Week 5 Muscles 3 Flashcards
How do you get release of Ca from sarcoplasmic reticulum?
Ryanodine receptors, on gated calcium realase channels
Transverse tubular system or T-system
Tubular invaginations of the plasma membrane that penetrate ALL levels of muscle fibers associated with the sarcoplasmic reticulum
sarcoplasmic reticulum is in close contact with?
Sarcolemma. * this is why the T-tubule system works*
Calcium activated ATPase pumps are where? Do what?
In the membrane of the sER andrestore calcium gradient
Ca realease = muscle _____
contraction
Ca uptake= muscle___
Relaxation, get ready for next contraction
What muscle type is voluntary?
skeletal
What muscle type is NOT striated?
Smooth
What muslce type IS striated?
Skeletal and cardiac
What muscle type is NOT voluntary?
Cardiac and smooth
What is the neuromuscular junction (motor end plate)?
Point at which the myelin sheath ends and the axon comes into contact with the muscle
What does an image of muscles with nerves look like?
a tree
Innervation is required to maintain muscle ____?
Integrity, either use it or lose it
Voltage centers are very close to? Does what?
Ryoidine receptors on the sER to TRIGGER Ca release.
The intimate relation between WHAT allows Ca to be released?
Sarcolemma, sER, and voltage centers on nerves
Cardiac muscle has a larger and better developed what compared to skeletal?
T-tubule system
What are intercalated discs?
They are the cross bands/striations found in cardiac muscle. * special cell to cell contacts linking cardiomycytes together
Main difference between skeletal and cardiac muscle?
1) Cardiac has single center nuclei
2) Cardiac has intercalated discs
3) Cardiac has a larger more developed T-tubule system
Smooth muscle has different contraction initiation
1) mechanical impulse
2) Electrical depolarization
3) Chemical stimuli
Smooth muscle does NOT have what system (but cardiac and skeletal do)?
T-tubule
Afferent vs efferent nerve?
Afferent=sensory; efferent= motor
Somatic vs autonomic nervous system?
Somatic=conscious and voluntary; autonomic= involuntary (smooth muscle, heart, glands)
Neuroglia or glia cells?
Supporting cells near neurons
Schwann cells
Surround the neuron processes and isolate them from adjacent cells and ECM
Satellite cells have various purposes for nervous system
1) Support and protect neurons
2) Insulate nerve cell bodies
3) Repair neurons
4) Clearance for synapse
Nerves have a lot of?
rER and free ribosomes, make a LOT of proteins
Nissel bodies (will ID on exam)
Give neurons granuole appearance from staining of ribosome
Three obvious structure to ID on neurons
1) Nissel bodies (aka ribosomes)
2) Nucleolus (nucleas is very light, nucleolus is dark)
3) Axon hillock
Dendrite
Receive info, short, unmyelinated, CAN see organelles
Axon
Convey info, only ONE, lacks large cytoplasmic organelles
Axon hillock
Useful landmark, axons originate from the cell body here
Difference in axodendritic, axosomatic, axoaxonic
- Axodendritic= axon that terminate on dendrite
- axosomatic= axon directly on cell body
- axoaxonic= one axoncontacting another axon
Difference in chemical synapses and electrical synapses
- Chemical= conduction by release of chemicals (neurotransmeitters)
- Electrical= in inverterbates, gap junction connections to allow passage of ions
Presynaptic, synaptic cleft, and postsynaptic
Presynaptic is where an impulse is coming from (axon), passes the synaptic cleft, before transmitting on postsynaptic membrane (axon, dendrite or cell)
