hala endocrine system

cAMP and Calcium

The two most common second messengers used by peptide hormones

Steroid Hormones

Lipid-soluble hormones that diffuse through the plasma membrane and bind to receptors inside the cell nucleus

Steroid Hormone Mechanism

Hormone binds to receptors in the nucleus and activates specific genes

Oral Steroid Hormones

Can be taken orally because they are lipids and are not easily digested

Hormone Release Mechanisms

Humoral, Hormonal, and Neural stimuli control hormone secretion

Anterior Pituitary Gland

Endocrine gland regulated by hypothalamic releasing and inhibiting hormones

ADH (Antidiuretic Hormone)

Increases water reabsorption by the kidneys and constricts blood vessels, raising blood pressure

Oxytocin Feedback

Controlled by positive feedback mechanisms

Oxytocin

Stimulates uterine contractions during childbirth and milk ejection during nursing

Diabetes Insipidus

Disorder caused by insufficient ADH secretion resulting in excessive urine production

Ovary

Endocrine gland regulated by anterior pituitary hormones such as FSH and LH

ACTH (Adrenocorticotropic Hormone)

Anterior pituitary hormone that stimulates the adrenal cortex

Adrenal Cortex

Outer region of the adrenal gland that produces cortisol and aldosterone

Growth Hormone (GH)

Stimulates protein synthesis, amino acid uptake, and fat metabolism but does not promote glucose metabolism

Acromegaly

Disorder caused by excessive growth hormone secretion in adults

Iodine

Essential mineral required by the thyroid gland to produce thyroid hormones

Simple Goiter Prevention

Adequate iodine intake, commonly through iodized salt

Myxedema

Adult hypothyroidism caused by an underactive thyroid gland

Hashimoto's Disease

Autoimmune disorder in which the immune system destroys thyroid tissue, causing hypothyroidism

Parathyroid Hormone (PTH)

Raises blood calcium levels by releasing calcium from bone, increasing kidney reabsorption, and activating vitamin D

Aldosterone

Primary mineralocorticoid of the adrenal cortex that increases sodium and water retention and increases blood pressure

Cortisol

Glucocorticoid hormone that promotes protein and fat metabolism and suppresses inflammation

Glucocorticoid

Hormone class involved in fuel metabolism and stress responses; cortisol is the primary example

Atrial Natriuretic Hormone (ANH)

Hormone produced by the right atrium of the heart that lowers blood pressure and opposes aldosterone

ANH (Atrial Natriuretic Hormone)

Antagonistic hormone to aldosterone

Cushing Syndrome

Condition caused by hypersecretion of adrenal cortex hormones, especially cortisol

Glucagon Release

Secreted by the pancreas when blood glucose levels are low

Glucagon

Pancreatic hormone that raises blood glucose by stimulating glycogen breakdown in the liver

Glycogenolysis

Breakdown of glycogen into glucose, stimulated by glucagon

Type 1 Diabetes Mellitus (IDDM)

Autoimmune destruction of pancreatic beta cells; treatment usually requires insulin injections

Glycosuria

Presence of excess glucose in the urine

Polyuria

Excessive urine production

Polydipsia

Excessive thirst

Polyphagia

Excessive hunger

Estrogen

Hormone responsible for maturation of the ovum and development of female secondary sex characteristics

Testosterone

Male sex hormone controlled by the anterior pituitary gland through LH secretion

Melatonin

Pineal gland hormone that regulates sleep-wake cycles and influences sexual development

Tumor Angiogenesis Factor

Growth factor released by cancer cells that stimulates formation of blood vessels to support tumor growth

Fuel Metabolism Hormones

Insulin, Glucagon, and Cortisol regulate fuel metabolism

Aldosterone

Does not directly regulate fuel metabolism; regulates sodium, potassium, water balance, and blood pressure

Peptide Hormones

Hormones that bind to receptors on the plasma membrane and use second messengers such as cAMP and calcium

Negative Feedback

Primary mechanism controlling most endocrine hormone secretion

Hypothalamus

Produces releasing hormones, inhibiting hormones, ADH, and oxytocin

Posterior Pituitary

Stores and releases ADH and oxytocin produced by the hypothalamus

Thyroid Hormone

Increases metabolic rate, growth, and development

Calcitonin

Thyroid hormone that lowers blood calcium levels by promoting calcium deposition in bone

Adrenal Medulla

Inner region of the adrenal gland that secretes epinephrine and norepinephrine

Epinephrine and Norepinephrine

Hormones that mimic sympathetic nervous system responses

Hormones Regulating Blood Pressure and Volume

ADH, Aldosterone, and ANH

Oxytocin

Does not regulate blood pressure or blood volume

Endocrine System and Nervous System

Work together to maintain homeostasis

Hormones

Chemical messengers that regulate metabolism, growth, development, reproduction, and homeostasis