Dysphagia and neural control of swallowing, digestive and respiratory systems

Question 1

What are signs of dysphagia?

Answer 1

reflux from esophagus or stomach; difficulty chewing food; coughing while swallowing food; struggle with starting a swallow; food sticking in the throat; hard to control food in the oral cavity;

Question 2

Oropharyngeal Dysphagia consists of ________ and __________ .

Answer 2

penetration; aspiration

Question 3

What is penetration?

Answer 3

foreign material enters the airway and makes contact to the true VFs

Question 4

What is aspiration?

Answer 4

foreign material enters the airway and passes the true VFs; known as tracheal aspiration

Question 5

Dysphagia is defined as _________ .

Answer 5

struggle to moving food from mouth to the stomach

Question 6

What are causes of dysphagia?

Answer 6

malnutrition, dehydration, and AP (aspiration pneumonia)

Question 7

What is dysphagia a symptom of?

Answer 7

COPD, HNC, developmental disability

Question 8

What are classic signs of AP (aspiration pneumonia)?

Answer 8

cyanosis; hypotension; hypoxemia (can lead to death); gastric material in the oropharynx; wheezing; coughing; shortness of breath; pulmonary edema;

Question 9

What are the four steps involved in neural control of swallowing?

Answer 9

afferent input (sensory information from vision, olfaction, and audition); medullary nuclei in the brainstem; efferent output (motor nuclei send messages to muscles involved in swallowing); descending cortical and subcortical inputs

Question 10

Regarding afferent input in the neural control of swallowing, what steps are involved?

Answer 10

Cephalic control —> oral phase —- > initiation of pharyngeal swallow —- > modulation of pharyngeal swallow

Question 11

Regarding the second phase of neural control of swallowing, the medullary nuclei are known as the __________ .

Answer 11

central pattern generator in the brainstem

Question 12

The central pattern generator has two parts:

Answer 12

dorsal swallowing group (programming component) and ventral swallowing group (motor component)

Question 13

What is pneumonitis? What causes it?

Answer 13

lung inflammation caused by exposure to chemicals, irritants, or allergens as well as a side effect of a medical procedure or a medication (i.e., iatrogenic)

Question 14

What is pneumonia? What causes it?

Answer 14

lung infection caused by bacterial/viral pathogen from the oropharynx

Question 15

What is dysphagia related aspiration pneumonia?

Answer 15

features of pneumonia; patient has dysphagia; infiltrates found in the gravity dependent parts of the lungs

Question 16

What is non-dysphagia related aspiration pneumonia?

Answer 16

Features of pneumonia; no dysphagia symptoms; can conceivably be related to GER or vomit (i.e., emesis), community acquired pneumonia, hospital acquired pneumonia

Question 17

What are classic signs of massive AP?

Answer 17

fever, leukocytosis (i.e., increasd white blood cell count, cough, sputum (combo of mucous and saliva) production, inspiratory crackles; infiltrates (e.g., pus, blood, protein), in lung on chest x-ray (white appearance on chest x-ray

Question 18

How does foreign material interfere with gas exchange?

Answer 18

blocks small airways, reduces amount of surfactant which inflammes the lungs; consequently, atelectasis (i.e., collapse of alveoli) can occur, thereby increasing likelihood of pneumonia

Question 19

Regarding the third phase of neural control of swallowing, efferent output refers to __________ .

Answer 19

cranial nerves (CN 5, 7, 8-12) and motor nuclei and cervical segments (C1-C3)

Question 20

What motor nuclei are involved in efferent output (i.e., third phase of neural control of swallowing)?

Answer 20

trigeminal nucleus (pons), facial nucleus (pons), nucleus ambiguus (medulla), hypoglossal nucleus (medulla), spinal nucleus (C1-C3), dorsal motor nucleus of CN X

Question 21

Modulation of swallowing depends on

Answer 21

type of material to be swallowed; properties of bolus to be swallowed; swallowing task

Question 22

Regarding the fourth phase of neural control of swallowing, the cortical regions involved in swallowing are

Answer 22

primary sensorimotor cortex, premotor cortex, anterior insula (also related to emotional processing)

Question 23

Regarding the fourth phase of neural control of swallowing, the subcortical circuits involved are

Answer 23

basal ganglia, internal capsule, hypothalamus, midbrain ventral tegmental field (facilitates reflexive swallow)

Question 24

Describe the lateralization of swallowing.

Answer 24

It is a tendency for one hemisphere to be greatly involved in swallowing. Swallowing is controlled mainly by the left hemisphere. However, the right hemisphere is involved too. People who have right hemisphere dominant showed stronger lateralization than people who were left hemisphere dominant; thus, such individuals have the RT hemisphere be more responsible for the RT. Left hemisphere dominant have bilateral lateralization. Swallowing should be thought of as involving both hemispheres (i.e., bilateral)

Question 25

What regions of the brain are not important in activating the muscles involved in the pharyngeal and esophageal stages of swallowing?

Answer 25

cortical and subcortical regions

Question 26

What region of the brain plays a role in the initiation of swallowing and level of neuromuscular activity?

Answer 26

cerebral cortex

Question 27

What are the functions of the digestive system?

Answer 27

Removes waste; breaks down ingested material and absorbs nutrients from such material

Question 28

What are the organs of the digestive system?

Answer 28

Large intenstine, anus, mouth, esophagus, small intestine, and stomach

Question 29

What are the accesory organs of the digestive system?

Answer 29

Pancrease, gallbladder, salivary glands, liver

Question 30

Describe the physiology of the digestive system.

Answer 30

food is ingested and them propulsed down the esophagus. Then, it is broken down mechanically (via chewing) and chemically (nutrients from the chewed up food are absotred). Then, food that is not needed is defecated as waste.

Question 31

What are the factors related to aspiration tolerance?

Answer 31

mobility, nutritional status, pulmonary status, status of immune system, age, nature of aspirate, prior history of pneumonia, level of consciousness

Question 32

Describe airway clearance in the proximal LRT (lower respiratory tract).

Answer 32

Airway clearance is mechanical, which means that the structures of proximal LRT are involved. Coughing and mucociliary action are the two ways foreign particles are cleared from the proximal LRT.

Question 33

What is coughing?

Answer 33

a reflex that expels foreign material in the proximal LRT. To occur, the trachealis muscle of the trachea narrows and subglottal pressure rises.

Question 34

What is mucociliary action?

Answer 34

one of two respiratory defense mechanisms in the proximal LRT. It occurs when the movement of cilia in the trachea propels mucus and other foreign particles up towards major airways

Question 35

Describe airway clearance in the distal LRT

Answer 35

In the distal LRT, alveolar macrophages remove foreign particles and lymphatics remove liquids. The alveolar macrophages eat the foreign material (i.e., perform phagocytosis) and then kill them. Lymphatics (lymphatic vessels and lymph nodes) drain liquids from the distal LRT which may contain foreign material

Question 36

What is the proximal LRT?

Answer 36

The trachea, lungs, and larynx

Question 37

What is the distal LRT?

Answer 37

Bronchi, bronchioles, and alveoli