Nokea
Which of the heart's four chambers is the largest and the strongest?
- A. Left ventricle
- B. Left atrium
- C. Right ventricle
- D. Right atrium
Correct Answer: A
Rationale: The correct answer is the left ventricle. The left ventricle is the largest and strongest chamber of the heart. It pumps oxygenated blood to the entire body, making it a vital component of the circulatory system. The left atrium receives oxygen-rich blood from the lungs, the right ventricle pumps deoxygenated blood to the lungs for oxygenation, and the right atrium receives deoxygenated blood from the body.
You may also like to solve these questions
What is the function of the liver in the body?
- A. To filter blood
- B. To produce bile and detoxify substances
- C. To produce insulin
- D. To produce red blood cells
Correct Answer: B
Rationale: The correct answer is B: 'To produce bile and detoxify substances.' The liver's primary functions include producing bile, which aids in the digestion and absorption of fats, and detoxifying harmful substances in the blood. While the liver does play a role in blood filtration, its key functions are related to bile production and detoxification. Choices C and D are incorrect because the liver does not produce insulin (produced by the pancreas) or red blood cells (produced in the bone marrow).
Which hormone is released during the body's fight-or-flight response?
- A. Insulin
- B. Adrenaline
- C. Thyroxine
- D. Cortisol
Correct Answer: B
Rationale: Adrenaline, also known as epinephrine, is released during the body's fight-or-flight response. This hormone prepares the body for rapid action by increasing heart rate, dilating airways, and redirecting blood flow to essential organs in response to stress or danger. Insulin is not released during the fight-or-flight response; its primary role is to regulate blood sugar levels. Thyroxine is a hormone produced by the thyroid gland that regulates metabolism, and cortisol is released in response to stress to regulate various bodily functions, but adrenaline is the hormone specifically associated with the fight-or-flight response.
Which gland produces hormones that regulate metabolism?
- A. Pituitary gland
- B. Thyroid gland
- C. Adrenal gland
- D. Pineal gland
Correct Answer: B
Rationale: The thyroid gland is responsible for producing hormones, such as thyroxine, that play a crucial role in regulating metabolism, energy production, and overall growth and development in the body. The pituitary gland, while important for hormone regulation, does not primarily regulate metabolism. The adrenal gland is responsible for producing hormones like cortisol and adrenaline, which are more related to stress response than direct metabolism regulation. The pineal gland mainly produces melatonin, which regulates sleep-wake cycles and not metabolism. Therefore, the correct answer is the thyroid gland.
Which part of the brain is involved in the regulation of heart rate and breathing?
- A. Cerebrum
- B. Cerebellum
- C. Medulla oblongata
- D. Hypothalamus
Correct Answer: C
Rationale: The correct answer is C: Medulla oblongata. The medulla oblongata, situated in the brainstem, plays a crucial role in regulating vital functions such as heart rate, breathing, and blood pressure. It serves as the control center for involuntary actions, ensuring the body's automatic functions work properly. Choices A, B, and D are incorrect because the cerebrum is primarily responsible for functions such as thinking, voluntary movements, and sensory processing; the cerebellum is involved in coordination, balance, and muscle control; and the hypothalamus regulates body temperature, thirst, hunger, and some aspects of the autonomic nervous system but not specifically heart rate and breathing.
Which type of muscle tissue is voluntary?
- A. Cardiac muscle
- B. Skeletal muscle
- C. Smooth muscle
- D. Striated muscle
Correct Answer: B
Rationale: The correct answer is B, Skeletal muscle. Skeletal muscle is a type of voluntary muscle tissue, allowing conscious control over its movement. Unlike smooth and cardiac muscle, which are involuntary, skeletal muscle is under direct voluntary control. Cardiac muscle (choice A) is involuntary and found in the heart. Smooth muscle (choice C) is also involuntary and found in the walls of internal organs. While skeletal muscle is striated (contains stripes), choice D is not the best answer as it does not specifically address the voluntary nature of skeletal muscle.