Endocrines Flashcards
An hormone is
A bioregulator this will participate in the coordinated interplay between cells, organs , and tissues. It allows them to interact
Autocrine substance
It is secreted by the cell and it will affect the same cell
Why does the product of autocrine secretion work outside of the same cell
Because there are receptors that are located on the plasma membrane eg growth factors
Paracrine secretion
This do not act via the blood they are local acting chemical, they are produced by the cell in the local vicinity, they are deactivated when they get into the blood or can’t move through the capillaries eg prostaglandins
Cytokines
These are growth factors that are produced by cell for specifically for cells that are similar eg immune cells lymphokines these are local in action
Neurotransmitter
Highly specialized transmitting molecules, involves communication between two neuron, information is moved from pre synaptic to post synaptic, does not gain access to the blood, has a very short life eg acetyl COA , noepiernphrine,dopamine
Neurosecretion or neurohormone
Product of a neuron, that is transported dismally away from the neuron where it is in effect, longer half, travels by blood eg ADH anti diuretic hormone and oxytosin
ADH
A vasopressin produced in the hypothalamus super optic nucleus and stored in the posterior lobe pituitary and it has pleotropic effects
Oxytosin
Oleo tropic molecules involved with the contraction of the uterus during birth process
Pheromones
It is the product of a cell of an organism that affect another organism of the Same species, these are ectohormones released to the environment
VNO
Vomronasal organ in humans and animals very functional in animals
Allelomones
These are types of pheromones there are two types allomones and kairomones
Allomones
The donor receives the benefit and the recipient doesn’t eg skunk
Kairomones
The donor doesn’t receive the benefit while the recipient does, when humans sweat it attract female Mosquitos due to the production of l lacate in sweat
Intrakines
This are chemical that are produced within the cell that will affect the activity of the cell
The secondary messenger in signal transduction are
cAMP,cGMP, ca,IP3
Exocrine glands secrete
Enzymes especially the ones used for digestion
The function of mucus
Act as a lubricant. Guards against dehydration,abrasio, and dissolving odorants. It is a unicellular exocrine
Glycocalyx fuzzy coat
These are glycoproteins secreted or embedded on the surface of the membrane, the carbohydrate chains extend off the cell giving a fuzzy like appearance, this found in only animal cells only
Packaging and transport of secretion non steroidal
Transcription occurs packaging and transporting occurs at different rate.synthesis and packaging are independent. Except for steroids they can move through the plasma membrane and released outside the cell.
Steps of synthesis of hormones
A secretory vesicle is formed containing material, trafficking occurs where it is guided to the surface of the cell by specific trafficking protein, the vesicles fuse to the membrane leading to the membrane opening and let out the vesicle by excocytosis. This process is by ATP
Synthesis of hormones begins
With translation in RER, it is a vase intracellular system and has canal in which the product of the ribosome can be deposited. SER is well developed for production of steroid producing cells.
The product from RER moves
To the TGN to modify and packaging of the material.
TGN has three parts
Cis phase initial part, medial phase and trans phase
House keeper proteins
Manufacture secretory product the budding processes is the formation of the vesicles at the end
The buddying process of secretory product is done by
TGN coatomer protein which are 7 members be protein that are embedded in the TGN they are connected with ARF
ARF is a
G protein..
Trafficking of protein
Is done by the binding of ARF to coatomers and vesicle to were they will be processed dissociation is done by the hydrolysis of the G protein from GDP to GTP
Folding of protein, congregation of peptides, and condensation occurs in the
TGN
Modes of secretion
Merocine, apocrine, Holocrine,cytocrine, and cyotgenous
Metro rinse
Excretions of the secretion by exocytosis into an epithelial walled duct or into the lumen. The gland releases its product and no part of the gland is lost or damaged
Apocrine secretion
Apex of the cell is involved example epocrine sweat gland. The secretory material aggregates at the apex of the cell then is secreted .. The cell becomes apoptosis
Eccrine sweat gland are used for
Themoregualtion not apocrine
Holocrine secretion
The entire cell is the secretion eg sabeseous gland
Cytocrine secretion
The transfer of secretory materials from one cell to another. Eg the transferring of melanonin to keratinocytes because they do not make their own melanin
Cyotgenous secretion
This occurs when you have an impact cell, the impart cell actually becomes the secretion eg sex cells
Endocrine glands
A group of cell that function to produce or secrets a usable substance, ductless glands, hormones are their products deposited into the blood by fenestrayted capillaries
Exocrine glands
This have duct that carries the secretion away, the secretory material does not enter into the blood
Hormones
It has to be a product of an endocrine gland transported by blood, and acts dismally Fromm site of origin on target cells
Categories of hormones
Steroids from the nucleus, formed from a precursor molecule cholesterol, estrogen, progesterone vitamin , glucocorticoid… proteins and polypeptide , derivatives of tyrosine
Hormones transported by blood
Water insoluble and soluble
Water insoluble proteins
Are conjugated with proteins from the liver for transport
Water soluble hormones
Peptide and catecholamines, dissolve in the plasma and transported by diffusing into interestial fluid eg protein and peptides
Secretion rate
Determine the level of hormone in the blood
Metabolic clearance rate
Kidney and liver removes the hormone from the blood, target cells removes the it from the receptor… Basically rate of disappearance of the hormone from the blood
Location of hormone receptors
Located internally and externally of the membrane, or in the cell or in the nucleus
Receptor characteristics
Specific, isoforms, saturation, competition, affinity
Saturation
Given the response of the cell, the amount of the response is regulated,
Competition
Another substance or agonist can bind to the receptor mucking the responses of the original substance
Affinity
Some receptor exist in low and high receptor, high quickly binds and low rarely binds but can be forced to
Down regulation
Reduction of response of the cell overtime which can involve modification of receptor and of the removal of the receptor
