Human Phys Flashcards
What is another name for red blood cells?
Erythrocytes.
What is another name for white blood cell?
Leukocyte
What is non-specific immunity ?
Ingestion of pathogens by phagocytic WBC.
What are lymphocytes ?
Any WBC that is responsible for the immune response. They detect infections, give the alarm, produce antibodies.
What is specific immunity ?
Antibody production by lymphocytes in response to particular pathogens.
Define antibody.
Substances that are produced in response to a specific antigen in a pathogen and that bind to an antigen on that pathogen.
Define plasma cells.
Mature B lymphocytes that produce and secrete large amounts of antibodies during an immune response.
Define memory cell.
B lymphocytes that remain in the body to identify pathogens.
What’s the principle of ‘Challenge and Response’ ?
Principle to produce antibodies in vast quantities quickly
Define zoonosis.
When a pathogen crosses a species barrier.
Define opsonisation.
Antibodies make the pathogen more recognisable so that the pathogen is more readily engulfed by phagocytosis.
What is neutralisation of viruses & bacteria ?
When antibiotics prevent viruses/bacteria from docking at cells so they can’t enter cells.
What is neutralisation of toxins ?
When antibodies bind to toxins produced by pathogens which prevents them from affecting susceptible cells.
Define activation of complement.
Antibodies activate the complement system. This is a group of proteins that forms pores in the membranes of pathogens, allowing water and ions to enter by osmosis, leading to lysis.
Define agglutination.
Antibodies can cause pathogens to stick together so they can’t enter cells and are easier for phagocytes to ingest.
Define hybridoma and what they’re used for.
A cell resulting from the fusion of a tumour cell with an antibody-producing plasma cell. Hybridoma cells produce monoclonal antibodies.
Used for cancer cells and rabies.
Define pathogen.
An organism or virus that causes a disease.
Define antibiotics.
A chemical substance that inhibits the growth of prokaryotic cells.
Define antigens.
Substances or molecules that stimulate an immune response.
Define allergens.
Environmental substances that trigger an immune response despite not being intrinsically harmful.
Define histamine.
A chemical that is released by mast cells as an immune response.
What is IgE ?
Immunoglobulins are a type of antibody
What do HIV & AIDS stand for ?
HIV : human immunodeficiency virus
AIDS : acquired immunodeficiency syndrome
What are opportunistic infections ?
Infections that are normally easily fought off by the immune system of a healthy person.
Define spermatogenesis.
The production of male gametes, sperm, in the seminiferous tubules in the testes.
Define oogenesis.
The production of female gametes, ova, in the ovary tissues.
Define gas exchange.
Passive movement of CO2 and O2 from the blood & alveoli due to concentration gradients between the tissues and blood
Define ventilation
A process that maintains concentration gradients of O2 and CO2 in alveoli and blood flowing in adjacent capillaries.
What are antagonistic muscles ?
Muscles that work together but have opposite effects.
What are type I pneumoncytes ?
Flat, thin, permeable cells that make up 95% of alveolar cells.
What are type II pneumocytes ?
Rounded cells that make up 5% of alveolar cells and secrete surfactant to prevent alveoli from adhering to each other & lungs from collapsing.
Define ventilation rate.
The number of times that air is drawn in or expelled per minute
Define tidal volume
Volume of air drawn in or expelled during one normal breath
Define vital capacity
The maximum volume of air breather in and out from deepest inhalation to deepest exhalation
What happens to tidal volume and ventilation rate during exercise ?
Increase
What are Schwann cells ?
Cells that produce myelin sheath around nerve fibres to allow for saltatory conduction.
Name the 3 types of neurons
Relay neuron
Motor neuron
Sensory neuron
What is a resting potential ?
The potential difference across a neuron’s membrane when it is not transmitting an impulse
In the sodium potassium pump, how many sodium and potassium ions are used ?
3 sodium ions go out, 2 potassium ions come in
Define depolarisation
A change from a negative potential to a positive potential (-70mV to +30mV). Occurs when Na+ diffuse into the axon through Na+ voltage gated channels
Define repolarisation
A change from a positive potential to a negative potential (+30mV to -70mV). Occurs when K+ diffuse out of the axon through K+ voltage gated channels
What are cholinergic synapses ?
Chemical synapses that use acetylcholine molecules as neurotransmitters
Define hormones
Chemical substances that send information to specific cells or organs to trigger a response. They are produced in glands
What is positive & negative feedback ?
+ : enforces the action that is happening
- : suppresses the action that is happening (brings it back to normal)
What is thyroxin ?
A hormone produced by the thyroid gland that regulates metabolic rate & body temperature. Iodine deficiency can lead to thyroxin deficiency
What is leptin ?
A hormone secreted by adipose tissue to regulate appetite
What is melatonin ?
A hormone secreted by the pineal gland to control circadian rhythms
What are circadian rhythms ?
Rhythms of behaviour that fit in a 24 hour cycle
Define polyspermy
The fertilisation of an oocyte by more than 1 sperm
Define infertility and state some of its causes.
The inability of a person to reproduce by natural means.
Caused by decrease in amount of sperm per unit volume of semen (fell by 50% in the last 50 years), could be due to to release of progesterone and oestrogen into the environment from contraceptive pill.
