Cells, Tissues and Organs

Question 1

Where is the mucosal membrane present?

Answer 1

Lines all the moist hallow internal organs of the body and can be continuous with the skin in the eyes, ears and nose

Question 2

What is the function of mucosal membrane?(3)

Answer 2

1. Prevent pathogen and dirt ingress
2. Prevent dehydration
3. Lubricator surfaces

Question 3

What does mucous contain? (4)

Answer 3

1. Mucin
2. Electrolytes
3. Lysosomes
4. Immunoglobulin

Question 4

What are the three layers of the mucous membrane?

Answer 4

1. Epithelial cell layer (and basal lamina)
2. Lamina propria
3. Smooth muscle

Question 5

What is the mucosa lining?

Answer 5

Epithelial cell lining and supporting mesenchymal layer (basal lamina)

Question 6

What is the mucous mucosa?

Answer 6

Thin discontinuous smooth muscle layer

Question 7

What is the submucosa?

Answer 7

Layer of connective tissue that contains arteries and veins

Question 8

Muscularis Externa

Answer 8

Smooth muscle layer that has 2 orientations :

• inner circular muscle
• outer longitudinal muscle

Question 9

Serosa

Answer 9

Connective tissue layer containing collagen and elastin fibres with small arteries, veins and some nerve fibres

Question 10

Describe the structure of the oesophagus (3)

Answer 10

1. Epithelium = stratified squamous non keratinised
2. Submucosa = contain mucus secreting glands - lubrication
3. Muscularis externa = inner circular muscle and outer longitudinal muscle for peristalsis

Question 11

Stomach structure (3)

Answer 11

1. Mucosa lining - secretes acid, gastric and digestive enzymes to break down food
2. Muscularis externa - 3 layers - oblique, inner circular and outer longitudinal - aids movement of chyme out of stomach
3. Rugae- folds of gastric mucosa forming longitudinal ridges - increase SA and allows expansion

Question 12

Jejunum (small intestine) (4)

Answer 12

1. Mucosal lining - simple columnar
2. Submucosa - circular folds forming pilae in gut lumen - increases SA and gut absorption
3. Glands - secrete enzymes that break down chyme
4. Villi - increase SA

Question 13

Large intestine colon (2)

Answer 13

1. Mucosa lining - Simple columnar

2. Numerous crypts - secrete mucus

Question 14

3 functions of colon mucosa

Answer 14

1. Absorb water
2. Prevent ingress of pathogens - lamina propria contains lymph
3. Move contents and remove waste - peristalsis by muscularis externa

Question 15

Urinary tract

Answer 15

Parietal layer - outside
Visceral layer - inside

Corpuscle lining - squamous
Ducts - cuboidal with thick basal lamina - barrier against urine

Question 16

Ureter

Answer 16

Muscularis externa
Outer circular muscle - prevents ureter bursting
Inner Longitudinal muscle - isn’t as defined due to gravity

Question 17

Bladder

Answer 17

Muscularis externa : Destructor muscle thick - prevent bursting
Adventitia - fat cells - shock absorber
Mucosa lining - Transitional epithelial - less acidic urine damage
Umbrella cells secrete mucus - protect cell lining and prevent pathogen ingress
Tight junctions tightly packed together - prevent pathogen ingress

Question 18

Urethra

Answer 18

Stratified squamous keratinised - protect against abrasion

Secrete lots of mucus - prevent pathogen ingress

Question 19

Urinary tract function

Answer 19

1. Absorb essential nutrients in kidney
2. Prevent pathogen entry
3. Remove waste

Question 20

Trachea

Answer 20

Thin lamina propria - rich in immune cells - prevent pathogen ingress
Muscularis externa - only contain inner circular muscle
Hyaline cartilage holds trachea open
Submucosa - seromucous - watery mucous
Cilia - move dust towards mouth
Goblet cells - produces mucous

Question 21

Alveoli

Answer 21

Specialised epithelial cells bearing type 1 pneumocytes (simple squamous )
Folded basal lamina - increase SA
Collagen - add rigidity
Elastin fibres - recoil