Ianowski - theme 15

Question 1

Batch reactor:

Answer 1

Cnidarians (coelenterates). Pulsed input, pulsed output. Batch must be processed before the next one can come in.

Question 2

Continuous-flow stirred-tank reactor:

Answer 2

Continuous input and continuous output. Contents get mixed. Overflow moves on.

Question 3

Plug-flow reactor:

Answer 3

Continuous input and continuous output. Contents are different at different points (not mixed).

Question 4

Divisions of gut tube:

Answer 4

Headgut, foregut, midgut, hindgut

Question 5

Headgut:

Answer 5

Mouth to glottis. Mouthy things happen here.

Question 6

Who has tongues?

Answer 6

Chordates.

Question 7

Swallowing (deglutition): process of reflex

Answer 7

Tongue forces bolus to pharynx. Pharyngeal pressure receptors send impulses to medulla oblongata. Swallowing centre activates all-or-none response.

Question 8

Where does the swallowing reflex begin?

Answer 8

Pharynx

Question 9

Stages of swallowing reflex:

Answer 9

Oropharyngeal stage: uvula seals nasal passage, epiglottis covers airways, pharyngeal muscles contract to push food to esophagus.
Esophageal stage: peristalsis of esophagus, relaxation of gastroesophageal sphincter to allow food into stomach.

Question 10

Foregut:

Answer 10

Esophagus. Conducts food from headgut to stomach.

Leeches have crop. Birds throw up.

Question 11

Midgut:

Answer 11

Stomach. Storage. Breakdown of macromolecules by liver bile and pancreatic juice. Absorption of products.

Question 12

Human stomach: parts

Answer 12

Fundus: where esophagus fuses
Body: secretion of acid and mucus
Antrum: muscular to push stuff on

Chyme is formed here

Question 13

What separates duodenum and stomach?

Answer 13

Pyloric sphincter

Question 14

Gastric mucosal tissue:

Answer 14

Need to keep acid out. Cells are impermeable and tight junctioned together. Mucus serves as a physical and chemical barrier to penetration.

Question 15

Parts of the digastric stomach:

Answer 15

Esophagus, groove, rumen, reticulum, omentum, abomasum, pylorus.
Fermentation happens in rumen. Enzyme digestion begins in abomasum.

Question 16

Central lacteal:

Answer 16

Terminal lymphatic vessel associated with small intestine villi. Important for fat absorption.

Question 17

Most absorption takes place where? Absorption of what?

Answer 17

Duodenum and jejunum. Fat (passive), carbs (secondary active), protein (secondary active), vitamins.

Question 18

Hindgut of fermenters:

Answer 18

In large fermenters - plug-flow.

In small fermenters - continuous-flow.

Question 19

Parts of vertebrate hindgut:

Answer 19

Colon, cecum, and rectum/cloaca.

Question 20

Vermiform appendix:

Answer 20

In humans and higher apes. Stores lymphocytes. No digestive function.

Question 21

Regions of the colon:

Answer 21

Ascending, transverse, descending.

Question 22

Colon size vs diet: (carnivore vs…)

Answer 22

Carnivores have short colons. Omni and herbivores have long colons with expandable side bits (haustra).

Question 23

What parts of the GI system are controlled by CNS?

Answer 23

Esophagus is controlled. Everything else is myogenic.

Question 24

BER:

Answer 24

Basic electric rhythm (peristalsis). Amplitude is determined locally/intrinsically by mechano anc chemoreceptors.

Question 25

Types of muscular contractions:

Answer 25

Peristalsis, segmentation (kneading and mixing)

Question 26

Enteric nervous system:

Answer 26

Nuclei are inside the cells they control. The only part of PNS that has autonomy.

Question 27

GI exocrine and endocrine functions:

Answer 27

Endocrine: hormones to circulatory system
Exocrine: digestive enzymes, water, mucus, electrolytes into GI lumen

Question 28

Mammalian salivary gland (exocrine gland):

Answer 28

Acinar portion: mucin, amylase, water, and electrolytes come in.
Duct portion: further modification of saliva.

Question 29

Activating pepsinogen:

Answer 29

Acid breaks pepsinogen down into active pepsin.

Question 30

Who secretes pepsinogen? Who secretes intrinsic factors?

Answer 30

Pep - chief cells

Factors - parietal cells

Question 31

Phases of stomach secretion regulation:

Answer 31

Cephalic: brain stuff (smell, mental)
Gastric: when food enters stomach. gastrin is produced in response to peptides, stomach stretch, and ANS. gastrin stimulates secretion of HCl and pepsinogen.
Intestinal: gastric inhibitory protein in response to fatty acids. GIP inhibits HCl and pepsinogen. secretin stimulates pancreas and inhibits stomach.

Question 32

Sugar transport from intestinal lumen to blood:

Answer 32

Glucose and galactose: secondary transport with Na+ by SGLT1. Powered by basolateral Na/K pump.
Fructose: brought in by GLUT5.
GLUT2 transports sugars.

Question 33

Lipid absorption, a beautiful story:

Answer 33

Bile salts break lipids into monoglycerides, fatty acids, and glycerol. Once inside the cell, ER and golgi reassemble triglycerides and send them out of the cell wrapped in a protein blanket. The blanketed triglyceride is called a chylomicron.