2. Chew, Taste and Swallow

Question 1

What are lips and cheeks composed of?

Answer 1

Skeletal muscle embedded in elastic fibro-connective tissue (think about it as you need to move your cheeks so skeletal)

Question 2

What epithelia are the lips and cheeks lined with?

Answer 2

Stratified squamous

Question 3

Are the lips and cheeks keratinised? Where?

Answer 3

Slightly on the gums, tongue and hard palate

Question 4

Describe the composition of the tongue

Answer 4

• Skeletal muscle for the body and root
• Covered with a mucous membrane

Question 5

Where does the oesophagus pass down?

Answer 5

• Midline of thorax
• Pierces diaphragm at oesophageal hiatus to enter the abdomen

Question 6

What is the oesophagus innervated by?

Answer 6

Vagus nerve (10th cranial nerve) (“eat in vagas”).

Question 7

Describe the composition of the mucosa of the oesophagus and their shape.

Answer 7

• Non-keratinised (doesn’t have to be waterproof as it transports water and food)
• Stratified squamous epithelium
• Longitudinal folds when empty and then flatten when filled.

Question 8

Describe the composition of the muscularis (the superior part of the oesophagus).

Answer 8

Skeletal

Question 9

What connective tissue is the upper and lower oesophageal sphincters composed of? What are the other names for this?

Answer 9

• They are made of skeletal muscle fibres
• The upper is called the hypopharyngeal sphincter
• The lower is called the gastro-oesophangeal sphincter

Question 10

What is the lower oesophageal sphincter also known as?

Answer 10

Gastro-oesophageal sphincter

Question 11

What receptors detect chemicals in solution?

Answer 11

Chemoreceptors in taste buds

Question 12

What sense is close to smelling ?

Answer 12

Taste - 80% of taste is actually smell

Question 13

Name the 5 primary tastes and what they originate from.

Answer 13

• Sweet (caused by sugars, aminoacids and alcohols)
• Sour (caused by H+ ions)
• Bitter (Caused by plant alkaloids)
• Salt (casued by metal ions e.g. Na+)
• Umami (caused by meatiness, deliciousness)

Question 14

What is a papilla?

Answer 14

The small bumps on the tongue - known as taste buds

Question 15

Name the different types of papillae

Answer 15

• Filiform - not involved with taste (they just fill forms)
• Fungiform (mushroom shaped and on the dorsal surface of tongue)
• Circumvallate (at the intersection of the anterior and posterior tongue) (like around penis)
• Foliate (sides and tips of tongue)

Question 16

How and how often are taste buds replaced?

Answer 16

Every 7-10 days through basal stem cell division.

Question 17

What are microvilli known as?

Answer 17

Gustatory hairs - receptor membranes

Question 18

How are microvilli surfaced on the epithelium?

Answer 18

Through the pores

Question 19

What are gustatory cells surrounded by?

Answer 19

Dendrites

Question 20

What is aguestia and how is it caused?

Answer 20

Loss of taste Neuronal damage or medication like penicillamine

Question 21

How many pairs of salivary glands are there? Name them.

Answer 21

3

• Submandibular
• Sublingual
• Parotid

Question 22

State whether each gland pair is serosal or mucosal and its output

Answer 22

Parotid - Serous - Water + a-Amylase

Submandibular - Mucosal and Serosal - Weak a-Amylase

Lysozyme Sublingual - Mucosal - Thick, Viscous Secretion

Question 23

Describe the protective function of saliva

Answer 23

• Bacteriostatic
• IgA
• Large volume
• Mucins
• Alkaline solution

Question 24

What is Sjorgen’s Syndrome?

Answer 24

Autoimmune inflammatory disease

Question 25

What can the lack of saliva lead to?

Answer 25

• Harder to swallow
• mouth infections
• halitosis (bad breath)
• Digestion is not likely to be impaired as long as there is a-amylase from pancreas.

Question 26

Number of milk teeth and adult teeth

Answer 26

20 and 30 respectively

Question 27

How is chewing controlled?

Answer 27

1. Voluntary jaw movements
2. Strength of bite controlled by sensory receptorsin teeth
3. Tongue moves with lower jaw
4. bolus of food is formed for swallowing

Question 28

The three phases of deglutition

Answer 28

This is also known as swallowing:

• Voluntary (food forms a bolus),
• Pharyngeal (breathing is inhibited via impulses in trigem and glossophar nerves while the bolus gets into the oesophagus)
• Oesophageal (food moves by peristalsis and this contraction of smooth muscle is autonomic.

Question 29

What is the oesophageal hiatus?

Answer 29

This is a gap in the diaphragm that allows the oesophagus to pass through. (think about the hilus as being the area where vessels enter and the hiatus is similar).

Question 30

What type of muscle is the inferior part of the oesophagus?

Answer 30

Smooth muscle (stomach is smooth so it becomes smoother as it gets nearer to the stomach).

Question 31

What do the different positions on the tongue speciaise in detecting?

Answer 31

• Tip: sweet (the tip of the cake is sweet like a cherry)
• Sides of the tip: salty (the side tings of the tip are salty)
• Back: bitter (the people at the back are bitter)
• Sides: sour (SS, the sides are sour)

Question 32

What is the mumps disorder?

Answer 32

Infection of the parotid gland by the myxovirus

Question 33

Describe xerostomia disorder.

Answer 33

Dry mouth, causes may be autoimmune, diabetes sacroidosis and age related atrophy of glands.

Question 34

Other name for chewing

Answer 34

Mastication