Internal surfaces

Question 1

What is a mucous membrane and what does it consist of?

Answer 1

Line certain internal tubes, which open to the exterior. Consists of:
An epithelium lining the lumen of the tube
An adjacent layer of connective tissue referred to as the lamina propria
In the alimentary tract, a third layer consisting of smooth muscle referred to as the muscularis mucosae

Question 2

What is a serous membrane and what does it consist of?

Answer 2

Thin, two-part membrane which line certain closed body cavities. Envelop the viscera. Secrete lubricating fluid promoting friction free movement.
Consists of:
A simple squamous epithelium (mesothelium) which secretes a watery lubricating fluid
A thin layer of connective tissue which attaches the epithelium to adjacent tissues (also carries blood vessles and nerves)

Question 3

What is the Visceral serosa?

Answer 3

The internal serosa membrane, the one that lies closest to the organ

Question 4

What is the parietal serosa?

Answer 4

The second layer of serosa

Question 5

Why is the lung shiny?

Answer 5

Because its covered in moist pleura

Question 6

Where are the Duodenum, jejunum and the illeum located?

Answer 6

small intestine

Question 7

What are the four layers of the gut wall?

Answer 7

the mucosa (inner most) 
The submucosa 
The external muscle layers (muscularis externae- smooth muscle)
The serosa (outermost)

Question 8

What are Peyers patches and where are they located?

Answer 8

Aggregations of lymphocytes, often in the lamina propria (near where bacterial attack might occur)

Question 9

What does the mucosa include?

Answer 9

The muscularis mucosae, lamina propria and the epithelium (simple columnar for most of the gut)

Question 10

What is the submucosa?

Answer 10

A layer of connective tissue bearing glands, arteries, veins and nerves

Question 11

What is the muscularis externa?

Answer 11

2 layers of smooth muscle: Outer longitudinal layer and inner circular layer.
Creates peristaltic waves to move luminal contents along the gut

Question 12

What does the mesentery contain?

Answer 12

Arteries, veins and nerves

Question 13

What are plicae circularis?

Answer 13

Located in the jujuenum, circular folds of mucosa and submucosa project into the gut lumen

Question 14

Describe the internal surfaces of the oesophagus.

Answer 14

Stratified squamous non-keratinized epithelium
Lamina propria (containing blood and lymph vessels, some muscle cells and many cells of the immune system)
Muscularis mucosa
Submucosa (connective tissue containing mucus secreting cells)
Muscularis externae (inner and outer)
Adventitia- the outermost layer of connective tissue

Question 15

Describe the internal surfaces of the stomach.

Answer 15

Simple columnar epithelia (absorption)
Gastric mucosa (secretes acid, digestive enzymes and gastrin)
Muscularis mucosa
Submucosa
Muscularis externa (3 layers; oblique, circular and longitudinal)
Rugae- folds in the gastric mucosa forming longitudinal ridges in an empty stomach

Question 16

Describe the internal surfaces of the jejunum

Answer 16

Jejunal mucosa (simple columnar epithelium, lamina propria and MM)
Simple columnar (absorption)
Submucosa
Muscularis Externa (two layers)
Pilicae circularis- circular folds of mucosa and submucosa that project in the gut lumen

Question 17

Describe the internal surfaces of the colon

Answer 17

Simple columnar epithelium (absorption)
The simple columnar epithelium of the crypts produce a lot of mucus and supplies cells to the surface. The surface epithelial cells absorb water and electrolytes 
Mucosa 
Submucosa 
Musclaris externa

Question 18

What is the conducting portion of the respiratory tract?

Answer 18

The nasal cavity to the bronchioles

Question 19

What is the respiratory portion of the respiratory tract

Answer 19

Respiratory bronchioles to the alveoli

Question 20

Describe the internal surface of the trachea

Answer 20

Pseudostratified ciliated epithelium
Submucosa (containing sero-mucous glands)
fibroelastic membrane with trachaelis muscle
C-shaped hyaline cartilage (prevent collapse)
Adeventitia

Question 21

What is adventitia?

Answer 21

Loose connective tissue

Question 22

Describe the internal surface of the bronchus

Answer 22

Psuedostratified ciliated
Smooth muscle
Submucosa
Cresent shaped cartilage (smaller than in trachea)

Question 23

Describe the internal surface of the bronchioles

Answer 23

Simple columnar ciliated/ cuboidal. (in smaller bronchioles the epithelium is not ciliated)
Smooth muscle
Alveoli (no cartilage because surrounding alveoli keep the lumen open)

Question 24

What are termina bronchioles lined with?

Answer 24

ciliated cuboidal epithelium

Question 25

Describe the internal surface of alveoli

Answer 25

One cell thick, purely epithelial:
Type 1 cells (squamous) 90% of the SA and permit gas exchange with capillaries
Type 2 cells (cuboidal) 10% of SA and produce surfactant
Numerous macrophages line alveolar surface
Basketwork of capillaries and elastic fibres surround the alveoli

Question 26

Describe the internal surcae of the Ureter (tube from kidney to bladder)

Answer 26

Transitional epithelium
Lamina propria (fibroelastic)
Muscular externa (circular)

Question 27

Describe the internal surface of the bladder wall

Answer 27

Transitional epithelium 
Smooth muscle (in the lamina propria) 
Muscilaris externa (three interwoven layers)

Question 28

Why is the transitional epithelium impermeable to urine?

Answer 28

Thick plasma membrane and tight intercellular junctions

Question 29

Describe the internal surfaces of the Urethra (bladder to the outside)

Answer 29

Transitional epithelium (in penile urethra stratified columnar)
Lamina propria
Muscularis externa (circular and longitudinal)
Adventitia