Chapter 12 ENDOCRINE

Exocrine glands

Glands that secrete products into ducts.

Endocrine glands

Ductless glands that secrete hormones.

Hormones

Chemical substances regulating target cell activity.

Target cells

Cells affected by hormones in target organs.

Nonsteroid hormones

First messengers binding to cell membrane receptors.

Steroid hormones

Bind to nuclear receptors, affecting DNA activity.

Negative feedback

Mechanism reversing physiological changes in the body.

Positive feedback

Mechanism amplifying physiological changes, less common.

Hypersecretion

Excessive secretion of hormones by glands.

Hyposecretion

Insufficient secretion of hormones by glands.

Polyendocrine disorders

Multiple hormones experiencing hyper or hyposecretion.

Target cell insensitivity

Reduced response to hormones, mimicking hyposecretion.

Prostaglandins (PGs)

Local hormones acting on nearby cells.

Prostaglandin A (PGA)

Class of prostaglandins influencing various body functions.

Prostaglandin E (PGE)

Class of prostaglandins affecting respiration and blood pressure.

Prostaglandin F (PGF)

Class of prostaglandins involved in reproduction.

Anterior pituitary gland

Gland secreting several key hormones.

Thyroid-stimulating hormone (TSH)

Stimulates thyroid gland growth and hormone secretion.

Adrenocorticotropic hormone (ACTH)

Stimulates adrenal cortex growth and glucocorticoid secretion.

Follicle-stimulating hormone (FSH)

Initiates ovarian follicle growth and maturation.

Luteinizing hormone (LH)

Triggers ovulation and stimulates ovarian hormone production.

Growth hormone (GH)

Stimulates growth and cell reproduction.

Prolactin

Stimulates milk production in mammary glands.

LH

Stimulates estrogen secretion and follicle growth.

FSH

Works with LH to promote follicle maturation.

GH

Stimulates growth and accelerates protein anabolism.

Hyperglycemia

Elevated blood glucose levels due to GH effects.

Gigantism

Excess GH in childhood causing abnormal growth.

Acromegaly

Excess GH in adulthood causing enlarged features.

Pituitary Dwarfism

GH hyposecretion in childhood leading to stunted growth.

Prolactin (PRL)

Stimulates breast development and milk secretion.

ADH

Increases water reabsorption in kidneys.

Diabetes Insipidus

Condition from ADH hyposecretion causing excessive urination.

Oxytocin (OT)

Stimulates uterine contractions and milk ejection.

Thyroxine (T4)

Thyroid hormone that increases metabolic rate.

Triiodothyronine (T3)

Active thyroid hormone enhancing metabolism.

Calcitonin (CT)

Lowers blood calcium by inhibiting bone breakdown.

Hyperthyroidism

Excess thyroid hormones increasing metabolic rate.

Graves Disease

Inherited hyperthyroidism with symptoms like exophthalmos.

Hypothyroidism

Insufficient thyroid hormones leading to decreased metabolism.

Goiter

Painless thyroid enlargement from iodine deficiency.

Cretinism

Severe hypothyroidism in early development causing retardation.

Myxedema

Hypothyroidism in adults characterized by edema.

Parathyroid Hormone (PTH)

Increases blood calcium by promoting bone breakdown.

Homeostasis

Regulation of body functions like temperature and appetite.

Glucocorticoids

Chiefly cortisol; regulates glucose metabolism.

Mineralocorticoids

Primarily aldosterone; manages sodium and potassium levels.

Sex Hormones

Androgens secreted by adrenal cortex in both sexes.

Adrenal Cortex

Outer layer secretes mineralocorticoids, middle glucocorticoids.

Cortisol

Maintains blood glucose; increases gluconeogenesis.

Hyperglycemia

Elevated blood glucose levels; can result from cortisol.

Blood Pressure Regulation

Glucocorticoids help maintain normal blood pressure.

Immune Response

Glucocorticoids decrease immune and allergic responses.

Epinephrine

Adrenaline; intensifies sympathetic nervous system effects.

Norepinephrine

Enhances stress response; increases heart rate and blood pressure.

Cushing Syndrome

Caused by glucocorticoid hypersecretion; symptoms include moon face.

Addison Disease

Hyposecretion of cortical hormones; leads to muscle weakness.

Glucagon

Secreted by alpha cells; increases blood glucose levels.

Insulin

Secreted by beta cells; decreases blood glucose levels.

Type 1 Diabetes

Autoimmune destruction of pancreas; insulin hyposecretion.

Type 2 Diabetes

Insulin resistance; common in overweight adults.

Polydipsia

Excessive thirst; symptom of uncontrolled diabetes.

Estrogen

Feminizing hormone; develops female body characteristics.

Testosterone

Masculinizing hormone; promotes male physical traits.

Thymosin

Hormone from thymus; matures T-lymphocytes.

Chorionic Gonadotropins

Indicates pregnancy; maintains corpus luteum.

Melatonin

Regulates sleep-wake cycle; secreted by pineal gland.

Ghrelin

Stimulates appetite; secreted by stomach lining.

Atrial Natriuretic Hormone (ANH)

Stimulates sodium loss; secreted by heart atrial wall.

Leptin

Regulates hunger; secreted by fat-storing cells.