Exam 3- Mechanisms Of Hormonal Regulation Flashcards
Pineal gland
Secretes one hormone, melatonin.
Hypothalamus
Secretes 6 hormones: Corticotropin-releasing hormone (CRH) Thyrotropin-releasing hormone (TRH) Growth hormone-releasing hormone (GHRH) Somatostatin Gonadotropin-releasing hormone (GnRH) Prolactin-releasing factor
Connected to the posterior pituitary by a nerve tracts and to the anterior pituitary by portal blood vessels.
Anterior pituitary gland
Releases 7 hormones: Adrenocorticotropic hormone (ACTH) Melanocyte-stimulating hormone (MSH) Thyroid-stimulating hormone (TSH) Growth hormone (GH) Leutinizing hormone (LH) Follicle-stimulating hormone (FSH) Prolactin
Posterior pituitary gland
Secretes 2 hormones:
Antidiuretic hormone (ADH)
Oxytocin
Thyroid gland
Secretes 3 hormones:
T3
T4
Calcitonin
Adrenal gland
Consists of the adrenal cortex and the adrenal Medela.
Adrenal cortex
Part of the adrenal gland. Releases 3 hormones: Aldosterone (mineralcorticoids) Cortisol (glucocorticoids) Adrenal androgens
Adrenal medulla
Part of the adrenal gland. Release catecholamines. Releases 2 hormones: Epinephrine Norepinephrine
Pancreas gland (islets)
Releases 4 hormones: Insulin Glucagon Amylin Somatostatin
Parathyroid gland
Releases parathyroid hormone.
Antidiuretic hormone (ADH)
Alters body fluid osmolality. Releases by posterior pituitary.
Water soluble hormones. Do not need carrier proteins.
Parathyroid hormone (PTH)
Releases by parathyroid gland. Responsible for plasma calcium concentration.
Insulin
Release by pancreas. Responsible for blood glucose regulation.
The net effect is to decrease blood glucose concentration and increase synthesis of proteins and fat.
A peptide.
Gonadotropin-releasing hormone (GnRH)
Releases by hypothalamus. Responsible for menstrual cycle regulation.
Aldosterone
Released from adrenal cortex. Responsible for extracellular fluid volume and plasma potassium concentration.
A steroid.
Water-soluble hormones
Relatively short half-life.
Circulate in free forms.
Bind with cell membrane receptors. Do not need carrier proteins in the blood. Examples are ADH & ACTH.
Up-regulation
Action on cell receptors that increase their cellular sensitivity to a certain hormone. Done in response to a low hormone concentrations.
Hormone receptors
Proteins
Growth hormone
Secreted by the anterior pituitary.
A somatotropic hormone.
Many of the actions are mediated through the effects of insulin like growth factors, which are also known as somatomedins.
A peptide.
Lipid soluble hormones
Alter gene expression when the hormone receptor complex binds to the promoter region of DNA.
Need carrier proteins in the blood. Examples are thyroid hormones and steroid hormones.
Incretins
Released from the gastrointestinal tract and act to decrease postprandial blood glucose concentration.
Cortisol
Released by the adrenal cortex.
Act to increase blood glucose concentration, inhibit inflammation, and caused numerous other effects.
A steroid.
Damage to the thyroid gland
Results in increase blood levels of thyroid stimulating hormone and decreased levels of thyroid stimulating hormone. The cells that secrete them no longer receive negative feedback from the thyroid hormones.
Individuals are likely to gain weight and become intolerant environmental cold.
Renin angiotensin system
Renin acts on angiotensin which normally circulate in the blood. It converts it to angiotensin one. Then enzymes in the capillaries of the lungs convert angiotensin one to angiotensin II, which stimulates the cortex of the adrenal gland to secrete the hormone aldosterone. Aldosterone circulates to the kidneys and causes them to put more salt in water back into the blood. That kidney action increases the blood volume and can increase the blood flow in the kidney blood vessels.
Pheochromocytes
Released from the adrenal Medela. Secrete catecholamines: epinephrine and norepinephrine. Catecholamines are responsible for the fight or flight response and hyperglycemia.
