U7 Skeletal Flashcards
What is the purpose of the skeletal system?
- support framework for the body
- protection of vital organs
- body movements via joints
- hematopoiesis
- mineral reservoir for calcium & phosphorus
Axial skeleton consists of…
- Head
- Vertebral column
- bony thorax
- misc.
the head includes…
- skull (8)
- facial bones (14)
- ossicles (16)
the vertebral column includes…
- cervical (7)
- Thoracic (12)
- lumbar (5)
- sacrum (1 fused)
- coccyx (1 fused)
the bony thorax includes…
- sternum (1)
- Ribs (24)
axial skeleton misc.
- hyoid bone
appendicular skeleton consists of…
- upper extremities
- lower extremities
- pelvis
the upper extremities include..
- phalanges (28)
- metacarpals (10)
- carpals (16)
- radius & ulna (4)
- humerus (2)
- scapula (2)
- clavicle (2)
the lower extremities include..
- phalanges (28)
- metatarsals (10)
- tarsals (14)
- tibia & fibula (4)
- femur (2)
- patella (2)
the pelvis includes
- ilium
- ischium
- pubis
skull bones
8
facial bones
14
ossicles
6
cervial vertebrae
7
thoracic vertebrae
12
lumbar vertebrae
5
sacrum
1 fused
coccyx
1 fused
sternum
1
ribs
24 (12 ea.)
hyoid bone
1
phalanges
28
metacarpals
10
carpals
16
radius & ulna
4
humerus
2
scapula
2
clavicle
2
metatarsals
10
tarsals
14
tibia & fibula
4
femur
2
patella
2
ilium
1 fused
ischium
1 fused
pubis
1 fused
long bones
- humerus
- radius
- ulna
- metacarpals
- phalanges
- femur
- tibia
- fibula
- metatarsals
short bones
- carpals
- tarsals
flat bones
- ribs
- sternum
- scapula
- clavicles
- skull cap
irregular bones
- vertebra
- facial bones
- skull bones
sesamoid bones
- patella
- foot
condyle
round projection that forms an articular surface
head
-round projection that extends from a constricted neck
- forms an articular surface
trochanter
very large projection for tendon attachment
tuberosity
medium sized projection for tendon attachment
tubercle
small projection for tendon attachment
spine
sharp projection (ilium, post. scap)
Crest
ridge or edge running the length of a bone
Foramen
round opening in bone for blood vessels & nerves
fissures
narrow but deep slit-like opening
meatus
opening into a canal
fossa
furrow or hollow area (like a cup)
sulcus
groove
sinus
air-filled cavity in bones
Periosteum
-thin but dense outer bone covering
- not present @ articulating surfaces of long bone
Cortical bone
- “compact)
- thick, dense layer under periosteum
- provides strength & support
cancellous bone
- Trabecular or spongy
- very porous at the end of long bones and in flat bones
- contains red bone marrow
trabeculae
-evident at ends on long bones
- web-like structure of cancellous bone only
endosteum
- inner most lining
- only in diaphysis
- trabecular membrane that lines the medullary cavity
medullary cavity
- central shaft of bones
- contains yellow bone marrow
Articular cartilage
-cartilage that covers the articular surface in long bones
-provides a cushion
yellow bone marrow
-in shaft of long bones
-fat reservoir in the medullary cavities
-not essential for life
red bone marrow
- found in spongy part of long & flat bones
- red blood cells are produced
-essential for life
diaphysis
- shaft of long bones
- primary ossification center
- first portion of bone to develop
epiphysis
-ends of long bones
- secondary ossification center
- develops later in childhood
epiphyseal plate
-“growth plate”
-between diaphysis and epiphysis
- slowly narrows as bones mature
- last part to turn into bone
metaphysis
-wider portion of long bone
-where diaphysis transitions to epiphyseal plate
osteons
-rings of microscopic bone
-consisting of bone cells and protein fibers (collagen)
-gives cortical bone strength & rigidity
Haversian canal
-center of each osteon
-where blood vessels are found to deliver nutrients to bone tissue
osteocytes
-star-shaped bone cells
- bound together by collagen
-more densely packed in compact bone than in spongy
osteoclasts
-specialized bone cells
-dissolve osteocytes and collagen
osteoblasts
-become osteocytes during bone repair/growth
-“build” bone
-located in the periosteum & endosteum
-migrate to osteon to create new bone
ossification
-process of bone forming from cartilage
-two types:
intramembranous
endochondral
intramembranous ossification
process of bone replacing cartilage in flat bones
endochondral ossification
process of bone replacing cartilage @ the epiphyseal plate of long bones
where does skeletal growth begin?
diaphysis
where does post partum growth occur
center of diaphysis toward the epiphysis
When does the epiphyseal plate appear in radiographs?
up until adulthood
how do bones grow?
from the inside out
when is skeletal growth complete?
between 18 and 21 years
when is post-puberty bone formation done?
during remodeling and repair
bone remodeling
normal process of bone recycling itself
Osteoporosis
-there is less bone mass/lose rigidity
-osteoblasts are not properly rebuilding bone
Osteropetrosis
-too much bone mass
- overly dense
-osteoclasts are not properly resorbing bone
what is a DEXA scan?
bone density test
DEXA
Dual Energy X-ray Absorption
Stages of bone repair
- Swelling
- bridging
- hardening
- shaping
Inflammatory stage
-fractured bone -> torn blood vessels
-torn vessels -> swelling
-chemicals are released to kill pathogens
-phagocytes move in to destroy dead cells & pathogens
-week 0-1
Soft callus stage
-soft-bridge is formed
-osteoblasts migrate to fracture to begin developing fibrous cartilage
-fibroblasts move in to create collagen fibers to bind cartilage cells together
-week 1-2
Hard callus stage
-fibrous cartilage -> cancellous bone
-cancellous bone -> compact bone
- compact bone takes longer to form due to its density
-bone is structurally sound
-callus has formed
-week 4-5
remodeling stage
-osteoclasts begin dissolving the callus to create original bone shape
-fx. site will be slightly thicker from additional osetocytes
-may take years depending on severity, age, etc.
-week 6 -years
