Histology

Question 1

Give 3 descriptors of skeletal muscle cells

Answer 1

Striated, unbranched and multinucleate

Question 2

Describe the length and width of skeletal muscle cells

Answer 2

Fibres span the whole length of the muscle (so are very long) but are a normal width.

Question 3

Where are the nuclei in muscle cells?

Answer 3

At the peripheries as pushed by all the proteins

Question 4

Type 1 fibres also known as ___1____ appear darkest due to ___2___ Type 2A fibres are relatively ___3____ Type 2B fibres also known as ___4_____ contain much less _____5______ so appear ___6_____

Answer 4

1) red fibres
2) abundant mitochondria and myoglobin
3) uncommon
4) white fibres
5) mitochondria and myoglobin
6) lighter

Question 5

Muscle fibres are grouped into bundles called?

Answer 5

Fascicles

Question 6

Define the perimysium, the epimysium and the endomysium

Answer 6

Perimysium- connective tissue around the fascicle
Endomysium- connective tissue surrounding individual fibres
Epimysium- connective tissue around the whole muscle

Question 7

Each muscle fibre contains many what? What do these contain?

Answer 7

Many myofibrils that consist of many sarcomeres placed end to end

Question 8

4 characteristics of cartilage?

Answer 8

Semi rigid, deformable, permeable and avascular

Question 9

What are cell found in cartilage called?

Answer 9

Chondrocytes (chondroblasts when immature)

Question 10

Where are chondrocytes found?

Answer 10

Extracellular matrix termed a lacuna

Question 11

What do chondrocytes do?

Answer 11

They secrete and maintain the ECM around them

Question 12

What is the extracellular matrix of hyaline cartilage made up of?

Answer 12

75% water, 25% organic material

Question 13

Of the organic material in hyaline cartilage, what is this made up of?

Answer 13

60% is type 2 collagen which is a less common finer form of collagen that forms a 3D meshwork as opposed to linear bundles. 40% is proteoglycan aggregates.

Question 14

What are the 3 types of cartilage?

Answer 14

Hyaline, elastic and fibrocartilage

Question 15

Describe hyaline cartilage?

Answer 15

blue, white, translucent, most common, found on articulation surfaces of bones

Question 16

Describe elastic cartilage?

Answer 16

yellow in colour, elastic fibres add flexibility, found in the ear

Question 17

Describe fibrocartilage?

Answer 17

white, hybrid between tendon and hyaline, found in the pubic symphysis.

Question 18

Functions of bone?

Answer 18

Provides support, levers for movement, protection, calcium store and haemopoiesis,

Question 19

Three characteristics of bone?

Answer 19

Rigid
Not Permeable
Cells within the bone must be nourished by blood vessels that pervade the tissue.

Question 20

By early 20s usually only axial and limb girdle skeleton is involved in __________

Answer 20

blood production

Question 21

What are the two types of bone?

Answer 21

Dense cortical and spongy trabecular, cortical bone is on the outside

Question 22

Main difference between trabecular and cortical bone?

Answer 22

Presence of spaces adjacent to trabecular bone

Question 23

Why is bone strong?

Answer 23

It is backed up by layers of collagen fibres that overlap at 90

Question 24

Bone is living tissue penetrated by____1_____ It contains living cells called ___2______

Answer 24

1) small canals for blood vessels and nerves

2) osteocytes

Question 25

What are cement lines?

Answer 25

Visible lines surrounding osteon

Question 26

What contains blood vessels?

Answer 26

Contains the blood vessels in bones

Question 27

What is an osteon?

Answer 27

Cylindrical structures containing mineral matrix and living osteocytes connected by cannaliculi which transports blood

Question 28

Trabecular bone often lacks _______ as osteocytes can survive from contact with marrow spaces

Answer 28

haversion canals

Question 29

What are osteoprogenitors?

Answer 29

pool of reserve for osteoblasts

Question 30

What are osteoblasts?

Answer 30

bone forming cells

Question 31

What are osteocytes?

Answer 31

Bone cells within the bone matrix

Question 32

What are osteoclasts?

Answer 32

cells that break down bone

Question 33

Bone is constantly being remodelled. A number of __1____ congregate to drill a tunnel in the bone ___2____ grows bringing ___3____ which begin laying down lamellar bone

Answer 33

1) osteoclasts
2) blood vessel
3) osteoblasts

Question 34

Describe woven bone

Answer 34

This occurs during development or following injury. Collagen fibres are laid down in a haphazard fashion. It will later be remodelled into lamellar bone.