rutgers integ physiology endocrinology

What is the primary function of hormones in the endocrine system?

Hormones serve as cell-to-cell communication molecules that activate physiological responses.

What are the four main aspects of the endocrine system covered in the notes?

Function and purpose of hormones, classification and structure of hormones, pathways of nervous to endocrine regulation, and effects of hormone interactions.

What are the main types of hormones classified in the endocrine system?

Peptide or protein hormones, steroid hormones, and amine hormones.

What is a preprohormone?

A large, inactive form of a hormone that undergoes post-translational modification to become active.

What is the role of peptide hormone-receptor complexes?

They initiate signal transduction systems that lead to physiological responses in target cells.

What are steroid hormones derived from?

Cholesterol.

How do steroid hormones exert their effects?

They bind to cytoplasmic or nuclear receptors, activating DNA for protein synthesis, and typically have a slower action with a longer half-life.

What are amine hormones derived from?

They are derived from the amino acids tyrosine and tryptophan.

What is the significance of the half-life of hormones?

The half-life indicates the length of time the hormone remains active in the bloodstream.

What is the endocrine reflex pathway?

It includes a stimulus, afferent signal, integration, efferent signal (the hormone), physiological action, and negative feedback.

What hormones are secreted by the posterior pituitary gland?

Vasopressin and oxytocin.

What are the cell types found in the anterior pituitary gland?

Somatotrophs, thyrotrophs, corticotrophs, lactotrophs, and gonadotrophs.

What is the function of releasing hormones from the hypothalamus?

They regulate the release of hormones from the anterior pituitary gland.

What is the role of inhibiting hormones from the hypothalamus?

They inhibit the release of specific hormones from the anterior pituitary gland.

What is the hypothalamic-hypophyseal portal system?

It is a system that allows hormones from the hypothalamus to directly influence the anterior pituitary gland.

What are the physiological actions of insulin?

Insulin regulates glucose levels in the blood by promoting its uptake into cells.

How do peptide hormones typically function?

They bind to surface receptors, activating second messenger systems to elicit cellular responses.

What are the examples of steroid hormones mentioned?

Cortisol, estrogen, and testosterone.

What are catecholamines?

They are a type of amine hormone that includes epinephrine, norepinephrine, and dopamine.

What is the primary role of pheromones?

Pheromones are used for organism-to-organism communication.

What is the significance of hormone interactions?

Hormone interactions can amplify or inhibit physiological responses, affecting overall homeostasis.

What are the three types of hormone interactions?

Permissive, synergistic, and antagonistic.

What hormones are involved in the example of synergism?

Glucagon and epinephrine.

What is the shape of the thyroid gland?

Butterfly shaped.

What do follicular cells in the thyroid gland produce?

T3 and T4 (thyroid hormones).

What do parafollicular cells in the thyroid gland produce?

Calcitonin.

What are the primary functions of thyroid hormones?

Increase basal metabolic rate, enhance catecholamine actions, and regulate development and growth of nervous tissue and bones.

What are the effects of hyperthyroidism?

Increased oxygen consumption, metabolic heat production, protein catabolism, muscle weakness, hyperexcitable reflexes, and psychological disturbances.

What are the effects of hypothyroidism?

Slow metabolic rate, decreased protein synthesis, effects on the nervous system, and bradycardia.

What hormone is released by the parathyroid glands?

Parathyroid hormone (PTH).

What is the role of calcium ions (Ca2+) in the body?

They serve as intracellular signals, contribute to bone strength, aid in blood coagulation, and are required for normal excitability of neurons and muscles.

How is total body calcium balanced?

Total body calcium = intake - output.

What are the three pools of total body calcium?

Extracellular calcium (0.1%), intracellular calcium (0.9%), and calcium in bone matrix (99%).

What is the function of parathyroid hormone (PTH)?

Mobilizes calcium from bone, enhances renal reabsorption of calcium, and stimulates release of calcitriol.

What does calcitonin do?

Decreases bone resorption and increases renal calcium excretion.

What are the two main regions of the adrenal glands?

The inner medulla and the outer cortex.

What hormones are produced by the adrenal medulla?

Norepinephrine and epinephrine.

What are the three zones of the adrenal cortex?

Zona glomerulosa (mineralcorticoids), zona fasciculata (glucocorticoids), and zona reticularis (androgens).

What is the primary function of cortisol?

Helps the body cope with long-term stress and protects against hypoglycemia.

What is the role of melatonin secreted by the pineal gland?

Influences circadian rhythm, induces sleep, protects against free radicals, and inhibits reproductive functions.

What are the main types of cells in the pancreas and their functions?

Alpha cells (secrete glucagon), beta cells (secrete insulin), delta cells (secrete somatostatin), and F cells (secrete pancreatic polypeptide).

What is the main function of insulin?

Promotes anabolism, including cellular uptake of glucose, amino acids, and fatty acids.

What is the main function of glucagon?

Antagonistic to insulin; it promotes breakdown of glycogen and gluconeogenesis.

What is hypercortisolism, and what are its clinical effects?

Cushing's syndrome; it leads to increased glucocorticoid hormone effects such as weight gain, high blood pressure, and muscle weakness.

What is the screening test for plasma cortisol levels?

Overnight dexamethasone suppression test or 24-hour urine free cortisol measurement.