Chapter 7 - Skeletal system Flashcards
calcitonin (CT)
a hormone produced from the thyroid gland that increases mineralization of bone and thus reduces blood calcium
parathyroid hormone (PTH)
a hormone from the parathyroid glands that counterbalances the effects of calcitonin by decreasing calcium in the bone and thus increasing blood calcium
homeostasis of blood calcium
a reference to the fact that the body regulates the amount of calcium in the blood by moving the calcium to the bones when the blood calcium is too high and taking calcium away from the bones when the blood calcium is too low
red bone marrow
soft connective tissue inside the hard walls of some bones that produces both red and white blood cells
hematopoiesis
the process of blood cell formation
four major types of bones
Long bones—e.g., humerus or arm bone
Short bones—e.g., carpals or wrist bones
Flat bones—e.g., frontal or skull bone
Irregular bones—e.g., vertebrae or spinal bones
sesamoid bones
also called round bones; the term sesamoid means “like a sesame seed”; it refers to certain bones which may develop around a tendon, like the kneecap; sometimes considered to be a fifth type of major bone
diaphysis
also known as the shaft; a hollow tube made of hard, compact bone, hence a rigid and strong structure light enough in weight to permit easy movement
medullary cavity
the hollow area inside the diaphysis of a bone; contains soft yellow bone marrow
epiphyses (singular: epiphysis)
the ends of the bone—red bone marrow fills in small spaces in the spongy bone composing the epiphyses; some yellow marrow may appear as a person ages
articular cartilage
a thin layer of cartilage covering each epiphysis; functions like a small rubber cushion would if it were placed over the ends of bones where they form a joint
periosteum
a strong membrane of dense fibrous tissue covering a long bone everywhere except at joint surfaces
endosteum
a thin membrane that lines the medullary cavity
yellow bone marrow
marrow made mostly of fat that contains stem cells that can become cartilage, fat, or bone cells
diploe
the cancellous bone layer in flat bones, sandwiched between compact bone
trabeculae
a small, often microscopic, tissue element in the form of a small beam, strut or rod that supports or anchors a framework of parts within a body or organ
strut
(1) a rod or bar forming part of a framework and designed to resist compression
(2) a stiff, erect, and apparently arrogant or conceited gait
concentric lamella
tubes of different sizes fitting inside each other to surround the central canal of an osteon
haversian canal
also called the central canal; the center of an osteon, surrounded by concentric lamella; it is filled with blood vessels
lacuna
a small space, containing an osteocyte in bone, or a chondrocyte in cartilage
Volkmann canals
also called transverse canals; they are canals that connect haversian canals to each other
canaliculi
canals that connect the lacuna together and that are involved in distributing nutrients to all the bone cells in bone
cartilage
a strong and smooth substance made up of “chondrocytes,” or specialized cartilage cells, that functions to cover and protect bones and nerves and forms the structural component of some body parts like the ear and nose
osteoblast
a type of bone cell that creates bone tissue
osteoclast
a type of bone cell that breaks down bone tissue
osteocyte
a bone cell
endochondral ossification
one of the two essential processes during fetal development of the mammalian skeletal system by which bone tissue is created; it creates bone from a cartilage model
epiphyseal plate
also called the growth plate; a thin layer of cartilage that lies between the epiphyses and metaphysis, and is where the growth of long bones takes place during childhood
metaphysis
the neck portion of a long bone between the epiphysis and the diaphysis. It contains the growth plate, the part of the bone that grows during childhood, and as it grows it ossifies near the diaphysis and the epiphyses
intramembranous ossification
the process by which some bones, such as the skull bones, are formed; they are formed by calcification of fibrous membranes
fontanels
the soft spots on a newborn baby’s skull; they are areas of fibrous membrane that have not yet fully ossified
axial skeleton
the bones of the skull, spine, and chest and the hyoid bone in the neck
appendicular skeleton
the bones of the upper extremities (shoulder, pectoral girdles, arms, wrists, and hands) and the lower extremities (hip, pelvic girdles, legs, ankles, and feet)
osteoporosis
a bone disease that occurs when the body loses too much bone, makes too little bone, or both
sinus
space or cavity within some of the cranial bones
suture
(1) an immovable junction between two bones, such as those of the skull
(2) a stitch or row of stitches holding together the edges of a wound or surgical incision
hyoid bone
a U-shaped bone in the neck which supports the tongue
cervical vertebrae
the vertebrae of the neck, immediately below the skull; It consists of 7 bones, from top to bottom, C1, C2, C3, C4, C5, C6, and C7.
thoracic vertebrae
the middle segment of the vertebral column, between the cervical vertebrae and the lumbar vertebrae. In human, thoracic vertebrae consists of 12 bones. From top to down, T1, T2, …, T12
lumbar vertebrae
In human anatomy, the five vertebrae between the rib cage and the pelvis. They are the largest segments of the vertebral column. It consists of 5 bones, from the top down, L1, L2, L3, L4 and L5.
sacrum
a large, triangular bone at the base of the spine that forms by the fusing of the sacral vertebrae (S1–S5) between ages 18 and 30.
coccyx
commonly referred to as the tailbone, is the final segment of the vertebral column in all apes and humans; in child, three to five separate vertebrae and in adult, fused into one
vertebral foramen
a hole in the cervical and vertical vertebra, through which the spinal cord passes
meninges
The three thin layers of tissue that cover and protect the brain and spinal cord
transverse process
a small bony projection off the right and left side of each vertebrae
articular processes
also called zygapophyses; projections of the vertebra that serve the purpose of fitting with an adjacent vertebra. The actual region of contact is called the articular facet.
atlas (anatomy)
the most superior (first) cervical vertebra of the spine, located in the neck
axis (anatomy)
the second cervical vertebra (C2) of the spine, immediately posterior to the atlas, upon which the head rests
concave curvatures (spine)
the concave cervical and lumbar curves of the spine in adults and non-infant children
convex curvatures (spine)
the convex thoracic and sacral curves of the spine in adults and non-infant children
spinal curvature of an infant
a reference to the fact that the spine in infants forms a continuous convex curve from top to bottom
purpose of spinal curvature
the spine is curved because that gives it greater ability to support the weight of the body
true ribs
upper seven pairs of ribs; attached to sternum by costal cartilages
false ribs
Lower five pairs of ribs; first three pairs attached to sternum by costal cartilage of seventh ribs; lowest two pairs do not attach to sternum, therefore called floating ribs
costal cartilage
segments of cartilage that connect the sternum to the ribs and help to extend the ribs into a forward motion
radius and ulna
the two bones in the forearm (part of arm between hand and elbow)
it helps to think of the radius as the bone in line with the thumb, considered lateral as it is away from the body’s midpoint (in the anatomic position)
ulna is medial, towards the body’s midpoint, and in line with the small finger
humerus
the arm bone between your shoulder and your elbow
articulation
(1) a joint or juncture between bones or cartilages in the skeleton of a vertebrate
(2) a movable joint between rigid parts of an animal
(3) the action or manner of jointing or interrelating
(4) the state of being jointed or interrelated
(5) the act of giving utterance or expression
(6) the act or manner of articulating sounds
phalanges (singular: phalanx)
the bones that make up the fingers of the hand and the toes of the foot
acetabulum
a deep, cup-shaped socket that connects the femur to the hips
pelvic girdle
also called hip girdle; part of body that connects the legs to the trunk
girdle
something that encircles or confines: such as (1) an article of dress encircling the body usually at the waist; (2) a woman’s close-fitting undergarment
loins
(1) the part of the body on both sides of the spine between the lowest (false) ribs and the hipbones
(2) the region of the sexual organs, especially when regarded as the source of erotic or procreative power
patella
the kneecap
fibula and tibia
one of the two bones that make up the lower part of the leg
tibia is in line with the toe and is bigger, fibula is in line with the smallest toe and is smaller
calcaneus
the largest of the tarsal bones in the foot. It lies at the back of the foot (hindfoot) below the three bones that make up the ankle joint
fallen arches
also called flatfeet; a condition where the foot ligaments and tendons weaken, causing the foot to sit completely flat on a surface (the reason why I need custom arches)
foot arch
the foot has three arches normally (except in the case of fallen arches): the medial longitudinal and lateral longitudinal arches which run from near the ankle to near the toes and the anterior transverse which runs from side to side of the foot
longitudinal
(1) running lengthwise rather than across (length is the longest dimension)
(2) relating to longitude (not related to length); measured from east to west
transverse
(1) acting, lying, or being across; set crosswise
(2) made at right angles to the long axis of the body
palpable
(1) capable of being touched or felt
(2) easily perceptible
three types of joint classifications
One classification method classifies joints into three types according to the degree of movement they allow:
- Synarthrosis —no movement
- Amphiarthrosis —slight movement
- Diarthrosis —free movement
joint capsule
an envelope surrounding a synovial joint; each joint capsule has two parts: an outer fibrous layer or membrane, and an inner synovial layer or membrane
synovial joint
the type of joint found between bones that move against each other, such as the joints of the limbs (e.g. shoulder, hip, elbow and knee)
ball-and-socket joints
a ball-shaped head of one bone fits into a concave socket of another bone. Shoulder and hip joints, for example, are ball-and-socket joints. Of all the joints in our bodies, these permit the widest range of movements.
hinge joints
like the hinges on a door, allow movements in only two directions, namely, flexion and extension. Flexion is bending a joint and extension is straightening it out. Elbow and knee joints and the joints in the fingers are hinge joints
pivot joints
those in which a small projection of one bone pivots in an arch of another bone. For example, recall that a projection of the axis (second cervical vertebra) is a point around which an arch of the atlas (first cervical vertebra) can pivot. This permits rotation of the head, which rests on the atlas.
saddle joints
Only one pair of saddle joints exists in the body—between the metacarpal bone of each thumb and a carpal bone of the wrist (the name of this carpal bone is the trapezium). Because the articulating surfaces of these bones are saddle-shaped, they make possible the human thumb’s great mobility, a mobility no animal’s thumb possesses.
saddle
(1) a seat fastened on the back of a horse or other animal for riding, typically made of leather and raised at the front and rear.
(2) a low part of a ridge between two higher points or peaks
gliding joints
the least movable diarthrotic joints. Their flat articulating surfaces allow limited gliding movements, such as that at the superior and inferior articulating processes between successive vertebrae
condyloid joints
those in which a condyle (an oval projection) fits into an elliptical socket. An example is the fit ofthe distal end of the radius into depressions in the carpal bones
total hip replacement (THR)
The THR procedure involves replacement of the femoral head by a metal prosthesis and the acetabular socket by a polyethylene cup. The prostheses are usually coated with a porous material that allows natural growth of bone to mesh with the artificial material. Such meshing of tissue and prostheses ensures stability of the parts without the loosening that the use of glues in the past often allowed. First introduced in 1953, THR technique has advanced to the state that the procedure has very high success rates in older adults.
prosthesis
an artificial body part, such as a leg, a heart, or a breast implant
acetabular socket
the socket of the ball-and-socket hip joint
polyethylene
the most common plastic in use today
gamete
an organism’s reproductive cells
arthropod
Any of numerous invertebrate animals of the phylum Arthropoda, including the insects, crustaceans (e.g shrimp, lobster, crayfish), arachnids, and myriapods (e.g. centipede, millipede)
