Nokea
Which neurotransmitter is responsible for stimulating muscle contraction?
- A. Dopamine
- B. Acetylcholine
- C. Serotonin
- D. Norepinephrine
Correct Answer: B
Rationale: Acetylcholine is the neurotransmitter responsible for stimulating muscle contraction at the neuromuscular junction. When an action potential reaches the end of a motor neuron, acetylcholine is released into the synaptic cleft and binds to receptors on the muscle cell membrane, leading to muscle contraction. Dopamine, serotonin, and norepinephrine are neurotransmitters that have different functions in the nervous system and are not directly involved in stimulating muscle contraction. Dopamine is involved in reward and pleasure pathways, serotonin regulates mood and behavior, and norepinephrine is involved in the 'fight or flight' response.
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How can you differentiate between a bacterial and viral infection based solely on symptoms?
- A. It's impossible to differentiate solely based on symptoms.
- B. Bacterial infections typically respond well to antibiotics, while viral infections don't.
- C. Bacterial infections usually cause fever, while viral infections don't.
- D. Viral infections often present with respiratory symptoms like a cough, while bacterial infections don't.
Correct Answer: A
Rationale: It is impossible to differentiate between a bacterial and viral infection based solely on symptoms because many symptoms overlap between the two types of infections. Symptoms like fever, cough, and others can be present in both bacterial and viral infections. Additional diagnostic tests such as cultures or blood tests are often needed to determine the cause of the infection accurately. Relying only on symptoms can lead to misdiagnosis and inappropriate treatment. Choices B, C, and D are incorrect because they oversimplify the differentiation process and do not encompass the complexity of symptoms associated with bacterial and viral infections. While it is true that bacterial infections may respond to antibiotics and some differences in symptoms may be observed between bacterial and viral infections, these are not definitive indicators without proper diagnostic tests.
What is the name of the bone marrow cavity in the long bones where red blood cells are produced?
- A. Periosteum
- B. Diaphysis
- C. Medullary cavity
- D. Epiphysis
Correct Answer: C
Rationale: The medullary cavity is the correct answer. It is the central cavity within the shafts of long bones where red bone marrow is located, responsible for the production of red blood cells. The periosteum is the outer layer of bone that provides nourishment and participates in bone repair. The diaphysis refers to the shaft of a long bone that contains yellow bone marrow. The epiphysis is the end of a long bone involved in joint articulation and contains red bone marrow in children for blood cell production.
Which organ plays a significant role in immune cell production and maturation?
- A. Liver
- B. Kidneys
- C. Bone marrow
- D. Spleen
Correct Answer: C
Rationale: The bone marrow is the correct answer. It is the primary site for immune cell production and maturation. The bone marrow is responsible for generating various types of blood cells, including white blood cells crucial for the immune system's function. The liver, kidneys, and spleen have essential functions in the body, such as filtering blood, detoxification, and storage of blood, respectively. However, they are not primarily involved in immune cell production and maturation, making them incorrect choices for this question.
What type of muscle tissue is responsible for causing the hair follicles to stand on end when you get a goosebump?
- A. Skeletal muscle
- B. Smooth muscle
- C. Cardiac muscle
- D. None of the above
Correct Answer: B
Rationale: Smooth muscle is responsible for causing the hair follicles to stand on end when you get a goosebump. This type of muscle tissue is found in the skin attached to hair follicles and contracts in response to stimuli such as cold or fear, causing the hair to stand up. Skeletal muscle is responsible for voluntary movements, and cardiac muscle is found in the heart and is not directly involved in causing goosebumps. Therefore, choices A, C, and D are incorrect as they do not represent the specific type of muscle tissue responsible for this physiological response.
Identify the opposing muscle pair.
- A. Bicep and tricep (Arm flexion and extension)
- B. Hamstring and quadriceps (Knee extension and flexion)
- C. Pectoralis major and pectoralis minor (Chest muscles)
- D. Trapezius and deltoid (Shoulder movement)
Correct Answer: A
Rationale: The correct answer is A. The bicep and tricep muscles form an antagonistic muscle pair, where one muscle contracts while the other relaxes. The bicep, located on the front of the upper arm, is responsible for arm flexion (bending the elbow), while the tricep, situated on the back of the upper arm, is responsible for arm extension (straightening the elbow). This opposing action allows for controlled movement at the elbow joint. Choice B, hamstring and quadriceps, are not opposing muscles in the context of the knee joint; the hamstring group flexes the knee, while the quadriceps group extends it. Choices C and D do not represent an opposing muscle pair related to joint movement.