Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
47 Cards in this Set
- Front
- Back
List the sequence of events for the Oropharyngeal Phase of Swallowing.
5 steps |
elevation of tongue
closure of nasopharynx relaxation of UES Closure and protection of airway pharyngeal peristalsis |
|
Sensory input to the swallowing center is via branches of what cranial nerves?
Where is the swallowing center located? |
CN 5 , 9 , 10
medulla |
|
Motor output for swallowing from the medulla comes from what Cranial Nerves?
|
CN 5 , 9 , 10 , 12
|
|
The ? follows pharyngeal contraction.
|
Primary Peristaltic Wave
|
|
When does the LES relax in swallowing?
|
Bolus enters into the esophagus
|
|
? 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.
|
Secondary Peristalsis
|
|
True or False
The resting state of LES pressure > intragastric pressure. |
True
|
|
What is the vagal neural mechanism for INCREASED LES pressure?
(contraction) |
Vagal Excitatory Fibers
release ACh --> bind to M3 receptor on smooth muscle => CAUSE CONTRACTION |
|
Vagal inhibitory fibers for the LES release what type of neurotransmitters?
|
Non-Adrenergic Non-cholinergic (NANC)
|
|
What is the sympathetic stimulation for increased LES pressure?
|
Norepinephrine
=> bind to α-receptors on Postganglionic Myesteric Excitatory neurons => these neurons release ACh => CAUSE CONTRACTION |
|
What is Dysphagia?
What is GERD? |
difficulty swallowing
Gastroesophageal Reflux --gastric reflux into esophagus due to problems with LES |
|
What causes the RECEPTIVE RELAXATION of the Proximal Stomach?
When does this occur? |
Vago-Vagal Reflex
during swallowing |
|
? prevents increased INTRAGASTRIC PRESSURE with filling.
Compliance of the gastric muscle is dependent upon intact ? |
Accomodation
Vagal fibers ---VAGO-VAGAL REFLEX |
|
True or False
Contractions of the FUNDUS are INDEPENDENT of gastric slow waves |
True
|
|
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. |
Triphasic
Amplitude |
|
? of contents results in shearing (grinding action). This helps reduce the food particle size.
|
Retropulsion
|
|
The emptying of isotonic non-caloric contents is DIRECTLY PROPORTIONAL to the ?
|
Gastric Volume
|
|
ACID in the DUODENUM
=> SLOWS GASTRIC EMPTYING via ? reflex => release of ? |
Enterogastric Refelex
Secretin (cause HCO3- release) |
|
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. |
True
|
|
Typically particles greater than ? are not emptied into the duodenum. This underscores the importance of actions of the ANTRUM on RETROPULSION and SHEARING.
|
1 mm
|
|
During fasting repeated cycles of ? occur.
|
Migrating Motor Complexes (MMC)
|
|
Describe the cyclic pattern of the MMC:
Phase I 45-60 min Phase II 30-45 min Phase III 5-10 min |
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 |
|
The plasma concentration of ? increases prior to PHASE III
|
Motilin
|
|
True or False
The Migrating motor Complexes begin in the GASTRIC ANTRUM and end in the LARGE COLON. |
False
Cycle begins in the Gastric ANTRUM ends in the ILEUM |
|
Absence of MMC activity causes ? in the gastric antrum and small intestines.
|
Bacterial overgrowth
|
|
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 |
Phase III
Caloric content |
|
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 |
phase II
Segmentation Predominates |
|
During peristalsis--
describe what happens in the RECEIVING SEGMENT |
Excitatory motor neurons to LONGITUDINAL SMOOTH MUSCLE ---> ON
INHIBITATORY neurons to CIRCULAR MUSCLES -->ON |
|
During peristalsis
describe what happens in the PROPULSIVE SEGMENT |
excitatory neurons to LONGITUDINAL smooth muscle --> OFF
Inhibitory neurons to CIRCULAR smooth muscle --> OFF |
|
As inhibitory motor neurons to CIRCULAR muscle are turned OFF -- contractions occur synchronized with the ? and with activation of EXCITATORY motor neurons.
|
SLOW WAVES
|
|
Mixing of intestinal contents occurs in ? segments to enhance digestion and absorption.
|
Receiving
|
|
Intestinal Obstruction can result in ? --where motility is impaired and normal bowel sounds are absent.
|
Dynamic or Adynamic Ileus
abdominal distention is the hallmark symptom |
|
Several brain stem nuclei can initiate emesis. many emetic drugs act on the area ? of the ?
|
Postrema of the Medulla
|
|
As emesis occurs--
contents mvoe through a relaxed LES and into the esophagus as ? pressure INCREASES and ? pressure decreases. |
Abdominal pressure INCREASE
intra-thoracic pressure DECREASE |
|
? is a CYCLIC FILLING and EMPTYING of the esophagus. Contents return to the stomach and the cycle is repeated.
|
Retching
|
|
Describe the motility in the Large Intestine --
slow waves? frequency gradient? phases? |
Variable slow wave frequencey
NO proximal to distal Frequency Gradient NO PHASE 3 of MMC |
|
Stimulation of the ? causes contractile activity in ileum and relaxation of ileocecal sphincter.
ileal contents move into proximal colon |
GASTROILEAL reflex
|
|
What are the two primary types of motor activity that the COLON exhibits?
|
Non-propulsive Segmentation
Mass Peristalsis |
|
? occurs 1-3 times daily. Colon contents are shifted over distance.
|
Mass peristalsis
|
|
True or False
SEGMENTING contractions CEASE during MASS MOVEMENTS. |
True
|
|
Filling of the rectum causes distention and stimulates the ? to relax as the urge to defecate occurs.
|
INTERNAL ANAL SPHINCTER
|
|
Eating a meal stimulates the ? reflex and the release of ? and ? which results in NON-PROPULSIVE SEGMENTATION and MASS PERISTALSIS.
|
Gastrocolic Reflex
release of CCK and GASTRIN |
|
? secretion facilitates transport through the anal canal.
|
Mucous
|
|
Describe the two anal sphincters neural control
|
Internal anal sphincter --> Parasympathetic stimulation causes RELAXATION
External anal sphincter --> Sympathetic via α-adrenergic receptors stimulation => Constriction |
|
increased ? pressure and flexion at the hips facilitates defication.
What are the effects of Valsalva on cardiovascular function? |
increase ABDOMINAL pressure
increase blood flow and then lead to DECREASE venous return => lower Cardiac output |
|
Describe the events occurring in the colon associated with continence.
|
contraction of puborectalis
maintenance of anorectal angle contraction of anal sphincters |
|
Describe the events occurring in the colon associated with defecation.
|
relaxation of puborectalis
straightening of anorectal angle relaxation of anal sphincters |