Upper Gi Physiology And Swallowing

Front 1

What are the two components of the extrinsic GI nervous system?

Back 1

Sympathetic and parasympathetic nervous systems

Front 2

What is the name of the intrinsic GI nervous system?

Back 2

Enteric nervous system

Front 3

What are the three ganglia of the sympathetic nervous system to the gut?

Back 3

Celiac ganglion, superior mesenteric ganglion, inferior mesenteric ganglion.

Front 4

What are the two plexi associated with the intrinsic nervous system?

Back 4

Myenteric (Auerbach's) plexus and Submucosal (Meissner's) plexus

Front 5

GI function is regulated by __________ and nervous input. These two entities regulate secretory activity and motility

Back 5

Hormonal

Front 6

What sympathetic ganglion is associated with the organs of the foregut?

Back 6

Celiac ganglion

Front 7

What sympathetic ganglion is associated with the organs of the midgut?

Back 7

Superior mesenteric ganglion

Front 8

What sympathetic ganglion is associated with the organs of the hindgut?

Back 8

Inferior mesenteric ganglion

Front 9

Parasympathetic innervation to the foregut and midgut is from the _______.

Back 9

Vagus nerve

Front 10

Parasympathetic innervation to the hindgut is from the ___________ (Spinal levels __ to __)

Back 10

Pelvic splanchnic nerves, S2-S4

Front 11

The ____________ plexus is located between the longitudinal and circular layers of muscle in the tunica muscularis and exerts control over the digestive tract motility.

Back 11

Myenteric (Auerbach's)

Front 12

The _________ plexus is buried in the submucosa. Its principal role is in sensing the environment within the lumen, regulating GI blood flow and controlling epithelial cell function.

Back 12

Submucosal (Meissner's)

Front 13

In regions where sensing the environment within the lumen and regulating GI blood flow/epithelial cell function are functions carried out to a MINIMAL degree, the ___________ plexus is sparse and may actually be missing.

Back 13

Submucosal (Meissner's)

Front 14

The preganglionic fibers of the _____________ nervous system synapse with ganglion cells located in the enteric nervous system. Their cell bodies, in turn, send signals to smooth muscle, secretory and endocrine cells.

Back 14

Parasympathetic

Front 15

These afferent nerves relay information from receptors located in the mucosa and in smooth muscle to higher centers. This may result in ____________ (long) reflexes.

Back 15

Vagal afferents, vasovagal

Front 16

These reflexes to the digestive system involve a sensory neuron sending information to the brain, which integrates the signal and then sends messages to the digestive system. While in some situations, the sensory information comes from the GI tract itself; in others, information is received from sources other than the GI tract. When the latter situation occurs, these reflexes are called feedforward reflexes. This type of reflex includes reactions to food or danger triggering effects in the GI tract. Emotional responses can also trigger GI response such as the butterflies in the stomach feeling when nervous. The feedforward and emotional reflexes of the GI tract are considered cephalic reflexes.

Back 16

Long reflexes (vasovagal reflexes)

Front 17

These reflexes occur when the enteric nervous system relays information up and down the length of the GI tract. They regulate secretion, motility and growth.

Back 17

Short reflexes

Front 18

Communication within the myenteric and submucosal plexi is referred to as _____________ reflexes

Back 18

Intramural/local reflexes

Front 19

These specialized smooth muscle cells are derived from mesenchyme and are associated with smooth muscle cells and enteric neurons in the myenteric plexus. They have pacemaker ability.

Back 19

Interstitial cells of Cajal (ICC)

Front 20

These cells are responsible for making slow waves, which control the impulse to contract constantly. They receive humoral/neuronal/hormonal input, which allows for spike potentials. They are found in the ________, but not in the body of the esophagus.

Back 20

Interstitial cells of Cajal (ICC), lower esophageal sphincter

Front 21

Smooth muscle cells in the GI tract are associated with one another via _______ junctions, which means that, following an action potential, a single area of the GI system can respond as a unit, causing regionalized contractions

Back 21

Gap

Front 22

The pharynx, upper esophagus and external anal sphincters are comprised of _________ muscle.

Back 22

Striated

Front 23

The majority of the GI tract (save the pharynx, upper esophagus and external anal sphincters) is comprised of __________ muscle.

Back 23

Smooth

Front 24

This type of smooth muscle contraction is slow and sustained, lasting minutes to hours. It occurs in non-busy regions such as the sphincters and orad stomach.

Back 24

Tonic

Front 25

This type of smooth muscle contraction is rapid, lasting only seconds. It occurs in the esophagus, antral stomach and small intestine.

Back 25

Phasic

Front 26

What are the three segments of the esophagus?

Back 26

Cervical, thoracic, abdominal

Front 27

Normally, the lower esophageal sphincter straddles the _______________ so that its upper half is in the chest and the lower half is below the diaphragm in the abdominal cavity.

Back 27

Esophageal hiatus

Front 28

Unlike the rest of the gut, the esophagus has no true ______ outer layer, but is covered by a thin and poorly defined layer of connective tissue.

Back 28

Serosal

Front 29

What kind of epithelial tissue makes up the esophagus?

Back 29

Stratified squamous

Front 30

Compared to the rest of the gut, the esophagus has relatively few __________, and its ___________ function is limited.

Back 30

Glands, secretory

Front 31

Where does the stratified squamous epithelium of the esophagus become the simple columnar epithelium of the stomach?

Back 31

Lower esophageal sphincter

Front 32

What are the four phases of swallowing?

Back 32

Oral, oropharangeal, esophageal, gastric

Front 33

During which phase of swallowing does the action become involuntary?

Back 33

Oropharyngeal

Front 34

Swallowing in the oral phase involves striated/smooth muscle with ____ neurotransmission via nicotinic receptors.

Back 34

Striated, ACh

Front 35

Motor neurons from the ____ (trigeminal, facial) and _______ (nucleus ambiguous, hypoglossal) and cervical spine C1-2 (CNs V, VII, XI and X) are involved with the oral phase of swallowing.

Back 35

Pons, medulla

Front 36

What is the preparatory phase of the oral phase of swallowing?

Back 36

Mastication

Front 37

The bolus entering the oropharynx while the dorsal tongue remains seated against the palate to prevent retrograde movement of the bolus describes the ___________ portion of the oral phase of swallowing.

Back 37

Transfer

Front 38

________ input to the oral cavity is critical in the expulsion of noxious material and sensing when a bolus is properly sized for transport. This input comes from the tract of the nucleus ______________

Back 38

Sensory, solitarius

Front 39

Which tract has central control of swallowing (swallowing pattern generator)?

Back 39

Nucleus solitarius

Front 40

The period of swallowing that lasts from the time the bolus enters the pharyngeal cavity until it exits the upper esophageal sphincter is known as the ___________ phase.

Back 40

Oropharyngeal phase

Front 41

The oropharyngeal phase of swallowing involves striated/smooth muscle with ACh+ neurotransmission via __________ receptors.

Back 41

Striated, nicotinic

Front 42

Motor neurons from the pons (________), medulla (nucleus ________, ___________ nucleus) and cervical spine C1-2 (CN V, IX and XII) are involved with the oropharyngeal phase of swallowing.

Back 42

Trigeminal, ambiguous, hypoglossal

Front 43

___________ from pharynx coordinate activity in medulla to stimulate peristalsis and inhibit respiration and speech.

Back 43

Afferents

Front 44

At what spinal level is the upper esophageal sphincter?

Back 44

C5-6

Front 45

To what muscle does the location of the upper esophageal sphincter respond?

Back 45

Cricopharyngeus

Front 46

This portion of the esophagus controls lumenal volume, remains closed unless involved in bolus transport, and opens in response to pressure from a bolus, due to inhibition of tone, contraction of strap muscles and in response to lower esophageal pressure (belching).

Back 46

Upper esophageal sphincter

Front 47

The upper ___________ muscles pull the palate down to keep the nasopharynx from being exposed to food during swallowing. The ________ keeps the food from reentering the oral cavity.

Back 47

Constrictor, tongue

Front 48

The esophageal phase of swallowing takes place in the 18-20 cm between the lower _______________ to the ______________.

Back 48

Upper esophageal sphincter, lower esophageal sphincter

Front 49

In the ____________ portion of the esophagus, there is peristaltic activity that is influenced by the ____________ (mediated by the ________ nerve). It is excitatory via ACh and nicotinic cholinergic receptors

Back 49

Cervical, parasympathetic nervous system, vagus

Front 50

Which plexus/plexi is/are involved with the cervical portion of the esophagus? (Purpose unknown)

Back 50

Myenteric plexus

Front 51

In this portion of the esophagus (esophageal phase of swallowing), there is peristaltic activity with PNS fibers from the dorsal medial nucleus. Vagal afferents are involved in peristalsis; splanchnic afferents are involved in nocioception and sensory.

Back 51

Thoracic

Front 52

Which plexus/plexi is/are involved with the thoracic portion of the esophagus?

Back 52

Myenteric and submucosal

Front 53

The myenteric plexus of the thoracic esophagus has excitatory motor neurons containing ____/substance P (cholinergic) and inhibitory motor neurons containing ____/NO (nonadrenergic noncholinergic)

Back 53

ACh, VIP

Front 54

Afferent neurons in both plexi in the thoracic esophagus respond to distension with ________ aborally and ________ orally.

Back 54

Relaxation, contraction

Front 55

Which sphincter is found in the abdominal portion of the esophagus?

Back 55

Lower esophageal sphincter

Front 56

Vagal pathways going to the abdominal portion of the esophagus originate in which nucleus? Both inhibitory and excitatory cholinergics synapse on myenteric plexus.

Back 56

Dorsal motor nucleus of vagus

Front 57

Input from esophageal sensory neurons descend to affect __________ neurons in the myenteric plexus (inhibitory)

Back 57

Nitrogenic

Front 58

Input from gastric sensory neurons ascend to affect _________ receptors in the myenteric plexus (stimulatory)

Back 58

Cholinergic

Front 59

Primary/secondary peristalsis occurs when the bolus enters the esophagus during swallowing. It forces the bolus down the esophagus and into the stomach in a wave lasting about 8–9 seconds. The wave travels down to the stomach even if the bolus of food descends at a greater rate than the wave itself, and will continue even if for some reason the bolus gets stuck further up the esophagus.

Back 59

Primary peristalsis

Front 60

In the event that the bolus gets stuck or moves slower than the primary peristaltic wave (as can happen when it is poorly lubricated), stretch receptors in the esophageal lining are stimulated and a local reflex response causes a ____________ peristaltic wave around the bolus, forcing it further down the esophagus. These waves will continue indefinitely until the bolus enters the stomach.

Back 60

Secondary

Front 61

The process of peristalsis is controlled by __________________, which is the swallowing center. It coordinates activation of vagal nuclei with other centers such as the respiratory centers.

Back 61

Medulla oblongata

Front 62

This wave of peristalsis is elicited by esophageal distention; it is a reflex involving esophageal afferents and confined peristaltic activity in the esophagus that is elicited by local sensory nerves.

Back 62

Secondary peristalsis

Front 63

This wave of peristalsis is swallow-induced peristalsis due to sequential activation of motor neurons in the nucleus ambiguus.

Back 63

Primary peristalsis

Front 64

Thoracic peristaltic activity is directed by swallowing program center in the ____________.

Back 64

Nucleus tractus solitarius

Front 65

This portion of the esophagus (upper or lower) is innervated by extrinsic nerves and is comprised of striated muscle.

Back 65

Upper esophagus

Front 66

This portion of the esophagus is innervated by extrinsic and intrinsic nerves and is comprised of smooth muscle (upper or lower)

Back 66

Lower

Front 67

Diseases of myoneuronal junction, striated muscle or stroke will affect the ___________ and upper ___________ during swallowing.

Back 67

Pharynx, esophagus

Front 68

Diseases of enteric nerves or smooth muscle will affect __________ peristalsis and tone of the ___________.

Back 68

Lower, lower esophageal sphincter

Front 69

Esophageal peristalsis and relaxation of the lower esophageal sphincter induced by swallow result from the excitation of receptors in the ___________. The afferent stimulus travels to the sensory nucleus, the nucleus __________. A programmed set of events from the dorsal _________ nucleus and the nucleus _________ mediates esophageal peristalsis and sphincter relaxation.

Back 69

Pharynx

Front 70

Vagal efferent fibers communicate with _______ neurons that mediate LES relaxation

Back 70

Myenteric

Front 71

Postganglionic neurotransmitters that induce relaxation of the LES are _____ and _____.

Back 71

NO/VIP

Front 72

What is the principal mechanism of reflux? It shares the same efferent pathway as the swallow reflex. The afferent signals for this may originate in the pharynx, larynx or the stomach.

Back 72

Transient lower esophageal relaxation

Front 73

What is the efferent pathway for the transient lower esophageal relaxation mechanism?

Back 73

Vagus nerve

Front 74

What postganglionic neurotransmitter does the vagus nerve use to cause LES relaxation?

Back 74

Nitrous oxide

Front 75

Inhibitory neurons of the LES are normally active/inactive, but are active/inactive for a swallow.

Back 75

Inactive, active

Front 76

Tone of the LES is independent/dependent of/on neural influences and may be influenced by _____________.

Back 76

Interstitial cells of Cajal.

Front 77

Myogenic tone of the LES responds to ________ to stimulate contraction.

Back 77

Stretch

Front 78

Cholinergic input is stimulatory, and mediates contraction in response to increased _______________ after peristaltic associated relaxation.

Back 78

Intraabdominal pressure

Front 79

Nitergic input is inhibitory and mediates relaxation in response to ________ via NO.

Back 79

Deglutition/swallowing

Front 80

__________ quantifies intraluminal esophageal and LES pressure during swallowing to detect abnormalities of peristalsis and sphincter relaxation.

Back 80

Manometry

Front 81

The orad portion of the stomach plays a small part in gastric emptying, but is primarily used for ___________.

Back 81

Accommodation

Front 82

The caudad portion of the stomach is primarily responsible for ____________.

Back 82

Gastric emptying

Front 83

Another term for receptive relaxation of the road stomach is __________.

Back 83

Vaso-vagal reflex.

Front 84

This type of orad relaxation occurs in response to each swallow.

Back 84

Receptive relaxation/vago-vagal reflex

Front 85

This type of orad relaxation is caused by distention; it is a vago-vagal reflex combined with a local reflex.

Back 85

Adaptive relaxation

Front 86

This type of orad relaxation is a local reflex mediated by hormones and stimulated by nutrients.

Back 86

Feedback relaxation

Front 87

Contraction of inspiratory muscles increases/decreases intraesophageal pressure (Favors GER)

Back 87

Decreases

Front 88

_______________ increases contraction in response to increase in gastroesophageal pressure gradients.

Back 88

Crux diaphragm

Front 89

Most swallows occur during inspiration/expiration, but if many swallows occur in a row, respiration may resume in an inspiration/expiration phase.

Back 89

Expiration, inspiration