Flashcards in Skeletal System Deck (121):
Five types of bone
Give ex of each of the five bones
1. Long- femur
2. Short- tarsal
3. Flat- parietal
4. Irregular- vertebra
5. Sesamoid (round)- patella
Organic matter in bone
Only found in bone!!
Relationship btwn skeleton and calcium
Skeleton is reservoir of calcium, it stores extra
Rings start out small and get larger toward outside
What kind of tissue is bone
Hyaline cartilage; where your bone grew from as you grew; forms a model for bone to replace
Will eventually give rise to bone
Basic stuctural unit of compact bone
Does periosteum rot
Yes over time
Cavity inside bone
Bone salts are located ?
In the matrix
What are 2 bone salts and what do they do
Calcium carbonate and hydroxyapatite (unique to bone!!!)
Make bone hard
2 diff btwn bone and cartilage
Bone has concentric rings
Cartilage has chondroblasts, bones has osteoblasts (both sit in lacunae)
Is bone vascular?
What is in the middle of each osteon?
Central canal (Haversion)
Another name for central canal
What tissue are the rings in osteon
Where are osteocytes located?
In lacunae in between concentric circles
Perforating (volkmann's) canal
Enter bone from outside and inside feeding into Haversian systems carrying nerves and blood vessels
Keep periosteum so strong and from peeling off; anchor it
Where is red marrow
Canals btwn lacunae of ossified bone; osteocytes project into them
What kind of marrow is in the medullary cavity?
How many vertebrae are there?
How many cervical vertebrae are there and what are the first 2 specifically called?
How many thoracic vertebrae are there
How many lumbar vertebrae are there
How many sacrum vertebrae are there
How many coccyx are there?
Put together; where they meet
Projection or outgrowth of tissue from after body
Nodule/small eminence, especially one on a bone for attachment of a tendon
What percent of our skeletal system being broken down and remade in one year?
Smallest bones in the body
3 ear bones
Floating bone; only bone not connected to anything
What kind of cartilage is the articular cartilage at the ends of long bones (epiphysis)?
What kind of cartilage is in the ribs?
Another name for the body of vertebrae
What are four main functions of bone?
Support/protection, body movement, inorganic salt storage, and blood cell formation
Hint: SIP 'double' B
How many bones are in the adult
How many bones in newborn
Axial skeleton consists of:
skull, middle-ear bones, hyoid, rib cage, vertebral column, and sternum
Appendicular skeleton consists of:
upper/lower extremities, and the pectoral and pelvic girdles
shaft of long bone
ends of long bone
slender plates of spongy bone
Function of osteoblasts
Make bone by making matrix (concentric circles); store calcium in bone; (become osteocytes)
Where are osteogenic cells?
Endosteum, inner periosteum, and the Haversian canals; only source of new cells of osteoblasts and osteocytes
osteoblasts trapped in bone matrix; remain active in maintenance of bone
bone-DISSOLVING cells that form by fusion of monocytes; break down bone and release its minerals to the blood
What comes out of bone when osteoclasts break it down?
As you get older you get (more/less?) osteoclasts
What helps you to absorb calcium
What systems won't work without calcium
muscular, skeletal, and nervous
Organic matter in bone
collagen, GAGS, proteoglycans, and glycoproteins
Mineral components in bone
ESPECIALLY hydroxyapatite (unique to bone) and calcium carbonate; phosphate
How are lamellae of bone arranged
concentric circles around Haversian canals
Within the lamellae of concentric rings lie the.....
lacuna with osteocytes
Extend between adjacent lamellae
Do red blood cells have nuclei
Do RBC divide when out of marrow?
What is RBC main function
to transport oxygen
In children, red marrow also called ___? is _____ and resides where?
also called myeloid tissue is hemopoietic (blood maker) and fills the medullary cavity
pertaining to the marrow
formation of blood/blood cells
Where is most of the marrow in adults? (age 30)
in the medullary cavity; its YELLOW marrow that stores fat (long bones)
In older adults (age 70), what is yellow marrow mostly replaced with?
Gelatinous marrow- no tremendous function; bones become more fragile
making of bone
Occurs within a membrane of soft tissue that represents the location of a future flat bone (ref. to skull). Its cells differentiate into osteogenic cells and osteoblasts, (in skull of fetus) and trabecular are formed
What did the bones of the skull used to be?
membrane of soft tissue
How do osteoblasts form bone?
they form on the trabecular and lay down an organic matrix and deposit calcium phosphate within it; when trapped, they become osteocytes.
cartilage stops diving so bones won't grow anymore
bone formation using a cartilage model. in the center of the model is the primary ossification center where lacunae enlarge and minerals are deposited around them. (cartilage becomes bone)
Whats the primary ossification center for endochondral ossification?
cells of the PERICHONDRIUM develop into a periosteum (bone lining) where osteogenic cells and osteoblasts produce bone on the OUTSIDE of the model
Where on the cartilage model is bone produced
Outside of it
What is formed on the inside in the center of the cartilage model in endochondral ossification
A primary marrow space is formed
What is the metaphysis?
The transition between the head of hyaline cartilage and the primary marrow space; "meta-" = middle and "-physis" = to grow
How many zones does the metaphysis exhibit that represent the stages of ossification
Where do secondary ossification centers form at birth?
In the epiphyses of long bones
What happens to the epiphysis at the secondary ossification center
It's hollowed out from the center outward and is replaced by bone
Where does cartilage remain until adulthood?
at the epiphyseal plate
Deficiency of vitamin A
retards bone development
deficiency of vitamin C
results in fragile bones
deficiency of vitamin D
rickets: metabolic disorder: phosphorous/calcium
osteomalacia= bone softening
Excess of vitamin A
cause lysosome cells to burst prematurely
Insufficient growth hormone
excessive growth hormone
insufficient thyroid hormone
delays bone growth
promote bone formation: stimulate ossification of epiphyseal plates
stimulates bone growth
the process of dissolving bone to release its minerals to the BLOODSTREAM
Osteoclasts dissolve bone
What do osteoclasts dissolve bone with
The skeleton serves as a reservoir for...
calcium, phosphorus, and other minerals that play important roles in physiology
excessively low calcium concentration that causes the nervous system to become hyper excitable (lose ability to stay calm)
What can result from hypocalcemia
excessive calcium which can cause nervous system depression and sometimes cardiac arrest
What controls balance between calcium storage and calcium resorption?
calcitonin and parathyroid hormone (PTH)
Acts t o LOWER blood levels of calcium by stimulating osteoblasts and inhibiting osteoclasts
calci[ton]in= TONE it down, too much calcium
Parathyroid Hormone (PTH)
Raises blood calcium when it drops too low; stimulates osteoclasts, lessens urinary excretion of calcium, and stimulated the synthesis of vitamin D
Where is body is vitamin D produced?
skin, liver, and kidney; need it from an outside source
most active form of vitamin D; produced together by the skin (with UV light), live, and kidney
What does calcitrol promote?
Intestinal absorption of calcium and phosphate while reducing urinary elimination of these minerals
Bruise; can result from bone fracture from torn blood vessels
Order of healing of bone fractures
hematoma---> soft granulation tissue forms as blood vessels grow into hematoma ---> macrophages remove debris ---> fibroblasts deposit collagen----> chondroblasts form fibrocartilage callus (soft first, replaced w/ bony tissue)
How long is the area of a fracture remodeled?
3-4 months until broken bone fragments are resorbed
Two ways fractures may be set by
1. closed reduction- no surgery; caste
2. open reduction- surgical placement of bones using pins and plates
branch of medicine dealing with injuries/disorders of bones, joints, and muscles
MOST COMMON bone disease in which bone lose mass and become brittle
Whose most prone to osteoporosis
elderly, postmenopausal white women (black women rarely afflicted)
From osteoporosis, spine becomes compressed
occurs at any age due to immobilization or inadequate weight-bearing exercise
Reasons for falls among elderly
frailty, decrease in muscle strength, decreased coordination; side effects of medicine; slowed reaction time due to stiffening joints; poor vision and/or hearing, disease (cancer, arthritis, infection)
Organic matter in bone