Organisation of Cells Into Tissue and Organs

Question 1

3 major salivary glands and locations? Other glands?

Answer 1

Parotid (under ear and cheekbone)
Submandibular (posterior top of neck)
Sublingual (below mouth)

Many smaller glands scattered in oral mucosa

Question 2

What type of cells does the parotid gland have?

Answer 2

Serous secreting cells (stain intensely)

Question 3

What type of cells does the submandibular gland have?

Answer 3

Mucous secreting cells

Question 4

Striated ducts in relation to salivary glands? What does this do?

Answer 4

In most glands with ducts, they only convey the product but striated ducts MODIFY saliva passing though, by pumping salt out of fluid so saliva is HYPOTONIC to blood (saliva does not taste salty)

Question 5

What are basal striations?

Answer 5

Infoldings of cell membrane accompanied by lines of mitochondria to power molecular pumps in membrance

Question 6

4 layers of the digestive tract?

Answer 6

Mucosa
Submucosa
Muscularis externa
Serosa/adventitia (if the layer attaches to surrounding tissue, it is adventitia, but otherwise, it is serosa)

Question 7

Structure of the mucosa?

Answer 7

3 parts:
Epithelium - sits on BASAL LAMINA
Lamina propria - loose connective tissue
Muscularis mucosae - thin layer of smooth muscle

Question 8

What is the submucosa?

Answer 8

Loose connective tissue

Question 9

What is the muscularis externa?

Answer 9

2 thick layers of smooth muscle (inner circular layer and outer longitudinal layer)

Question 10

What is the serosa?

Answer 10

Outer layer of connective tissue that either suspends the digestive tract or attaches to other organs

Question 11

Different types of mucosa?

Answer 11

Protective - non-keratinised, stratified, squamous epithelium, as in oral cavity, pharynx, oesophagus, anal canal
Absorptive - columnar epithelium with villi and tubular glands, as in small intestine
Secretory - columnar epithelium with extensive tubular glands, as in the stomach
Protective and absorptive - columnar epithelium with tubular glands, as in the large intestine

Question 12

What is the digestive tract’s own nervous system? How does it work?

Answer 12

Enteric Nervous System (ENS) - receives input from autonomic nervous system but coordinates gut mobility locally.
Neurones are arranged as groups -called ganglia - between the 2 muscle layers of muscularis externa

Question 13

What are the layers of the trachea?

Answer 13

Respiratory epithelium
Lamina propria (loose connective tissue)
Submucosae (contain seromucous glands)
Hyaline cartilage of tracheal ring

Question 14

How is mucous produced in trachea?

Answer 14

Goblet cell in respiratory epithelium produce mucous together with submucosal glands.

Question 15

Difference between bronci and bronchioles?

Answer 15

Bronchi are large diameter airways and have hyaline cartilage in walls
Bronchioles have no cartilage in walls; have smooth muscle (allow contraction)

Question 16

How do epithelial cells of respiratory tree vary?

Answer 16

Epithelial columnar cells tend to get shorter further down tree

Question 17

Lining of alveoli?

Answer 17

Simple squamous epithelium

Question 18

Structure of liver?

Answer 18

Consist of lobules - have similar hexagonal arrangement

At each corner, branch of hepatic portal vein and hepatic artery (deliver blood to lobule)
Blood passes sheets of liver cells,called hepatocytes, when passing from corner to centre lobule
In centre is central vein which drains to hepatic vein

Question 19

What is the portal triad?

Answer 19

Branch of hepatic portal vein + bile duct + hepatic arteriole

Question 20

Functions of exocrine pancreas?

Answer 20

Produce approx 1 litre of digesetive juices per day, containing proteases (to breakdown proteins), lipases (to breakdown lipids), nucleases (to breakdown DNA/RNA, etc)
These enter duodenum (1st part of small intestine) via pancreatic duct

Question 21

Structure and function of endocrine pancreas?

Answer 21

Consists of small, scattered island of tissues (Islets of Langerhans) which produce a number of hormones, including insulin

Similar in appearance to parotid gland

Question 22

Structure of kidney?

Answer 22

Renal corpuscle - tuft of capillaries, surrounded by epithelium, where production of urine begins
Complex tubule system - many components (liquid/dissolved) of blood pass into here and are then selectively reabsorbed

Renal corpuscle + tubule units = NEPHRONS

Question 23

Structure of the blood?

Answer 23

45% cells and 55% plasma
99% of cell are rbcs (erythrocytes) - lack a nucleus
1% are wbcs (leukocytes); 5 principal types:
Eosinophils
Neutrophils
Basophils
….are collectively termed granulocytes

Monocytes
Lymphocytes

Question 24

Structure of muscular arteries?

Answer 24

3 layers:
Tunica intima - extends to an internal elastic membrane
…and separated by the external elastic membrane are the
Tunica media
Tunica adventitia

Question 25

Structure of arterioles?

Answer 25

Only 1 or 2 layers of smooth muscle in tunica media and almost no adventitia

Question 26

Structure of capillaries?

Answer 26

Composed of endothelial cells and a basal lamina

Question 27

Structure of veins?

Answer 27

Thin muscular walls - lower BP than arteries

Question 28

What is the lymph vascular system?

Answer 28

System of relatively thin-walled vessels that drain excess tissue fluid into bloodstream
Lymph transported to lymph nodes for immunological surveillance

Question 29

Lymphatic system structure and method for flow production?

Answer 29

System has no central pump but no smooth muscle in walls and this, together with hydrostatic pressure in tissue and compression of vessels by voluntary muscle, combines with valves in vessels, produce FLOW.