Which of the following is NOT synthesized in the pituitary gland?

Correct Answer: C

Rationale: The correct answer is C: ADH. The pituitary gland consists of two parts: the anterior and posterior pituitary. ADH, also known as vasopressin, is synthesized in the hypothalamus and stored in the posterior pituitary. Therefore, it is not synthesized in the pituitary gland itself. LH, FSH, and TSH are all hormones synthesized and released by the anterior pituitary gland.

Correct Answer: C

Rationale: The correct answer is C: Its isthmus is at the level of thyroid cartilage. The isthmus of the thyroid gland is located at the level of the cricoid cartilage, not the thyroid cartilage. The thyroid gland is closely related to the inferior (recurrent) laryngeal nerve (A), it moves on swallowing (B), and it is invested by pretracheal fascia together with the parathyroids (D). These choices are correct anatomical characteristics of the thyroid gland.

Correct Answer: c

Rationale: The correct answer is C because when an action potential reaches the axon terminal, endosomes containing neurotransmitters fuse with the cell membrane and release neurotransmitter into the synaptic cleft. This process is known as exocytosis. This neurotransmitter then binds to receptors on the postsynaptic neuron, initiating a new action potential. Choice A is incorrect because the muscle fiber contraction is initiated by the binding of the neurotransmitter to receptors on the muscle cell, not directly by the action potential reaching the axon terminal. Choice B is incorrect because acetylcholinesterase breaks down acetylcholine in the synaptic cleft after it has already been released and has completed its role in transmitting the signal. Choice D is incorrect because sodium channels opening at the motor end plate is part of the process of muscle cell depolarization and contraction, not directly related to the release of neurotransmitter at the axon terminal.

Correct Answer: C

Rationale: The correct answer is C: anterior pituitary gland. Portal capillaries carry releasing hormones from the hypothalamus to the anterior pituitary gland, where they regulate the release of hormones. Releasing hormones do not target the neurohypophysis (choice A) or the posterior pituitary gland (choice D) directly. They also do not affect the pancreas (choice B) in this context. Thus, the correct answer is the anterior pituitary gland due to its role in receiving and responding to releasing hormones from the hypothalamus.

Correct Answer: C

Rationale: Rationale: 1. Lactogenic hormone stimulates mammary glands to produce milk, essential for lactation. 2. Oxytocin is a different hormone that causes milk ejection, not production. 3. Gonadotropins like FSH and LH affect gonads, not lactation. 4. Choice C directly relates to lactation, making it the correct answer.