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Flashcards in Physiology 2 Deck (108)
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1

The GI Tract is all smooth muscle except?

upper 1/3 of esophagus and anal sphincter (striated)

2

Types of Smooth Muscle Contraction?

1. Phasic - parastalic
2. Tonic - can last hours

3

Chewing does?

1. breaks down food particles
2. mixes food with saliva
3. increase surface are to digest better

4

Functions of stomach?

1. storage-most in orad area
2. break down food particles in small cubic sizes
3. gastric emptying

5

GERD

-acid reflux
-heartburn
-hiatal hernia, pregnancy, failure of secondary peristalsis

6

Oxyntic Cells

Parietal Cells, in body of stomach, weak motility

7

Pyloric

antrum, very strong contractions, muscle is thicker in this area

8

accommodation

relaxation

9

Cells of Caja

-slow waves always present from these intestinal cells
"gastric pacemaker"
3-5 depolarizations/min

10

Vagal Stimulation effect on slow waves

-increase height of waves (so increase frequency of contraction)

11

What empties fastest in the stomach?

-isotonic water (everything becomes isotonic when it goes in duodenum)

12

CCK effect on emptying?

inhibits

13

Effect of acid on peristalsis?

decrease from neural reflex

14

Failure of Gastric Emptying

-fullness, loss of appetite, nausea
-obstruction-ulcer, nausea
-vagotomy

15

Increased Gastric Emptying

-inadequate regulation
-diarrhea, duodenal ulcer

16

Reason for irregular contractions in small intestine?

1. mixing
2. digesting
3. absorption

17

Peristalsis

propulsion, moves food only 4-5cm at a time, short

18

Migrating Motor Complex

-"housekeeper" reflex
-goes away when you start to eat
-# of contractions per minute except areas of extreme contractility (90min) b/c of motiline (creates wave beginning in stomach)

19

Small Intestine Motility

-must have spikes to have contraction

20

Teniae Coli

-longitudinal muscle

21

Haustra

-segmentation in colon, can disappear and reappear in different areas

22

Achalsia

food stuck in esophagus

23

rectosphinteric reflex

when rectum is distended, it will contract external sphincter
absent in paraphalgicts (rectal sphincter causes defication)
voluntary rexed for deification

24

Salivary Secretion Components

1. alpha amylase - pH 7, lingual lipase (acidic), solubilization (to taste food)
2. lubrication - needed for speech
3. protective function - allows drinking hot, dilute noxious substances, dec. cavities, sec. F, Ca, P, lysosomes to wash particles from teeth

25

Salivary Glands`

1. Parotid - watery 25-40% of output
2. Submaxilary - watery and mucus
3. Submandibular
-recieve lots of blood flow, CN nerves VII & IX both sympathetic and parasympathetic

26

Acinar cells

secretion goes unchanged in intercalated duct, then modified: abs NaCl, sec. K+ and bicarb in striated duct

27

Xerostamia

-absence of saliva

28

Ion concentration with flow rate

-hypotonic at all rates
-high K+ concentration all the time
-Na+ concentration low at low rates
-bicarb high at high rates

29

Changes in concentration as saliva moves from acinus to duct opening?

-Na+ decreases, K+ increases (secreted into duct)
-more happens the longer it stays in the gland

30

Kallikrein

salivary glands secrete it into the blood stream, acts on plasma proteins to cause secretion of Bradykinin to increase blood flow