which hormone initiates the preparation of the endometrium of the uterus for pregnancy

HESI A2

HESI A2 Anatomy and Physiology Practice Test

1. Which hormone initiates the preparation of the endometrium of the uterus for pregnancy?

A. FSH
B. Estrogen
C. LH
D. Progesterone

Correct answer: D

Rationale: Progesterone initiates the preparation of the endometrium of the uterus for pregnancy. It promotes the growth of blood vessels and glands in the endometrial lining, making it conducive for implantation and supporting early pregnancy. While estrogen helps in thickening the endometrium, it is progesterone that plays a crucial role in preparing it for pregnancy. FSH (Follicle-stimulating hormone) is involved in stimulating ovarian follicles, not directly in preparing the endometrium. LH (Luteinizing hormone) triggers ovulation but does not primarily prepare the endometrium for pregnancy.

2. Which vitamin is important for the absorption of iron?

A. Vitamin C
B. Vitamin D
C. Vitamin K
D. Vitamin B12

Correct answer: A

Rationale: The correct answer is Vitamin C. Vitamin C is essential for the absorption of iron, especially from plant-based sources. It aids in converting non-heme iron (found in plants) into a form that is easier for the body to absorb. This is crucial in preventing iron-deficiency anemia, making Vitamin C a key nutrient for overall health. Vitamin D (choice B) is important for calcium absorption and bone health, not iron absorption. Vitamin K (choice C) plays a role in blood clotting and bone metabolism, not iron absorption. Vitamin B12 (choice D) is important for red blood cell formation and neurological function but is not directly involved in iron absorption.

3. Which type of blood vessel carries deoxygenated blood back to the heart?

A. Arteries
B. Capillaries
C. Veins
D. Lymphatic vessels

Correct answer: C

Rationale: Veins are the blood vessels that carry deoxygenated blood from the body's tissues back to the heart. Deoxygenated blood is transported from the body to the heart through veins, while arteries carry oxygenated blood away from the heart. Capillaries facilitate the exchange of nutrients and gases between the blood and tissues. Lymphatic vessels are responsible for returning excess tissue fluid to the bloodstream and do not primarily carry deoxygenated blood.

4. What does trypsin break down in the body?

A. Fat
B. Starch
C. Proteins
D. Nucleic acids

Correct answer: C

Rationale: Trypsin is an enzyme that specifically breaks down proteins into smaller peptides by hydrolyzing peptide bonds. It is a key enzyme involved in the digestion of proteins in the body, particularly in the small intestine where it helps in the final stages of protein digestion. Choices A, B, and D are incorrect because trypsin does not break down fats, starch, or nucleic acids; its primary function is the digestion of proteins.

5. What is the function of hemoglobin in red blood cells?

A. To fight infections
B. To transport oxygen
C. To carry carbon dioxide
D. To store oxygen

Correct answer: B

Rationale: The correct answer is B: 'To transport oxygen.' Hemoglobin in red blood cells plays a crucial role in transporting oxygen. It binds to oxygen in the lungs and carries it to the body's tissues and organs for cellular respiration. Choices A, C, and D are incorrect because hemoglobin's primary function is to bind and transport oxygen, not to fight infections, carry carbon dioxide, or store oxygen.