1. The main function of the nephrons is to:

A. Store urine
B. Filter blood and remove waste products
C. Produce hormones
D. Control blood pressure

Correct answer: B

Rationale: The correct answer is B: 'Filter blood and remove waste products.' Nephrons are the functional units of the kidneys responsible for filtering blood to remove waste products, excess ions, and water, while reabsorbing essential substances like glucose and amino acids. This process forms urine, which is stored in the bladder before being excreted. Options A, C, and D are incorrect because nephrons do not store urine, produce hormones, or directly control blood pressure; although the kidneys do play a role in long-term blood pressure regulation through mechanisms like the renin-angiotensin-aldosterone system.

2. How is power related to work and time?

A. Power = Work Ã· Time
B. Power = Work Ã— Time
C. Power = Work + Time
D. Power = Work - Time

Correct answer: a

Rationale: Power is calculated as the amount of work done or energy transferred per unit of time.

3. What is the medical term for heartburn, a burning sensation in the chest caused by stomach acid?

A. Dysphagia
B. Gastroesophageal reflux disease (GERD)
C. Peptic ulcer
D. Ulcerative colitis

Correct answer: B

Rationale: Rationale: A) Dysphagia refers to difficulty swallowing and is not specifically related to heartburn. B) Gastroesophageal reflux disease (GERD) is the medical term for heartburn, which is a burning sensation in the chest caused by stomach acid flowing back up into the esophagus. C) Peptic ulcer is a sore that develops on the lining of the stomach, small intestine, or esophagus, and it can cause symptoms such as abdominal pain, not specifically heartburn. D) Ulcerative colitis is a type of inflammatory bowel disease that affects the colon and rectum, and it does not typically cause heartburn.

4. What is the main component of sweat?

A. Urea
B. Glucose
C. Water
D. Electrolytes

Correct answer: C

Rationale: Rationale: - Sweat is primarily composed of water, making up the majority of its content. Water helps regulate body temperature by evaporating from the skin's surface, which cools the body down. - While sweat does contain small amounts of other substances like urea, glucose, and electrolytes, water is the main component that is secreted by sweat glands to help regulate body temperature during physical activity or in response to heat.

5. Which hormone plays a key role in stimulating the release of milk from breast tissue after childbirth?

A. Follicle-stimulating hormone (FSH)
B. Luteinizing hormone (LH)
C. Prolactin
D. Estrogen

Correct answer: C

Rationale: The correct answer is C: Prolactin. Prolactin is the hormone responsible for stimulating the production and release of milk from breast tissue after childbirth. It is produced by the pituitary gland and plays a crucial role in lactation. FSH and LH are reproductive hormones involved in the menstrual cycle and ovulation, not milk production. Estrogen is a sex hormone that plays a role in the development of female reproductive organs. Therefore, the hormone that specifically stimulates milk release from breast tissue after childbirth is prolactin.

6. Which type of glial cell provides structural support and insulation for neurons in the central nervous system?

A. Schwann cells
B. Astrocytes
C. Oligodendrocytes
D. Microglia

Correct answer: C

Rationale: The correct answer is C: Oligodendrocytes. Oligodendrocytes are a type of glial cell found in the central nervous system that provide structural support and insulation for neurons by forming myelin sheaths around axons. Schwann cells, on the other hand, are found in the peripheral nervous system. Astrocytes play a role in nutrient transfer and maintaining the blood-brain barrier. Microglia are responsible for immune defense and clearing debris in the CNS. Therefore, oligodendrocytes are specifically responsible for providing structural support and insulation for neurons in the central nervous system.