GI Salvia

Question 1

What is saliva?

Answer 1

A mix of water, electrolytes, mucus and enzymes.

Question 2

Where is saliva produced?

Answer 2

In the salivary glands- parotid, submandibular and sublingual.

Question 3

Where is unstimulated saliva mainly produced?

Answer 3

The submandibular glands.

Question 4

Where is stimulated salvia mainly produced?

Answer 4

The parotid glands.

Question 5

What type of saliva is produced from the parotid glands?

Answer 5

A serous, watery secretion.

Question 6

What type of saliva is produced from the submandibular glands?

Answer 6

A mixed serous and mucous secretion.

Question 7

What type of saliva is produced from the sublingual glands?

Answer 7

A predominantly mucous secretion.

Question 8

What is the function of saliva?

Answer 8

It is a lubricant of mastication to allow swallowing and speach. It acts as a bicarbonate/carbonate buffer to quickly neutralise acids so the mouths pH remains at approx 7.2.

Question 9

What cells are the salivary ducts made of?

Answer 9

Two types of epithelial cells acinar cells and ducts.

Question 10

What are the types of acinar cells?

Answer 10

Serous and mucous.

Question 11

What are serous acinar cells?

Answer 11

Small central ducts secreting water and alpha amylose. They are dark staining and have a nucleus in the basal third.

Question 12

What are mucous acinar cells?

Answer 12

Large central ducts secreting mucous. They are pale staining and have nucleus in the base of the cell.

Question 13

What are the two main types of ducts from small to large?

Answer 13

Interlobular ducts drain into the main excretory duct.

Question 14

What parts are the interlobular ducts split into?

Answer 14

The intercalated and striated regions.

Question 15

What are the intercalated interlobular ducts?

Answer 15

They are short narrow duct segments connecting the acini to larger striated ducts. They are made of cuboidal epithelium.

Question 16

What are the striated interlobular ducts?

Answer 16

The major site of NaCl reabsorbtion. The basal membrane is highly folded and there are micro villi for large SA. HCO3- is pumped out against the concentration gradient. Cells are filled with mitochondria.

Question 17

How is primary saliva different to the saliva at the in the main excretory duct?

Answer 17

Primary saliva is isotonic with an ionic composition resembling that of plasma. Through the interlobular ducts NaCl is reabsorbed and HCO3- is excreated into the saliva.

Question 18

What is the defense function of the salivary glands?

Answer 18

Salivary glands secrete saliva which washes away food particles, bacteria and viruses. They are also surrounded by lymphatic systems which are linked to the thoracic duct and blood vessels.

Question 19

What are the salivary flow statistics?

Answer 19

800-1500 ml a day, ph-6.2-7.4, flow rate- 0.3-7 ml/min.

Question 20

What is the innervation of the parotid gland?

Answer 20

It recieves parasympathetic input from the glossopharyngeal nerve (CN IX) via the otic ganglion and sympathetic innervation from T1-T3 from the superior cervical ganglion.

Question 21

What is the innervation of the submandibular gland?

Answer 21

Parasympathetic from the facial nerve (CN VII) via the submandibular ganglion.
Sympathetic from T1-T3 from the superior cervical ganglion.

Question 22

What is the innervation of the sublingual gland?

Answer 22

Parasympathetic from the facial nerve (CN VII) via the submandibular ganglion.
Sympathetic from T1-T3 from the superior cervical ganglion.

Question 23

What is the parasympathetic neurotransmitter in the salivary glands?

Answer 23

Acetylcholine and substance P

Question 24

What is the sympathetic neurotransmitter in the salivary glands?

Answer 24

Norepinephrine, which is then received by β-adrenergic receptors causing increase cAMP and therefore more saliva excreation.

Question 25

What is the blood supply to and from the parotid gland?

Answer 25

The external carotid arterys terminal branches-superficial temporal and the posterior auricular arteries. Venous return is to the retromandibular vein.

Question 26

What is the blood supply to and from the submandibular gland?

Answer 26

Blood supply is via the submental arteries which arise from the facial artery; a branch of the external carotid artery.

Venous drainage is through the submental veins which drain into the facial vein and then the internal jugular vein.

Question 27

What is the blood supply to and from the sublingual gland?

Answer 27

Blood supply is via the sublingual and submental arteries which arise from the lingual and facial arteries respectively; both of the external carotid artery.

Venous drainage is through the sublingual and submental veins which drain into the lingual and facial veins respectively; both then draining into the internal jugular vein.