MSK histology

Question 1

What are the three types of muscle?

Answer 1

Skeletal
Cardiac
Smooth

Question 2

What is the plasma membrane of a skeletal muscle cell called?

Answer 2

Sarcolemma

Question 3

Are skeletal muscles striated?

Answer 3

Yes

Question 4

Are skeletal muscles branched or unbranched?

Answer 4

Unbranched

Question 5

Are skeletal muscles multinucleate or uninucleate?

Answer 5

Multinucleate

Question 6

Where in the skeletal muscles do the nuclei lie?

Answer 6

Peripherally

Question 7

What is the epimysium?

Answer 7

The connective tissue surrounding a muscle

Question 8

What is the perimysium?

Answer 8

The connective tissue surrounding a muscle fascicle

Question 9

What do we call the connective tissue which surrounds a single muscle fibre?

Answer 9

Endomysium

Question 10

What are sarcomeres?

Answer 10

Smallest contractile elements in skeletal muscle

Question 11

What are myofibrils?

Answer 11

Structure formed when loads of sarcomeres form end to end

Question 12

Muscle fibres are composed of what?

Answer 12

Myofibrils

Question 13

Why does skeletal muscle appear striated?

Answer 13

Because of the alternating thick and thin filaments in the sarcomere

Question 14

What is a motor unit?

Answer 14

One motor neurone (nerve) and all the muscle fibres which it innervates

Question 15

What denotes fine muscle control in relation to the motor unit?

Answer 15

The smaller the number of muscle cells that the nerve innervates the more precise the control

Question 16

What is the synapse between motor nerves and muscle cells called?

Answer 16

Neuromuscular junction

Question 17

Describe the three subtypes of skeletal muscle cell

Answer 17

Type I (red) - slow contracting & aerobic, many mitochondria, low force, fatigue resistant

Type IIA - intermediate of other two subtypes, relatively fast contracting and fatigue resistant

Type IIB (white) - fast contracting & anaerobic, fatigue easily, minimal mitochondria, high force

Question 18

Which of the three skeletal muscle subtypes is the least common?

Answer 18

Type IIA

Question 19

Describe the vasculature of cartilage

Answer 19

It’s avascular

Question 20

How does the cartilage receive nutrients?

Answer 20

Diffusion through the extracellular matrix

Question 21

Is bone permeable?

Answer 21

No - it’s cartilage that is permeable

Question 22

What do we call cartilage cells?

Answer 22

Chondrocytes

Question 23

What do we call immature cartilage cells?

Answer 23

Chondroblasts

Question 24

Where are chondrocytes found within the cell?

Answer 24

Lacuna

Nb - spelling similar to laluna but this is a structure found on your nail!

Question 25

What is the major component of the extracellular matrix in cartilage?

Answer 25

Water

Question 26

What type of collagen is found in cartilage?

Answer 26

Type II

Question 27

What type of collagen is found in most connective tissues?

Answer 27

Type I

Question 28

What are the three subtypes of cartilage?

Answer 28

Hyaline Elastic Fibrocartilage

Question 29

Which is the most common subtype of cartilage?

Answer 29

Hyaline

Question 30

List some common sites where cartilage is found

Answer 30

``` Articular surfaces Tracheal rings Costal cartilage Growth plates Pre-bone ossification bones are cartilage ```

Question 31

List some functions of bone

Answer 31

``` Support Movement Protection Calcium metabolism Haemopoiesis ```

Question 32

What is haemopoiesis?

Answer 32

Red blood cell production

Question 33

In adulthood which bones remain involved in haemopoiesis?

Answer 33

Axial skeleton | Limb girdles

Question 34

Which type of collagen is found in bone?

Answer 34

Type I

Question 35

Which type of bone morphology can be seen at the diaphysis?

Answer 35

Cortical bone

Question 36

Which type of bone morphology can be seen at the epiphysis?

Answer 36

Trabecular/cancellous

Question 37

What is the difference between cortical and trabecular bone?

Answer 37

Presence of spaces

Question 38

Is bone avascular or vascular?

Answer 38

Vascular

Question 39

What do we call bone cells?

Answer 39

Osteocytes

Question 40

Where are the osteocytes found within the bone?

Answer 40

Canals

Question 41

Name the two types of canals found within bone and the difference between them

Answer 41

Haversion canal - longitudinal | Volkman canal - horizontal

Question 42

How does bone transfer nutrients from blood from one osteocyte to the other?

Answer 42

Osteocytes possess dendritic cell processes which run in canaliculi

Question 43

What are cement lines in relation to bone?

Answer 43

Visible lines surrounding an osteon

Question 44

What is an osteon?

Answer 44

Functional unit of bone

Question 45

What cells do bone cells derive themselves from?

Answer 45

Osteoprogenitor cells

Question 46

What are osteoblasts?

Answer 46

Cells which produce new bone

Question 47

What are osteoclasts?

Answer 47

Cells which reabsorb old bone

Question 48

What are osteocytes?

Answer 48

Cells trapped within bone matrix

Question 49

What is the basic multicellular unit?

Answer 49

Osteoclasts and osteoblasts which participate in bone remodelling

Question 50

Describe bone remodelling briefly

Answer 50

Osteoclasts drill down into bone --> Blood vessels form and bring osteoblasts --> Osteoblasts begin laying down new bone in this drilled tunnel --> Only haversion and/or volkmans canals remain

Question 51

What do osteoblasts need a good supply of to function normally?

Answer 51

Calcium

Question 52

What is osteoid?

Answer 52

Osteoblast secretion consisting of collagen, GAGs & other organic compounds which eventually becomes mineralised

Question 53

What is woven bone?

Answer 53

Bone fibres which have been laid down in a haphazard manner in response to a break within the bone

Question 54

What will woven bone eventually become?

Answer 54

Lamellar bone