histology

Question 1

what are the bundles called that muscle fibres are grouped into

Answer 1

fascicles

Question 2

what is epimysium

Answer 2

the connective tissue that surrounds the muscle as a whole

Question 3

what is perimysium

Answer 3

the connective tissue around a single fascicle

Question 4

what is endomysium

Answer 4

the connective tissue around a single muscle fibre

Question 5

what are sarcomeres

Answer 5

the unit f contraction of the muscle cell, smallest contractile elements in the striated muscle cell

Question 6

how long does a sarcomere extend

Answer 6

from one Z line to the next

Question 7

what does a motor unit consist of

Answer 7

one motor neurone and all of the muscle fibres that innervates it

Question 8

what is type 1 muscle fibre

Answer 8

• slow contracting that depend on oxidative metabolism
• mitochondria and myoglobin
• resistant to fatigue

Question 9

what is type 2A fibres

Answer 9

• intermediate
• relatively fast
• reasonably resistant to fatigue

Question 10

what is type 2B fibres

Answer 10

• fast contracting
• depend on anaerobic metabolism
• few mitochondria and less myoglobin
• fatigue easily

Question 11

where are chondrocytes found

Answer 11

a space in the extracellular matrix called a lacuna

Question 12

how is type II collagen different from type I

Answer 12

its finer and forms 3D meshwork

Question 13

what are proteoglycan aggregates made up of

Answer 13

GAGs bound to a core protein and often linked to hyaluronan

Question 14

colour of hyaline cartilage

Answer 14

blue-white and translucent

Question 15

colour of elastic cartilage

Answer 15

light yellow

Question 16

colour of fibrocartilage

Answer 16

white

Question 17

examples of where hyaline cartilage is found

Answer 17

articular surfaces
tracheal rings
costal cartilage
epiphyseal growth plates

Question 18

functions of bone

Answer 18

support
levers
protection
calcium store
haemopoiesis

Question 19

what are the two types of bone

Answer 19

cancellous and cortical

Question 20

what are cement lines

Answer 20

the lines that are often visible surrounding the osteon

Question 21

does trabecular bone have haversian canals

Answer 21

no

Question 22

what are osteoprogenitor cells

Answer 22

located on bone surfaces, for example under the periosteum, these cells serve as a pool of reserve osteoblasts

Question 23

what are osteoblasts

Answer 23

bone forming cells found on the surface of developing bone.

Question 24

what are osteocytes

Answer 24

a bone cell trapped within the bone matrix.

Question 25

what are osteoclasts

Answer 25

large (up to 40µm or more) multinucleated cells. They are found on the surface of bone and are responsible for bone resorption.

Question 26

what is the basic multicellular unit

Answer 26

the collection of osteoclasts and osteoblasts that participate in bone remodelling

Question 27

how does bone remodelling work

Answer 27

In this process, a number of osteoclasts will congregate and begin to ‘drill’ into the bone, forming a tunnel. A blood vessel will grow into the tunnel bringing with it osteoblasts which line the tunnel and begin laying down new lamellar bone. This process continues until only the space of a Haversian canal remains.

Question 28

what is osteoid

Answer 28

when the osteoblasts secrete collagen, glycosaminoglycans, proteoglycans and other organic components this matrix is called osteoid