Lecture - MSK (Napper Joints + Liga + Skele Muscle)

Question 1

So we know that connective tissue is made of cells, and ECM. The cells can be permanent and transient. What’s in the ECM?

Answer 1

Fibres and ground substance

Question 2

There are three types of joints: what are they?

Answer 2

-

Question 3

Fibrous Joints:

1. What is the tissue that unites the two bones?
2. Give two examples
3. What sort of movement?

Cartilaginous joints:

1. What is between the two bones?
2. Give two examples of this joint
3. What sort of movement?

Now that we are on the topic of fibrocartilage (cartilaginous joints have fibrocartilage between them, not DFCT):

1. Give some example of fibrocartilage - menisci…..
2. It is cushioning buuuuut also what? (2)
3. What sort of CT is it? D____ r_____ with hyaline cartilage (just remember this lol)
4. Does it have a perichondrium? What else doesn’t have a perichondrium? What cells does it have?

Synovial joints:

1. What sort of cartilage is between the bones?
2. What is in the synovial cavity? What the function of having that constant volume of fluid?
3. What does the synovial membrane (the layer of cells - not epithelium!) secrete?
4. What sort of stimulation also leads to secretion?
5. What does this fluid give nutrition to? (since this part is avascular)
6. Talking more about the synovial membrane - the lining cells aren’t epithelium so what are they like? (2). These are the intimal cells but what’s the subintima layer? Why have that?

Answer 3

4. Fibrocartilage doesn’t have perichondrium, neither does articular cartilage. It has chondrocytes in rows and fibroblasts too. It has both type 1 and type 2 collage.
5. Synovial cavity - fluid-filled and it is a shock absorber

Question 4

Ligaments!

1. What do they hold together?
   - they have some f____ and high ______ strength
   - transmit what from bone to bone?
2. It also provides something else at the joint that maintains the joint congruency

Tendons!
1. What is this CT specialised to do? Like it’s a harness….
2. It is dense regular connective tissue so what does that mean in terms of
-fibres
-array
-packaged in….
3. It is relatively avascular, so what does that mean?
4. What is endotendineum? What does it contain?
5 What are the two junctions it has?
6. What dominates in the tendon? What type of collagen?
7. What are the cells in tendons? (equivalent to fibroblasts). What do they have cytoplasmic processes?

Myotendinous Junction:
-how is the muscle connected to the tendon?

Answer 4

For the myotendinous junction:

So you have the actin filaments of the muscle and they are held together with each other through alpha-actin. The actin filaments are held onto the protein complexes in the plasma membrane through the desmin proteins (if desmin deficiency, you are prone to tearing tendons off muscle). Laminin is the actual protein that goes from integrin in the plasma membrane to the ECM of the tendon (the laminin probably attaches to the collagen fibres).

Question 5

Skeletal muscles!

1. What’re the three CT coverings?
2. What’s the function of the CT here? (2)
3. How many nuclei in muscle cell?
4. Where are the nuclei located?
5. There are fibroblast nuclei and nuclei of nuclei cells - how do they appear?
6. Why are there striations? Talk about the I and A bands and all
7. How are the muscle cells developed from myoblast?
8. What attaches at the Z line?
9. So there are G actin sites and they all bind to the myosin heads - what covers the G actin sited at rest and what does Ca bind to to induce the conformational change?
10. How does myofilament movement generate muscle movement:
    - myofilaments

Answer 5

6. So you have the light bands which are I bands (between the myosins so in the middle of I band is the Z line). The A band is the myosin
7. 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