Nokea
What distinguishes endocrine and exocrine glands from one another?
- A. The biochemistry of their secretions
- B. The presence or absence of ducts
- C. The presence or absence of nerve innervation
- D. The effect their secretions have on the target cell
Correct Answer: B
Rationale: The correct answer is B. The presence or absence of ducts is the key factor that distinguishes endocrine and exocrine glands. Endocrine glands secrete hormones directly into the bloodstream without ducts, while exocrine glands secrete substances through ducts to the external environment or onto a surface. Choice A is incorrect because both types of glands can have different biochemistries in their secretions. Choice C is incorrect because both types of glands can receive nerve innervation. Choice D is incorrect as it does not differentiate between endocrine and exocrine glands based on the effect of their secretions on target cells.
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Which of the following are the major parts of the nervous system?
- A. PNS and Somatic Nervous System
- B. Autonomic Nervous System and CNS
- C. PNS and CNS
- D. Autonomic Nervous System and Somatic Nervous System
Correct Answer: C
Rationale: The nervous system comprises two major parts: the peripheral nervous system (PNS) and the central nervous system (CNS). The PNS includes nerves outside the brain and spinal cord, while the CNS consists of the brain and spinal cord. Choice C (PNS and CNS) correctly identifies the primary divisions of the nervous system, encompassing both the peripheral and central components. Therefore, the correct answer is C.
Which of the following is classified as a noninfectious disease?
- A. Dengue
- B. Psoriasis
- C. Chikungunya
- D. Brucellosis
Correct Answer: B
Rationale: Psoriasis is classified as a noninfectious disease because it is linked to an overactive immune system that leads to skin inflammation and rapid skin cell growth. Unlike infectious diseases such as Dengue, Chikungunya, and Brucellosis, which are caused by bacteria, viruses, or other pathogens, Psoriasis does not spread through pathogens. Therefore, Psoriasis is the correct choice for a noninfectious disease.
Which of the following is an efferent neuron responsible for releasing a neurotransmitter that stimulates a muscle?
- A. Neuron
- B. Motor neuron
- C. Nephrons
- D. Neurotransmitter
Correct Answer: B
Rationale: The correct answer is B, 'Motor neuron.' Motor neurons are efferent neurons that carry signals from the central nervous system to muscles or glands. These neurons release neurotransmitters, such as acetylcholine, at the neuromuscular junction to stimulate muscle contraction. Choice A, 'Neuron,' is a broad term for a nerve cell and does not specifically describe the function mentioned. Choice C, 'Nephrons,' are structural components of the kidney and are not related to muscle stimulation. Choice D, 'Neurotransmitter,' refers to the chemical messenger released by neurons to communicate with other cells and is not the specific neuron type responsible for muscle stimulation.
Which of the following organs filters excess solutes from the blood?
- A. Stomach
- B. Kidney
- C. Gallbladder
- D. Spleen
Correct Answer: B
Rationale: The correct answer is B: Kidney. The kidneys are vital organs responsible for filtering excess solutes, wastes, and toxins from the blood to produce urine. The stomach's primary function is digestion, the gallbladder stores bile, and the spleen aids in blood filtration and fighting infections. However, it is the kidneys that specifically filter solutes from the blood, making them crucial for maintaining proper fluid and electrolyte balance in the body.
In a hypertonic solution, water flows through aquaporins embedded in the plasma membrane of the cell. This type of transport is best known as which of the following?
- A. active transport
- B. diffusion
- C. osmosis
- D. facilitated diffusion
Correct Answer: C
Rationale: In a hypertonic solution, water moves out of the cell through aquaporins due to the higher solute concentration outside the cell. This process is known as osmosis, which involves the movement of water across a selectively permeable membrane from an area of low solute concentration to an area of high solute concentration. Osmosis is a passive process, meaning it does not require energy input. Active transport, on the other hand, requires energy to move substances across a membrane. Diffusion is the movement of molecules from an area of high concentration to low concentration without the involvement of aquaporins. Facilitated diffusion, while also passive, requires specific carrier proteins for transport but does not involve the movement of water as seen in osmosis.