lecture 9 review Flashcards
what does the force of muscle contraction depend on
the force of muscle contraction depends on the number of cross bridges
what is the number of cross bridges related to
the number of muscle fibers that are stimulated
what is muscle recruitment
so muscle recruitment is the number of muscle fibers that are stimulated in response to a stimulus.
if you want more contraction what do you need
As more muscle fibers are recruited and stimulated, then you will have more muscles contraction
what is hypertrophy
. Remember that hypertrophy is an increase in the size of a cell
hypertrphy can increase due to…
exercise
list the 4 things that force of contraction depends on
1- number of muscle fibers
2relative size of fibers
3frequency of stimulation
4 degree of muscle strength
as more muscle fibers are recruited….more
more are stimulated and there is greater force
if there is bulkeir muscles / hypertrophy there will be ….
more strength
if there is more muscle stimulation … there will be more
force
muscles that are 80-120% normal resting force =
more force
what happens if your muscle fibers are stretched too much
if your muscle fibers are stretched too much then your myocin and actin will not overlap
what does aerobic or endurance exercise leads to
aerobic or endurance exercise leads to increased muscle capillaries , and there is an increased need for o2, increase in the mitochondria , and an increase in the the amount of myoglobin sythesis. T
what is the main thing that aerobic exercise does to muscles
Aerobic exercise also increases strength and resistance.
list the 4 things that aerobic exercise leads to
1- increased muscle capillaries
2. increased mitorchondria
3. increased myogloben synthesis
4 increased endurance
is restitance exercies arobic or anerobic
anarobic
list the 5 things that resistance exercise leads to
1. muscle hypertrophy 2increased mitochondria 3. increased myofilaments 4increased glyocogen storage 5 increased connective tissue
where is smooth muscle found
smooth muscle is found in most hollow organs, except for the heart
list 3 places where smooth muscle is found
It is found in places like the stomach , intestines, uterus .
how many layers is smooth muscle arranged into and what are they called .
. Smooth muscle is usually arranged in 2 layers; There is a longitudinal layer and a circular layer.
describe the longitudinal layer of smooth muscle
The longitudinal Layer- the fibers run parallel to the axis , when this layer contracts its function is to dilate and shorten the organ . For example the contraction of your stomach.
describe the circular layer of smooth muscle
The circular layer - it runs around the circumference. It constricts the open space and it will cause it to elongate.
does the circular or longitudnal muscle elongate
circular
what is peristalsis
alternating contractions and relaxations that squeeze something through
smooth muscle is made up of what shaped fibers
Smooth muscle is made up of spindle shaped fibers.
are skeletal or smooth muscles shorter
smooth are thin and short compared to skeletal fibers
is smooth muscle T multinucleated and / or striated
They are NOT multinucleated and they are not striated
does smooth muscle have an alternating pattern of a and i bands
They do not have the alternating pattern of the i bands and the a bands
what is the structure that surrounds the smooth muscle cell, and are there more than 1
There is only endomyceuim that surrounds the muscle cells not the 2 laters like in the skeletal muscles
what is the function of caveole
They have enfoldings on the sarcolema called cavioli. They function to sequester calcium from the extra cellular fluid.
does smooth muscle have myofibrals or sarcomeres
They do not have sarcomeres and they do not have myofibrals.
is there a neruomuscular junction in smooth muscle like the one that we saw in skeletal muscle
There is NOT a neromuscular junction like the one that we saw in the skeletal muscle. There are autonomic nerve fibers .
what does smooth muscle have instead of a neuromuscular junciton
There are autonomic nerve fibers . It is in response to the involuntatry nervous system . The nerve fibers that are associated with smooth muscle have merocosities that are like swellings on them that can store and release neurotransmitters. This is a much more diffuse process then in skeletal muscles
what are variocosites
The nerve fibers that are associated with smooth muscle have merocosities that are like swellings on them that can store and release neurotransmitters.
does smooth muscle have actin and myacin
yes
does smooth muscle have myofilaments
no
does smooth or skeletal muscle have a higher ration of myacin to actin
In smooth muscle, The ratio of myacin to actin is much lower than in skeleton muscle.
is the myocin head big or small in smooth muscle
The myocin heads run the entire lenght of the filament unlike in skeletal musle.
is there tropnonen is smooth muscle
There is no troponen , so that interaction when calcium binds to troponen is not found in smooth muscle, there is a different protein that binds the smooth muscle
what is dens bodies
. Smooth muscle also has an area called dens bodies. These dens bodies are proteins that will anchor different filaments to the sarcolema. They function in the same way as the z disks in the skeletal muscle.
dens bodies in smooth muscle are like the … is skeletal muscle
z disks
what is the name of the protein that smooth muscle has instead of troponin
calmodulin
when a smooth muscle contracts what does it look like
When the muscle contracts, it does so in a corkscrew manner,
how many nucleus are in a smooth muscle
also note that there is only one nucleus. So it is a uninucleated cell.
list 3 ways that contraction of smooth muscle is similar to that of skeletal muscle:
- there is a sliding filaments models, there is still myocin connecting to actin and contracting . This is still the model in which muscles contract.
- the final trigger for contraction is an increase in intracellular contraction.
- atp is needed to energize it.
what are the 3 ways that smooth muscle contraction is regulated
nerves
hormones
local chemical
what can nerotransmitters result in
neurotransmitters can result in an increase of calcium in the sarcoplasm and then you can have graded potentials or action potentials. The response of smooth muscle is going to depend on the neruotransmitter.
what enrgiezes the sliding process of the contraction of smooth muscles
atp
what is the final trigger for the contraction of smooth muscle
higher levels of intracellular calcium
do all nerve muscles have a nerve supply
no
describe stress relaxation resoponse
Special features of smooth muscle. has a stretch relaxation response. so it can respond to being stretched , hold that stretched and it can relax and stay stretched. This is very important for things like your stomach and your bladder and your intestines.
what is hyperplasia
hyperplasia = an increase in the number of cells. An example of this is that estrongen effects the uteris at puberty. When girls hit puberty, their uteris will start growing to an adult size , also during pregnancy . This is why hyperplasia is important .
female skeleton is made of % muscle mass
36%
male skeleton is made up % muscle mass
42%
why do mens bodies have more muscle mass
testosterone
with age what increases and what decreaes
with age connectie tissue increaes and muscle fiber decreases
what happens to muscle mass at age 30 and what is this called
loss of muscle mass , sarcopenia
what can reverse sarcopenia
exercise
the heart can be thought of as …
2 side by side pumps
what does the right side of the heart recieve
oxygen poor blood from the tissues
where does oxygen poor blood from tissues go
it goes to the right side of the heart
after the right side of the heart recieves blood, where does it go?
it pumps it to the lungs
what does blood do in the lungs
it gets rid of co2 and picks up o2
where does blood get rid of co2 and pick up o2
in the lungs
what does the pulmonary circuit refer to
the right side of the heart recieves blood from the tissues that is oxygen poor, it pumps the blood to the lungs it gets rid of co2 and picks up o2 in the lungs
what does the left side of the heart recieve
it recieves oxygenated blood from the lungs
what is the systemic circuit
it refers to the left side of the heart pumping blood to the body tissues via the systemic circuit
what are the receiving chanmbers of the heart
the right atrium and the left atrium
what does the right atrium reicieve
blood returning from the systemic circuit
what does the left atrium recieve
it receives blood returning from the pulmonary circuit
where does blood returning from the systemic circuit go to
the right atrium
list the 2 pumping chambers of the heart
right ventricle
left ventricle
what does the right ventricle do
it pumps blood through the pulomonary circuit
what does the left ventricle do
it pumps blood through the systemic circuit
how big is the heart
it is about the size of a fist
where is the heart located
in the mediastinum ( medial cavity of the thorax )
what is the pericardium
it is the covering of the heart
what is the function of the fiberous pericardium
protects, anchors to surrounding structures and prevents overfilling
name the 2 layers of the serous pericardium
parietal layer
viscral layer
name the layers of the heart wall
epicardium
myocardium
endocardium
