Ch. 15 The Endocrine System Flashcards
This is the control system of the metabolic chemistry of the body by use of hormones.
The endocrine system
These are chemical messengers released into the blood.
Hormones
The endocrine system is composed of what 2 types of glands?
- Exocrine
2. Endocrine
This gland secretes substances (saliva and sweat) using ducts.
Exocrine gland
This gland secretes into surrounding tissues which happen to be richly vascularized. It is ductless.
Endocrine gland
What are the major glands of the endocrine system?
- Pineal
- Pituitary
- Thyroid
- Parathyroid
- Adrenal
- Pancreas’s
- Gonads
This is a neuroendocrine organ.
Hypothalamus
These glands of the endocrine system are part of the immune response.
- Autocrines- affect releasing cell
2. Paracrines- affect nearby cells
What are the 3 chemical classifications of hormones?
- Amino acid based
- Steroids
- Eicosanoids
This classification of hormone is modified amino acids such as epi and NE, peptides, and proteins.
Amino acid based
This classification of hormone is derivatives of cholesterol (gonadal and adrenocortical hormones)
Steroids
This classification of hormone are derivatives of arachidonic acid (leukotrienes and prostaglandins). Most of these are used in a paracrine manner.
Eicosanoids
This classification of hormone is water soluble.
Most amino acid based hormones
This classification of hormone is lipid soluble.
Steroids and eicosanoids
What do hormones do in the body?
- They alter plasma membrane permeability or membrane potential or both.
- Stimulate synthesis of proteins or regulatory molecules.
- Activate/deactivate enzymes
- Induce secretions
- Start mitosis
Water soluble hormones require ______ receptors.
Membrane
Lipid soluble hormones use ____ receptors.
Intracellular
Hormones work by activating what at the plasma membrane receptor?
Second messenger system
cAMP second messenger activates what protein?
Kinase
The second messenger changes what?
The cell
Protein kinase A ____/______ other enzymes and proteins.
Activates and inhibits
This is an enzyme that rapidly degraded cAMP.
Phosphodiestrase
Inhibitory G proteins can inhibit ____ cyclase. It has antagonistic effects of different hormones and receptors.
Adenylate
During PIP calcium signaling, a G protein is activated which in turn activated what?
Phospholipase C
Phospholipase C cleaves PIP into what’s 2 things?
DAG
IP3
During PIP calcium signaling the DAG activates protein ______.
And ___ triggers the release of calcium.
Kinase C
IP3
Once calcium is activated during PIP signaling what occurs?
It activates enzymes and binds calomodulin two activate other enzymes.
These are lipid soluble hormones that diffuse into target cells and bind receptors found within the cell.
Intracellular receptors
In the nucleus hormones and receptor bind DNA and activate.
Hormone response element
Hormone release controls are usually a ____ feedback loop.
Negative
What are the three stimuli that activate production and release of hormones?
Humoral
Neural
Hormonal
Hormone release caused by altered levels of certain critical ions or nutrients.
Stimulus is a low concentration of Ca2+ in capillary blood.
Response is the parathyroid glands secrete parathyroid hormone which increases Ca2+.
Humoral
Hormone release caused by neural input.
Stimulus is action potentials in preganglionic sympathetic fibers to adrenal medulla.
Response is adrenal medulla cells secrete epinephrine and norepinephrine.
Neural
Hormone release caused by another hormone (a tropic hormone).
Stimulus is a hormone from the hypothalamus.
Response is the anterior pituitary gland secretes hormones that stimulate other endocrine glands to secrete hormones.
Hormonal
_____ system can override controls in response to severe changes in body homeostasis.
Nervous
What are the 8 major endocrine glands?
- Pituitary or hypophysis
- Thyroid
- Parathyroid
- Adrenal
- Pancreas
- Gonads
- Pineal
- Thymus
What are the 2 parts of the pituitary gland?
- Anterior
2. Posterior
The posterior pituitary gland is also called the ?
neurohypophysis
The posterior pituitary gland releases what?
neurohormones- hormones produced by neurons
The anterior pituitary gland is also called what?
adenohypophysis
The anterior pituitary gland acts as a what?
endocrine gland
These are axons from supraoptic and paraventricular nuclei of the hypothalamus and run through the infundibulum to neurohypophysis. Hormones released to capillaries in the neurohypophysis.
Hypothalamic hypophyseal tract
The anterior pituitary produces ___ hormones than the posterior.
more
What are the hormones produced by the anterior pituitary gland?
- Tropins
- Growth Hormone (GH)
- Thyroid Stimulating Hormone (TSH)
- Adrenocorticotropic Hormone (ACTH)-adrenal cortex
- Gonadotropins- follicle stimulating hormone and luteinizing
- Prolactin-produce milk
These are hormones of the anterior pituitary gland that regulate other endocrine glands. They are produced by cells called thyrotrophs. They are triggered by thyrotropin releasing hormone and inhibited by rising levels of thyroid hormone.
Tropins
These are produced by cells called somatrophs and their largest targets are muscles and bones. They are anabolic hormones.
Growth Hormones
These are hormones produced by corticotrophs and stimulate the adrenal cortex. They are inhibited by rising levels of glucocorticoids from the adrenal cortex.
Adrenocorticotropic hormone
These are follicle stimulating hormones (FSH) and luteinizing hormones (LH). They are produced by cells called gonagotrophs and regulate the gonads.
FSH is for gamete production and LH is for sex hormone production.
Gonadotropins
This hormone is produced by cells called lactotrophs and stimulates milk production in women. It is inhibited by dopamine.
Prolactin
What are the 2 hormones produced in the posterior pituitary (neurohypophysis)?
- Antidiuretic Hormone (ADH)
2. Oxytocin
This is a strong stimulate of uterine contractions and a trigger for milk ejection. It uses PIP-calcium pathways.
Oxytocin
This inhibits urine production to maintain bodys water balance. It is activated by high osmolarity, pain, low BP, and drugs. Alcohol also inhibits this.
Antidiuretic Hormone.
This endocrine gland is located in the anterior neck inferior to the larynx just above the aorta.
Thyroid gland
The thyroid gland is 2 lobes connected by?
isthmus
The thyroid is composed of spherical follicles that contain _____.
Colloid-jelly like substance
These are glycoproteins called thyroglobulin bound t iodine atoms.
Follicles containing colloid
These follicle cells of the thyroid gland produce hormone calcitonin.
Parafollicular cells
What are the 2 iodine containing hormones of the thyroid?
- Thyroxine (T4)
2. Triiodothyronine (T3)
What is the purpose of iodine hormones?
To increase the basal metabolic rate and body heat production.
Which is the major iodine hormone released by the thyroid? The other is mostly produced by target cells.
T4
T3
This is the formation of thyroglobulin via an accumulation of iodide which is converted to iodine and attaches to thyroglobulin to form T1 or T2. These combined form T3 or T4.
Thyroid Hormone Synthesis
This is a direct antagonist of the parathyroid hormone. It stimulated uptake of calcium from blood to be stored in bones and inhibits osteoclasts.
Calcitonin
These are 4 glands on the posterior surface of the thyroid gland. They are produced by cheif cells and release is triggered by falling blood calcium levels.
Parathyroid glands.
Parathyroid hormone (PTH) stimulates osteoclasts to removes ____. Stimulates reabsorption of ___ in the kidneys, stimulates ____ absorption in the small intestine.
calcium
These are pyramidal shaped glands on the top of the kidneys. They each function as 2 separate endocrine glands.
Adrenal Glands
What are the 2 parts to the adrenal glands?
- Adrenal medulla
2. Adrenal cortex
This is the inner part of the adrenal gland and is part of the sympathetic nervous system.
Adrenal medulla
This is the outer part of the adrenal gland.
Adrenal cortex.
The adrenal glands contain 2 dozen steroid hormones called?
Corticosteriods
The cells of the adrenal gland are arranged in what 3 layers?
- Zona Glomerulus
- Zona Fasciculata
- Zona Reticularis
This layer of the adrenal gland produces mineralocorticoids to control mineral and water balance of blood.
Zona Glomerulus
This layer of the adrenal gland produces metabolic hormones called glucocorticoids that inhibit adrenocortical tropic hormones.
Fasciculata
This layer of the adrenal gland produces sex hormones called gonadocorticoids.
Zona Reticularis
This is the most produced mineralocorticoids thats purpose is to maintain sodium ion balance.
Aldosterone
How is aldosterone stimulated?
By rising levels of potassium, falling sodium levels and decreasing blood volume and pressure. Na K pump
This is a cell of the adrenal medulla that is a modified ganglionic sympathetic neuron.
Chromaffin cell
What do chromaffin cells produce? And why is it released?
80% epinephrin
20% norepinephrin
Released in response to stress
This is a major digestive system organ.
Pancreas
The pancreas is composed of what 2 cells/structures?
- Acinar cells
2. Pancreatic islets
These are cells that form the bulk of the pancreas and produce and release digestive enzymes.
Acinar cells
These are small clusters of cells in the pancreas that produce pancreatic hormones and regulate blood glucose levels.
Pancreatic islets
The pancreatic islets produce 2 types of cells?
- Alphs cells
2. Beta cells
The alpha cells in the pancreatic islets produce?
glucagon
The beta cells in the pancreatic islets produce?
insulin
This increases blood glucose levels.
glucagon
This decreases blood glucose levels.
insulin
These maintain blood glucose levels and blood pressure.
Glucocorticoids
The major hormone of glucocorticoids is?
Cortisol (hydrocortisone)
This will greatly increase the release of cortisol/
Stress
Excessive glucocoricoid levels can cause what to occur within the body?
- Depress cartilage
- inhibit inflammation
- depress immune system
- change cardiovascular, neural and gastrointestinal functions.
These are weak androgens and are believed to contribute to the onset of puberty.
Gonadocorticoids
The gonads include which organs.
- Ovaries
2. Testes
This produce progesterone and estrogens.
Ovaries
These are maturation of female reproductive organs and secondary sex characteristics.
Estrogen and progesterone
This produces testosterone.
Testes
These are maturation of male reproductive organs and secondary sex characteristics.
Testosterone
This gland hangs from the roof of the third ventricle and releases the hormone melatonin which makes us drowsy and peaks at night.
Pineal gland
This gland is deep to the sternum and is large in infants and non-existant in adults. It is necessary for normal development of T lymphocytes.
Thymus
What are the 5 minor organs involved in the endocrine system?
- Heart- Atrial natureric peptide (ANP) reduces blood volume, pressure, and sodium concentration
- GI Tract- peptide hormone regulates digestive system activities
- Placenta- hormone to help maintain pregnancy
- Kidneys- erythrpoietin activates RBC production
- Adipose- leptin released after uptake of glucose to activate satiety centers of the brain