Physiology 4.2

Front 1

List the sequence of events for the Oropharyngeal Phase of Swallowing.

5 steps

Back 1

elevation of tongue

closure of nasopharynx

relaxation of UES

Closure and protection of airway

pharyngeal peristalsis

Front 2

Sensory input to the swallowing center is via branches of what cranial nerves?

Where is the swallowing center located?

Back 2

CN 5 , 9 , 10


medulla

Front 3

Motor output for swallowing from the medulla comes from what Cranial Nerves?

Back 3

CN 5 , 9 , 10 , 12

Front 4

The ? follows pharyngeal contraction.

Back 4

Primary Peristaltic Wave

Front 5

When does the LES relax in swallowing?

Back 5

Bolus enters into the esophagus

Front 6

? typically occurs in response to distention of the esophagus by a bolus after an INEFFECTUAL primary wave or to refluxed gas or acid from the stomach.

Back 6

Secondary Peristalsis

Front 7

True or False

The resting state of LES pressure > intragastric pressure.

Back 7

True

Front 8

What is the vagal neural mechanism for INCREASED LES pressure?

(contraction)

Back 8

Vagal Excitatory Fibers

release ACh --> bind to M3 receptor on smooth muscle

=> CAUSE CONTRACTION

Front 9

Vagal inhibitory fibers for the LES release what type of neurotransmitters?

Back 9

Non-Adrenergic Non-cholinergic (NANC)

Front 10

What is the sympathetic stimulation for increased LES pressure?

Back 10

Norepinephrine

=> bind to α-receptors on Postganglionic Myesteric Excitatory neurons

=> these neurons release ACh

=> CAUSE CONTRACTION

Front 11

What is Dysphagia?



What is GERD?

Back 11

difficulty swallowing



Gastroesophageal Reflux
--gastric reflux into esophagus due to problems with LES

Front 12

What causes the RECEPTIVE RELAXATION of the Proximal Stomach?

When does this occur?

Back 12

Vago-Vagal Reflex


during swallowing

Front 13

? prevents increased INTRAGASTRIC PRESSURE with filling.

Compliance of the gastric muscle is dependent upon intact ?

Back 13

Accomodation


Vagal fibers ---VAGO-VAGAL REFLEX

Front 14

True or False

Contractions of the FUNDUS are INDEPENDENT of gastric slow waves

Back 14

True

Front 15

Slow waves that elicit contractions int he Body and Antrum of the stomach are ?

(referring to the shape of the Action potential)

The strength of contraction is DEPENDENT on the ? of the slow wave.

Back 15

Triphasic


Amplitude

Front 16

? of contents results in shearing (grinding action). This helps reduce the food particle size.

Back 16

Retropulsion

Front 17

The emptying of isotonic non-caloric contents is DIRECTLY PROPORTIONAL to the ?

Back 17

Gastric Volume

Front 18

ACID in the DUODENUM

=> SLOWS GASTRIC EMPTYING via ? reflex

=> release of ?

Back 18

Enterogastric Refelex


Secretin (cause HCO3- release)

Front 19

True or False

The DELIVERY RATE of gastric emptying is relatively constant.

Therefore the greater the caloric content -- the longer the time required to deliver them.

Back 19

True

Front 20

Typically particles greater than ? are not emptied into the duodenum. This underscores the importance of actions of the ANTRUM on RETROPULSION and SHEARING.

Back 20

1 mm

Front 21

During fasting repeated cycles of ? occur.

Back 21

Migrating Motor Complexes (MMC)

Front 22

Describe the cyclic pattern of the MMC:

Phase I 45-60 min

Phase II 30-45 min

Phase III 5-10 min

Back 22

phase I -- quiescent period // slow waves are rarely associated with spikes // continuously running slow waves


Phase II --intermittent spikes and contractions


Phase III --spikes and contractions associated with each slow waves

Front 23

The plasma concentration of ? increases prior to PHASE III

Back 23

Motilin

Front 24

True or False

The Migrating motor Complexes begin in the GASTRIC ANTRUM and end in the LARGE COLON.

Back 24

False

Cycle begins in the Gastric ANTRUM

ends in the ILEUM

Front 25

Absence of MMC activity causes ? in the gastric antrum and small intestines.

Back 25

Bacterial overgrowth

Front 26

The feeding state interrupts the interdigestive MMC Phase ? activity.

The duration of the inhibition of the fasting motor activity is DIRECTLY PROPORTIONAL to the ? of the meal

Back 26

Phase III



Caloric content

Front 27

After feeding--

1/2 of slow waves are associated with spikes and contractions resembling Phase ? of the MMC.

Both propulsive and segmenting contractions occur but ? predominates

Back 27

phase II


Segmentation Predominates

Front 28

During peristalsis--

describe what happens in the RECEIVING SEGMENT

Back 28

Excitatory motor neurons to LONGITUDINAL SMOOTH MUSCLE ---> ON


INHIBITATORY neurons to CIRCULAR MUSCLES -->ON

Front 29

During peristalsis

describe what happens in the PROPULSIVE SEGMENT

Back 29

excitatory neurons to LONGITUDINAL smooth muscle --> OFF

Inhibitory neurons to CIRCULAR smooth muscle --> OFF

Front 30

As inhibitory motor neurons to CIRCULAR muscle are turned OFF -- contractions occur synchronized with the ? and with activation of EXCITATORY motor neurons.

Back 30

SLOW WAVES

Front 31

Mixing of intestinal contents occurs in ? segments to enhance digestion and absorption.

Back 31

Receiving

Front 32

Intestinal Obstruction can result in ? --where motility is impaired and normal bowel sounds are absent.

Back 32

Dynamic or Adynamic Ileus

abdominal distention is the hallmark symptom

Front 33

Several brain stem nuclei can initiate emesis. many emetic drugs act on the area ? of the ?

Back 33

Postrema of the Medulla

Front 34

As emesis occurs--

contents mvoe through a relaxed LES and into the esophagus as ? pressure INCREASES and ? pressure decreases.

Back 34

Abdominal pressure INCREASE


intra-thoracic pressure DECREASE

Front 35

? is a CYCLIC FILLING and EMPTYING of the esophagus. Contents return to the stomach and the cycle is repeated.

Back 35

Retching

Front 36

Describe the motility in the Large Intestine --

slow waves?

frequency gradient?

phases?

Back 36

Variable slow wave frequencey


NO proximal to distal Frequency Gradient


NO PHASE 3 of MMC

Front 37

Stimulation of the ? causes contractile activity in ileum and relaxation of ileocecal sphincter.

ileal contents move into proximal colon

Back 37

GASTROILEAL reflex

Front 38

What are the two primary types of motor activity that the COLON exhibits?

Back 38

Non-propulsive Segmentation


Mass Peristalsis

Front 39

? occurs 1-3 times daily. Colon contents are shifted over distance.

Back 39

Mass peristalsis

Front 40

True or False

SEGMENTING contractions CEASE during MASS MOVEMENTS.

Back 40

True

Front 41

Filling of the rectum causes distention and stimulates the ? to relax as the urge to defecate occurs.

Back 41

INTERNAL ANAL SPHINCTER

Front 42

Eating a meal stimulates the ? reflex and the release of ? and ? which results in NON-PROPULSIVE SEGMENTATION and MASS PERISTALSIS.

Back 42

Gastrocolic Reflex

release of CCK and GASTRIN

Front 43

? secretion facilitates transport through the anal canal.

Back 43

Mucous

Front 44

Describe the two anal sphincters neural control

Back 44

Internal anal sphincter --> Parasympathetic stimulation causes RELAXATION


External anal sphincter --> Sympathetic via α-adrenergic receptors stimulation => Constriction

Front 45

increased ? pressure and flexion at the hips facilitates defication.

What are the effects of Valsalva on cardiovascular function?

Back 45

increase ABDOMINAL pressure


increase blood flow and then lead to DECREASE venous return => lower Cardiac output

Front 46

Describe the events occurring in the colon associated with continence.

Back 46

contraction of puborectalis

maintenance of anorectal angle

contraction of anal sphincters

Front 47

Describe the events occurring in the colon associated with defecation.

Back 47

relaxation of puborectalis

straightening of anorectal angle

relaxation of anal sphincters