Unit 6A Part 3 and 4 - Screencasts

Question 1

What is the functional unit of the liver?
a) Nephron
b) Lobule
c) Alveolus
d) Crypt

Answer 1

b) Lobule

Explanation: Liver lobules are hexagonal structures that organize hepatocytes and ducts for bile and blood flow.

Question 2

What is the direction of bile flow in a liver lobule?
a) Center to edges
b) Edges to center
c) Random
d) Circular

Answer 2

a) Center to edges

Explanation: Hepatocytes produce bile that drains outward via canaliculi to ductules at the edges of the lobule.

Question 3

What vessels form the portal triad at each corner of a liver lobule?
a) Hepatic artery, hepatic vein, bile duct
b) Central vein, bile duct, lymphatic
c) Portal vein, hepatic artery, central vein
d) Portal vein, hepatic artery, bile duct

Answer 3

d) Portal vein, hepatic artery, bile duct

Explanation: These three components bring blood in and carry bile out at each lobule corner.

Question 4

What is the significance of the hepatic portal vein?
a) Brings oxygen-rich blood to liver
b) Brings blood from kidneys
c) Carries nutrient-rich blood from GI tract to liver
d) Drains bile into gallbladder

Answer 4

c) Carries nutrient-rich blood from GI tract to liver

Explanation: This portal system allows the liver to process nutrients and detoxify substances before systemic circulation.

Question 5

What causes jaundice?
a) Excess glucose
b) Liver failing to clear bilirubin
c) Excess lactase
d) Portal vein collapse

Answer 5

b) Liver failing to clear bilirubin

Explanation: Impaired bilirubin clearance leads to yellowing of skin and sclera — a condition called jaundice.

Question 6

What is the final goal of digestion?
a) Acid secretion
b) Immune activation
c) Motility
d) Nutrient breakdown for absorption

Answer 6

d) Nutrient breakdown for absorption

Explanation: Digestion breaks food into small molecules that can be transported across the gut epithelium.

Question 7

Which carbohydrate transporter is sodium-coupled and found at the apical membrane?
a) GLUT2
b) GLUT5
c) SGLT1
d) PEPT1

Answer 7

c) SGLT1

Explanation: SGLT1 brings glucose and galactose into enterocytes using the Na⁺ gradient.

Question 8

How are proteins absorbed in the intestine?
a) As amino acids and small peptides
b) Only as whole proteins
c) Only via passive diffusion
d) Via micelles

Answer 8

a) As amino acids and small peptides

Explanation: Amino acids are absorbed via Na⁺-coupled transporters; di- and tri-peptides are also absorbed and broken down inside enterocytes.

Question 9

What enzyme initiates protein digestion in the stomach?
a) Trypsin
b) Pepsin
c) Amylase
d) Carboxypeptidase

Answer 9

b) Pepsin

Explanation: Pepsin, activated in acidic gastric juice, starts breaking proteins into smaller peptides.

Question 10

Why don’t artificial sweeteners contribute to caloric intake?
a) They’re not absorbed across the epithelium
b) They enhance glucose absorption
c) They’re metabolized in the liver
d) They block insulin

Answer 10

a) They’re not absorbed across the epithelium

Explanation: Artificial sweeteners taste sweet but are chemically different enough that they don’t enter the bloodstream.