea aspera are the ______ and ______ _______ ______
lateral and medial supercondylar lines
the _____ is a triangular sesamoid bone enclosed in the tendon that secures the quadriceps muscles of the anterior thigh to the tibia
patella
what bones form the leg?
tibia and fibula
an _____ _____ connects the tibia and fibula along their entire length
interosseous membrane
the _____ receives the weight of the body from the femur and transmits it to the foot
tibia
at the proximal end of the tibia are the brand _____ and _____ _____, which resemble two thick checkers lying side by side on top of the shaft, articular with the corresponding condyles of the femur
medial and lateral condyles
the tibial condyles are separated by an irregular projection, the _____ ______
intercondylar eminence
just inferior to the tibial condyles, on the anterior surface, is the _____ _____, attachment its of the patellar ligament
tibial tuberosity
on the shaft of the tibia, the sharp _____ _____ lies just below the skin and is easily palpated
anterior border
medial to the joint surface, the tibia has an inferior projection called the _____ _____, which forms the medial bulge of the ankle
medial malleolus
the _____ _____ on the lateral side of the distal tibia articulates with the fibula, forming the inferior tibiofibular joint
fibular notch
the _____, located lateral to the tibia, is a thin long bone with 2 expanded ends
fibula
on the fibula, its superior end is its _____, and its inferior end is the _____ _____
head
lateral malleolus
the _____ makes up the posterior half of the foot and contains several bones called tarsals
tarsus
the weight of the body is carried primarily by the 2 largest most posterior tarsal bones: the talus which articulates with the _____ and the strong calcaneus which forms _____
tibia
heel
the tibia articulates with the talus at the _____ _____ _____ _____
trochlea of the talus
the part of the calcaneus that touches the ground is the _____ _____, and the medial, shelf-like projection is the _____ _____
calcaneal tuberosity
sustentaculum tali
the metatarsus of the foot, which corresponds to the metacarpus of the hand, have 5 long bones called _____
metatarsals
how has limb posture changed in vertebrates from amphibians through Humans
discuss changes in the pelvic girdle that enable humans to walk upright
3 joint classes
fibrous
cartilaginous
synovial
describe the structure of a fibrous joint
adjoining bones united by collagenic fibers
describe the structure of cartilaginous joints
adjoining bones united by cartilage
describe the structure of synovial joints
adjoining bones separated by a joint cavity, covered with articular cartilage, and enclosed within an articular capsule lined with synovial membrane
describe the structural characteristics shared by all synovial joints
ligaments
joint cavity containing synovial fluid
articular cartilage (hyaline)
articular capsule (with a fibrous layer and synovial membrane)
periosteum
discuss the role of weeping lubrication in the function of synovial joints
- the pressure placed on joints during normal movement squeezes synovial fluid into and out of the articular cartilages
- this nourishes the cells in the articular cartilages and lubricates the free surface of these cartilages, allowing the adjoining bones to move across each other with a minimum of friction
describe the structure and function of articular discs
a disc of fibrocartilage
- extends internally from the capsule and completely or partially divides the joint cavity in 2
- fills the gaps and improves the fit, thereby distributing the load more evenly and minimizing wear and damage
- allow 2 different movements at the same joint
describe the structure and function of bursae
contain synovial fluid and often are associated with synovial joints
- act as “ball bearings” to reduce friction between body elements that move over one another
- tendon sheaths are enlongated bursa
describe the structure and function of tendon sheaths
an elongated bursa that wraps around a tendon
- only in tendons that are subjected to friction
what shape is a plane joint and what movement does it allow?
square
gliding
what shape is a hinge joint and what movement does it allow?
cylinder
flexion and extension
what shape is a pivot joint and what movement does it allow?
sleeve and axle
rotation
what shape is a condylar joint and what movement does it allow?
oval articular surface (funnel for cooking)
flexion and extension, adduction and abduction
what shape is a saddle joint and what movement does it allow?
articular surfaces are both concave and convex (saddle on a horse)
adduction and abduction, flexion and extension
what shape is ball and socket joint and what movement does it allow?
cup and spherical head
flexion and extension, adduction and abduction, rotation
what type of joint is the shoulder joint?
ball and socket
what type of joint is the knee joint?
all?
acts as a hinge
permits some medial and lateral rotation
