Lab 3 - Epithelial and Connective tissue

Question 1

What is epithelial tissue divided into

Answer 1

• Covering epithelia

- Glandular epithelia

Question 2

What is connective tissue

Answer 2

• Acellular
• Consists of:
  
  • Ground subsntance
  • Different types of fibres
  • Small number of various types of cell

Question 3

What is connective tissue divided into

Answer 3

Loose and Dense

Question 4

Loose connective tissue

Answer 4

Aereolar

Adipose

Question 5

Dense connective tissue

Answer 5

Regular

Irregular

Question 6

What is mesentery

Answer 6

Aerolar loose connective tissue that binds together the loops of intestine.

Question 7

Guinea Pig Mesentery

Answer 7

Which cells do the smaller, darker, elongate nuclei belong to?
Nucleus of a fibroblast

Question 8

What is the function of fibroblasts

Answer 8

• Secrete fibres and ground substance
• Thermal insulation,
• Energy store
• Protection against mechanical shock

Question 9

What fibres are secreted by fibroblasts

Answer 9

Collagen

Question 10

Where in the eye do you find aereolar connective tissue?

Answer 10

The stroma (body) of the iris

Question 11

Monkey Gut

Answer 11

What is the white bit…

Lumen

Question 12

How wide is the lumen of a typical goblet cell

Answer 12

11 micrometers in diameter

Question 13

Why do all goblet cell lumen not appear to reach the surface of the gut AND what do they secrete

Answer 13

Some lumens look closed – circular shape because of the tissue attached and the angle it has been cut.
Secrete mucus via exocytosis

Question 14

Which ocular tissue contains goblet cells and why?

Answer 14

Conjunctiva in the upper eyelid. In the conjunctiva goblet cells are a source of mucin in tears and they also secrete different types of mucins onto the ocular surface. Mucus binds aqueous and tear film in your eye + Secrete proteins

Question 15

Why does the simple columnar epithelium appear to have several layers of nuclei?

Answer 15

Because of the way the cells were cut.

Question 16

The Skin

Answer 16

What 3 layers does skin contain:

• Outer epidermis
• Underlying dermis
• Hypodermis

Question 17

What type of epithelium is epidermis and why

Answer 17

Stratified squamous

Protection - Skin easily flakes off if damaged therefore protection is needed so epithelial cells are present at top

Question 18

What is the outer, acellular, layer of the stratified squamous epithelium composed of?

Answer 18

Dead cells made up of keratin, good for abrasion and waterproof

Question 19

The outer surface of the cornea has a similar epithelium but the upper, acellular, layer is missing…. Why

Answer 19

So light can get through

Question 20

What is the shape of the epithelial cells in epidermis

Answer 20

Irregular dense squamous

Question 21

How thick is the entire epithelium

Answer 21

10micrometres

Question 22

What is the dermis mostly composed of

Answer 22

Irregular dense connective tissue

Question 23

What is the main protein component of irregular connective tissue

Answer 23

Collagen and elastin

Question 24

What is the advantage of irregular arrangement of the fibres

Answer 24

Support and elasticity in all different directions and sizes

Question 25

What structures does dermis contain

Answer 25

* Hair follicles * Sebaceous glands * Sweat glands * Blood vessels

Question 26

Why variable appearance of hair follicles

Answer 26

Edges are darker - lots of nuclei. Lumen in centre = white

Question 27

What are the hairs in hair follicles made of

Answer 27

Keratin

Question 28

What type of epithelium lines cup in which hair follicles sit

Answer 28

Covering

Question 29

Sebaceous glands - what is the secretion

Answer 29

Holocrine, whole cell raptures and empties its contents

Question 30

What is the relationship between sebacceous gland and hair follicle

Answer 30

Sebaceous glands are usually attached to hair follicles and release a fatty substance, sebum, into the follicular duct and thence to the surface of the skin

Question 31

Function of sebacceous gland

Answer 31

Secretes oil - hydration, lubrication of skin and hair

Question 32

Why does sweat gland appear to be made up of a series of independent circular structures

Answer 32

Loose adipose tissue containing fat droplets - thermal insulation

Question 33

What sort of epithelium line blood vessels

Answer 33

Covering

Question 34

What are the functions of adipose connective tissue?

Answer 34

Thermal insulation + energy store + protect against mechanical shock

Question 35

What adipose connective tissue is associated with the eye?

Answer 35

Loose adipose connective tissue around outside of eye – surrounds lacrimal gland.

Question 36

How many layers of cells is the epithelium made of?

Answer 36

5

Question 37

What type of epithelium is sweat gland composed of?

Answer 37

Simple cuboidal epithelium

Question 38

Describe the range of diameters of the blood vessels you observe

Answer 38

25um

Question 39

Can you distinguish arteries from veins?

Answer 39

Veins are generally larger in diameter, carry more blood volume and have thinner walls in proportion to their lumen. Arteries are smaller, have thicker walls in proportion to their lumen and carry blood under higher pressure than veins.

Question 40

What sort of epithelium is blood vessels lined with

Answer 40

Simple squamous endothelium

Question 41

What is the average size of the adipocytes?

Answer 41

38um in diameter

Question 42

Why are these cells sometimes referred to as ‘signet ring’ cells?

Answer 42

Due to accumulation of fat particles in the cytoplasm, the nucleus of the adipose cell moves towards the cell membrane giving a look alike ring