Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

FHB - GI/Metabolism - Exam 3 > Lecture 4 - Swallowing Reflex > Flashcards

Lecture 4 - Swallowing Reflex Flashcards

1
Q

Which phase of swallowing is reflexive/voluntary?

What occurs during swallowing?

What is inhibited?

A

Initiated voluntarily

After that = REFLEX control

propel food from mouth to pharynx – and then to stomach.

  1. It inhibits respiration 2. inhibits food entrance into trachea while swallowing.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Where is the swallowing center located?

When is this activated?

A

Medullar & lower ponds

Activated when TOUCH RECEPTORS near the opening of the pharynx are stimulated

(afferent limb of the reflex)

Motor impulses from swallowing center travel to the pharynx and upper esophagus (via cranial nerves) and to the remaining esophagus (via vagal motor neurons).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the main afferent limb of the swallowing reflex?

Where does this travel?

A
  1. Stretch receptors in the pharynx
  2. Travels to the swallowing center in the
    medulla/lower pons
  3. travels to the respiratory and speech centers in the medulla/cortex
  4. then to the esophagus (vagal)

and pharynx & upper esophagus ( motor neurons –> cranial nerves)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the 3 phases in swallowing?

Briefly describe what occurs in each.

A
  1. Oral
    Tongue forces a bolus of food back towards the pharynx
    - activates stretch receptors
    ** includes involuntary swallowing reflex**
  2. Pharyngeal
    - INVOLUNTARY & FAST
    - soft palate pulled up & palatopharyngeal fold moves in
    NARROW PASSAGE CREATED
    - prevents reflux into nasopharynx
    - epiglottis closes larynx momentarily (no breathing) = prevent food from entering trachea
  3. Esophageal
  • swallowing reflex & enteric nervous system
  • UES & LES propel food and protect airways from swallowed material
  • protect from acidic gastric reflux
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

When food approaches the UES, what areas contract and what areas relax?

What is initiated at the pharynx?

A
  1. UES relaxes
    - receives food bolus
  2. Pharynx contracts
    - enhances the propulsion of food into the esophagus
  3. PERISTALTIC WAVE is initiated
    - forces bolus through relaxed UES

-After the bolus crosses the UES (pharyngeal phase) the swallowing reflex closes the sphincter – prevents reflux into the pharynx.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the 2 controls of the Esophageal Phase of swallowing?

A
  1. Swallowing reflex

2. Enteric Nervous System

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the 2 main functions of the esophagus, UES, and LES?

A
  1. Propel food from pharynx to stomach
  2. Sphincters protect airway from swallowed material
    - ptoect esophagus from acidic gastric reflux
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What closes the sphincter once the UES is crossed by the bolus (pharyngeal phase)

A

Swallowing Reflex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What propels food down the esophagus?

A

Primary Peristaltic Contraction (wave)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What action initiates the SECONDARY peristalsis?

What Mediates this action?

A
  1. Distension of esophagus by moving bolus

2. Enteric Nervous System

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What mediates the relaxation of the LEW as the food bolus approaches it by peristaltic waves?

What hormones are involved?

A

Peptidergic fibers in vagus nerve that release VIP & NO

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

At the same time that the LES relaxes, what other region relaxes?

What is this phenomenon called?

Is pressure increased or decreased?

A
  1. Orad region of stomach relaxes
  2. called RECEPTIVE relaxation
  3. Pressure is REDUCED in Orad Stomach
    - moves bolus into stomach
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

When does LES return to high resting tone?

Where is the pressure higher during this:

  1. Esophagus
  2. Orad stomach
A

When bolus enters the ORAD stomach, LES contracts

= HIGH RESTING TONE

Pressure is higher at the SPHINCTER than the esophagus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What procedure removes the relaxation associated with the proximal/ORAD stomach?

A

VAGOTOMY

  • no receptive relaxation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What two problems are created on account of the fact that the intraesophageal pressure is LESS than the abdominal pressure?

A
  1. Keeping air out of UES

2. Keeping gastric acidic contents out at LES

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Increases in intra-abdominal pressure lead to what clinical problem?

A

Gastroesophageal Reflux
GERD

  • especially in pregnant and obese patients:
    LES becomes leaky and heartburn is common
17
Q

What is the main role of the ESOPHAGUS

A

TRANSPORT of food from oral area to the stomach

  • mucosa is not well developed in the upper esophagus
  • epithelial layers seen in the INITIAL area of esophagus and at the anal sphincter
18
Q

What type of cells are found in the MIDDLE Esophagus?

In the gastric area?

A
  1. Stratified Squamous Epithelia (mucosa)
  • as well as the anal sphincter
  • handles frictional force
  1. Columnar Epithelial
19
Q

What glands in the esophagus release mucous?

A

Cardiac Glands!

  • near the stomach
20
Q

What cells are absent in patients with CHRONIC gastroesophageal reflux?

Why is this problematic?

A

NO SQUAMOUS EPITHELIA

changes squamous to simple columnar (intestinal cells)
–> metaplasia due to long standing GERD

Problematic because the goblet cells reside in the COLUMNAR cells

  • more mucous secretions
  • higher risk of cancer
21
Q

What is Barret’s Disease?

How is this different from Intestinal Metaplasia?

A

BARRET’s - (metaplasia) in the cells of the lower portion of the esophagus.

It is characterized by the replacement of the normal stratified squamous epithelium lining of the esophagus by simple columnar epithelium with goblet cells (which are usually found lower in the gastrointestinal tract).

Intestinal metaplasia only means that the cells have changed shape, but does not indicate as to whether GOBLET cells are present

(TEST)

22
Q

What is a common symptom of Gastroesophageal Reflex
associated with pregnancy & obesity (higher intra-abdominal pressure)?

What is the condition called once it is long term?

A
  1. acid in the esophagus will activate pain fibers
    - LES is unable to prevent gastric acid from reflexing back

= pain, discomfort, etc

  1. GERD
23
Q

How is GERD treated?

(2)

Which of these is most commonly prescribed and why?

A
  1. H2 receptor antagonists
    - ranitidine to reduce gastric acid secretion

BUT only blocking one specific receptor, thus acidic gastric secretions still occur elsewhere

  1. Proton pump inhibitors
    – example omeprazole.

** more commonly prescribed since it directly stops the acidic secretions = MORE EFFECTIVE

24
Q

What is a Hiatal Hernia?

What muscles are involved?

What are the major symptoms?

What no longer works that leads to the above symptoms?

A

Upper portion of stomach protrudes into the chest cavity through an opening of the DIAPHRAGM called the esophageal hiatus.

This opening usually is large enough to accommodate the esophagus alone.

  1. Muscle weakening of diaphragm
  2. Pain, Acid Reflux,
  3. LES
    DOES NOT
    WORK
  • 60% of ppl. over 60
  • obesity, weight lifting, constipating
  • genetic predisposition
25
Q

In Hiatal Hernia, pressure is higher in the esophagus or in the stomach?

A

Higher in the stomach!

Pushes the stomach through the esophageal hiatus

26
Q

What is Achalasia?
What is no loner functioning?

What are some symptoms?

What is the Treatment most often?

A
  1. Smooth muscle layer does not have normal peristalsis
    - LES does not relax in response to swallowing
  2. Dysphagia (difficulty swallowing), regurgitation, chest pain
  3. TX: surgical (myotome along esophagus)
  • Ca channel blockers
  • botox injections in LES (to relax)
  • muscle relaxants
27
Q

In achalasia, which nervous system is no longer functioning?

A

MYENTERIC PLEXUS

  • thus LES is not functioning properly MAIN ISSUE
28
Q

What medication can be given to inhibit the vagal acetylcholine muscarinic receptors for Achalasia?

What does this treat mainly?

What if this does not change LES function?

A
  1. ATROPINE
    - inhibit vagal stimulation
  2. PAIN stimulation
    - relieved by atropine
  3. if LES does not RELAX after ATROPINE, this signals that the nerve is damaged

the MYENTERIC PLEXUS is damaged!

29
Q

What are the 2 main issues of Achalasia?

A
  1. Pain receptors being stimulated
  2. LES is tonically contracted
    - atropine blocks the smooth muscle pain receptors, but if LES is still contracted this means the myenteric plexus is damaged
30
Q

What are some causes of vomiting? Which is the most important?

A
  1. Tactile (stimulation of back of throat)
  2. Irriation/distension of stomach/duodenum
  3. ELEVATED INTRACRANIAL PRESSURE ***
    = cerebral hemorrhage
  4. Motion Sickness –> rotation of head
  5. Chemical Agents
  6. Emotional Factors
31
Q

What is reverse peristalsis?

A

Vomiting

32
Q

Where is the vomiting center for the Reflex located?

What occurs during this reflex?
(where does pressure increase)

What contracts and what relaxes:

  1. LES
  2. UES
  3. Pyloris
  4. Antrum

How is this different from retching?

A
  1. Reticular formation in pons
  2. Reverse peristalsis & relaxation of pyloric sphincter & stomach
  3. LES & UES relax, pyloris and antrum contract
  4. Retching: UES remains closed
    - gastric content does NOT ENTER PHARYNX (in esophagus)
33
Q

What are the 4 main changes in vomiting?

A
  1. Pyloric sphincter relaxed
  2. Increased intra-abdominal pressure
  3. Muscles in abdomen contract
  4. EVERYTHING IS RELAXED: LES, UES, and esophagus
34
Q

How does the valsalva maneuver help a patient with Achalasia?

A

Increased intraesophageal pressure, resulting from increased intrathoracic pressure during valsalva maneuver

  • can force OPEN the LES and help allow the passage of food bolus into the stomach

FHB - GI/Metabolism - Exam 3 (21 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions