Class Ten Flashcards
skeletal muscle is..
voluntary muscle
skeletal and cardiac muscle are..
striated muscle
three different types of muscle
skeletal
cardiac
smooth
what do tendons attach
muscle to bone
abducting vs adducting
abducting - moving away from body
adducting - moving towards the body
antagonistic muscles
muscles that are responsible for movement in opposite directions
synergistic muscles
muscles that move a joint in the same direction
single skeletal muscle cell
individual muscle fibers
cell membrane of a myofiber
sarcolemma
what do myofibrils do
generates contractile force of skeletal muscle
make up the myofibers
proteins in myofibril that generates contraction
actin and myosin
actin forms..
thin filaments
myosin forms..
thick filaments
what makes up myofibrils
sacromeres
what are sacromeres bound by
two Z lines
regions of a sarcomere only composed of thin filaments
I bands
full length of the thick filament is..
the A band
region composed of only thick filaments
H zone
what causes contraction
thin and thick filaments sliding across each other + bringing the Z lines closer together
what powers filament sliding
ATP hydrolysis
describe the process of the contractile cycle
myosin head binds to myosin binding site on actin (cross bridge formation)
myosin head pulls on actin chain (power stroke, ADP is released)
actin is released by the myosin head by binding of a new ATP molecule
what needs to be present for contraction to occur
calcium
troponin-tropomyosin complex
prevents contraction when calcium is not present
what is tropomyosin
protein that blocks myosin binding sites (head can’t bind)
what is troponin
protein that is bound to tropomyosin that can bind calcium
what happens when troponin binds to calcium
troponin changes shape which moves tropomyosin out of the way so the myosin head can bind
what is a neuromuscular junction
synapses between an axon terminus and a myofiber
what neurotransmitter is used at the NMJ
ACh
purpose of t tubules
deep invaginations of the cell membrane → allows AP to travel into the thick cell
purpose of the sarcoplasmic reticulum
stores calcium ions and releases them into the sarcoplasm on the generation of action potential during muscle contraction
what is rigor mortis
rigidity of skeletal muscles which occurs after death → complete ATP exhaustion
what causes cramps
temporary lack of ATP
slow vs fast twitch fibers
depends on their contractile speeds
type 1 slow twitch fibers
aka red slow twitch → high myoglobin content
have good oxygen content & can maintain contraction for a long time
e.g. useful for marathons
type IIA fast twitch fibers
contract quickly and somewhat resistant to fatigue
have more mitochondria than type IIB
type IIB fast twitch fibers
aka white fast twitch fibers → lack of mitochondria
contract quickly with great force
fatigue very, very quickly
functions of the skeletal system
support the body
framework for movement
protect vital organs
store calcium
synthesize formed elements of blood
hematopoiesis
creation of formed elements in the blood
occurs in the marrow of the flat bones
axial skeleton
skull, vertebral column and rib cage
connective tissue cells are derived from..
the fibroblast
what cells are derived from fibroblasts (3)
adipocytes, chondrocytes & osteocytes
dense vs loose connective tissue
dense - tissues that have a lot of fibers (e.g. collagen)
loose - packing tissue and fat tissue
two bone shapes
flat and long
location of hematopoiesis
flat bones
main shaft of a long bone
diaphysis
flared end of a long bone
epiphysis
diaphysis of a long bone is composed of..
compact bone
bone can either be..
compact or spongy
where is bone marrow found
shafts of long bones and pores of spongy bone
where is red marrow found
spongy bone in flat bones
where is yellow marrow found
shafts of long bones → filled with fat
2 main ingredients of bone
collagen and hydroxyapatite
what is hydroxyapatite
solid material consisting of calcium phosphate crystals
what secretes cartilage
chondrocytes
3 types of cartilage
hyaline, elastic and fibrous
hyaline cartilage
strong and somewhat flexible
found at the larynx and trachea
elastic cartilage
very flexible
found in outer ear and epiglottis
fibrous cartilage
very rigid
found at the pubic symphysis
what do ligaments connect
bone to bone
synarthroses
immovable joints
amphiarthroses
provide movability and support
diarthroses
freely movable joints
what lubricates movable joints
synovial fluid
surfaces of 2 bones in a joint are lined by..
articular cartilage (type of hyaline cartilage)
arthritis
inflammation of joints
most bone growth occurs by..
endochondral ossification
endochondral ossification
hyaline cartilage is produced and then replaced by bone
intramembranous ossification
synthesis of bone from an embryonic tissue called mesenchyme
intramembranous ossification results in..
flat bones
epiphyseal plate is composed of..
hyaline cartilage
osteoblasts
cells that make bone by laying down collagen and hydroxyapatite
osteoblasts become..
osteocytes
osteoclasts
destroy bone by dissolving the hydroxyapatite crystals
what does parathyroid hormone do → bones
stimulates osteoclast activity its
increases reabsorption of calcium
what does calcitriol do → bones
may stimulate osteoclast activity → minor effect
what does calcitonin do → bones
inhibits osteoclast activity
decreases reabsorption of calcium
what is a myofibril
string of sacromeres
what is a fascicle
group of muscle cells
unit of muscle contraction
sarcomere
what happens if theres no ATP - muscle contraction
myosin can’t release actin
what fills up the medullary cavity
yellow marrow
what is ventilation
movement of air in and out of the lungs
what is respiration
exchange of gases
part of the respiratory system that participates in only ventilation
conduction zone
part of the respiratory system that participates in gas exchange
respiratory zone
what is hyperventilation
too much breathing
what does hyperventilation cause
respiratory alkalosis
what is hypoventilation
too little breathing
what does hypoventilation cause
respiratory acidosis
purpose of the mucociliary escalator
protects from harmful inhaled particles
purpose of surfactant
reduces surface tension
epithelial cells that secrete surfactant
type 2 alveolar cells
pressure in the pleural space is..
negative
what is the pleural space
space in-between the parietal pleura and the visceral pleura
what muscles contract during inspiration (2)
diaphragm and intercostal muscles
muscles involved in forced expiration
contraction of abdominal muscles
spirometry
measurement of the volume of air entering or exiting the lungs
tidal volume
amount of air that moves in and out of the lungs in normal breathing
expiratory reserve volume
volume of air that can be expired after a passive resting expiration
inspiratory reserve volume
volume of air that can be inspired after a relaxed inspiration
functional residual capacity
volume of air left in the lungs after a resting expiration
inspiratory capacity
maximal volume of air that can be inhaled
residual volume
amount of air that remains in the lungs after a strong expiration
vital capacity
maximum amount of air that can be forced out of the lungs after a deep breath
total lung capacity
vital capacity + residual volume
deoxygenated blood is carried toward the lungs by..
the pulmonary artery
pulmonary edema
fluid in the lungs resulting from increased blood pressure
where is the respiratory control center located
medulla of the brain stem
where are peripheral chemoreceptors located
in the aorta and carotid arteries
where are central chemoreceptors found
in the medullary respiratory control center
3 layers of the skin
epidermis
dermis
hypodermis
deepest part of the epidermis
stratum basale
where is melanin found
in the epidermis
where are sensory receptors in the skin found
in the dermis
sudoriferous glands + where they’re found
sweat glands
dermis
sebaceous glands
oil glands
dermis
what does the trachealis muscle do
changes diameter of the trachea → faster airflow
where are rings of cartilage found
primary bronchi
where are plates of cartilage found
secondary bronchi
what forms the walls of the alveoli
type 1 alveolar cells
