Chemical Coordination and Integration

Flashcards about Chemical Coordination and Integration, covering endocrine glands, hormones, and their functions.

Endocrine Glands

Ductless glands that secrete hormones into the bloodstream.

Hormones

Non-nutrient chemicals acting as intercellular messengers produced in trace amounts.

Hypothalamus

The basal part of diencephalon, forebrain, regulating body functions and secreting releasing and inhibiting hormones.

Gonadotrophin Releasing Hormone (GnRH)

Hormone from the hypothalamus that stimulates pituitary synthesis and release of gonadotrophins.

Somatostatin

Hormone from the hypothalamus that inhibits the release of growth hormone from the pituitary.

Pituitary Gland

Gland located in the sella tursica, divided into adenohypophysis and neurohypophysis.

Pars Distalis

Anterior pituitary, producing GH, PRL, TSH, ACTH, LH, and FSH.

Neurohypophysis

Posterior pituitary, storing and releasing oxytocin and vasopressin.

Growth Hormone (GH)

Stimulates abnormal body growth (gigantism) or disfigurement (acromegaly); low secretion results in pituitary dwarfism.

Prolactin (PRL)

Regulates mammary gland growth and milk formation.

Thyroid Stimulating Hormone (TSH)

Stimulates synthesis and secretion of thyroid hormones.

Adrenocorticotrophic Hormone (ACTH)

Stimulates synthesis and secretion of glucocorticoids from the adrenal cortex.

Luteinizing Hormone (LH) and Follicle Stimulating Hormone (FSH)

Stimulate gonadal activity; LH stimulates androgen synthesis in males and ovulation in females, FSH regulates spermatogenesis in males and follicle development in females.

Melanocyte Stimulating Hormone (MSH)

Regulates skin pigmentation.

Oxytocin

Stimulates smooth muscle contraction, uterine contraction during childbirth, and milk ejection.

Vasopressin

Stimulates water and electrolyte reabsorption in kidneys; also known as antidiuretic hormone (ADH).

Diabetes Insipidus

Condition resulting from impaired ADH synthesis, causing water loss and dehydration.

Pineal Gland

Gland located on the dorsal side of the forebrain, secreting melatonin.

Melatonin

Hormone regulating diurnal rhythms, sleep-wake cycle, body temperature, metabolism, and defense capability.

Thyroid Gland

Gland composed of two lobes on either side of the trachea, interconnected by the isthmus.

Thyroxine

Tetraiodothyronine (T4) and triiodothyronine (T3); regulate basal metabolic rate.

Goitre

Condition resulting from iodine deficiency, causing thyroid enlargement.

Cretinism

Condition caused by hypothyroidism during pregnancy, leading to stunted growth and mental retardation.

Hyperthyroidism

Condition caused by increased thyroid hormone synthesis, leading to enlargement of the thyroid gland and increased metabolic rate.

Thyrocalcitonin (TCT)

Hormone secreted by the thyroid gland that regulates blood calcium levels.

Parathyroid Glands

Four glands on the back of the thyroid gland, secreting parathyroid hormone (PTH).

Parathyroid Hormone (PTH)

Increases blood calcium levels by stimulating bone resorption and reabsorption of Ca2+ by the kidneys.

Thymus Gland

Lobular structure behind the sternum, secreting thymosins.

Thymosins

Promote T-lymphocyte differentiation and antibody production.

Adrenal Glands

Located on top of each kidney, composed of the adrenal medulla and adrenal cortex.

Adrenal Medulla

Secretes adrenaline and noradrenaline in response to stress, increasing alertness and heart rate.

Catecholamines

Adrenaline or epinephrine and noradrenaline or norepinephrine; increase heart rate, respiration, and blood glucose levels.

Adrenal Cortex

Secretes corticoids like glucocorticoids and mineralocorticoids.

Addison’s Disease

Condition resulting from underproduction of adrenal cortex hormones, causing weakness and fatigue.

Glucocorticoids

Regulate carbohydrate metabolism; cortisol is the main one.

Mineralocorticoids

Regulate water and electrolyte balance; aldosterone is the main one.

Pancreas

Acts as both exocrine and endocrine gland, with Islets of Langerhans containing α-cells and β-cells.

α-cells

Secrete glucagon, increasing blood glucose levels.

β-cells

Secrete insulin, decreasing blood glucose levels.

Glucagon

Increases blood sugar (hyperglycemia) by stimulating glycogenolysis and gluconeogenesis.

Insulin

Decreases blood sugar (hypoglycemia) by enhancing cellular glucose uptake and glycogenesis.

Diabetes Mellitus

Disorder caused by prolonged hyperglycemia, associated with glucose loss in urine.

Testis

Produce androgens (mainly testosterone) regulating male sex characteristics and spermatogenesis.

Androgens

Regulate development and functions of male accessory sex organs and stimulate spermatogenesis.

Ovary

Produce estrogen and progesterone, regulating female sex characteristics and menstrual cycle.

Estrogen

Stimulate growth of female sex organs and secondary sex characteristics.

Progesterone

Supports pregnancy and stimulates milk secretion.

Heart

Secretes atrial natriuretic factor (ANF), decreasing blood pressure.

Kidney

Produces erythropoietin, stimulating RBC formation.

Gastrointestinal Tract

Secretes gastrin, secretin, cholecystokinin (CCK), and gastric inhibitory peptide (GIP).

Atrial Natriuretic Factor (ANF)

Decreases blood pressure by dilating blood vessels.

Erythropoietin

Stimulates RBC formation.

Gastrin

Stimulates secretion of hydrochloric acid and pepsinogen.

Secretin

Stimulates secretion of water and bicarbonate ions from the exocrine pancreas.

Cholecystokinin (CCK)

Stimulates secretion of pancreatic enzymes and bile juice.

Gastric Inhibitory Peptide (GIP)

Inhibits gastric secretion and motility.