Anatomy Exam 1

Pituitary Gland

Location: Base of the brain, attached to the hypothalamus.

Anterior Pituitary (Adenohypophysis)

Produces and secretes several hormones.

Posterior Pituitary (Neurohypophysis)

Stores and releases hormones produced by the hypothalamus.

Growth Hormone (GH)

Stimulates growth and metabolism.

Thyroid-Stimulating Hormone (TSH)

Stimulates thyroid to produce thyroid hormones.

Adrenocorticotropic Hormone (ACTH)

Stimulates the adrenal cortex to produce cortisol.

Prolactin (PRL)

Stimulates milk production in mammary glands.

Follicle-Stimulating Hormone (FSH)

Stimulates ovarian follicle growth (females), sperm production (males).

Luteinizing Hormone (LH)

Triggers ovulation and corpus luteum formation in females; stimulates testosterone production in males.

Melanocyte-Stimulating Hormone (MSH)

Involved in melanin production (skin pigmentation).

Oxytocin

Stimulates uterine contractions during childbirth, and milk ejection from mammary glands.

Antidiuretic Hormone (ADH, Vasopressin)

Stimulates kidneys to retain water, which helps maintain blood pressure and fluid balance.

Thymus Gland

Location: Behind the sternum, between the lungs. Function: Produces thymosin, which plays a role in the maturation of T-cells (important for immune response).

Pineal Gland

Location: Deep in the brain. Function: Secretes melatonin, which regulates the sleep-wake cycle and circadian rhythms.

Adrenal Glands

Location: On top of each kidney.

Aldosterone

Regulates sodium and potassium balance; affects blood pressure.

Cortisol

Involved in stress response, increases glucose levels, and suppresses inflammation.

Androgens

Contribute to secondary sex characteristics.

Catecholamines (Epinephrine and Norepinephrine)

Involved in the 'fight or flight' response. These hormones increase heart rate, blood pressure, and energy production during stress.

Ovaries

Produce Estrogen and Progesterone.

Estrogen

Responsible for the development of female secondary sex characteristics and regulation of the menstrual cycle.

Progesterone

Prepares the uterus for pregnancy.

Testes

Produce Testosterone.

Testosterone

Stimulates male secondary sex characteristics and sperm production.

Diabetes Mellitus

Symptoms: Polyphagia (excessive hunger), Polydipsia (excessive thirst), Polyuria (excessive urination), Fatigue, Dry mouth.

Type 1 Diabetes

Insulin deficiency due to autoimmune destruction of pancreatic beta cells.

Type 2 Diabetes

Insulin resistance due to impaired cellular response to insulin.

Hormonal Communication

Hypothalamus-Pituitary Interaction.

Anterior Pituitary

The hypothalamus produces releasing or inhibiting hormones that travel through the hypothalamo-hypophyseal portal system to control hormone secretion from the anterior pituitary.

Target Cells

Cells that respond to a specific hormone due to the presence of receptors for that hormone on their surface or inside the cell.

Membrane-bound receptors

For water-soluble hormones (e.g., insulin, ADH).

Intracellular receptors

For lipid-soluble hormones (e.g., thyroid hormones, steroids).

cAMP pathway

A common second messenger system where water-soluble hormones (e.g., epinephrine) bind to membrane-bound receptors, activating enzymes like adenylate cyclase, which produces cyclic AMP (cAMP).

Lipid-soluble Hormones

These hormones can cross the plasma membrane and bind to intracellular receptors, affecting gene expression directly without the need for second messengers.

Calcitonin

Secreted by parafollicular cells in the thyroid, it lowers blood calcium levels by promoting calcium storage in bones.

Parathyroid Hormone (PTH)

Released by the parathyroid glands, it increases blood calcium levels by promoting calcium release from bones, increasing calcium absorption in the intestines, and decreasing calcium excretion via the kidneys.

ANP (Atrial Natriuretic Peptide)

Produced by heart (atrial cells), it reduces blood volume and blood pressure by promoting sodium and water excretion in the kidneys.

Zona Glomerulosa

Produces mineralocorticoids (e.g., aldosterone) that regulate sodium and potassium balance.

Zona Fasciculata

Produces glucocorticoids (e.g., cortisol) that affect metabolism and stress response.

Zona Reticularis

Produces androgens that contribute to sex drive and secondary sex characteristics.

Leptin

Released by fat cells (adipocytes), it helps regulate appetite and energy balance.

Erythropoietin

Produced by kidneys to stimulate red blood cell production in response to low oxygen levels.

Insulin

Lowers blood sugar by promoting glucose uptake into cells.

Glucagon

Raises blood sugar by stimulating the liver to release glucose into the bloodstream.

Follicular Cells

Produce T3 and T4 (thyroid hormones) that regulate metabolism.

Parafollicular Cells (C Cells)

Produce calcitonin, which lowers blood calcium levels.

Transport of Carbon Dioxide in Blood

20% on Hemoglobin: Carbon dioxide binds to hemoglobin (not at the oxygen-binding site) to form carbaminohemoglobin. 80% in Plasma as Bicarbonate (HCO₃⁻).

Bohr effect

Increased Temperature lowers hemoglobin's affinity for oxygen, promoting oxygen unloading in tissues.

White Blood Cells (Leukocytes)

Identify and Match Function: Neutrophils: Phagocytize bacteria.

White Blood Cells (Leukocytes)

Cells that are part of the immune system, helping the body to fight infections.