Lecture 23- Mouth And Stomach

Question 1

Where does ingestion occur?

Answer 1

Only at the mouth

Question 2

Mouth

Answer 2

Stratified squamous epithelial mucosa-lined cavity

Lips and cheeks have core of skeletal muscle covered by skin that helps keep food between teeth when we chew

Question 3

Hard palate

Answer 3

Bony,aids in manipulation of food

Question 4

Soft palate

Answer 4

Rises during swallowing to close nasopharynx

Question 5

Tongue

Answer 5

Made of skeletal muscle and used to reposition foods when chewing mix food with saliva, initiate swallowing and aid in speech production

Papillae on tonguehouse taste buds

Question 6

What cells compose salivary glands?

Answer 6

Serous cells- produce watery secretion
Mucous cells- produce mucous

Question 7

Saliva

Answer 7

Mostly water but contains electrolytes, enzymes salivary glands and lingual lipase, muffins, lysozyme and antibodies along with a. Small amount of metabolic waste

Question 8

Teeth

Answer 8

Tear and grind food to break it into small pieces

Question 9

Mastication

Answer 9

Chewing, the mechanical breakdown of food

Question 10

Primary dentition

Answer 10

Baby teeth, 20 teeth hat are lost to make room for permanent dentition

Question 11

Permanent dentition

Answer 11

Consists of 32 teeth including wisdom teeth and third molars

Question 12

Types of teeth

Answer 12

Incisors- used for cutting
Canines- tear or pierce
Premolars and molars- used for grinding

Question 13

Adult dental formula

Answer 13

I 2/2 C1/1 P2/2 M3/3

Question 14

Three Regions of tooth

Answer 14

Enamel covered crown
Gingiva (gums)
Root embedded in mandible

Question 15

Cementum

Answer 15

Calcified connective tissue that anchors root to periodontal ligaments holding tooth in bony socket of jaw

Question 16

Dentin

Answer 16

Bone like material, underlies enamel and surrounds pulp cavity which contains blood and nerve supply

Question 17

Cardiac orfice

Answer 17

Where laryngopahrynx and stomach join together

Question 18

Gastroesophaeal sphincter

Answer 18

Located in between esophagus and stomach, prevent contents from stomach to move upward

Question 19

Deglutition

Answer 19

Swallowing

Question 20

Tw o major phases of deglutition

Answer 20

Buffalo phase- voluntary, occurs in mouth where blues of food is forced into oropharnx by tongue

Pharyngeal-esophageal phase- involuntary, occurs when food is squeezed through pharynx into esophagus, controlled by swallowing centre of medulla and pons

Question 21

Functions of stomach

Answer 21

1. Mechanical breakdown of food
2. Holding area for food
3. Delivers chyme to small intestiene
4. Denatures protein with HCL
5. Pepsin carries out enzymatic digestion of proteins
6. Lipid soluble alcohol and aspirin absorbed into blood through stomach endothelium
7. Only stomach function essential to life is secretion of intrinsic factor for B12 absorption

Question 22

Stomach

Answer 22

Temporarily stores food and begins protein digestion

Empt stomach has volume of 50mL and a capacity of 4L, when empty walls fall into folds called RUGAE

Question 23

Major regions of stomach

Answer 23

Cardia
Fundus
Body
Pylorus

Question 24

Histology of stomach

Answer 24

Surface epithelium of stomach mucosa is simple columnar epithelium with goblet cells which produce protective two-layer coat of alkaline mucous

Question 25

Gastric glands of stomach

Answer 25

Produce gastric juice
May be composed of combination of mucous, HCLm intrinsic factor, pepsinogen and variety of hormones

Question 26

Surface mucous cells and mucous neck cells

Answer 26

Secrete mucous, which helps protect epithelium from HCL of stomach

Question 27

Parietal cells

Answer 27

Secrete HCL to denature proteins
Activate pepsin
Break down plant cell walls
Kill many microbes
Secret intrinsic factor

Question 28

Chief cells

Answer 28

Secrete pepsinogen that is activated to pepsin which hydrolysis denatured proteins
Produce lipase enzymes that hydrolysis small portion of lipids

Question 29

Enteroendocrine cells

Answer 29

Secrete chemical messenger and hormones, interacting with enteric nervous system, in the same way the endocrine system interacts with nervous system