Intercellular Communication Flashcards
what does the multicellular state lead to?
leads to specialization and division of labour
what does cellular specialization give rise to?
tissues and organs with highly specific functions
what can the breakdown in cell communications cause?
malfunction and disease
what are the 3 ways that animal cells communicate in?
- secretion of chemical messengers, we can refer to this as remote communication bc something is produced by the cell, it leaves the cell and needs to be picked up by another cell. there is no direct contact between cells.
- contact communication - occurs with membrane bound molecules so like
glycosylated protein in plasma membrane of cells (things on the surface) - inter-cellular communications via gap junctions, holes in the plasma membrane of one cell can line up with hole in the plasma membrane of another cell, so that things can be passed backwards and forwards between the cells
whats the best way you can send something a long way in the body?
through the blood
do all signalling mechanisms operate the same distance?
signalling mechanisms vary in the distances over which they operate
how are long distance chemical signals produced?
the cells of the endocrine system secrete hormones which travel through the bloodstream to specific target cells e.g. adrenaline and testosterone
how are medium distance chemical signals produced?
paracrine cells secrete local chemical mediators which act only on cells in the immediate environment.
usually to do with tissue regeneration/ wounds
how are short distance (synaptic) chemical signals produced?
nerve cells produce neurotransmitters. the chemicals only move a very short distance between adjacent cells - only across the synaptic junction.
the electrical message travels a long distance whereas the chemical signals travels a short distance - this is why its short distance chemical signalling
what do exocrine cells do?
they are secretory cells (like endocrine), they also produce chemicals but usually those chemicals are things to do with digestion, they are certainly not hormonal substances.
an exocrine cell produces and secretes stuff that is non hormonal, and it goes into a duct - a tube that drains the organ thats producing it.
give an example of an exocrine cell
gall bladder producing bile - excorine secretion. it tips the bile material into the duct so the bile duct of the liver.
what do paracrine cells secrete?
local chemical mediators, they diffuse to neighbouring cells only.
what is a neuroendocrine?
nerve cell with endocrine function
can you get cells with dual functions?
yes
what is a neurocrine?
a nerve cell with paracrine function
what produces hormones?
endocrine cells, or specialised nerve cells in the brain
what is the pituitary gland also known as? and why?
the master gland bc the hormones it produce tend to regulate all the other primary glands
what are the primary parts of the endocrine system?
the pineal gland, hypothalamus, pituitary gland (all in the head), then the thyroid gland, parathyroid glands, thymus, adrenal glands, pancreas, ovaries, testes and placenta
what do the primary endocrine organs do?
their primary function is the secretion of hormones
what do the secondary endocrine organs do?
secondary endocrine organs have a non endocrine primary function
what are the secondary organs of the endocrine system?
heart, stomach, liver, kidney, small intestine, skin
what can horomones be?
modified amino acids, small peptides, small proteins, steroids
what can local chemical mediators be?
amino acid deriatives, fatty acid deriatives, small proteins, dissolved gases
what can neurotransmitter be?
amino acids, amino acid deriatives, choline deriatives, small peptides
what do cells need simply to survive?
cells need input (Chemical signals) from other cells simply to survive)
what is apoptosis?
programmed cell death
do all cells react the same way to the same chemical signal?
no, different cells can react in different ways to the same chemical signal
do neurotransmitters act rapidly?
yes, information is transmitted over long distances at high speed by electrical impulses. because of this, locl concentrations tend to be high
where is the information converted to a chemical signal?
at the nerve terminal (synapse)
do hormones act rapidly?
no, hormones act at low concentrations, they have slow, widespread lasting effects
what are hormones important in?
they are important in developmental processes, e.g. human sex hormones may act over a period of many months
what does endocrine signalling rely on?
diffusion and blood flow, it is often slo
