musculoskeletal system and skin Flashcards
types of connective tissue
bone, blood, muscle, fat
- cartilage
cartilage
type of connective tissue that is made of CHONDROCYTES which produce collagen
chondrocytes
cells of cartilage that produce collagen
collagen
strucural protein found in EC of connective tissue
ligaments
connect bone to bone
tendons
connect bone to muscle
axial skeleton
starts at skull and runs down vertebrae
appendicular skeleton
upper and lower extremeties
cervical spine
top
c1-c7
thoracic spine
middle
t1 - t12
lumbar spine
L1-L5
long bones
bones in upper and lower extrememties
diaphysis
long shaft (middle) of bone between 3 epiphysis
joints
where bones meet
synovial joints
bones meet in fibrous synovial cavity
- diathrosis (free movement)
which joints are diathrosis
synovial
fibrous joints
synathrosis (no movement)
cartilagenous joints
amphiathroisis (little movement)
exoskeleton of insects
formed from a polymer of chitin ; N - acetylglucosamine
functions of blood
- regulates blood calcium levels
- produce new blood cells in bone marrow
matrix of bone
water. collagen, minerals
cellular components of bone
osteoclasts, osteocytes, osteogenic stem cell, osteoblast
function of bone
regulate calcium/ phopshate levels
produce new blood cells in BM
osteoblasts
produce hydroxyapatite and depsot into bone matrix
- build bone
osteoclasts
break down bone
- increase blood calcium levels
osteocytes
inactivated osteoblasts
PTH
increses blood calcium levels by increasing osteoclast activity and decreasing osteoblast
calcitrol
derivative of vitamin D that increases blood calcium levels by increasing osteoclast activity
calcitonin
antagonist to calcitrol and PTH
- decreases blood calcium by decreasing osteoclast activtiy
compact bone
cortical bone
- hard and stiff outer layer of most bone
cancelloous bone
spongey bone
- less dense interior of bone
bone marro
location of hematopoeisis
- red and white blood cells
yellow bone marrow –> fat
muscle types
smooth, cardiac, skeletal
myocytes. myofibers
muscle cells made up of myofibrils (actin and myosin)
sarcomeres
repeating unnit of muscle with thick and thin filament
sarcoplasmic reticulum
smooth endoplasmic reticulum of muscle, stores calcium inside the cell
- mediates transmission of nerve impuslses and is in contact with t tubules
myoglobin
red colored protein that stores oxygen in myocytes
- has greater bonding affinity for O2 than hemoglobin
T tubules
projection from the sarcolemma (membrane). tjat reaches toward the middld of the cell and has ion channels for rapid AP
- initiate muscle contraction
what system innervates skeletal muscle
somatic nervous system
- under concious control
skeletal muscle striated or no
striated
thin filiments are light, thick are dark
skeletal muscle mononucleated or multinucleated
multi, immature cells fuse together
types of skeletal muscle fibers
white and red
red fibers
lots of mitochondria
- good for long distance
- lots of o2 from a lot of myoglobin
- perfer oxidative metabolism
white fibers
- less mit and myoglobin
- perfer anerobic metabolism
- short bursts of E
smooth muscle
innervated by autonomic nervous system so involuntary control
- no striations
- mononucleated
- involved in peristalsis
cardiac muscle
intercalated junctions (gap junctions)
- involuntary control
- striated
- branched cells
intercalated discs
gap juncitons that connect cytoplasm of adjacent cells for rapid action potential
myogenic activity
ability of a muscle to contract without nervous stimulation in response to other stimuli like stretchin
-smooth and cardiac muscle can do
- SA node
sliding filament theory
myosin filaments use energy from ATP to “walk” along the actin filaments with their cross bridges
- pull actin closer together
- The movement of the actin filaments also pulls the Z lines closer together, thus shortening the sarcomere.
myofibrils
long linear muscle fibers composed of alternating thick and thin filament
sarcomere
unit of contraction
- contain a thick fiber and 2 half thin fibers that over lap
M line
middle of sarcomere
- runs through middle of thick filament
Z line
defines the ends of the sarcomere
- runs through the thin band
I band
region where only thin filament is
A band
thick and thin over lap
h zone
only thick filament
which regions of sarcomere have no overlap
H zone and I badn
what happens to M line during contraction
M lines of adjacent sarcomeres move closer together
what happens to Z line during contraction
Z lines move closer together
what happens to A band during contraction
nothing bc not compressed
what happens to I band during contraction
shrinks because of overlap
what happes to H zone during contraction
shrinks becusae overlap
cross bridge cycling
actin and myosin slide past eachother
power stroke force of contrction
myosin heads
project from thick filament and have an atp binding site, and an actin binding site
what does absense of calcium do to actin
it blocks the myosin binding site via tropomyosin
tropomyosin
blocks atp from binding to myosin in the absense of calcium
how do myosin and actin dissociate after contractio
atp. is required to bind to the myosin head, which releases actin and atp is hydrolyzzed
- myosin goes into cocked positiion
cocked myosin position
after atp is hydrolyzed, can weakly imteract with actin, tropomyosin rebinds to actin
what removes tropomyosin from actin
ca binds to troponin and causes tropomyosin to dissociate
power stroke
myosin and actin bind and there is a confirmational change when Pi is released , ADP is released and actin and myosin are stuck togethre untila nother atp comes in
neurotrasmitter released at NMJ
acetocholine
motor unit
muscle cells innervated by a single motor neuron
rigor mortis
when someone is dead and all muscles contracted becaue there is no atp to deteach filaments
where does ach bind on muscle cell
receptors on sarcolemma , which then depolarizes
what happens when action potential reaches the sarcolemma
it causes release of ca2+ and binds to troponin, to allow myosin and actin to cross cycle and contract
twitch
isolated contraction
summation
more coordinated contraction
- contraction becomes stronger with time
tetnus
maximum contraction for a period of time
acetylcholinesteras
breaks down excess ach and ecnourages relaxation
build up of what occurs with extensive anerobic muscle metabolism
lactic acid
layers of skin
epidermis, dermis, hypodermis
layers of epidermis
Come Lets Get Some Beer
stratum corneum
layers of dead karatinocytes
stratum spinocum and basale
make keratinocytes
langherhans cells
antigen presening dendritic cells of the spinosum
melanocytes
pigment , protect from UV
merkel cells
mechanoreceptors in stratum basale that detect deep touch
dermis
vascular , hair follicles, sweat glands , ruffini endings, pacinian corpuscles, meisner corpuscles
ruffini endings
sense stretching
pancian corpuscles
deep vibration and pressure
meisner corpuscles
gentle touch
hypodermis
lots of fat for protection
- macropgahges
thermoregulation of skin
layer of fat in hypodermis
sweat glands cool
vasodilation and constriction
piloerection (goose bumps)
