Lecture - MSK (Napper Nervous Tissue)

Question 1

Describe how the contractile unit attaches to the ECM so the whole muscle works as one unit

Answer 1

So you have the myofilaments (actin and myosin) are they are anchored within the cell. The msucle cytoskeleton attaches to the ECM Dystrophin is a cytoskeleton protein (inside the cell) and it links the actin filaments to the laminin of the external lamina (around the sarcolemma and it’s like the basal lamina but in the muscle, I think) of the muscle to the endomyesium Basically a transmission of the movement from the actin to the dystrophin to the laminin in the external lamina and then to the endomyseium and the whole muscle acts in one unit

Question 2

Okay, looking at skeletal muscle fibre types:

1. What do you dtain for using NADH-TR?
2. What is contractile speed?
3. What is enzymatic velocity?
4. What is metabolic profile?
5. What is the intense staining fibres in this image?
   - what strong enzyme activity
   - what type of fibre?
   - what sort of msucle would you find this fibre in?
   - What kind of person?
6. What is the pale staining fibres in this image?
   - what low enzyme staining?
   - what type of fibre?
   - what do you call this fibre?
7. There is a fibre type IIa and it’s fast twitch but what? What sort of people is it found in?

Answer 2

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Question 3

What’s a triad?

Answer 3

So triad is just the place where the sarco meets the t-tubule (sarco on either side of t-tubule)

Question 4

Why is the synaptic knob in the NMJ so swollen?

Answer 4

End of an axon - synaptic knob etc

Needs to be large and large surface area and lies close to muslce bc holds lots of vesicles and needs to release them

Question 5

Why is there a depression and folding of the sarcolemma in the muscle cell?

Answer 5

Increase SA for receptors

Question 6

What does the peripheral nerve contain?

Answer 6

It’s a mixed nerve - have both motor and sensory within this nerve fibre bc the dorsal and ventral combined to make it

Question 7

1. Describe what you see in this image
2. If you see a nucelus in the peripheral nerve, is it a neuronal nucelus?
3. Why have Nissl bodies?

Answer 7

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Question 8

Label this peripheral nerve

Question 9

What are the CT constituents of a (mised) peripheral nerve?

What’s a motor end plate?

Question 10

How do you lable all the Ach receptors to see where they are?

Answer 10

Like if you had a muscle biopsy - how to measure the Ach receptors if in right place and how many there are

Immunohistochemistry - you have an AB to that protein you want to identify and to make it visible, you attach a dye molecule to that protein. Most of the time, we attach a secondary AB that goes to a primary AB that actually binds to the antigen we want to see. the primary one will get into the little spaces and maybe have a tail and the second one will bind to the tail so you can see ish

If we put a dye molecule on primary AB then we might not be able to get tahe AB in the small location we want

Question 11

Describe a sesory neuron and where the cell body sits

Answer 11

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Question 12

What do you see here?

Question 13

What is the difference between a myelinated and an unmyelinated axon?

Are most motor fibres myelinated or nah?

Answer 13

Slide 24

Question 14

Are sensory axons in the peripheral nerve myelinated or nah?

Answer 14

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Question 15

What are the four regions along the lenght of an axon with regards to myelin? What do you find in each of the four regions?

Answer 15

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Question 16

How much of the axon is covered in myelin?

The axon only has some mitochondria so how does it get extra energy if it needs it?

Answer 16

Oligodendrocyte can provide lactate through special channel proteins to get lactate to exit to the periaxonal space and then through the lactate transporter through to axon to use as energy supply

Schwaan and oligo are far mroe imp than just forming myelin sheath - imp supply of energy