Histology

Question 1

What are the 3 types of muscle in the body?

Answer 1

Skeletal/voluntary
Cardiac
Smooth

Question 2

What are muscle fibres grouped into?

Answer 2

Fascicles

Question 3

What is the connective tissue that surrounds:
a single muscle fibre
a single fascicle
a whole muscle?

Answer 3

muscle fibre = endomysium
fascicle = perimysium
muscle = epimysium

Question 4

What is the functional unit of skeletal muscle?

Answer 4

sarcomere

Question 5

why do skeletal muscle fibres appear striated?

Answer 5

myofibrils are arranged in sarcomeres along the long axis, so the alternating light and dark (actin and myosin) filaments create a striated appearance

Question 6

What makes up a motor unit?

Answer 6

one alpha motor unit and all of the muscle fibres that it innervates

Question 7

what type of cells are found in cartilage?

Answer 7

chondrocytes

Question 8

where are chondrocytes found and what is their function?

Answer 8

they live in the lacuna in the extracellular matrix and secrete and maintain the extracellular matrix around them

Question 9

what is another name for the extracellular matrix cartilage?

Answer 9

hyaline cartilage

Question 10

what makes up hyaline cartilage?

Answer 10

75% water

25% Type II collagen and proteoglycan aggregates

Question 11

name 3 types of cartilage?

Answer 11

hyaline
elastic
fibrocartilage

Question 12

describe the composition of bone?

Answer 12

65% bioapatite (form of calcium phosphate)
23% collagen
10% water
2% non-collagen proteins

Question 13

where is cortical bone found?

Answer 13

makes up the dense shaft of the bone

Question 14

where is trabecular bone found?

Answer 14

at the ends of the bone (the epiphyses)

Question 15

what are the living cells found in bone?

Answer 15

osteocytes

Question 16

what are osteons?

Answer 16

found in cortical bone, cylindrical structures that are aligned parallel to the long axis of the bone

Question 17

what are volkmann’s canals?

Answer 17

any channel in cortical bone that transmits blood vessels from the periosteum into the bone

Question 18

what are Haversian canals?

Answer 18

small canals that transmit blood vessels in cortical bone (like volkmanns canals but smaller)

Question 19

what are cement lines?

Answer 19

visible lines surrounding osteons that have formed during remodelling

Question 20

what is the difference between osteoblasts and osteoclasts?

Answer 20

osteoclasts breakdown bone, osteoblasts lay down new bone

Question 21

explain bone remodelling?

Answer 21

osteoclasts drill a tunnel into the bone - a blood vessel grows along the tunnel, bringing osteoblasts with it - osteoblasts line the tunnel and lay down new bone - process continues until only the Haversian canal remains