Physiology Flashcards Preview

Year Two Revision Super-Deck > Physiology > Flashcards

Flashcards in Physiology Deck (45):
1

What is the function of the mouth and saliva?

Foodstuffs broken down by chewing (mastication) and saliva is added as lubricant

2

What is the function of the oesophagus?

Conduit between the mouth and the stomach

3

What is the function of the pancreas?

Digestion enzymes for digestion of lipids.

Helps with the absorption of fats, carbohydrates and proteins

4

What is the function of the liver?

Secretes bile salts to aid the absorption of fats in the ileum

5

What is the function of the gallbladder?

Stores and concentrates bile

6

What is the function of the small intestine?

Final stage of chemical digestion and nutrient absorption

7

What is the function of the stomach?

Digestion of proteins; foodstuffs reduced to liquid.

Also plays a role in storage and sterilisation

8

What is the function of the large intestine?

Water absorption, bacterial fermentation and formation of faeces

9

Describe the length, diameter and organisation of the GI tract

Approx. 8m long, varying diameter and organisation of cells vary depending on function

10

Describe the difference in the microscopic composition of the GI tract

Mouth, anal canal and oesophagus - Stratified Squamous epithelium

Stomach and intestines - simple columnar epithelium

11

What are the four layers common to the GI tract?

- Mucosa
- Submucosa
- Muscularis externa
- Serosa/Adventitia

12

What structures comprise the mucosa?

Epithelium, lamina propria, muscularis mucosa

13

What is the function of the mucosa?

- Synthesis and secretion of enzymes
- Absorbs products of digestion

14

What is the lamina propria?

Loose connective tissue containing glands and blood/lymph vessels

15

What is the muscularis externa?

A thin layer of muscle

16

What is the structure of the submucosa?

Thick, irregular connective tissue

17

What is the function of the submucosa?

Supports the mucosa

18

What structures permeate the submucosa?

Neurones, blood vessels (to the mucosa, adventitia and muscularis externa)

19

What is the network of neurones in the mucosa known as?

Meissner's plexus (parasympathetic)

20

Where are submucosal glands located?

Oesophagus and duodenum

21

What is the structure of the muscularis externa?

Two layered ring of muscle

22

What are the function s of the two layers of muscle in the muscularis externa?

Inner - circular - contraction of lumen

Outer - longitudinal - constriction of tube length

Allows peristalsis and segmentation

23

What is peristalsis?

Rhythmic longitudinal contractions of the lumen of the GI tract to promote transit of bolus

24

What is segmentation?

Contraction of the circular (inner) muscles of the gut tube - slowing down the transit of chyme through the system.

25

What neural system lies between the layers of the muscularis externa?

Auerbach's Myenteric Plexus

26

What is the enteric nervous system comprised of?

Submucosal (Meissner's) and Myenteric (Auerbach's) plexi

27

What is the function of the enteric nervous system?

Independent control of the GI tract

28

What is the difference between the adventitia and the serosa?

Both are outer layers of connective tissue for the alimentary canal

Location is the difference:

Serosa = inside the peritoneal cavity

Adventitia = outside the peritoneal cavity

29

What division of the autonomic nervous system governs long reflexes in the alimentary canal?

Parasympathetic

30

What division of the autonomic nervous system governs short reflexes in the alimentary canal?

Sympathetic

31

What nerve delivers parasympathetic innervation?

Vagus nerve (CN X) except for salivation (Facial CN VII and glossopharyngeal IX)

32

What is the effect of the parasympathetic system in the GI tract?

Increases gut motility and secretion

33

What is the effect of the sympathetic system on the GI tract?

Decreases gut motility and secretion

34

What nerve delivers sympathetic innervation to the GI tract?

Splanchnic

35

What three branches of the descending aorta supply the GI tract?

Celiac trunk, superior and inferior mesenteric arteries

36

What organs does the coeliac trunk supply?

Stomach, small intestine, pancreas and liver

37

What organs does the superior mesenteric artery supply?

Small intestine, caecum, ascending colon and transverse colon

38

What organs do the inferior mesenteric artery supply?

Descending colon, sigmoid colon and rectum

39

What vein(s) drain from the stomach?

Gastric

40

What vein(s) drain from the pancreas?

Splenic vein

41

What organs rain into the superior mesenteric vein?

Small intestine, caecum, ascending and transverse colon

42

What organs drain into the inferior mesenteric vein?

Descending colon, sigmoid colon and rectum

43

Where do the gastric, splenic and mesenteric veins drain into?

Hepatic portal vein

44

Outline the route to the inferior vena cava from the hepatic portal vein

Hepatic portal vein (through the liver) to the hepatic vein and into he inferior vena cava

45

What is the purpose of the hepatic portal system?

To clean blood in the liver before deoxygenation in the CVS