DIGESTION

Question 1

Alimentary canal

Answer 1

continuous tube from the mouth to anus

Question 2

Examples of accessory digestive organs

Answer 2

mouth, pancreas, liver, gallbladder

Question 3

What do the pancreas, liver, and gallbladder do?

Answer 3

secrete enzymes in the system

Question 4

The function of the Gastrointestinal tract do?

Answer 4

Convey food along GIT, allowing it to be broken down into small molecules which can be absorbed into the circulation

Question 5

Purpose of secretion

Answer 5

chemical breakdown by glandular activity - exocrine and endocrine

Question 6

Purpose of motility

Answer 6

propulsion and physical breakdown - muscular activity

Question 7

Purpose of absorption

Answer 7

transfer to blood circulation

Question 8

GITs role

Answer 8

provide nutrients to the body

Question 9

Digestive and Absorptive capacity of GIT

Answer 9

The GIT is efficent
Carbs = 99%
Fat = 95%
Protein = 92%

Question 10

GIT structure

Answer 10

Tubular Nature

Communication with External Environment at Both Ends

Question 11

Size of GIT compared to human

Answer 11

4.5 m vs 1.5 m

GIT Length is way larger

Question 12

Internal vs external GIT surface area

Answer 12

600x larger internal surface area

200-250 m^2

Question 13

Four functional layers of the GI tract (inside to outside)

Answer 13

mucosa, submucosa, muscularis externa, serosa

Question 14

Serosa

Answer 14

Thin, tough layer of connective tissue

Question 15

Muscularis Externa

Answer 15

two layers of muscle (longitudinal and circular fibres)

Question 16

Muscularis Externa muscle types

Answer 16

Mouth to Esophagus - striated muscle type
Esophagus to Anus - smooth muscle type
Anus - striated muscle type

Question 17

Submucosa

Answer 17

Loose connective tissue containing lymphatics and blood vessels

Question 18

Mucosa layers (outside to inside)

Answer 18

Muscularis mucosae, Lamina propria, Epithelial layer

Question 19

Muscularis mucosae

Answer 19

smooth muscle

Question 20

Lamina propria

Answer 20

loose connective tissue

Question 21

Epithelial layer

Answer 21

epithelial and glandular cells play a role in the absorption

Question 22

Longitudinal fibres

Answer 22

outer layer, when it contracts, GIT shortens

Question 23

Circular fibres

Answer 23

inner layer, when it contracts, lumen narrows

Question 24

Where is Muscularis Externa in striated?

Answer 24

oral cavity, pharynx, upper 1/3 esophagus and external anal sphincter

Question 25

Where is Muscularis Externa in smooth?

Answer 25

rest of the GIT

Question 26

Plexus

Answer 26

collection of nerve cell bodies

Question 27

Two types of plexus

Answer 27

submucosal plexus, myenteric plexus

Question 28

What do the plexus contain?

Answer 28

sensory neurons, motor/effector neurons

Question 29

Purpose of Interneurons in the GIT

Answer 29

expand the responses to stimuli in the GIT

Question 30

motor/effector neurons in the GIT

Answer 30

activate the secretory and muscle cells

Question 31

Types of Enteric Neurons

Answer 31

excitatory, inhibitory

Question 32

Excitatory enteric neurons release

Answer 32

ACh

Question 33

Inhibitory enteric neurons release

Answer 33

NANC (NO)

Question 34

What is Ach blocked by?

Answer 34

atropine

Question 35

Non-adrenergic, non cholinergic

Answer 35

NANC

Question 36

The ENS consists of the myenteric plexus between

Answer 36

longitudinal and circular muscle layers

Question 37

The ENS consists of ganglion cells and their processes which synapse with

Answer 37

smooth muscle cells, endocrine and exocrine cells, and other ganglion cells

Question 38

Enteric sensory fibers get information from

Answer 38

gut chemoreceptors and mechanoreceptors

Question 39

Parasympathetic ganglions

Answer 39

preganglionic

Question 40

Sympathetic ganglions

Answer 40

postganglionic

Question 41

Where does the parasympathetic system innervate from?

Answer 41

vagus X, pelvic nerves

Question 42

Where does the sympathetic system innervate from?

Answer 42

celiac, superior mesenteric, inferior mesenteric ganglion

Question 43

How does ANS influence the GIT

Answer 43

through the ENS

Question 44

Parasympathetic input on blood vessels

Answer 44

dilation of blood vessels

Question 45

Sympathetic input on blood vessels

Answer 45

constriction of blood vessels

Question 46

Parasympathetic affect on ENS

Answer 46

neurons reach the wall of the GIT as preganglionic fibers, synapsing (via nicotinic ACh receptors) with enteric neurons (both excitatory and inhibitory) exerting an excitatory effect.

Question 47

Sympathetic affect on ENS

Answer 47

neurons reach the wall of the GIT as postganglionic fibers, synapsing (via NA receptors) with enteric neurons (both excitatory and inhibitory) exerting an inhibitory effect

Question 48

Sympathetic neurons affect on smooth muscle in blood vessels

Answer 48

vasoconstriction

Question 49

What allows for long reflexes

Answer 49

Sensory neurons

Question 50

What does the ENS innervate (reflex)

Answer 50

independent, integrative innervation; regulates GIT via SHORT, INTRAMURAL REFLEXES

Question 51

What does the ANS innervate (reflex)

Answer 51

“modulates” ENS activity via LONG, EXTRINSIC REFLEXES – synaptic connections with ENS neurons

Question 52

What may influence the growth and development of GIT

Answer 52

Non-GIT hormones

Question 53

What may influence outside the GIT

Answer 53

GIT hormones