Exam 4 Flashcards
The sarcolemma is a muscle fiber that?
Special proteins that allow AP conduction
Sarcoplasm is and contains what?
Cytoplasm of a muscle fiber or cell that contains myoglobin ( what makes you red) and glycogen ( long chains of glucose)
Sarcomere is ?
Smallest contractile unit of a muscle fiber composed of actin and myosin
Is actin the thin or thick filament
Thin.
What are the 2 actin proteins?
1.Tropomyosin (long filament) extending over openings in actin @rest
2. Trompin (small protein) that attaches to tromysin and has a Ca+ binding site
When a muscle fiber receives an AP signaling contraction, what happens?
Ca+ is released in the sarcoplasm
Is tropnin the only actin protein that changes shape when binding to Ca+
No, once tropnin changes shape tropomysin changes as well because the are attached
Sarcomere Anatomy: H-Zone consists only of?
Myosin
I-Band consists only of?
Actin
A-Band
Contains a WHOLE myosin and an overlapping actin
Muscles rely on a what to do what?
A motor unit to send signals to stimulate contraction
Step 1 of Muscle Contraction:
An AP is sent along an axon to stimulate muscle contraction
Step 2 of Muscle Contraction:
When the AP reaches the axon terminal, Ca+ proteins in the terminal open and Ca+ enters
Step 3 of Muscle Contraction:
Ca+ binds to the synaptic vesicles and causes them to move to the axon terminal mem. releasing ACh
Step 4 of Muscle Contraction:
ACh moves across the synaptic cleft by diffusion to the mother end plate
Step 5 of Muscle Contraction:
ACh bind to its receptors opening the the receptor causing Na+ to rush into the muscle fiber
Myofibrils are wrapped w/ a spider web like ‘’shawl’’ called?
Sarcoplasmic reticulum
Step 6 of Muscle Contraction:
AP continues to T tubule is reached then stimulates a cisternae to release Ca+
Step 7 of Muscle Contraction:
Ca+ binds to troponin that changes shape while tromyosin changes change also
Step 8 of Muscle Contraction:
Myosin binds to actin causing a ratchet
Step 9 of Muscle Contraction:
Sarcomere shortens until AP is stopped or Sarcomere reaches max contraction
How many ways can you steps can you stop an AP?
3
Stopping AP steps
- Stop AP along axon
- Remove ACh from synaptic cleft
- Ca+ must be removed
What are the 3 ways to remove ACh?
- Diffuse
2.AChE - Storing it in synaptic vessel
What 3 ways remove Ca+?
- Store it
2.allow it bind it it’s Ca+ proteins (calsequestin or calmodulin)
Optimal Sarcomere placement?
Where actin just over lies myosin heads
Overly contracted Sarcomere?
When actin is already close to myosin and little additional room is available to move a-disc closer to myosin
Overly stretched Sarcomere?
When actin barely overlaps myosin heads making it difficult to shorten a muscle
Latent period is
When a relaxed muscle receives the signal to contract
Treppe is ? Tetanus is ?
More rapid stimuli and a constant stimuli
Muscle tone is
A slight state of contraction @ all times ( erector spinae )
Isotonic contraction
When a muscle maintains a constant tension as they change lengths
Eccentric isotonic contraction -muscle lengthens to bear weight
Concentric isotonic contraction - muscle shortens as it bears weight
What 3 ways does muscle obtain ATP?
- Cellular respiration
- Fermentation
- Creating kinase
What are the 2 parts of the nervous system?
CNS and PNS
Describe the afferent division
Sends info about stimuli from extremities to the CNS
Has 2 parts somatic brings stimuli from skin, muscle, & joints
Visceral afferent bring stimuli from organs like heart lungs etc
Describe efferent division
Somatic motor sends decisions to glands and skeletal muscles
Autonomic sends decisions from CNS to visceral specifically cardiac & smooth
Autonomic has 2 parts describe them
Sympathetic NS is freight or flight
Parasympathetic NS brings the body back down, regulate homeostatic
What do neurons specifically do?
Send and receive info
What do glial cells specifically do?
Keep environment ideal allowing normal neuron function
What are the 3 parts of a neuron
Dendrites, cell body, and axon
Nissel bodies
Groups of rough endoplasmic reticulum
What is difference between unmyelinated axons and myelinated axons?
Unmyelinated send ‘’slow AP’’ while myelinated send faster
Schwann cells are..
Numerous wraps around the axon
Nodes of ranvier
Open axon mem. sections btw. Schwann cells
Myelin sheath
Many layers of cell mem. wrapped tightly around axon
What are the 4 types of glial cells of CNS
Astrocyte, microglia, oligodendrocytes, ependymal
What are the 2 types of glial cells in the PNS
Satellite and Schwann cells
Groups/clusters of cell bodies in the CNS are called and in the PNS are called?
CNS-nuclei
PNS-ganglia
Groups/Clusters of Axons
CNS-tracts
PNS-nerve
White matter consist of
Myelinated axon
Grey matter consist of
Dendrites, soma, unmyelinated
Multipolar neuron is
Neurons with multiple dendrites and 1 axon
Bipolar neuron is
Neuron with 1 axon and 1 dendrites
Unipolar neuron
Neuron with 1 extension
Presynaptic vs postsynaptic
Before synapse vs after synapse