physiology - digestive system

Question 1

Gut —General Functions

Answer 1

motility
absorption
secretion
digestion

Question 2

Swallowing reflex – Oropharyngeal Stage

3 parts

Answer 2

position of oropharyngeal structures at rest

oral part

pharyngeal part

Question 3

Swallowing reflex – Oropharyngeal Stage

position of oropharyngeal structures at rest

Answer 3

-swallowing happens voluntarily, tongue presses bolus against hard palate

Question 4

oral part

Answer 4

• tongue propels bolus to pharynx
• swallowing centre inhibits respiratory centre in brain stem
• elevation of uvula prevents food going into nasal cavity

Question 5

pharyngeal part

Answer 5

• position of tongue prevents food entering mouth again

- epiglottis folds over closed glottis

Question 6

Swallowing reflex – Oesophageal Stage
«passes between
« runs from

Answer 6

• pharynx and stomach

- CVI to TXI

Question 7

Swallowing reflex – Oesophageal Stage

3 parts

Answer 7

beginning of Oesophageal Stage

completion of Oesophageal Stage

Question 8

beginning of Oesophageal Stage

Answer 8

pharyngoesophageal sphincter closes , oropharyngeal structures returns to rest

Question 9

completion of Oesophageal Stage

Answer 9

• peristalsis propels food down oesophagus

- gastroesophageal spincter relaxes and swallowing is complete

Question 10

The Stomach – Function

Answer 10

storage and mixing

digestion … secretory function :HCl / pepsinogen

Question 11

how many liters of gastric juice/day

Answer 11

2 litres

Question 12

Stomach Mucosa and Gastric Secretion

exocrine cells

Answer 12

• -mucous cells ….. alkaline mucous
• -chief cells … pepsinogen
• • parietal cells … hydrochloric acid

Question 13

Stomach Mucosa and Gastric Secretion

endocrine/paracrine cells

Answer 13

ECL cells - histamine
G cells - gastrin
D cells -somatosatin

Question 14

gut function

motility

Answer 14

• food moves down digestive tract due to to peristalsis

- breakdown and mixing of ingested nutrients all the way down until eliminated of unabsorbed waste from the body

Question 15

gut functions

secretion

Answer 15

• release of enzymes , hormones and other substances that help body digest the food
• hormones tell the body when to produce digestive juices and signal the brain whether you are hungry or full

Question 16

gut functions

digestion

Answer 16

ingested nutrients are reduced to small molecules that can pass through the gut lining and enter bloodstream

Question 17

gut functions

absorption

Answer 17

digested nutrients that have passed into blood are now in circulatory or lymphatic system where they can be passed around the body and stored

Question 18

absorption
lymphatic system
bloodstream
livers

Answer 18

• absorbs fatty acids and vits
• carries simple sugars , amino acids , some vits and salts to liver
• stores processes and delivers these nutrients to the body when needed

Question 19

digetsive tract wall

mucosa
3 layers

Answer 19

mucous membrane- epithelial lining
lamina propia - connective tissue sheath
muscularis mucosa - smooth muscle layer

all the compose the inner lining of digestive tract

Question 20

digestive tract wall

submucosa

Answer 20

connective tissue sheath that allows flexibility

Question 21

digestive tract wall

Answer 21

outer longitundial muscle

inner circular muscle