Digestive System BETTER

Question 1

Oral Cavity

Answer 1

• Cheeks, tongue and palate frame the mouth

Question 2

Describe the palate briefly

Answer 2

• Forms roof of mouth
• Arched shape allows digestion and respiration to occur simultaneously

Question 3

Cheeks

Answer 3

• Sidewalls
• outer covering = skin
• inner = mucous membrane (non-keratinised, stratified squamous epithelium

Question 4

Hard palate

Answer 4

• Anterior 2/3 of palate
• Structure: bone tissue and external mucous membrane covering
• Function: divides oral and nasal cavity. And a shelf which tongue can push food on

Question 5

Soft palate

Answer 5

• Posterior part
• Structure: Skeletal muscle and external mucous membrane covering
• Function: moves with uvula to help keep foods from entering nasal cavity

Question 6

Uvula

Answer 6

• Median inferior tissue extension of soft palate

Question 7

Tongue

Answer 7

• Location: floor of oral cavity
• Function: facilitates ingestion, mechanical digestion, chemical digestion, sensation, swallowing, vocalisation

Question 8

Name the tonsils

Answer 8

• Nasopharyngeal
• Palatine
• Lingual
• Clusters of lymphoid tissue that protect pharynx

Question 9

What are baby teeth

Answer 9

• Deciduous teeth
• appear 6 months of age
• 20 teeth

Question 10

Baby teeth development

Answer 10

PERMANENT DENTITION
- added: 4 molars (wisdom) + 8 premolars
- 32 teeth

Question 11

Types of teeth

Answer 11

• 8 incisors: sharp front teeth bite into food
• 4 canines: pointed to tear food
• 8 premolars: flat surface for mashing food
• 12 molars: crush food ready for swallowing

Question 12

Types of salivary glands

Answer 12

• Parotid gland: paired, located subcutaneously, anteroinferior to ear
• Submandibular gland: paired, floor of the mouth

Question 13

Lips and Cheeks action and outcome

Answer 13

Action: Confine food between teeth
Outcome: Food is chewed evenly during mastication

Question 14

Salivary Glands action and outcome

Answer 14

Action: Secrete saliva

Outcome:
- Moisten and lubricate lining of mouth and pharynx; moisten, soften and dissolve food
- Clean mouth and teeth
- Salivary amylase breaks down starch

Question 15

Teeth action and outcome

Answer 15

Action: Shred and crush food

Outcome: Breakdown solid food into smaller particles for deglutition

Question 16

Pharynx Function

Answer 16

• Digestive and respiratory functions
• receives food and air from mouth, and air from nasal cavity

Question 17

Parts of pharynx (digestive functions)

Answer 17

Oropharynx and laryngopharynx (continuous w/ oesophagus)

Question 18

Oesophagus

Answer 18

• Muscular tube, connects pharynx and stomach
• Penetrates thoracic diaphragm through esophageal hiatus

Function: transmits bolus of food and liquids to stomach

Question 19

Histology of oesophagus

Answer 19

Non-keratinised stratified squamous epithelium (mucosa)
Protects against erosion

Question 20

Peritoneum

Answer 20

Broad, serous membranous sac
Squamous epithelial tissue

Question 21

Parietal peritoneum

Answer 21

Lines walls of a abdominopelvic cavity

Question 22

Visceral peritoneum

Answer 22

Envelopes abdominal organs

Question 23

Intraperitoneal Organs

Answer 23

Abdominopelvic organs surrounded by visceral peritoneum
E.g: liver, stomach, spleen, SI (not duodenum), transverse and sigmoid colons

Question 24

Retroperitoneal organs

Answer 24

Organs that are located along posterior abdominal wall

E.g: kidneys, adrenal glands, pancreas, ascending and descending colons, aorta, inferior vena cava

Question 25

Extraperitoneal organs

Answer 25

Structures that lie deep to parietal peritoneum

Question 26

Falciform ligament

Answer 26

Anchors liver to anterior abdominal wall and inferior border of thoracic diaphragm Fold of peritoneum Forms boundary between R and L lobes of liver

Question 27

Mesentery of small intestine

Answer 27

Only jejunum and ileum. Anchors to posterior abdominal wall Structure: 2 layers of peritoneum Carries all BVs, LVs and nerves to and from jejunum and ileum

Question 28

Mesocolon

Answer 28

Attaches 2 portions of LI (transverse and sigmoid colon) to posterior abdominal wall

Question 29

Describe the stomach

Answer 29

Location: inferior to thoracic diaphragm in upper left region of abdomen Links oesophagus and duodenum.

Question 30

3 main regions of stomach

Answer 30

Fundus: Superior pouch of the stomach. Dome shaped. Body: main region of the stomach Pylorus: funnel-shaped, connects stomach to duodenum.

Question 31

Pyloric sphincter

Answer 31

Smooth muscle, located distally in stomach Function: controls entry of chyme into SI

Question 32

Rugae

Answer 32

Temporary mucosal folds (present when stomach is empty) Diminish as stomach expands

Question 33

Regions of small intestine

Answer 33

1. Duodenum (shortest): Retroperitoneal. 20-25cm. Forms C-shaped loop to the right of pancreas 2. Jejunum: Intraperitoneal. Duodenum ascends anteriorly, back to peritoneal cavity to join jejunum 3. Ileum: Intraperitoneal

Question 34

Hepatopancreatic ampulla

Answer 34

Location: duodenal wall Common bile duct and main pancreatic duct unite Opens into duodenum

Question 35

Ileocaecal sphincter

Answer 35

Where ileum joins caecum

Question 36

Plicae circulares

Answer 36

Permanent mucosal folds in SI. Decrease in number and size in distal parts of SI Shape causes chyme to spiral, increasing time for nutrient absorption

Question 37

Caecum and vermiform appendix

Answer 37

1st part of LI. Intraperitoneal. Sac like structure, suspended inferior to ileocaecal valve Function: receives contents of ileum, continues abs of water and salts. Vermiform appendix: winding tube that attaches to caecum. Many lymph nodules

Question 38

Parts of colon

Answer 38

Ascending: retroperitoneally located in right side of abdominal cavity. Transverse: Intraperitoneal, horizontal, in L side it angles inferior to spleen Descending: Retroperitoneal in L side. Sigmoid: S-shaped, Intraperitoneal, extend medially to midline

Question 39

Rectum

Answer 39

Food residue leaves sigmoid colon and enters rectum in pelvis. Extends anterior to sacrum and coccyx

Question 40

Anal canal

Answer 40

Outside of abdominopelvic cavity. Internal anal sphincter: smooth muscle (involuntary) External anal sphincter: skeletal muscle (voluntary