Unit 5 Rat Disection

Question 1

Role of small intestine?

Answer 1

Digestion and absorption.
Two types of digestion:
Mechanical: digestion by peristalsis
Chemical: digestion using stomach secretions (acid chyme) and pancreas (digestive enzymes)
Lining made of villi and microvilli and is very long to maximize absorption
Digests: proteins, nucleic acids, lipids and carbohydrates.

Question 2

Role of large intestines

Answer 2

Reabsorbs water and electrolytes. Only mechanical digestion, peristalsis.
Large masses of E. coli bacteria that produce vitamins and help digest

Question 3

What’s the caecum

Answer 3

Structure between small and large intestine. Houses bacteria and aids in digestion of cellulose, larger in herbivores than in carnivores.

Question 4

What’s the stomach

Answer 4

Mechanical digestion; contractions of the stomach wall
Chemical: gastric juices (pepsin and hydrochloric acid)
Digests proteins.
Coated in mucus to prevent it from being digested by the gastric juice. Contains gastric rugae to allow expansion of stomach after consumption.
Has cardiac(passage of food from esophagus to stomach) and pyloric (passes food from stomach to small intestine)sphincter.

Question 5

What is the pancreas

Answer 5

Glandular organ below stomach.
Aids in chemical digestion of food in small intestine. Secretions from pancreas are basic and neutralizes the acid chyme from the stomach
Secretes insulin that aids in sugar regulation. Release of insulin removes glucose and stores it in liver and muscles as glycogen.

Question 6

What is the liver

Answer 6

Produces bile, aids in emulsification of fat. Bile stored in gall bladder and secreted to small intestine. Excretes hormones, cholesterol, toxins, and bilirubin.
Synthesis of plasma proteins and clotting factors

Question 7

What does the excretory system do?

Answer 7

Removes intracellular waste

Question 8

What do kidneys do

Answer 8

Major Organ of excretion. Maintain water balance in the body.
Functional unit is the nephron. There are 1 million nephrons in each kidney. They filter the blood and form urine. Urine forms through passive transport.
Removes toxins, hormones, excess salts and water from blood.

Question 9

What do ureters do?

Answer 9

Carry’s urine to the bladder. Sphincters allow release of urine from the body though the urethra.