Chapter 7 Flashcards
the framework of the human body
skeletal system
approximate number of bones in the body
206
system that functions together with the skeletal system and the nervous system to make body movements possible
muscular system
the broad divisions that the skeletal system consists of
axial
appendicular
the “backbone” of the skeletal system is
axial skeleton
refers to the bones of the appendages, shoulder, and hips
appendicular skeleton
the skull can be divided into two main parts ….
cranium
facial bones
that largest portion of the skull
cranium
made up of 8 bones joined tightly together to form the armored shell for the brain
cranium
important cranial bones
frontal bone (forehead)
parietal bones (top of the head)
temporal bones (side of the head)
occipital bones (back of the head)
tough membranes made of fibrous connective tissue that connect the bones of an infant’s cranium
fontanels
fontanels are the ________ spots on the top and back of the infant’s head
soft
uneven lines at which the cranial bones are tightly joined together after the fontanel disappears
sutures
serve as the framework of the face and jaw
facial skeleton
number of bones in the facial skeleton
14
the most important of the facial bones
maxillary bones
form the central portion of the face and serve as the attachments for your upper teeth
two maxillary bones
the maxillary bones with the _______ bones form the roof of the mouth (aka the palate)
palatine
the only movable bone of the skull and is held to the cranium by ligaments
mandible
tissues that join bone to other bones
ligaments
an important bone hidden in the upper neck, just above the larynx is the U-shaped
hyoid bone
the smallest bones the human body are the three middle ear bones: ______ ________ and ______
malleus (hammer)
incus (anvil)
stapes (stirrup)
the chief structural member of the body
vertebral column ( aka spine, spinal column, backbone)
a massive, columnlike structure that in adults consists of 33 segments called vertebrae
vertebral column
disks of flexible cartilage which allow the spine to bend and twist somewhat and also act as shock absorbers
intervertebral disks
a tough, rubber connects tissue that cushions the joints between bones
cartilage
five regions of the vertebral column
cervical,
thoracic,
lumbar,
sacral or pelvic,
caudal or coccygeal
the cervical vertebrae that forms the neck is made of _______ vertebrae
7
the longest segment of the vertebral column is the
thoracic vertebrae
number of vertebrae in the thoracic vertebrae
12
the largest vertebrae
lumbar vertebrae
number of vertebrae in the lumbar vertebrae
5
the vertebrae in the pelvic region that are five separate vertebrae in infants but are fused into a single bone called the sacrum in adults
sacral vertebrae
is joined rigidly to the hip bones to form the foundation of the spine
sacrum
four tiny, separate vertebrae beneath the sacrum that are fused together into single bone in adults
coccyx
an attachment for various muscles that allow us to stand in an upright position and aid in eliminating wastes
coccyx or tailbone
the uppermost of the cervical vertebrae which is the mounting to which the head is connected
atlas
the second cervical vertebra which serves as the base for the atlas
axis
a severe lateral curvature of the spine is known as
scoliosis
the vital internal organs of the thoracic cavity are protected by the bones of the chest which make up the
thoracic cavity
the most prominent bones of the thoracic cage
long, curved bones that attached to the thoracic vertebrae in the back and to the sternum in the front
ribs
short segments of flexible cartilage that attach the sternum indirectly to the sternum
costal cartilage
the upper seven pairs of ribs
true ribs
the ribs that do no connect to the sternum
false ribs
the bottom two pairs of false ribs
floating ribs
includes the 126 bones that form the pectoral girdle, the pelvic girdle, and the appendages
appendicular skeleton
the collective name for the shoulder bones which includes the shoulder blades and the collarbones
pectoral girdle
the largest bone of the pectoral girdlle
shoulder blades (scapulae)
the most freely movable joint in the body
shoulder joint
attaches to the top of the sternum and braces each scapula
collarbone or clavicle
each upper arm has _______ bones
30
the wrist, hand, and fingers make up _______ bones
27
the largest of the three bones in the arm which makes up the upper arm
humerus
the bone on the same side of your forearm as your little finger
ulna
the bone on the same side as you thumb
radius
bones of the wrist
carpus
the 8 bones that form an intricate assembly which allows the wrist to bend in various directions
carpals
compose the base of the thumb and the main part of the hand
metacarpals
are attached to the metacarpals and fourteen of them make up the fingers and the thumb
phalanges
each finger consists of ________ phalanges
the thumb consists of ________ phalanges
3
2
is composed of two large, heavy pelvic bones, forming a rigid ring of thick bone that supports most of the body’s weight
pelvis or pelvic girdle
two large, heavey bones that attach to the sacrum of the axial skeleton,
pelvic bones
the largest bone of the leg and is also the longest bone in the body that composes the thigh
femur
the main weight-bearing bone of the leg which extends from the knee joint to the ankle
shinbone or tibia
bone of the lower leg that is much thinner than the tibia and does not attach to the femur
fibula
bone found in the front of the knee
kneecap or patella
serves as a brace for the tendon that straightens the leg
patella
a strong cable of tough fibers that attaches MUSCLE to BONE
tendon
the foot is attached to the tibia and fibula by the
tarsus (bones of the ankle)
seven bones that are similar to the carpals of the wrist but are thicker and stronger to support the weight of the body
tarsals
one of the largest tarsals which is the only tarsal that is directly connected to the tibia and the fibula
talus
lying beneath the talus is the largest tarsal called
calcaneus ( forms the heel)
five bones in front of the tarsals which correspond to the metacarpals of the hand
metatarsals
bones are classified by
shape
four groups of bones
short
long
flat
irregular
the shaft of the bone is called the
diaphysis
the bulged end of a bone is called the
epiphysis
bones that are longer than they are wide; mainly support the weight of your body and work with your muscles to provide movement
long bones
examples of long bones
humerus
ulna
femur
phalanges
bones that roughly cube shaped and are nearly as wide as they are long
short bones
examples of short bones
carpals
tarsals
bones which are often tasked with protecting vital organs
flat bones
examples of flat bones
ribs
cranial bones
bones that cannot be easily classified into one of the first three categories
irregular bones
examples of irregular bones
vertebrae
a protective sheath that encloses the bone as a whole and contains the blood vessels that supply the bones with nutrients
periosteum
the outer shell of the bone that is composed of a strong, dense substance and gives the bone great strength and rigidity
compact bone
the lightweight, porous tissue that replaces the dense compact bone in the epiphyses
spongy bone
special tissue that manufactures red blood cells and white blood cells for the body’s circulatory and immune systems
red marrow
the cavity that houses red marrow int he bones of infants and children
medullary cavity or marrow cavity
fatty substance that replaces the red marrow in the medullary cavity in adults
yellow marrow
microscopic crystals that are credited with hardening the bone; contain much calcium and phosphorous
hydroxyapatite
tough, resilient protein fibers that run between the crystals of hydroxyapatite
collagen
special cells that constantly move through your bones removing old materials to make room for new
osteoclasts
cells that move into the Haversian canals, constructing new collagen fibers and hydroxyapatite
osteoblasts
minerals and vitamens for the bones
calcium
phosphorous
Vitamins D, C, A
a disease in which the bones are weak and deformed
rickets
name for rickets in adults
osteomalacia
according to whose law do the bones adjust their shapes to the physical stress placed upon them
Wolff’s law
when special cells began to construct the forms of your body’s bones out of cartilage or membrane materials; then, once cartilage form is complete, osteoblasts began moving through them, replacing the soft rubbery cartilage with collagen-enforced hydroxyapatite
Ossification
a break or crack in a bone
fracture
occurs when a bone breaks cleanly in two places
transverse fracture
occurs when the bone cracks and bends but remains held together by its collagen fibers
greenstick fracture
occurs when the bone is twisted or exposed
spiral fracture
occurs when part of a bone is broken into multiple fragments
comminuted fractures
occurs when a bone cracks or breaks but does not pierce the skin
simple or closed fracture
occurs when the broken bone pierces through the skin
compound or open fracture
bones heal with _________ tissue
bone
the places where bones join or articulate
joints
joints of the cranium
immovable joints
joints between the vertebrae that make some bending and twisting movements possible
slightly movable joints
the most important joints in the body which allow a wide range of motion
freely movable joints or synovial joints
tough, slippery substance covering the ends of the bones which serves as bearings that allow the bones to glide smoothly over each other
articular cartilage
the articular cartilage is lubricated with clear, water-based lubricant which resembles egg whites called
synovial fluid
the bones are held together by strong bands of fibrous connective tissue
ligaments
enclosure formed by ligaments which serve as a container for the synovial fluid
joint capsule
lines the inside of the joint capsule and produces the synovial fluid
synovial membrane
6 types of freely movable joints are
hinge
ball and socket
pivot
ellipsoid
gliding
saddle
joint which allows a bone to move back and forth in a single plane
hinge joint
examples of hinge
knees
elbows
joints of the fingers
the most freely movable joints in which the rounded head of a bone fits into a hollow socket in another bone
ball and socket
joint in which a bone rotates in place against another bone; allows only rotating
pivot
joints between the metacarpals and phalanges which allow you to move your fingers up, ,down, left and right
ellipsoid
joints in which one bone merely slides across the surface of another
glide
joints found only in your hand in which one bone nestles into a saddle-shaped portion of another bone
saddle
a common degenerative condition of the joints;
inflammation of the joints
arthritis
the most common form of arthritis in which years of wear and tear on a joint cause the articular cartilage in the joint to deteriorate
osteoarthritis
arthritis which occurs when the body’s immune system attacks the tissues of a joint
rheumatoid arthritis
the most common types of joint injury which occurs when the ligaments of a joint are overstressed causing them to become tender and inflames
sprain
when a joint is overstressed to the extent that a bone pops out of alignment
dislocation
skeletal muscles are under conscious control, making them
voluntary muscles
two groups of involuntary muscles
smooth muscle
cardiac muscle
muscles whose primary function is to move the parts of the skeleton
skeletal muscles
individual cells which compose muscles
muscle fibers
skeletal muscle is also called
striated muscle
muscles which consist of shorter, wider cell sin a looser arrangement
smooth muscle
muscle specialized for relatively slow, powerful and prolonged contractions
smooth muscle
muscle found only in the heart which is specially designed to contract over and over without tiring
cardiac muscle
some of the chief muscles responsible for moving the head and connect the temporal bones of the skull to the sternum and clavicles are the two
sternocleidomastoid muscles
when both of the sternocleidomastoids contract simultaneously
your head bows
some of the most important muscles of the face
those that move the lower jaw, as when chewing or talking
muscles located on each side of the head which connect the mandible to the cranium and function to close the jaw,
temporalis and masseter
one of the most important muscles in shoulder movement is
trapezius
muscles which attach to the side of each scapula and stretch forward around the side of the rib cage
serratus anterior
the two muscle groups used to pull the shoulders forward
serratus anterior
pectoralis minor
the muscles between the ribs which are much smaller than most chest muscles but are very important because they help you breath
intercostal muscles
the largest chest muscles which are also some of the most important in the movement of your upper arm
pectoralis major
muscles which form the curves of your shoulder and lift the upper arms away from the body
deltoid
muscles which connect each humerus to the lumbar region of the spine and are responsible for drawing your arms to the rear (pulling rope and paddling canoe)
latissimus dorsi
the muscles which allow you to bend your forearms
biceps brachii
the muscles which extend or straighten the arms
triceps brachii
muscles which extend from the bottom of the sternum to the front of the pelvic girdle
use this when sitting up from reclining position
rectus abdominis
muscles connect the ribs to the pelvis but extend more to the side s
external oblique
some of the most important trunk muscles which extend vertically along the spinal column form the upper back to the pelvis
straighten back
erector spinae
the largest and strongest muscles in your whole body which pull your upper legs downward, away from the body and toward the rear
allow you to stand up
gluteus maximus
the primary muscles involved in moving your lower leg
quadriceps femoris
hamstrings
sartorius
group of four muscles that are all connected to the tibia by the patellar tendon
straighten the leg at the knee
quadriceps femoris
group of three muscles that work to bend the leg at the knee
hamstrings
extends diagonally downward from the front of the pelvic bone and passes around the side of the thigh
lifts the lower leg and turns it inward
sartorius
the largest muscle of the calf
forms the bulge on the back part of your calf
main job is to extend the foot downward
gastrocnemius
muscle performs the opposite job of the gastrocnemius
pulls foot upward
tibialis anterior
a tough, translucent sheath that encases the entire biceps muscle
binds the muscle together
fascia or epimysium
millions of individual muscles cells that compose the biceps muscle
muscle fibers
sheath of tough connective tissue which encase the muscle cells
serve to strengthen the muscle cells
endomysium
muscle cells are bundled into larger groups called
fascicles
sheet of connective tissue that bind endomysium-wrapped fibers
perimysium
surrounds muscle cells
cell membranes
a ___________ muscle cell contains more than one nuclei
skeletal
serve as the cell’s power plants
mitochondria
long cylinders which extend the length of the muscle cell
myofibrils
repeating units which give skeletal muscle its banded, or striated, appearance
sarcomeres
makes up the thick filaments of the overlapping protein fibers
protein myosin
makes up the thin filaments of the overlapping protein fibers
protein actin
muscle contractions are triggered by your nervous system, which transmits signals to individual muscle cells through
motor neurons
nerve cell
neuron
the point at which a moto neuron connects to a muscle cell is called a
neuromuscular junction
the nerve triggers the muscle cell to contract in the neuromuscular junction by releasing a special chemical know as a ______________________ into the junction
neurotransmitter
a motor neuron an the group of cells it controls are a
motor unit
principle that states that when a mucle fiber is stimulated to contract, it does so completely and then relaxes completely until another nerve impulse reaches it
all-or-none principle
enlargement of muscles through use
hypertrophy
muscle degeneration
atrophy
skeletal muscle must be ___________ or they will atrophy
used
muscle fibers that contain mitochondria and large amounts of myoglobin
red fibers
muscle fibers containing few mitochondria and less myoglobin
white fibers
are commonly called fast-twitch fibers because they contract very rapidly and more stongly than its counter part
white fibers
fibers that contract more slowly and less strongly than their counterparts and are therefore called slow-twitch fibers
red fibers
the total awareness of body movements
muscle sense
