Intro to struct./funct. of Alimentary Canal

Question 1

Alimentary Canal

Answer 1

series of hollow organs running from mouth to anus that are separated by sphincters, controlling movement

Question 2

Aboral

Answer 2

towards anus

Question 3

Function of Mouth

Answer 3

chop food, lubricate (saliva), begin carbohydrate digestion

Question 4

Function of Oropharynx

Answer 4

propels food to oesophagus

Question 5

Function of Oesophagus

Answer 5

propels food to stomach

Question 6

Function of Stomach

Answer 6

stores and churns food, continues carbohydrate digestion, begins protein digestion, regulates the deliver of chyme to duodeum

Question 7

Chyme

Answer 7

partially digested food, water, hydrochloric acid, various digestive enzymes
from bolus

Question 8

Function of Small intestine

Answer 8

digestion and absorption of nutrients (PRINCIPLE SITE)

Question 9

Function of Large Intestine

Answer 9

colon reabsorbs fluids/electrolytes, stores faecal matter before delivering it to the rectum

Question 10

Function of the Rectum and Anus

Answer 10

storage and regulated expulsion of faeces

Question 11

Accessory structures

Answer 11

Salivary glands
Pancreas
Liver and gall bladder

Question 12

Motility

Answer 12

mechanical movements of the GI tract

Question 13

4 layers of the digestive tract wall

Answer 13

mucosa
submucosa
muscular externa
serosa

Question 14

Serosa

Answer 14

Releases a sticky fluid that allows sliding movement

Question 15

Submucosa Plexus

Answer 15

Absorption + Secretin

Question 16

Muscularis Externa

Answer 16

Circular Muscle layer
Nerve network
Longitudinal Muscle

Question 17

Circular Muscular Contraction

Answer 17

Narrow / Long

Question 18

Longitudinal Muscle Contraction

Answer 18

Shorter / Fatter

Question 19

Muscular Mucosae Contraction

Answer 19

change in absorptive / secretory area of mucosa (folding) / mixing activity

Question 20

Taeniea Coli

Answer 20

longitudinal muscle layer presents as 3 longitudinal bands

Question 21

Junctions between smooth muscle

Answer 21

Gap junctions

Question 22

Single unit smooth muscle

Answer 22

hundreds of cells are depolarised and contract @ the same time as a synchronous wave

Question 23

Electrical activity occurs as …

Answer 23

slow waves

Question 24

Contraction is caused by

Answer 24

action potentials

Question 25

ICCs (interstitial cells of canal)

Answer 25

pacemakers cells between numerous SMCs

Question 26

Slow waves reach action potentials due to

Answer 26

underlying depolarisation

Question 27

Upstroke

Answer 27

Ca2+ channels

Question 28

Downstroke

Answer 28

K+ channels

Question 29

Myenteric Plexus

Answer 29

regulates motility and sphincters

Question 30

Submucous Plexus

Answer 30

modules epithelia & blood vessels

Question 31

Key transmitters

Answer 31

5-HT, ACh, NO, SiP, VIP

Question 32

3 neurones

Answer 32

Sensory neurones Interneurones Effector neurones

Question 33

Effector neurones

Answer 33

supply 1. smooth muscle 2. secretary epithelium 3. endocrine cells 4. blood vessels

Question 34

Intrinsic Reflex

Answer 34

Local reflex

Question 35

Local reflex example

Answer 35

local reflex

Question 36

Extrinsic reflex

Answer 36

short reflex | long reflex

Question 37

Short reflex

Answer 37

Intestino-intestinal inhibitory reflex

Question 38

Long reflex

Answer 38

Gastroileal reflex

Question 39

Local reflex

Answer 39

peristalsis

Question 40

Peristalsis

Answer 40

an orderly wave of relaxation, followed by contraction, that normally proceeds along the hut in an aboral direction - triggered distention of the gut

Question 41

VIP & NO

Answer 41

relax

Question 42

Each + SiP

Answer 42

exiting