Chapter 38: Musculoskeletal System Flashcards
abduction
when a bone moves away from the midline of the body
acetylcholinesterase
(AChE) enzyme that breaks down ACh into acetyl and choline
actin
globular contractile protein that interacts with myosin for muscle contraction
adduction
movement of the limbs inward after abduction
amphiarthrosis
joint that allows slight movement; includes syndesmoses and symphyses
angular movement
produced when the angle between the bones of a joint changes
appendicular skeleton
composed of the bones of the upper limbs, which function to grasp and manipulate objects, and the lower limbs, which permit locomotion
appositional growth
increase in the diameter of bones by the addition of bone tissue at the surface of bones
articulation
any place where two bones are joined
auditory ossicle
(also, middle ear) transduces sounds from the air into vibrations in the fluid-filled cochlea
axial skeleton
forms the central axis of the body and includes the bones of the skull, the ossicles of the middle ear, the hyoid bone of the throat, the vertebral column, and the thoracic cage (ribcage)
ball-and-socket joint
joint with a rounded, ball-like end of one bone fitting into a cuplike socket of another bone
bone
connective tissue that constitutes the endoskeleton
bone remodeling
replacement of old bone tissue by new bone tissue
calcification
process of deposition of mineral salts in the collagen fiber matrix that crystallizes and hardens the tissue
cardiac muscle tissue
muscle tissue found only in the heart; cardiac contractions pump blood throughout the body and maintain blood pressure
carpals
eight bones that comprise the wrist
cartilaginous joint
joint in which the bones are connected by cartilage
circumduction
movement of a limb in a circular motion
clavicle
S-shaped bone that positions the arms laterally
compact bone
forms the hard external layer of all bones
condyloid joint
oval-shaped end of one bone fitting into a similarly oval-shaped hollow of another bone
coxal bone
hip bone
cranial bone
one of eight bones that form the cranial cavity that encloses the brain and serves as an attachment site for the muscles of the head and neck
depression
movement downward of a bone, such as after the shoulders are shrugged and the scapulae return to their normal position from an elevated position; opposite of elevation
diaphysis
central shaft of bone, contains bone marrow in a marrow cavity
diarthrosis
joint that allows for free movement of the joint; found in synovial joints
dorsiflexion
bending at the ankle such that the toes are lifted toward the knee
elevation
movement of a bone upward, such as when the shoulders are shrugged, lifting the scapulae
endochondral ossification
process of bone development from hyaline cartilage
endoskeleton
skeleton of living cells that produces a hard, mineralized tissue located within the soft tissue of organisms
epiphyseal plate
region between the diaphysis and epiphysis that is responsible for the lengthwise growth of long bones
epiphysis
rounded end of bone, covered with articular cartilage and filled with red bone marrow, which produces blood cells
eversion
movement of the sole of the foot outward, away from the midline of the body; opposite of inversion
exoskeleton
a secreted cellular product external skeleton that consists of a hard encasement on the surface of an organism
extension
movement in which the angle between the bones of a joint increases; opposite of flexion
facial bone
one of the 14 bones that form the face; provides cavities for the sense organs (eyes, mouth, and nose) and attachment points for facial muscles
femur
(also, thighbone) longest, heaviest, and strongest bone in the body
fibrous joint
joint held together by fibrous connective tissue
fibula
(also, calf bone) parallels and articulates with the tibia
flat bone
thin and relatively broad bone found where extensive protection of organs is required or where broad surfaces of muscle attachment are required
flexion
movement in which the angle between the bones decreases; opposite of extension
forearm
extends from the elbow to the wrist and consists of two bones: the ulna and the radius
gomphosis
the joint in which the tooth fits into the socket like a peg
Haversian canal
contains the bone’s blood vessels and nerve fibers
hinge joint
slightly rounded end of one bone fits into the slightly hollow end of the other bone
humerus
only bone of the arm
hydrostatic skeleton
skeleton that consists of aqueous fluid held under pressure in a closed body compartment
hyoid bone
lies below the mandible in the front of the neck
hyperextension
extension past the regular anatomical position
intervertebral disc
composed of fibrous cartilage; lies between adjacent vertebrae from the second cervical vertebra to the sacrum
intramembranous ossification
process of bone development from fibrous membranes
inversion
soles of the feet moving inward, toward the midline of the body
irregular bone
bone with complex shapes; examples include vertebrae and hip bones
joint
point at which two or more bones meet
lamella
layer of compact tissue that surrounds a central canal called the Haversian canal
lateral rotation
rotation away from the midline of the body
long bone
bone that is longer than wide, and has a shaft and two ends
lower limb
thigh, leg and foot
medial rotation
rotation toward the midline of the body
metacarpals
five bones that comprise the palm
metatarsal
one of the five bones of the foot
motor end plate
sarcolemma of the muscle fiber that interacts with the neuron
myofibril
long cylindrical structures that lie parallel to the muscle fiber
myofilament
small structures that make up myofibrils
myosin
contractile protein that interacts with actin for muscle contraction
opposition
movement of the thumb toward the fingers of the same hand, making it possible to grasp and hold objects
osseous tissue
connective tissue that constitutes the endoskeleton
ossification
(also, osteogenesis) process of bone formation by osteoblasts
osteoblast
bone cell responsible for bone formation
osteoclast
responsible for bone remodeling
many nuclei
osteocyte
mature bone cells and the main cell in bone tissue
osteon
cylindrical structure aligned parallel to the long axis of the bone
connected by perpendicular canals
patella
the kneecap
pectoral girdle
bones that transmit the force generated by the upper limbs to the axial skeleton
pelvic girdle
bones that transmit the force generated by the lower limbs to the axial skeleton
phalange
one of the bones of the fingers or toes
pivot joint
joint with the rounded end of one bone fitting into a ring formed by the other bone
planar joint
joint with bones whose articulating surfaces are flat
plantar flexion
bending at the ankle such that the heel is lifted, such as when standing on the toes
pronation
palm facing backwards
protraction
anterior movement of a bone in the horizontal plane
radius
arm bone located along the thumb side of the forearm
articulates with the humerus at the elbow
resorption
process by which osteoclasts release minerals stored in bones
retraction
movement in which a joint moves back into position after protraction
rib
one of 12 pairs of long, curved bones that attach to the thoracic vertebrae and curve toward the front of the body to form the ribcage
rotational movement
movement of a bone as it rotates around its own longitudinal axis
saddle joint
joint with concave and convex portions that fit together; named because the ends of each bone resemble a saddle
sarcolemma
plasma membrane of a skeletal muscle fiber
sarcomere
functional unit of skeletal muscle
scapula
flat, triangular bone located at the posterior pectoral girdle
sesamoid bone
small, flat bone shaped like a sesame seed; develops inside tendons
short bone
bone that has the same width and length, giving it a cube-like shape
skeletal muscle tissue
forms skeletal muscles, which attach to bones and control locomotion and any movement that can be consciously controlled
skull
bone that supports the structures of the face and protects the brain
smooth muscle tissue
occurs in the walls of hollow organs such as the intestines, stomach, and urinary bladder, and around passages such as the respiratory tract and blood vessels
spongy bone tissue
forms the inner layer of all bones
supination
movement of the radius and ulna bones of the forearm so that the palm faces forward
sutural bone
small, flat, irregularly shaped bone that forms between the flat bones of the cranium
suture
short fiber of connective tissue that holds the skull bones tightly in place; found only in the skull
symphysis
hyaline cartilage covers the end of the bone, but the connection between bones occurs through fibrocartilage; symphyses are found at the joints between vertebrae
synarthrosis
joint that is immovable
synchondrosis
bones joined by hyaline cartilage; synchondroses are found in the epiphyseal plates of growing bones in children
syndesmosis
joint in which the bones are connected by a band of connective tissue, allowing for more movement than in a suture
synovial joint
only joint that has a space between the adjoining bones
tarsal
one of the seven bones of the ankle
thick filament
a group of myosin molecules
thin filament
two polymers of actin wound together along with tropomyosin and troponin
tibia
(also, shinbone) large bone of the leg that is located directly below the knee
trabeculae
lamellae that are arranged as rods or plates
tropomyosin
acts to block myosin binding sites on actin molecules, preventing cross-bridge formation and preventing contraction until a muscle receives a neuron signal
troponin
binds to tropomyosin and helps to position it on the actin molecule, and also binds calcium ions
ulna
bone located on the medial aspect (pinky-finger side) of the forearm
