Nerves Flashcards
Synaptic knob.
The sing at the end of a neurone where it forms a junction (synapse) with another neurone.
Summation
The way that several small potential changes can combine to produce one larger change in potential difference across a neurone membrane.
Stroma
Fluid filled matrix of chloroplasts. This is where the lirs of photosynthesis takes place.
Substrate-level phosphorylation.
Formation of ATP from ADP and Pi during glycolysis and the Krebs cycle.
Sodium potassium pumps.
Protein carriers embedded in the membranes if some cells, which use energy from ATP to move sodium ions and potassium ions in opposite directions simultaneously, against their concentration gradients. They are chemically gated ion channels.
Secondary messenger.
A chemical inside the cell released in response to a hormone binding to the cell surface membrane (e.g. cAMP).
Neurotransmitter.
A transmitter substance - a chemical that is released from the presynaptic membrane if one neurone to pass a signal to another neurone.
Neurosecretory cells.
Cells in the hypothalamus that are similar to neurones but release a hormone into the blood instead of a transmitter substance into a synapse.
Peritoneal dialysis.
A form of treatment for kidney patients in which dialysis fluid is pumped into the body cavity so that exchange can occur across the peritoneal membrane.
Nephrons.
Tubules in the kidney that are used to produce urine.
Haemodialysis.
A form of treatment for kidney patients in which blood is taken from a vein and passed through a dialysis machine so that exchange can occur across an artificial partially permeable membrane.
Hairpin countercurrent multiplier.
An arrangement of a tubule or blood vessel involving a 180’ bend so that the fluid in one end of the tubule flows back past the fluid at the other end. This arrangement facilitates the exchange of materials by ensuring that there is a contraption gradient all along the tubule.
Glycolysis.
Metabolic pathway. The first stage of respirationX it is anaerobic and occurs in the cytosol (cytoplasm). Although anaerobic, it involves oxidation as substrate molecules are dehydrogenated.
Glomerulus.
A small network of capillaries found inside the Bowman’s capsule.
Gas chromatography.
A technique used to separate substances in a gaseous state.
