Week 11- Endocrine System Flashcards
What is the endocrine system
Chemical messenger (hormones) system within the human body that maintains the constant internal environment of the human body (homeostasis)
Name endocrine organs in the brain
Pineal gland
Hypothalamus
Pituitary gland
Name endocrine organs in the throat
Thyroid
Parathymoid
Thymus
Name endocrine organs in the upper abdomen
Adrenal cortex
Kidney
Pancreas
Name endocrine organs in the lower abdomen
Testes (male)
Ovaries (female)
Uterus (female)
How are hormones activated
Change in the local environment
Low circulation of ions or nutrients (hum oral control)
Response to stress, anxiety (fight or flight)
Describe 2 ways in which hormones can alter the function of a target cell
1) bind to a receptor on the outside of a cell (G-protein coupled) that implements a sequence of reactions inside the cell that dictate a certain action/function
2) enter the cell and instigate a change in a receptor in the nucleus causing a shift in proteins being created by the cell, which can alter cell function (steroid hormones)
Describe fully the binding to a hormone on the outside of a cell
-hormone attatches to actioned site of the receptor
-triggers a release of G-protein
-this activates ADENYL CYCLASE which convert ATP into CYCLIC AMP
-cyclic AMP activates protein KINASE A (PKA)
-PKA can then phosphorylate a protein within the cell that can start a signal (activate/inhibit) causing a mechanism within the cell to change
Describe fully the binding to a hormone on the inside of a cell
-steroid hormones is lipid soluble so can pass into cytoplasmof the cell
-it can bind to a receptor and in its activated form enters nucleus of the cell
-this receptor-hormone complex can initiate a change in the transcription of new proteins from the DNA at a specific ‘hormone response elements’
-the newly transcribed mRNA will exit the nucleus and travel to ribosome for translation
- a new protein will be synthesised that can alter cell
Describe the interplay between endocrine system and nervous system
-nervous signals in the brain stimulate the secretion of hormones
-this happens at hypothalamus which activates pituitary gland
-this ‘master gland’ can stimulate other glands of endocrine system
-such as: hypothalamic-pituitary-adrenal (HPA) AXIS
-hypothalamic-pituitary-thyroid (HPT) axis
-hypothalamic-pituitary-gondal (HPG) AXIS
-hypothalamic-pituitary- prolactin (HPP) AXIS
-comminucation In the anterior pituitary is via the hypothalamic hypophyses portal system
Describe Hormones from testes
Testosterone, released from testes
Anabolic- promote tissue building and nutrient storage
Androgenic- promotes masculine characterisations
Describe Hormones from ovaries
Oestrogen and progesterone released from ovaries
Establish and maintain reproductive function
Controls phases of menstrual cycle
Anabolism definition
Biochemical process in METABOLISM where simple molecules combine to generate complex molecules. Requires energy.
Androgen definition
Any group of hormones that’s primarily influence growth and development of male reproductive system
-dominant hormone is testosterone
Describe POLYSISTIC OVARY SYNDROME (pcos)
Overproduction of androgens interfere with developments of eggs and their release from female ovaries. PCOS is a leading cause of infertility.
Describe HYPERTHYROIDISM
Thyroid gland produces too much thyroid hormone
Leads to weigh loss, fast HR, sweating and nervousness
Define HYPOTHYROIDISM
Thyroid gland doesn’t produce enough thyroid hormone
Leads to fatigue
Constipation
Dry skin
Depression
Under active gland can cause slow development in children
Describe type 1 diabetes
Autoimmune in origin
-Body attacks beta cells of pancreas.
-over time, pancreas loses all insulin producing cells
-patient becomes fully reliant on synthetic insulin to manage blood glucose
What does the pancreas secrete
Glucagon
Insulin
Describe pancreas secretion of hormones
GLUCAGON- alpha cells, promote breakdown of glycogen into glucose, promotes G;UCOGENESIS
INSULIN- beta cells, promote cellular uptake and storage of glucose and formation of glycogen
Describe how the anterior pituitary is stimulated and the process which follows
-hypothalamus sends hormones through hypothalamic-hypophyses portal system, stimulating the release
-this hormone sent is a RELEASING HORMONE as it signals the anterior pituatory to start producing hormones.
-the hormone from pituitary entering systemic circulation is then a STIMULATING hormone as it travels to the sites of action
-posterior pituitary doesn’t contain secretory cells. It stores hormones produced by hypothalamus ready for release into circulation when the signal arrives.
Name hormones with anterior pituitary gland secretes
-adrenocorticotropic hormone ACTH
-follicle stimulating hormone FSH
-lutienizing hormone LH
-melanocyte-stimulating hormoneMSH
-thyroid stimulation hormoneTSH
-growth hormone GH
-prolactin PRL
Name hormones with posterior pituitary gland secretes
-oxytocin
-anti-diuretic hormone ADH
Describe secretion of oxytocin
Posterior pituitary gland
-initiates muscular contraction of the uterus and stimulates milk production during lactation (female)
-increases production of testosterone in the testes (Male)
Describe secretion of anti-diuretic hormone ADH
-reduces water loss from the body to maintain plasma volume
(Via promoting water re-uptake from the collecting ducts in the kidney)
-release stimulated by high plasma ion conc (osmolaitiy) and low plasma volume
(Due to sweat/dehydration)
-Increase during exercise
(Maintain plasma volume)
Describe secretion of growth hormone in the anterior pituitary gland
Anterior pituitary gland
-promotes cell division and proliferation
-stimulate breakdown of fats for energy
-stimulates synthesis of glycogen
-promotes bone and cartilage growth
-stimulates uptake of amino acids and protein synthesis
Describe secretion of adrenocorticotrophic hormone in the anterior pituitary gland (ACTH)
anterior pituitary gland
-released after cortticotropin releaseinghormone has been secreted by HYPOTHALAMUS
-cause cortisol secretion from adrenal cortex
-causes aldosterone secretion from adrenal cortex
-can bind directly with melanocytes of the skin: causes increase in production of melanin
-stimulating hormone produced by anterior pituitary
Describe secretion of melanocyte stimulating hormone in the anterior pituitary gland
-regulates functions of skin pigments in cells (tanning)
Describe secretion of follicle stimulating hormone in the anterior pituitary gland
-initiates follicle growth in ovaries and oestrogen secretion (females)
-stimulates germinal epithelium growth in testes (males)
Describe secretion of luteinizing hormone in the anterior pituitary gland
-causes oestrogen secretion
-stimulates testes to secrete testosterone
Describe secretion of prolactin in the anterior pituitary gland
-stimulates location for milk production
-inhibits FSH and gonadotropin releasing hormone (GnRH)
Describe secretion of THYROID hormone in the THYROID GLANDS
-stimulated by thyroid releasing hormone ink thyroid gland
-2 types, THYROXINE (T4)
-TRIIODOTHYRONINE (T3)
-T4 raises metabolisms (body temp) in all tissues expect brain, spleen, testes, uterus and thyroid
-T4 AND T3 regulate tissue growth and development, skeletal and nervous system formation, maturation and reproduction
Where does T4 NOT raise metabolism
-brain
-spleen
-testes
-uterus
-thyroid
Describe Grave’s disease
Autoimmune condition where your immune system mistakenly attacks thyroid which causes it to become overactive
Unkiniown cause
Affects young or middle aged women and runs in families
Describe secretion of parathyroid hormone in the parathyroid glands
-increase blood calcium and phosphate levels
-stimulates osteoclasts
-promotes calcium re absorption in kidneys and phosphate excretion
-increase synthesis of vitamin D which in turn, increases absorption of calcium and phosphate by intestines. Net loss of phosphate with PTH
-regulation depends on circulating calcium levels
what does the thyroid hormone (T4) do
Increase metabolic rate in all cells through gene regulation
How could the body respond to low calcium
Increased parathyroid release which increases breakdown of bone
Which hormones are made In adrenal cortex
Aldosterone
Cortisol
What does aldosterone do
Increase reuptake of na+ in kidney
How does the hypothalamus communicate with anterior pituitary gland
Through hypothalamic hypophyseal portal system
What is adrenocorticotrophic hormone (ACTH)
-stimulating hormone produced by anterior pituitary
What is paracrine cellular communication
-hormones released by one cell that stimulate only local celll populations
What is paracrione cellular communication
-hormones release by one cell that stimulate only local cell populations
what does adrenal medulla secrete. describe these hormones functions
Secretes Adrenaline and Noradrenaline-
-These combine with adrenergic receptors on cells (G-protein coupled)
-Secretion of adrenaline prepares the body for physical activity (fight or flight)
- Effects are short-lived as these hormones are rapidly metabolised
-Increases blood levels of glucose
-Increases fat breakdown in adipose tissue
-Causes dilation of blood vessel in skeletal and cardiac muscles
what does adrenal cortex secrete. describe these hormones functions
Adrenal Cortex- Secretes Mineralocorticoids;Androgens; Glucocorticoids
-Mineralocorticoids:
Aldosterone – increases rate of sodium reabsorption by kidneys increasing blood sodium levels
-Glucocorticoid:
Cortisol – Increases fat and protein breakdown, increases glucose synthesis, decreases inflammatory response
describe addisons disease
also called adrenal insufficiency, is an uncommon disorder that occurs when your body doesn’t produce enough of certain hormones.
In Addison’s disease, your adrenal glands, located just above your kidneys, produce too little cortisol and, often, too little aldosterone
describe cushings syndrome
is a disorder that occurs when your body makes too much of the hormone cortisol over a long period of time. Cortisol is sometimes called the “stress hormone” because it helps your body respond to stress. Cortisol also helps maintain blood pressure. regulate blood glucose, also called blood sugar.
name a disease of the pancreas
type 1 diabetes
what does the anterior pituitary contain which the posterior pituitary does not
secretory cells.
therefore, posterior cannot secrete its own hormones. instead, it stores hormones produced by hypothalamus ready for release into circulation when the signal arrives
Where are adrenalglands located
On top of kidneys
What doe pituitary glands hormones influence
Growth
Reproduction
Metabolism
\stress response
What do adrenal glands secrete
Cortisol
What does cortisol affect
Metabolism
Stress response ‘fight or flight’
