-
Functions of skeletal system
- protects interal organs
- serves as anchor for muscle attachments
- aids in movement
- stores minerals
- produces blood cells
-
connective tissue of skeletal system
- cartilage
- ligaments
- tendons
- bones
-
5 kinds of bones
- long: (arm and leg)
- short: (hands and feet)
- flat: (skull)
- round: (kneecap)
- irregular: other
-
bones contain
- mineral salts, calcium, phosphate
- living cells, nerves, and blood vessels
-
blood cells are produced
in the interior of bones
-
compact bone
- outer hard shell of bone
- composed of osteons
-
osteocytes
bone cells are found in the lacune
-
lacunae
- concentric circles around a central canal
- house osteocytes
- connect to each other by canaliculi
-
spongy bone
- porous (spongy) found on the inner surface and ends of long bones.
- less dense but still strong becuase of trabeculae
-
trabeculae
strengthen spongy bone
-
red bone marrow
found in spaces beteween trabeculae
-
epiphysis
found at the ends of long bone
-
diaphysis
shaft of the long bone
-
medullary cavity
- inside diaphysis
- filled with yellow bone marrow (fat)
-
periosteum
- fibrous connective tissue
- covers bone except at joint surfaces
-
bone begins to develp
in utero at 6 weeks old as hyaline cartilage
-
ossification
bone replacing cartilage
-
steps of bone development
- chondroblast die and matrix dissolves making room for blood vessels
- periosteum forms and produces osteoblasts
- osteoblasts + collagen + enzyme that produces hydroxyapatite
-
chondroblast
cartilage producing cell
-
osteoblast
bone forming cell
-
hydroxyapatite
- released by an enzyme that promotes crystalization of calcium phosphate
- traps osteoblast and forms the lacunae
-
growth plates zones
- resting
- proliferating
- degenerating
- ossification
-
resting zone
attache epiphyseal plate to bony tissue of epiphysis
-
proliferating zone
produces new chrodroblasts
-
degenerating zone
cartilage cells die
-
ossification zone
bone formation
-
epiphyseal plate closes
in women at age 18 and men around 30
-
sex hormones stimulate
chrondoblasts and osteoblasts for a growth spurt. osteoblasts grow faster to overtake cartilage.
-
puberty lasts longer in
- males
- women have longer torso allowing for better balance
-
osteoclasts
cells that break down bone and minerals are released into the blood
-
calcium needed for
- blood clotting, muscle contraction and nerve function
- when low, osteoclasts break down bone to supply the needed calcium
-
Parathyroid hormone PTH
- releases calcium from bone
- signals kidneys to decrease calcium excretion
-
calcitonin
- produced by thyroid
- decreases calcium concentration in the blood
-
osteoblasts and osteoclats together
- maintain calcium levels
- when high: osteoblasts remove ca from blood and make bone
- when low: osteoclasts break down bone and release ca into blood
-
estrogen
stops osteoclast activity
-
osteoporosis
- older women- decline in estrogen- allows osteoclast activity to increase - bone breakdown
- increases bone breakage
-
hematoma
a mass of clotted blood cells
-
how many bones?
206 bones
-
axial skeleton
- trunk of body
- skull
- spine
- ribs
- sternum
-
-
function of skull
protect brain and form face
-
cranium functions to
- form the upper portion of the skull
- protects sight smell hearing and tast sense organs
-
-
sphenoid
extends across floor of cranium and attaches to all other skull bones
-
-
occipital
skull back base
-
parietals
form side of cranium
-
ethmoid
helps form the eye orbit and nasal septum- separates nasal cavity
-
maxillae bone
- two bones that form much of face.
- upper jaw and allows for nasals
-
-
zygomatic bone
cheek bone
-
sinuses
air pocket within bones of face
-
hyoid bone
- located at the root of the tounge
- attaches muscles and ligaments is NOT a joint
- anchors tounge and swallowing muscles
-
vertebral column
- 33 vertebrae
- houses and protects spinal cord
-
invertebral disks
fibrocartilaginous pads that cushion the vertebrae
-
cervical vertebrae
neck region
-
thoracic vertebrae
upper back
-
lumbar vertebrae
small of the back
-
sacrum and cocyx
bottom of spine
-
rib cage
thoracic vertebrae, 12 ribs, and sternum
-
bottom 2 ribs are
floating ribs only attached n back
-
pelvic gridle
- consists of three fused bones
- ilium
- ischium
- pubis
- contribute to acetabulum
-
acetabulum
cup shaped socket for the head of the femur to form hip joint
-
tarsal bones
seven bones form the ankle and heel
-
metatarsals
five bones form the arches
-
-
pectoral girdle
- scapula (shoulder blade)
- clavicle (collarbone)
-
humerus
long bone of the arm
-
radius and ulna
long bones of forearm
-
carpal bones
eight bones to form palm and fingers
-
thumb is
opposable which permits the grasping of many items with great percision
-
sutures
- immovable
- found between cranial bones
-
synovial joint
wide range of motion
-
hinge joint
knee and elbow
-
-
ball and socket joints
hips and shoulders
-
flexion
decreases joint angle
-
extension
increaswes joint angle
-
adduction
move toward the midline
-
abduction
movement away from midline
-
rotation
movement of a body part around its own axis
-
circumduction
movement of a body part in a wide circle
|
|