Lecture 4 - Parathyroid and Pineal Gland (Vocabulary Flashcards)

Vocabulary flashcards covering key terms from the Parathyroid and Pineal Gland lecture notes.

Parathyroid gland

Small endocrine glands located behind the thyroid; secrete parathyroid hormone (PTH) to regulate blood calcium.

Chief cells

Cells that make up the parathyroid gland; secrete parathyroid hormone (PTH).

PTH (parathyroid hormone)

Hormone that increases blood calcium by acting on bone (via osteoclasts), kidneys, and by activating vitamin D.

Osteoclast

Bone-resorbing cell activated by PTH to release calcium into blood.

Calcium (Ca2+)

Mineral essential for bone, muscle, and nerve function; blood calcium tightly regulated.

Hypercalcemia

Elevated blood calcium; often due to primary hyperparathyroidism (high PTH).

Vitamin D activation

Process stimulated by PTH in the kidneys to convert vitamin D to its active form, increasing calcium absorption in the gut.

Negative feedback

Regulatory loop in which rising levels of a product (e.g., calcium) inhibit its own production (e.g., PTH).

Positive feedback

Regulatory loop that amplifies the initial stimulus; less common in calcium regulation.

Normal calcium range

8.9-10.3 mg/dL in adults.

PTH normal range

10-75 pg/mL in blood.

Autoimmune polyendocrine syndrome (APS)

Autoimmune disorder where multiple endocrine glands are targeted and destroyed by the immune system.

Pineal gland

Endocrine gland in the brain that secretes melatonin to regulate sleep.

Melatonin

Hormone that promotes sleep and regulates circadian rhythm; release increased by darkness; also associated with immune function and antioxidant protection.

Darkness

Stimulus for melatonin release from the pineal gland; signals night.

Leptin

Hormone produced by adipose tissue that signals fullness to the brain and helps regulate appetite.

Adipose tissue

Body fat tissue that stores fat; produces leptin.

ANP (atrial natriuretic peptide)

Hormone produced by the heart's atria that lowers blood pressure by increasing salt and water excretion by kidneys.

Thymus

Lymphoid organ where T cells mature.

Thymosin

Thymic hormone that promotes T cell development and function.