GI-Part 2

Question 1

Jaw closing muscles include the: (3)

Answer 1

Masseter, Medial Pterygoid, Temporalis Muscle

Question 2

Jaw opening muscles are the: (2)

Answer 2

Lateral Pterygoid, Digastric Muscles

Question 3

What innervates the jaw muscles?

Answer 3

Trigeminal Nerve (V)

Question 4

The chewing rhythm is generated by … to the chewing center from the pressure receptors.

Answer 4

afferent stimuli

Question 5

The chewing rhythm cycle of about … duration is repeated until the colts of food is swallowed.

Answer 5

1 second

Question 6

The Chewing Reflex occurs when (initiated by) a … touches the lining of the mouth

Answer 6

blows of food

Question 7

What mediates the Chewing Reflex?

Answer 7

monosynaptic stretch reflexes are activated

Question 8

Deglutition (Swallowing) may be initiated … but after oral phase swallowing becomes exclusively …

Answer 8

voluntarily; reflexive

Question 9

Deglutition (Swallowing) is mediated through the…

Answer 9

Swallowing Center in the Medulla

Question 10

Buccal (Oral) phase of swallowing is initiated by …

Answer 10

Tactile Receptors in the back of the Mouth

Question 11

What are the Afferents Tactile/Pressure Receptors associated with the Buccal (Oral) Phase of Swallowing (4)?

Answer 11

V-Trigeminal Nerve
VII-Facial Nerve
IX-Glossopharyngral Nerve
X-Vagus Nerve

Question 12

What is the added (5th) Efferent nerve associated with the Buccal (Oral) Phase of Swallowing?

Answer 12

XII-Hypoglossal Nerve

Question 13

In the Pharyngeal Phase of Swallowing the Soft Palate and Uvula are pulled up and the … close to prevent …

Answer 13

Palatopharyngeal Folds close to prevent nasal reflux

Question 14

In the Pharyngeal Phase of Swallowing what accommodates around the bolus of food to squeeze it into the Esophageal Phase?

Answer 14

Pharyngeal Muscles (striated)

Question 15

What action in the Pharyngeal Phase of Swallowing inhibits respiration?

Answer 15

Vocal Cords contract to close the Glottis and Epiglottis covers the trachea

Question 16

The Esophageal Phase of Swallowing is through …

Answer 16

Primary Peristalsis

Question 17

In Primary Peristalsis the … contracts behind the bolus of food, beginning to propel the bolus of food down the Esophagus.

Answer 17

UES

Question 18

In the Primary Peristalsis the … relaxes independent of and prior to the arrival o the Peristaltic Wave.

Answer 18

LES

Question 19

In the Secondary Peristalsis what is not involved?

Answer 19

Pharyngeal Phase

Question 20

Usually caused by the LES not maintaining complete closure.

Answer 20

Dysphagia (difficulty swallowing)

Question 21

Occurs when the LES fails to relax (open)

Answer 21

Achalasia

Question 22

Achalasia is usually due to problems with the …

Answer 22

myenteric plexus

Question 23

In Achalasia food accumulates in the esophagus (instead of the stomach) and causes …

Answer 23

secondary peristalsis

Question 24

What NT is impaired in pts with Achalasia?

Answer 24

NO levels are decreased

Question 25

Is a potent constrictor of the LES, and levels of it may be increased in pts with Achalasia.

Answer 25

Acetylcholine

Question 26

Gastric Reflux during pregnancy and in infants since ... is not complete at birth.

Answer 26

Peristalsis circuitry

Question 27

The fundus and body of the stomach are very distensible (volumes may change from ... to ... with little change in internal pressure)

Answer 27

50 - 1500 mL

Question 28

What occurs upon swallowing allowing food to remain virtually unmixed for up to an hour, and allowing fats to flow to the top of the stomach for digestion by lingual lipase.

Answer 28

Receptive Relaxation

Question 29

What is the last to be digested in the stomach?

Answer 29

fats

Question 30

Receptive Relaxation is diminished by ...

Answer 30

vagotomy

Question 31

Antrum of the Stomach has strong contractions; function is to mix chyme with gastric secretions, most mixing is due to retropulsion.

Answer 31

Astral-Pyloric Systole

Question 32

Is Gastric Emptying occurring faster or slower with a larger volume (meal)?

Answer 32

faster

Question 33

The rate of Gastric Emptying is slowed by ...

Answer 33

high fat and protein concentrations

Question 34

In Gastric Emptying usually only particles smaller than ... are emptied

Answer 34

0.2 mm

Question 35

Gastric Motility is decreased by: (3)

Answer 35

GIP, CCK, and SNS

Question 36

Gastric Motility is increased by: (3)

Answer 36

- Distention (increase release of Gastrin from G-cells) - Closed Pyloric Sphincter - PSNS via Vagovagal Reflexes

Question 37

Where are the signals coming from that influence the Vagus Nerve during Cephalic Phase?

Answer 37

"above the chin" like conditioned reflex, smell, taste, sight

Question 38

In the Cephalic Phase of Digestion the efferent limb of regulation is the Vagus Nerve which can directly increase Stomach Motility by releasing ...

Answer 38

Acetylcholine

Question 39

In the Cephalic Phase the Vagus Nerve can stimulate the release of ... from cells located within the Antrum.

Answer 39

Gastrin Releasing Peptide (GRP)

Question 40

In the Cephalic Phase of Digestion the released GRP acts on nearby G-cells of the Antrum/Pylorus Region that release Gastrin, which then has what effect?

Answer 40

Gastrin is circulated through the stomach increasing motility at its target tissue the visceral smooth muscle

Question 41

The Gastric Phase of Digestion is similar to the Cephalic Phase except that the stimulus comes from ...

Answer 41

Mechanoreceptors and Chemoreceptors within the Mucosal Lining of the Stomach (ENT)

Question 42

The neural stimuli of the Gastric Phase of Digestion is ...

Answer 42

distention

Question 43

In the Intestinal Phase gastric emptying is decreased primarily through modification of ...

Answer 43

decreasing the stomach SV

Question 44

In the Intestinal Phase chemoreceptors for ... and ... and to a lesser extent MechanoReceptors are stimulated in the Mucosal Lining of the Duodenum as Chyme enters from the Pylorus.

Answer 44

duodenal pH and osmolarity (decrease gastric emptying)

Question 45

The stimulatory effects of the Cephalic and Gastric Phases are significantly reduced through a series of neural reflexes

Answer 45

Enterogastric Reflex

Question 46

The Intestinal Phase is controlled by ... and ... which act to inhibit the release of GRP.

Answer 46

Secretin and GIP (and CCK)

Question 47

Stomach pain is mediated by ...

Answer 47

SNS afferents in the mucosa

Question 48

Dumping Syndrome is the composite of dumping large bouts of osmotically active particles into the intestine thereby ...

Answer 48

drawing water out of the blood, decreasing overall blood volume and pressure