Intercellular Communication

Question 1

what does the multicellular state lead to?

Answer 1

leads to specialization and division of labour

Question 2

what does cellular specialization give rise to?

Answer 2

tissues and organs with highly specific functions

Question 3

what can the breakdown in cell communications cause?

Answer 3

malfunction and disease

Question 4

what are the 3 ways that animal cells communicate in?

Answer 4

1. 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.
2. contact communication - occurs with membrane bound molecules so like
   glycosylated protein in plasma membrane of cells (things on the surface)
3. 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

Question 5

whats the best way you can send something a long way in the body?

Answer 5

through the blood

Question 6

do all signalling mechanisms operate the same distance?

Answer 6

signalling mechanisms vary in the distances over which they operate

Question 7

how are long distance chemical signals produced?

Answer 7

the cells of the endocrine system secrete hormones which travel through the bloodstream to specific target cells e.g. adrenaline and testosterone

Question 8

how are medium distance chemical signals produced?

Answer 8

paracrine cells secrete local chemical mediators which act only on cells in the immediate environment.
usually to do with tissue regeneration/ wounds

Question 9

how are short distance (synaptic) chemical signals produced?

Answer 9

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

Question 10

what do exocrine cells do?

Answer 10

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.

Question 11

give an example of an exocrine cell

Answer 11

gall bladder producing bile - excorine secretion. it tips the bile material into the duct so the bile duct of the liver.

Question 12

what do paracrine cells secrete?

Answer 12

local chemical mediators, they diffuse to neighbouring cells only.

Question 13

what is a neuroendocrine?

Answer 13

nerve cell with endocrine function

Question 14

can you get cells with dual functions?

Answer 14

yes

Question 15

what is a neurocrine?

Answer 15

a nerve cell with paracrine function

Question 16

what produces hormones?

Answer 16

endocrine cells, or specialised nerve cells in the brain

Question 17

what is the pituitary gland also known as? and why?

Answer 17

the master gland bc the hormones it produce tend to regulate all the other primary glands

Question 18

what are the primary parts of the endocrine system?

Answer 18

the pineal gland, hypothalamus, pituitary gland (all in the head), then the thyroid gland, parathyroid glands, thymus, adrenal glands, pancreas, ovaries, testes and placenta

Question 19

what do the primary endocrine organs do?

Answer 19

their primary function is the secretion of hormones

Question 20

what do the secondary endocrine organs do?

Answer 20

secondary endocrine organs have a non endocrine primary function

Question 21

what are the secondary organs of the endocrine system?

Answer 21

heart, stomach, liver, kidney, small intestine, skin

Question 22

what can horomones be?

Answer 22

modified amino acids, small peptides, small proteins, steroids

Question 23

what can local chemical mediators be?

Answer 23

amino acid deriatives, fatty acid deriatives, small proteins, dissolved gases

Question 24

what can neurotransmitter be?

Answer 24

amino acids, amino acid deriatives, choline deriatives, small peptides

Question 25

what do cells need simply to survive?

Answer 25

cells need input (Chemical signals) from other cells simply to survive)

Question 26

what is apoptosis?

Answer 26

programmed cell death

Question 27

do all cells react the same way to the same chemical signal?

Answer 27

no, different cells can react in different ways to the same chemical signal

Question 28

do neurotransmitters act rapidly?

Answer 28

yes, information is transmitted over long distances at high speed by electrical impulses. because of this, locl concentrations tend to be high

Question 29

where is the information converted to a chemical signal?

Answer 29

at the nerve terminal (synapse)

Question 30

do hormones act rapidly?

Answer 30

no, hormones act at low concentrations, they have slow, widespread lasting effects

Question 31

what are hormones important in?

Answer 31

they are important in developmental processes, e.g. human sex hormones may act over a period of many months

Question 32

what does endocrine signalling rely on?

Answer 32

diffusion and blood flow, it is often slo