Alimentary Control

Question 1

What are the types of somatic nerves in the alimentary system?

Answer 1

motor
sensory

Question 2

What are the types of autonomic nerves in the alimentary system?

Answer 2

parasympathetic
sympathetic

Question 3

What hormones are secreted in the GIT?

Answer 3

CCK (cholecystokinin)
Gastrin
Gastric inhibitory peptide (GIP) (increase insulin!!)
Secretin

Question 4

What is CCK (cholecystokinin)?

Answer 4

secreted by the duodenum endocrine cells

bile sac mover and mainly works by promoting the digestion of fat and protein. It also is an appetite suppressant.

Question 5

What cells release gastrin?

Answer 5

G cells in the stomach

Question 6

What is gastric inhibitory peptide?

Answer 6

weak inhibition of stomach acid secretion, but actually stimulates insulin secretion, stops death of pancreatic beta cells (insulin producing cells), stimulates glucagon and also accumulation of fat.
main role is insulin secretion stimulation

Question 7

What does gastrin do?

Answer 7

stimulate production of HCL by parietal cells

Question 8

What does secretin do?

Answer 8

active in the duodenum
it reduces gastric acid secretion and increases bicarbonate (HCO3) secretion from the pancreas

Question 9

Where are hormones most active?

Answer 9

stomach

Question 10

What regions in the alimentary system are somatic?

Answer 10

mouth
anal canal

Question 11

What nerves have a role in taste and as a result cause an increase in saliva secretion?

Answer 11

facial nerve (VII) for front 2/3 of tongue
glossopharyngeal nerve (IX) for back 1/3 of tongue

Question 12

What nerve controls smell?

Answer 12

olfactory (I)

Question 13

What is the strongest stimuli of saliva?

Answer 13

chemical (taste and smell)

Question 14

What is the weakest stimuli of saliva?

Answer 14

psychic (visual)

Question 15

What muscle type controls chewing?

Answer 15

skeletal

Question 16

What nerve is involved in periodontal ligament loading and results in an increase in saliva secretion?

Answer 16

trigemenal nerve (V)

Question 17

What nerves control chewing and what muscles do they innervate?

Answer 17

trigeminal (V) nerve - muscles of mastication
facial nerve (VII) - facial muscles
hypoglossal (XII) – tongue muscles

Question 18

What muscle type controls swallowing?

Answer 18

skeletal

Question 19

What nerves control swallowing?

Answer 19

trigeminal (V)
vagus (X)
hypoglossal (XII)
glossopharyngeal (IX)

Question 20

What is inhibited during deglutition?

Answer 20

respiration

Question 21

Where is the swallowing centre found in the brain?

Answer 21

brainstem

Question 22

What nerve controls the oesophagus?

Answer 22

vagus (X)

Question 23

What muscle types are found in the oesophagus?

Answer 23

skeletal and smooth

Question 24

What is gastric juice and where is it found?

Answer 24

hydrochloric acid (HCl), lipase, and pepsin
stomach

Question 25

What are the muscle layers of the stomach?

Answer 25

innermost oblique, middle circular, longitudinal outer

Question 26

What is the process in which substances move in the GIT?

Answer 26

peristalsis

Question 27

What are the 3 phases that stimulate gastric activity?

Answer 27

Celiac phase Gastric phase Intestinal phase

Question 28

What is the cephalic phase compromised of?

Answer 28

mechanical (chewing- muscles of mastication) chemical (taste, smell) psychic (visual, emotional)

Question 29

What is the gastric phase compromised of?

Answer 29

mechanical (digestion) chemical (food in stomach)

Question 30

What is the intestinal phase compromised of?

Answer 30

mechanical (distension) chemical (acid, protein in the duodenum)

Question 31

What is a long reflex?

Answer 31

to the brain

Question 32

What is a short reflex?

Answer 32

locally

Question 33

What is the control (nervation and hormonal) of the cephalic phase?

Answer 33

long reflex

Question 34

What is the control (nervation and hormonal) of the gastric phase?

Answer 34

nerves (long and short reflexes) hormones (gastrin)

Question 35

What is the control (nervation and hormonal) of the intestinal phase?

Answer 35

nerves (long and short reflexes) hormones (GIP, CCK secretin)

Question 36

What are the controls of the small intestine?

Answer 36

mainly short reflexes in response to intra stimuli

Question 37

What muscle contracts in the small intestine?

Answer 37

smooth muscle

Question 38

What has the greatest effect on pancreatic bicarbonate secretion?

Answer 38

vagus nerve (cephalic and gastric phase), CCK and VIP all have a weak stimulatory effect on bicarbonate only secretin has a great one

Question 39

What is VIP?

Answer 39

Vasoactive intestinal polypeptide breaks down glycogen relaxes the smooth muscle of the gall bladder and the stomach.

Question 40

Is the gallbladder essential?

Answer 40

no

Question 41

What can the gallbladder sometimes have?

Answer 41

stones made of cholesterol

Question 42

What has the greatest effect on pancreatic enzyme secretion?

Answer 42

vagus nerve (celiac and gastric) = small effect gastrin and GIP = small effect CCK = big effect, stimulates secretion of enzyme rich pancreatic juice

Question 43

What is the effect of the vagus nerve on the secretion of bile?

Answer 43

relaxation of the sphincter of Oddi

Question 44

What is the effect of CCK on the secretion of bile?

Answer 44

stimulates contraction of gall bladder relaxation of the sphincter of Oddi

Question 45

What is the effect of secretin of the secretion of bile?

Answer 45

stimulates contraction of gall bladder relaxation of the sphincter of Oddi (weaker than CCK)

Question 46

What are the secretions of the large intestine and rectum?

Answer 46

mucus water and electrolytes

Question 47

What kind of reflexes control mixing in large bowl?

Answer 47

long

Question 48

How are long reflexes in the large intestine triggered?

Answer 48

food entering the stomach

Question 49

What is the gastro-ileal reflex?

Answer 49

gastric activity increased motility in ileum

Question 50

What is the gastro-colic reflex?

Answer 50

gastric activity increased motility in colon

Question 51

What is the nerve supply of the colon up to the splenic flexure?

Answer 51

vagus (X)

Question 52

What is the nerve supply of the descending colon and rectum?

Answer 52

pelvic nerves (S2-4)

Question 53

What somatic nerve controls the anal canal?

Answer 53

sacral nerve

Question 54

What ANS branch is the internal anal sphincter controlled by?

Answer 54

parasympathetic

Question 55

What nerves is the external anal sphincter controlled by?

Answer 55

skeletal muscle that is controlled by somatic nerve supply from the Inferior anal branch of the Pudendal nerve (S2,3,4), which allows conscious control of defecation.

Question 56

What does the defecation (rectosphincter) reflex result in?

Answer 56

relaxes the internal sphincter. If defecation is not desired, voluntary contraction of the external sphincter can delay it. series of reflexes take place that lead to: Contraction of abdominal wall muscles Relaxation of pelvic wall muscles Relaxation of external anal sphincter Peristaltic waves then facilitate the movement of faeces through the anal canal