HSCI: TEST 4

roles of smooth muscle in digestion

• inner oblique smooth muscle - gives Muscularis ability to churn and mix food

• Peristalsis (propulsion down tract) and segmentation (physical digestion in small intestine)

• Smooth muscles - involuntary

• Ingestion (take in food into mouth)

what’s the digestive process?

1. Ingestion

2. Mastication

3. Deglutination

4. Peristalsis

5. Digestion

6. Absorption

7. Utilization

8. Defecation

What’s the structure of the alimentary canal in order?

1. Salivary glands (mouth)

2. Pharynx

3. Esophagus

4. Stomach

5. Small intestine

6. Large intestine

7. Rectum

8. Anus

what are the 3 high accessory digestive organs?

1. Teeth

2. Salivary glands

3. Tounge

What are the 3 low accessory digestive organs?

1. Liver

2. Pancreas

3. Gallbladder - stores bile until its needed to be released (CKK activates gallbladder to contract and release bile to break fat droplets (triglycerides)

What are the roles of the liver?

• detoxification of blood

  • Removes hormones, drugs and other substances by

    • Exceed into bile

    • Phagicytuzed by kupffer cells

    • Chemically altered by hepatocytes

• Carbohydrate metabolism

  • Convert blood glucose > glycogen

  • Produce glucose from glycogen (gluconeogenesis)

  • Production of ketone bodies from fatty acids

• Protein synthesis

  • Production of

    • Albumin

    • Plasma transport proteins

    • Clotting factors (fibrinogen, prothrombin, and others)

• Secretion of bile

  • Synthesis of bile salts

  • Excrete bile pigment (bilirubin)

whats the different layers of digestive tract

Alimentary canal

• mucosa

• Submucosa

• Muscularis

• Serosa

what does the salivary glands and their outputs when stimulated or not

not stimulated:

• sublingual and submandibular salivary glands

Stimulated:

• parotid salivary glands

structure and regions of stomach

• cardia

• Fundus

• Body

• Pylorus

What’s the secretions of the different cells in stomach?

• parietal cells - HCI activate pepsinogen to pepsin)

• Chief cells - secrete pepsinogen and gastric lipase

• G cells - secrete gastrin

• Enterochromaffin cells - secrete histamine and serotonin

• Neck cells - secrete mucus

whats the parts of the small intestine and main roles?

• duodenum - short contains pancreatic enzymes and pancreatic juice

• Jejunum - most absorption

• Ileum - longest portion of small intestine

What can increase surface area in small intestine?

• length - coiled

• Presence of circular folds

• Villi

• Microvilli (brush border)

what’s bolus?

From mouth, chewed food mass

what’s chyme?

From stomach to small intestine (bolus > chyme)

What is absorbed into the lacteals?

• chylomicrons (note that lactears are a part of lymphatic system)

what are the roles of different lipoproteins (cholesterols)

• chylomicrons

• Very low density lipoproteins

• Low density lipoproteins

• High density lipoproteins

Ok