Internal regulation
A change in the environment of an organism that brings about a response
What is a stimulus?
The long, rarely branched fibres that extend from the nucleus of a neuron.
What is an axon?
A regulatory chemical capable of bringing about a response to a particular stimulus.
What is a hormone?
The two main parts of the immune system, are the innate and ___________ immune system.
What is the acquired immune system?
An agent that causes disease.
What is a pathogen?
The maintenance of a constant internal environment, mediated by feedback systems
What is homeostasis?
The three main types of neurons are sensory, motor and ....
Compared to nervous responses, hormones are ____ but _____ in duration.
What is slower and longer in duration?
The immune response involving mostly T-lymphocytes.
What is the cell mediated response?
The ability of a pathogen to cause disease.
What is virulence?
A change which reverses a particular trend
What is negative feedback?
The change in membrane potential that returns it to an overall negative charge after depolarisation.
What is repolarisation?
The proces of reducing or suppressing a response to a stimulus by reduction in the number of receptors in the cell surface.
What is down-regulation?
A system of about 20 proteins formed in the liver which may trigger phagocytosis, direct destruction of pathogens or agglutination.
What is the complement system?
A pathogen characterised by glycoprotein spikes and RNA strands.
What is a virus?
A chemical reaction in which large molecules are built up, usually with a net input of energy.
What is an anabolic reaction?
A stimulus causes which channels to open in the neuron cell membrane during depolarisation.
What are sodium channels?
The 'master gland' of the human body.
What is the pituitary gland?
Large white blood cells that play a role in the innate immune response by ingesting foreign particles by phagocytosis.
What are macrophages?
A protein that allows pathogens to enter cells.
Can be either a muscle or gland.
What is an effector?
The period immediately following an action potential when the nerve fibre cannot be stimulated.
What is the absolute refractory period?
The group of ganglia in the brain that release hormones that bring about the release or inhibition of other hormones.
What is the hypothalamus?
The release of chemokines stimulate the basophils and mast cells to produce this chemical.
What is histamine?
A chemical released by activated immune cells that induces fever.
What is a pyrogen?