Chapter 3: Functions and components of the skeletal system Flashcards
functions of the skeletal system (1)
movement
trade off - strength and range of motion
functions of the skeletal system (2)
structure/support
designed to bear our weight standing up
designed for movement
designed for standing
functions of the skeletal system (3)
protection
protects most important organs (heart, brain, lungs)
functions of the skeletal system (4)
blood production:
- red blood cells (bone marrow) is made in bones
- adolescents make more
- axial and appendicular in kids
- just axial in adults
functions of the skeletal system (5)
storing calcium
- every muscle contraction requires calcium
- you are always using calcium
- no calcium ——-> dead
- can reshape bones
components of the skeletal system (1)
Bones
components of the skeletal system (2)
Cartilage
- hyalin - ends of bones in joints (friction)
- fibrocardilage - intervertibral discs - pubic bones (shock absorption)
- elastic - outer ear (shape)
components of the skeletal system (3)
tendons - muscle to bone
ligaments - bone to bone
Types of cartilage (1)
chondroblasts
-builds cartilage - matrix around cell - collagen fibers
-proteiglycens (water)
cartilage
non-inerverated (no nerves)
avascular - no blood vessels
Types of cartilage (2)
chondrocyte
- cartilage cell
- when the chondroblast is completely surrounded by by matrix
Lacunae - cacoon for CB
Types of cartilage (3)
Perichondrium
- connective tissue membrane around the cartilage
- inside layer of membrane
- inside has CB
- outside layer has blood vessels
Types of cartilage (4)
Articular cartilage
covers bone at joint
Types of cartilage (5)
Appositional growth
New chondrocytes and new matrix at the periphery
Types of cartilage (6)
Interstitial growth
(between)
Chondrocytes within the tissue
divide and add more matrix
between the cells
Between what ages are blasts and clasts the same?
30-50
what is bone always doing?
being taken apart and put together
In whom are blasts the most active?
children
Bone histology - matrix
Collagen fibers for strength - if collagen is gonna bones become brittle
hydroxapitate
minerals gone - bone is bendy
Osteoblasts
Builds bone
ossification - formation of bone
osteocytes
maintainer
lacunae
room that contains osteocytes and chondrocytes
canaliculi
a canal that connects osteocytes to blood supply
osteoclasts
Bone cutters - takes apart bones
Spongy bone
Found in ends of long bones
makes bones lighter
trabeculae
interconnecting rods or plates of bone
- spaces filled with marrow
- covered with endosteum
- oriented along stress lines
Compact bone
- thickest in shaft
- all around bones
Haversian canals
central goes the length of the bone
- has blood
- cells are arranged around canal
Lamellae
- laminated
The matrix that is laid down in compact bone - concentric, circumferential, interstitial
Osteon
central canal, contents, associated concentric lamellae
perforating canal
allow connections in circulatory system, to provide different ways to get placds
Long bones
Upper and lower bones
- arms
- legs
- phalanges
Short bones
- Carpels
-Tarsels
Flat bones
- ribs
- sternum
- skull
- scapulae
(some flat and irregular bones of skull have sinuses lined by mucous membranes)
Irregular bones
- vertebrae
- facial (bones)
(some flat and irregular bones of skull have sinuses lined by mucous membranes)
Parts of a long bone
Diaphysis
- Shaft
- compact bone
Parts of a long bone
Epiphysis
- end of bone
- spongy bone
Parts of a long bone
Epiphyseal plate
line - when growth is done
Growth plate
- hyaline cartilage - present until growth stops
Parts of a long bone
Medullary cavity
- Hollow space in diaphysis
- makes bone marrow
- when bone marrow turns yellow - fat
Parts of a long bone
Periosteum
- Connective tissue around bone
- at end of bone it becomes a tendon/ligament
- Sharpey’s fiber - some tendon/ligament is penetrated into bone itself - strong
Parts of a long bone
Articular joints
- in joints
- hyaline
- left over
intramembranous ossification
starts with membrane
- takes place in connective tissue membrane
- forms many skull bones (mandable - top of skull)
Endochondral ossification
replace cartilage with bone
starts with cartilage
Steps to endochondral ossification (7 - HPPFSAG)
H - hyaline cartilage in the rough shape of bone
P - periosteum forms collar bone
P - Primary ossification is in the center of diaphysis (blood vessels have to go in cartilage - osteoblasts make spongy bone)
F - Forming medullary cavity
S - Secondary ossification is in the epiphysis
A - Almost all cartilage is bone - any cartilage left is in the epiphyseal plate
G - Growth is done - epiphyseal line is there - articular cartilage is all that’s left
Factors affecting bone growth (1)
Genetics - how big your bones are depends on your genetics
between age 12 (skull) and 25 (sacrum) all bones are done growing
Factors affecting bone growth (2)
nutrition - calcium, protein, vitamin D and C
Factors affecting bone growth (3)
hormones
growth hormone - thyroid hormone (all tissues need it)
pituitary hormones - makes growth
(both make you grow)
Sex hormones -
estrogen (2 years)
testosterone (longer than 2 years)
Factors affecting bone growth (4)
Stress -
- extreme stress as a kid can stunt growth
- regulate stress can make bones stronger
Bone remodeling (1)
Ca regulation -
Needed in muscles and neurons
- take in and out of bone
Bone remodeling (2)
density -
- osteoclasts and blasts always at work
- want to put pressure on bone to make them stronger
Bone repair (4 steps)
hematoma -
- mass of blood
comes from damaged blood vessels
Callus -
internal - form between ends of bones
external - forms collar around the break
Ossification -
“makes bone”
- replace callus (both internal and external) with spongy bone
Remodeling -
Compact bone replaces woven bone, part of the internal callus is removed, restoring medullary cavity.
Ca Homeostasis
Variety of things happening to keep calcium moving - keeps everything the same. calcium is used for a lot
What happens when you age (to your bones)
- bones get more brittle
- longer to heal
- less dense
Fractures - transverse
straight across
Fractures - oblique
upper angle break
Fractures - open
broke through skin
Fractures - close
under skin (didn’t break through)
Fractures - spiral
turned - twisted upward
Fractures - longitudinal
straight up and down
Fractures - green stick
bone bent and broke a little - but not all the way
Fractures - compression
gets jammed together
Fractures - depressed
indented break
Fractures - impacted
broken pieces get jammed together
Fractures - comminuted
3+ pieces
Health issues (osteoporosis)
- enough bone pause to cause problems
- affects posture, teeth fall out, and breaking of bone
- more common in women (happens near menopause - estrogen has to do with bone strength - so when estrogen goes down so does bone strength)
- more common in smaller people
Health issues (arthritis)
- inflammation in joint which causes pain
- rheumatoid arthritis - most common (caused by immune system problems)
- wears out joint
Health issues - Herniated disk
- tremendous amount of force on disk - some material from inside goes to outside
- pushes on nerves
health issues - scoliosis
when spine curves to the side
health issues - lordosis
too much curve to lumbar (more than normal) only bad if it pinches nerves
health issues - kyphosis
too much of a curve with thoracic (hunch back)
