A&P exam 2

syndesmology

the study of articulations between bones

joint

articulations between bones

simple joint

two articulating bones : shoulder joint

compound joint

two or more articulating bones : stifle

fibrous joint

united by fibrous tissue, no joint cavity

cartilaginous joint

united by cartilage, little to no joint cavity

synovial joint

united by a joint capsule, freely movable

syndesmosis

joint that permits only slight movement (fibrous)

suture joint

between bones of the skull (fibrous)

gomphosis joint

articulation of teeth in their sockets (fibrous)

periodontium

collagenous tissues and fibroblasts that join the tooth to the socket

cartilage

special type of connective tissue that is firmer than fibrous tissue but not as hard as bone

synchondrosis

immovable joint, uniting medium is hyaline cartilage, union of diaphysis and epiphysis of an immature bone (cartilaginous joint)

symphyses

united by flattened disks of fibrocartilage, between adjacent pelvic bones and bodies of adjacent vertebrae and stenebrae (cartilaginous joint)

what can replace symphyses with age

bone

synovial joints

articular surfaces, cartilage, cavity, a joint capsule, ligaments

what is the most common type of joint

synovial

articular surface of synovial joint

specialized layers of compact bone on the surfaces that articulate with other bones

articular cartilage of synovial joint

layer of hyaline cartilage covering the articular surface

articular cavity of synovial joint

space between the adjacent bones of the joint surrounded by the joint capsule, often called potential space

joint effusion

expansion of space due to inflammation with accumulation of fluid

what two layers make the joint capsule

outer fibrous layer (fibrous capsule) and inner delicate layer (synovial membrane)

fibrous capsule

may be thickened in certain areas to form the extracapsular ligaments that connect adjacent bones and help stabilize the joint

synovial membrane

specialized connective tissue, extend from the edges of the articular cartilages of the adjacent bones but not covering the articular cartilage, secretes synovial fluid

how is surface area of synovial membrane increased

folds that project into the joint cavity

villi

project into the joint cavity

primary purposes of synovial fluid

lubrication of joint surfaces, provision of a nutritional source for cartilage, removal of waste products from the joint

synovial fluid

normal joint has minimal, accumulation or change is indicative of pathology present, can be removed for analysis, colorless and very light yellow, viscous quality

ligaments

connective tissue bands that extend from bone to bone

intracapsular ligaments

found within joints and surrounded by synovial membrane : cruciate ligametns

extracapsular ligaments

external to the joint capsule include: collateral ligaments, dorsal and palmar ligaments, annular ligaments

collateral ligaments

medial and lateral aspects of the joint

dorsal and palmar ligaments

in front of and behind joint

annular ligaments

surround joint, fibers circle the joint

menisci

fibrocartilage disks interposed between the surfaces of some joints, truly intracapsular, found in TMJ and stifle

functions of mensicus

distrubutes compressive stress during weight bearing activities, augments joint stability

flexion

decreases angle between 2 bones making up the joint

extension

increases angle between 2 bones making up the joint

hyperextension

increases angle between 2 bones to greater than 180

adduction

movement toward median line

abduction

movement away from median line

rotation

twisting of a segment on its own segment or axis (shaking head)

circumduction

movement of an extremity to outline a cone

pronation

turning dorsal surface up

supination

turning dorsal surface down

ginglymus (hinge) joint

move only in sagittal plane (fetlock)

spheroid (ball and socket) joint

move in nearly any direction (hip)

saddle joint

all movement except rotation (carpometacarpal joint in human thumb)

temporomandibular joint

between madible and temporal bone of skull

atlanto-occipital joint

between 1st cervical vertebrae and occipital bone

atlanto-axial joint

between 1st and 2nd cervical vertebrae (atlas and axis)

joints of axial skeleton

intervertebal disk, flexible enough to permit some bending and twisting in any direction, fibrocartilaginous, cervical good movement, thorasic decreased movement, and lumbar good movement

scapula

no bony connection to thorax, synasarcosis (muscles and ligaments), scapulohumeral joint

what are the joints of appendicular skeleton

scapula, shoulder, elbow, carpus, fetlock, pastern, coffin joint

elbow

radius, ulna, humerous

carpus

radiocarpal joint, midcarpal joint, carpometacarpal joint

fetlock

metacarpophalangeal joint (fore) metatarsophalangeal joint (rear)

pastern

proximal interphalangeal joint

coffin

distal interphangeal joint

hind limb joints

sacroliliac joint, coxofemoral joint, stifle joint, tarsus (hock)

sacroiliac joint

mobility progressively diminished as matures, sacrum held tight to wing of the ilium by ligaments, may become more mobile at parturition, can be partially separated by fall or trauma

coxofemoral joint

best example of spheroid joint, head of femur fits into acetabulum of the os coxae, movement in nearly all directions

stifle joint

condyles of distal femur patella and proximal tibia, femoral condyles separated from tibia by menisci, stabilized by collateral and cruciate ligaments, patella sesamoid bone

tarsus (hock)

composite joint, common calceaneal tendon (achilles tendon)

pathology of joints

developmental problems, degenerative problems (osteoarthritis), inflammation (non-infection and infectious), trauma

luxation

dislocation

osteoarthritis

usually accompanies developmental problems, degenerative joint disease, treated with nonsteroidal anti inflammatory drugs

what are the 3 types of muscle tissue

skeletal, smooth, cardiac

skeletal muscle voluntary moves what

limbs, trunk, and head

skeletal muscle

most famliar as “meat”, cells (fibers) grouped into “organs” of variable size, individual muscles usually attached to bones with voluntary control by animal

what describes how skeletal muscle look

striated with multiple nuclei

smooth muslce

involuntary or unstriated muscle, cells have NO striations, found in systems with autonic functions

smooth muscle is a major component of organs of what

digestive system, urogenital system, blood vessels

contraction of smooth muscles

does not require stimulation by nerve and is regulated by autonomic nervous system

cardiac muscle

visible striations and contracts intrinsically, restricted to heart, constitutes most of the thickness of the wall, rhythmic contraction = circulation of blood

what is the function of the muscular system

contraction, relaxation is “passive”, functions based on contraction of muscle fibers

smooth muscles in stomach and intestines contract to

mix and propel food along GI tract

blood vessels

control distribution of blood

eye

adjust pupil and thickness of lens

skin

piloerection aka hair stands up

skeletal muscle functions

permit locomotion to change position of bones (maintain joint angle against gravity), respiration (move air in out by changing volume), heat production or shivering (brief contraction of muscles in body)

endomysium

between individual muscle fibers

perimysium

sheath surrounding bundles

epimysium

around entire muscle, deep fascia of the muscle

skeletal muscular arrangement

parallel sheets, narrow bands, fusiform muscles, pennate

parallel sheets

abdominal muscles, provides greatest potential for overall muscle shortening but weak

narrow bands

sartorius muscles of medial thigh, muscles fibers in these “strap muscles” parallel to one another

fusiform muscles

biceps brachii

pennate

penniform or feather like, tendon represent a “quill” for muscles attaching to a tendon, increased power but reduced distance over which it can contract

fleshy attachment

appears to arise directly from bone, really attach to short tendons: attached to periosteum or penetrate bone surface for short distance

tendons

fibrous bands of collagen connect muscles to bone, composed of dense regular connective tissue in parallel bundles, most are cords or bands attach spindle shape or pennate muscles to bone, other are flat sheets (aponeuroses) usually associated with flat muscles

muscular attachments

most muscles attach to two bones, some to soft tissue, less movable attachment = origin, more movable attachment = insertion, extremities origin = proximal and insertion = distal, muscle can only contract →bring one or both bones to move, some muscles have distinctive divisions,

functional grouping of muscles

decreasing

extensor

muscle on opposite side

adductors

tend to pull limb toward medial plane

abductors

tend to move limb away from medial plane

gastrocnemius

flexor of the stifle, extensor for the hock

sphincter

muscles encircle opening (smooth or striated)

pyloric sphincter

between stomach and small intestine

cutaneous muscles

in superfical fascia between skin and deep fascia covering skeletal muscles, attach to ski = responsible for skin movement