Identify the hormone that stimulates uterine contraction and the release of milk during nursing.

Correct Answer: C

Rationale: Oxytocin stimulates uterine contractions (labor) and milk ejection (nursing) via myoepithelial cells dual reproductive role. ADH manages water, not reproduction. Glucagon raises glucose, unrelated. Prolactin drives milk production, not release. Oxytocin's contractile action distinguishes it, key to birth and lactation, unlike water, glucose, or synthesis hormones.

Correct Answer: D

Rationale: Adrenal glands secrete cortisol (cortex, stress) and aldosterone (cortex, sodium) dual zones (fasciculata, glomerulosa). Thyroid produces T3/T4, calcitonin metabolism/calcium. Parathyroid releases PTH calcium only. Pancreas makes insulin/glucagon glucose. Adrenal's steroid output distinguishes it, key to stress and electrolyte balance, unlike metabolic or calcium glands.

Correct Answer: B

Rationale: ANH, from right atrial cells, responds to stretch (high volume), lowering pressure via natriuresis cardiac origin. Kidney tubules respond, not produce. Adrenal cortex makes aldosterone, opposing ANH. Pancreas focuses on glucose. Atrial production distinguishes ANH, key to heart-volume regulation, unlike renal, adrenal, or metabolic sources.

Correct Answer: D

Rationale: Progesterone (ovaries) grows the uterus, preparing it for pregnancy endometrial thickening. Secondary sex characteristics (e.g., breasts) are estrogen-driven, not progesterone. Estrogen aids follicle growth, not ovum maturation directly LH triggers that. Estrogen does aid breast development false to deny. Uterine growth distinguishes progesterone, key to reproductive support, unlike characteristics, maturation, or breast errors.

Correct Answer: B

Rationale: Synaptic signaling occurs when neurons release neurotransmitters (e.g., acetylcholine) across synapses to influence adjacent neurons fast, local neural communication. Autocrine involves cells signaling themselves (e.g., growth factors). Paracrine affects nearby cells (e.g., histamine), not specifically neurons. Endocrine uses blood for distant targets (e.g., insulin), not neuron-neighbor. Synaptic specificity distinguishes it, key to nervous system function, unlike self, nearby, or systemic signaling.