PM1A DEFINITIONS Flashcards
Immune system
includes all cells, tissues, molecules and barriers that mediate resistance to infections.
Immunity
The body’s ability to fight off harmful microorganisms (pathogens) that invade it.
e.g. bacteria, fungi and viruses.
Immune response
Is the collective and coordinated response to the introduction of foreign substances in an individual mediated by the cells and molecules of the immune system.
Phagocytosis
ingestion and digestion of pathogens
antigen
Is a foreign substance/toxin that stimulates an immune response leading to production of antibodies.
Give a definition of a skeletal motor unit at the NMJ
A motor unit is defined as a single motor neuron and all the muscle fibers that it activates.
Gene therapy
technique for correcting defective genes that are responsible for disease development.
A carrier molecule called a vector must be used to deliver the therapeutic gene to the patient’s target cells (for in vivo therapy).
The most common vector is a virus that has been genetically altered to carry normal human DNA.
Genetics
the study of heredity and the variation of inherited characteristics/ the genetic properties of features of an organism, characteristics etc
Vaccination
the process of induction of immunity to a pathogen by injecting a weakened, modified or related form of a pathogen which is inactivated.
cytokines in immune system
Are regulatory proteins secreted by WBC’s (macrophages and dendritic cells) bind bind to receptors on target cells and trigger signal transduction pathways and alter gene expression patterns, can be pro or anti inflammatory.
Pro- stimulate the immune system
Anti- suppress the immune system
TNF-alpha is the most important mediator of inflammation.
Proprioception
and describe the 2 way process
is defined as ‘the perception of self’, where your body is in relation to the surroundings.
2 way process where
1. proprioceptors signal to the spinal cord (affarent)
2. motor neurons signal to skeletal muscle (efferent)
surfactant
respiratory system topic
is a mixture of amphipatic complex, phospholipids, proteins and neutral lipid produced by type II pneumocytes
Cardiac output and give equation
Volume of blood pumped out of one ventricle in one minute
Cardiac output = heart rate x stroke volume
Define perfusion pressure and vascular resistance. For EACH, describe what happens to blood flow when they are increased
Perfusion pressure is the difference in pressure between arteries and veins
Increase perfusion pressure – blood flow increases
The blood vessels themselves offer resistance to flow this is the vascular resistance
Increase vascular resistance blood flow decreases
negative feedback and example
effector system opposes the initiating stimuli
e.g. increase in BP causes a compensatory decrease in BP
positive feedback and example
effector system amplifies or reinforces the initiating stimuli
e.g. formation of a blood clot leads to further blood clotting.
codon
Anticodon
Codon- found in mRNA, is a sequence of 3 nucleotides in a DNA/RNA molecule used to code for amino acids.
Anticodon- found in tRNA, also a sequence of 3 nucleotides that binds to corresponding mRNA sequence.
Genetic code
is the nucleotide base sequence on DNA and subsequently on mRNA by transcription which will be translated into a sequence of amino acids of the protein to be synthesis
3 features of genetic code
universal- the same code is used in all living organisms, prokaryotes and eukaryotes
specific- a SPECIFIC codon ALWAYS codes for the same amino acid.
Degenerate- more than codon can code for the same amino acid.
telomeres
protective caps at the end of linear chromosomes, they contain a unique repetitive sequence called telomere tandem repeats.
homologous chromosomes
A pair of chromosomes that are the same size, shape and carry the same genes, one is inherited from each parent.
They are numbered according to size.
replication origins
are nucleotide sequences where replication starts
TATA box
DNA sequence that indicates where a genetic sequence can be decoded. is an example of a promoter.
Transcription factors
def of general TF’s
the largest TF?
are proteins that regulate the transcription of genes.
They bind to regulatory DNA sequences are they recognise target sequences in DNA.
Two types are general and promoter:
general TF’s are active in most cell types and ALWAYS affect gene transcription positively.
General TF’s are the most basic proteins needed to activate gene expression.
TNF II D is the largest TF