principles_20190518182821 Flashcards
what are the oxidation states of carbon?
alkane (fats) > alcohol (carbs) > aldehyde > carboxylic acid > carbon dioxide
what is the first law of thermodynamics?
energy neither created or destroyed
what is the second law of thermodynamics?
energy converted from one form to another, some becomes unavailable to do work
where is collagen triple helix found?
connective tissue
role of smooth ER
synthesis of steroid hormones
role of rough ER
synthesises polypeptides
role of golgi apparatus
receives materials from ER and distributes, can also modify proteins
what is nucleoside
base and sugar
what are purines
adenine and guanine
what are pyrimidines
uracil, thymine and cytosine
what kind of bonds between 3 OH group and 5 triphosphate
phosphodiester
what is the leading strand
always has free 3’ end (dna always synthesised in 5-3 direction)
role of rRNA
combines with proteins to form ribosomes found in nucleolus
role of tRNA
carries amino acids to be incorporated into protein anticodon consists of 3 nucleotides
role of mRNA
carries genetic information for protein synthesis
what are the three types of RNA which eurkaryotic cells have
pol I, II and IIIpol II synthesises all mRNA
what is TFIID
general transcription factor required for all Pol II transcribed genes
steps in the initiation of translation
GTP provides energy, ribosomal subunit binds to 5’ end, initiator tRNA (located in P site) pairs to start codon and large subunit joins assembly and initiator tRNA
steps in the elongation of translation
elongation factor brings aminoacyl-tRNA to A site where second elongation factor regenerates the first to pick up next a-tRNA
what catalyses the peptide bond formation between amino acids in P and A sites
peptidyl transferase
steps in termination of translation
occurs when A site of ribosome encounters a stop codon (UAA, UAG, UGA)
where are free ribosomes found
in cytosol proteins for cytosol, nucleus or mitochondria post translational
where are bound ribosomes found
plasma membrane, ER, golgi, secretionco-translational
what are enzymes without cofactor called
apoenzymes
what are enzymes with cofactor called
holoenzymes
what is vmax?
maximal rate of reaction at unlimited substrate concentrationintersect of straight line with Y
what is Km
michaelis constant - 50% vmax intersection with X
what happens in competitive inhibition
km varies
what happens in non-competitive inhibition
vmax varies
what is the difference between haemoglobin and myoglobin
haemoglobin shows allosteric regulationmyoglobin - michaelis menten
anabolism
requires energy, endergonic and reductive
catabolism
breakdown to produce energy, exergonic and oxidative
basic steps in glycolysis
hexokinase phosphorylates glucosephosphofructokinase phosphorylates fructose-6-phosphatepyruvate kinase converts phosphoenolpyruvate to pyruvate
what is the fate of NAD
reduced to NADH+ H+ in glycolysis regenerated through oxidative metabolism of pyruvate
basic steps in aerobic metabolism of pyruvate
enters matrixconverted to acetyl-coA (by PDC)condenses with 4c to form 6c compound this 6c decarboxylated twice - yields CO24 oxidation reaction - yeilds NADH+ H+ and FADH2GTP formed 4c compound recreated
what enzyme of TCA is integrated in inner membrane of mitochondria rather than matrix?
succinate dehydrogenase
how many electrons transferred in conversion of NAD+ to NADH+ H+
3 pairs
how many electrons needed to reduce FAD to FADH2
1 pair
what does TCA cycle generate from each a-coA
3 NADH+ H+1 FADH21 GTP2 CO2
what is the first step of oxidative phosphorylation (electron transport)
electrons from NADH enter at complex 1, electrons from FADH2 enter at complex II (TCA), electrons handed down from higher to lower redox potentials, transferred onto O2 ti form H2Otransfer of electrons through respiratory chain is coupled to H+ transport 3/4 complexes pump H+ (1, 2 and 4)forms electrochemical gradient - more protons in intermembrane space than matrix, matrix negative so protons attracted
what is second step of oxidative phosphorylation
ATP synthesis
what inhibits oxidative phosphorylation
cyanide, azide and CO inhibit transfer of electrons to O2 (no proton gradient can be formed)
what is the final balance from respiration
glycolysis - 2 ATPTCA cycle - 2 ATP (2 GTP)glycolysis, PDH, TCA cycle - 25 ATP and 10 NADH+ H+TCA cycle - 3 ATP (2 FADH2)
how many ATP molecules does one glucose yeild
30-32
what are the stages of cell cycle
G1 - S - G2 - M - G1DNA synthesis at S
basics of DNA synthesis
DNA helicase unzips DNA, DNA polymerase copies 5-3 strand then the 3-5 strand in okazaki fragments which DNA ligase joins
what causes sequence variations within a gene
changes in promotor sequence and change in exon sequence
what causes sequence changes in DNA between genes
SNPslarger deletions or duplications
what is chromosome of normal female
46 XX
what is aneuploidy
whole extra or missing chromosome
47XY + 21
down syndrome, trisomy 21
47XY + 14
miscarriage, trisomy 14
47 XY + 18
edward syndrome, trisomy 18
45 X
turners syndrome
47 XXY
klinefelters syndrome
what is a roberstonian translocation
two acrocentric chromosomes stuck end to end - increases risk of trisomy in pregnancy
what is microarray CGH
1st line chromosome test, detects any missing of duplicated piece of chromosomesaCGH - paediatric
what is gonadal mosaicism
causes recurrence risk for autosomal dominant condition even if parent unaffected
what is somatic mosaicism
all cells suffer mutations as they divide, repair mechanisms exist
what genes start cells dividing when switched on?
oncogenes
what is mendelian disorder
disease caused by change in single gene umbrella term for autosomal dominant, recessive, x linkedhigh penetrance, small environmental contribution
what is chance of children getting disease in X linked mutations
mother carrier - 50% chance daughter is carrier and 50% chance male is affected no male - male transmission
what does mitochondrial DNA contain
important genes for mitochondrial metabolic pathways and ribosomal RNAs
what kind of mutations occur in mitochondria
point mutations and deletions, inherited almost exclusively materally
symptoms of mitochondrial mutations
myopathy, diabetes, deafness, optic atrophy, stroke like episodes and encephalitis
how do mutations cause disease
only having one working copy not enough (haploinsufficiency) so abnormal protein interferes with normal (dominant negative) and mutation activates gene resulting in loss of heterozygosity
what is the characteristics of a multifactorial disease
genetic change just another risk factor and penetrance for any one mutation is low
what is imprinting (non mendelian)
differences in gene expression depending on wether gene is maternally or paternally inherited
angelman syndrome is example of non mendelian inheritance, what symptoms?
neurogenetic disorder: developmental delay, intellectual disability, ataxia, epilepsy, happy, frequent laughing eg - chromosome 15
what is heteroplasmy (non mendelian)
different daughter cells contain different proportions of mutant mitochondria
what do drug metabolism genes do
metabolise carcinogens
what is the mechanism of gene activation
duplication of gene, activation of gene promotor and change in amino acid sequence
what is FISH
can light up specific bit of chromosome if you know which bit to light up
mutation in what gene can cause breast cancer?
BRCA1 - carriers have 80% risk of breast or ovarian
characteristics of rare autosomal forms of breast cancer
young age of onset, many cancer and rare tumours
characteristics of multifactorial predisposition breast cancer
everyone at same risk anyone with family history at increased risk
what is components of inner cytosol
solution of proteins, electrolytes and carbohydrates
what is the components and role of cytoskeleton
determines shape and fluidity of cells made from thin, intermediate filaments and microtubules
microfilaments
7nm, composed of actin
intermediate filaments
> 10nm, composed of proteins
microtubules
25nm, composed of tubulin, originate from centrosome, polar and dynein and kinesin attach to them and move them along
what are occluding junctions
link cells to form diffusion barrier (tight junctions)
what are anchoring juncitons
provide mechanical strength, link submembrane actin bundles of adjacent cells (adherent junctions)
what are the role of desmosomes in anchoring junctions
link submembrane intermediate filaments of adjacent cells
what are the role of hemidesmosomes in anchoring junctions
link submembrane intermediate filaments of cells to extracellular matrix through transmembrane proteins
what are communicating junctions
allow movement of molecules (gap junctions) each junction studded with pores produced by connexion proteins
haematoxylin dye
purple, basic dye (affinity for acidic molecules)
eosin dye
pink, acidic dye
sqaumous epithelium
flattened
cuboidal epithelium
cube
columnar epithelium
tall and thin
what are the different kinds of glandular epithelia
exocrine (product secreted towards basal end of cell, distributed by vascular system, ductless glands) and endocrine (apical end of cell, ducted glands)
what are the three types of cartilage
hyaline (articular surface, tracheal rings, costal cartilage, epiphyseal growth plates)elasticfibrocartilage
what is the outer shell of a cortical bone which makes up the shaft
diaphysis
what occupies end of cancellous/trabecular bone
epiphyses
what is the contents of the extracellular matrix of connective tissue
fibres (collagen, reticular and elastic fibres), ground substance and tissue fluid
what are the cells of connective tissue
fibroblasts, adipose cells, osteocytes, chondrocytes
characteristics of smooth muscle
involuntary and non-striated
characteristics of skeletal muscle
voluntary and striated, multinucleated nuclei are elongated and located at periphery, just internal to cell membrane (sarcolemma)
characteristics of cardiac muscle
involuntary and striated, have intercalated discs which contain multiple intercellular junctions to maintain mechanical integrity
what is the connective tissue coat surrounding nervous tissue
meninges in CNSepineurium in PNS
role of astrocytes (type of glia)
support and ion transport
role of oligodendrocytes (type of glia)
produce myelin
role of microglia (type of glia)
provide immune surveillance
role of schwann cells (PNS) - type of glia
produce myelin and support axons
types of salivary glands
parotid, submandibular and sublingual
1st layer of GI tract
mucosa:epithelium - sits on basal laminalamina propia - loose connective tissue muscularis mucosae - thin layer smooth muscle
2nd layer of GI tract
submucosa: loose connective tissue
3rd layer of GI tract
muscularis externa: 2 thick layers of smooth muscle, inner circular and outer longitudinal layer
4th layer of GI tract
serosa or adventitia: outer layer of connective tissue that either suspends digestive tract or attaches to other organs
characteristics of protective mucosa
non-keratinised stratified squamous epithelium
characteristics of absorptive mucosa
simple columnar epithelium with villi and tubular glands
characteristics of secretory mucosa
simple columnar epithelium with extensive tubular glands
in the large intestine (protective and absorptive) the outer longitudinal smooth muscle is not continuous, what is it?
found in 3 muscular strips called teniae coli
what is the nervous tissue in the digestive tract?
enteric nervous system - ganglia between 2 muscle layers that make up muscularis externa
product of exocrine gland of pancreas
pancreatic digestive enzymes
product of endocrine gland of pancreas
islets of langerhans - produce insulin
what does the kidney contain
nephrons
what is the different layers of artery
tunica intima (endothelial cells)tunica media (smooth muscle)tunica adventitia (supporting connective tissue)
layers of arteriole
1 or 2 layers of smooth muscle in tunica media and almost no adventitia
layers of capillaries
endothelial cells and basal lamina have pericytes (connective tissue cells with contractile properties)
where are continuous capillaries found
muscle, nerve, lung, skin
where are fenestrated capillaries found
have poresgut mucosa, endocrine glands and kidney
where are sinusoidal capillaries found
large gaps liver, spleen, bone marrow
layers of venules
endothelium and pericytes
layers of veins
tunica intima, thin continuous tunica media, obvious tunica adventitialarge veins have thick tunica adventitia
definition of variolation
exposure of individual to the contents of dried smallpox pustules from infected patient
what is commensal bacteria
friendly (barrier to infection) which competes with pathogen for scarce resources
what receptors involved in innate immune system
PAMPs : PRRs
what receptors involved in adaptive immune response
antigens : antigen receptors
what are phagocytes
neutrophils, monocytes, macrophages, dendritic cellsingest and kill bacteria important source of cytokines
what is the role of eosionophils, mast cells and basophils
granular cells which release chemicals for acute inflammation
what is the role of complement proteins
inflammation and defence
mast cells
reside in tissues and protect mucosal surfaces, degranulate and release histamine and tryptasegene expression - TNF, chemokines and leukotrienes
basophils and eosinophils
circulate in blood and recruited to sites of infection
by what three mechanisms do neutrophils attack pathogens
phagocytosis release of antimicrobial peptides and degradative proteasesgenerate extracellular traps
what do active neutrophils produce
TNF (cause cell death)
what do dead and dying neutrophils + tissue cells + microbial debris produce
pus
what are monocytes
precursor of macrophages - limit inflammation and involved in tissue repair and wound healing
role of macrophages
reside in tissues, ingest and kill pathogens, clear debris, inflammation, tissue repair and antigen presentation
role of dendritic cells
immature cells in peripheral tissues but when in contact with pathogen, mature and migrate to secondary lymphoid tissue where they stimulate adaptive response
CD4+ cells
helper T cellregulator of immune system and activate other immune cells
CD8+ cells
cytotoxic T cellskill virally infected body cells
what are interferons
type of cytokineanti-viral function
what are TNF
type of cytokinepro-inflammatory
what are chemokines
type of cytokinecontrol and direct cell migration
what are interleukins
type of cytokineIL2 - t cell proliferationIL10 - anti inflammatory
what is the acute phase response
result of infection, trauma or infectionliver produces acute phase proteins in response to pro inflammatory cytokines (IL1, IL6 and TNF)
what is the complement system
family of proteins produced in liver that circulate in blood which enter infected and inflamed tissues
what are the functions of complement system
membrane attack complexopsonisation chemotaxisclearance of immune complexes inflammation
what is opsonisation and what causes it
coating of microorganisms by immune proteins (opsonins)caused by C3b, CRP, antibodiesenhances phagocytosis
how does complement mediated lysis work
C5b bind to pathogen surfaceC6, C7, C8, C9 and C5b = membrane attack complex
how does complement mediated inflammation and chemotaxis work
C3a and C5a bind to receptors on mast cells / basophils and release granules which produce histamine and chemokines
what is a T cell antigen receptor
membrane bound protein heterodimer has alpha and beta chain
what is a B cell antigen receptor
membrane bound antibody (IgM or IgD)has light and heavy chain and disulphide bridges
how are pathogens activated
MHC/HLA proteins display peptide antigens to T cellsclass 1 - expressed on all nucleated cells - present peptide antigens to cytotoxic T cellsclass 2 - only dendritic cells, macrophages and B cells - present peptide antigens to helper T cells
what does each antibody contain
each heavy and light chain contains variable region (antigen binding site) and a constant domain
IgG
most abundant, actively transported across placenta
IgM
surface bound monomer, 1st Ig type produced in immune response
IgD
extremely low levels in blood, surface bound
IgE
extremely low levels normally, produced in allergic response
IgA
2nd most abundant type, monomeric form in blood, dimeric form in breast milk, saliva, tears and mucosal secretions
what types do mothers pass to baby
IgG and dimeric IgA
what is the effector function of antibodies
clearance mechanisms - mediated interaction of constant region with effector molecules by complement and Fc receptors
what is agglutination
immune complex formation
other characteristics of antibodies
can function as opsoninscan stimulate NK cellscan trigger allergic response can undergo class switching - b cells switch antibody heavy chain segment
what is the germinal centre reaction
b cell proliferation, antibody heavy chain switching, generation of high affinity antibodies and differentiation into plasma cells and memory B cells
what is pathogenicity
ability of a microorganism to produce disease
how do bacteria replicate
binary fission
what is microaerophilic atmosphere
reduced o2 conc and enriched co2
what secretes exotoxin
gram positive bacteria, produced inside cell and exported from it
what secretes endotoxin
gram negative bacteria, part of gram negative bacterial cell wall
what are moulds
type of fungi, produce spores and hyphae eg aspergillus
what are yeasts
type of fungi, single cells that reproduce by budding eg candida
characteristics of gram positive streptococcus
aerobic cocci chainsalpha haemolysis (partial) - strep pneumoniae (pneumonia, meningitis) and strep viridans (endocarditis)beta haemolysis (complete) - group A strep (throat and skin infection) and group B strep (neonatal meningitis)
characteristics of gram positive enterococcus
aerobic, cocci chains, non-haemolytic, normal gut commensal and cause of UTI
characteristics of gram positive staphylococcus
cocci clusterscoagulase positive (golden) - staph aureus - wound, skin infection - flucloxacillincoagulase negative (white) - staph epidermis - normal skin commensal, IV line infection
process of fever
antigen attacks macrophage, releases cytokines, travel to anterior hypothalamus of brain, stimulates production of prostaglandin E, resets bodys thermal set point and body shivers to conserve heat (slows growth of pathogens)
characteristics of gram negative cocci
diplococci, aerobic eg neisseria gonorrhoea and neisseria meningitidis
characteristics of coliforms
gram negative bacilli, aerobic (can be anaerobic)gut commensals eg e.coli, klebsiella, proteusgut pathogens eg salmonella, shigella, e.coli O157 gentamicin first line antibiotic
characteristics of strict aerobes
gram negative bacillieg pseudomonas aeruginosa and legionella pneumophilia
what are the types of spiral or curved gram negative bacilli
campylobacter - food poisoning helicobacter pylori - gastritis
what is haemophilus influenzae
small gram negative bacillus, common cause of chest infection (esp in COPD)
characteristics of gram positive anaerobic bacilli
CLOSTRIDIUM SPPpart of normal bowel flora, produces spores and exotoxin that cause severe tissue damage
characteristics of gram negative anaerobic bacilli
bacteroides sppnormal gut commensals, only pathogenic when found in other sites metronidazole - 1st line treatment for anaerobes
characteristics of mycobacteria
thick waxy outer coat acid fast bacilli or ZN stain TB
what is the process of gene transfer by transformation
DNA from dead bacteria taken up by living and incorporated in plasmids
what is process of gene transfer by conjugation
sex pilus (fimbria) produced by one bacteria through which plasmid DNA can be transferred
what is the process of gene transfer by transduction
viruses infecting bacteria can transfer bits of DNA from one bacterium to another
definition of bactericidal
kill bacteria
definition of bacteriostatic
inhibit bacterial growth
what are antibiotics what work on cell wall
penicillin cephalosporins (ceftriaxone)glycopeptides (vancomycin)
how to distinguish between gram positive and gram negative organisms
positive - thick peptidoglycan and single phospholipid bilayer negative - think peptidoglycan and two phospholipid bilayers
what are the different kinds and the characteristics of penicillin
flucloxacillin, co-amoxiclav and amoxicillininhibit cell wall synthesis by preventing cross linking of PGN subunits bactericidal, narrow spectrumbeta-lactam antibiotic excreted rapidly via kidneystype 1 hypersensitivity
characteristics of cephalosporins
inhibit cell wall synthesis bactericidal beta-lactam antibitic may cause c. diff excreted by kidneys
characteristics of glycopeptides
binds to end of growing chain, prevents cross linking and weakens cell wallbactericidal only active against gram positive cell wall excreted in urine
what are the antibiotics which inhibit protein synthesis
macrolides (erythromycin, clarithromycin, azithromycin) - bacteriostatictetracyclines (doxycycline) - bacteriostaticaminoglycosides (gentamicin) - bactericidal
characteristics of macrolides
lipophilic and pass through cell membranes easily (useful for infection where bacteria hides from immune system)excreted via biliary tract
characteristics of tetracyclines
broad spectrum, can destruct intestinal flora (cause secondary infections)permanently stain teeth of children <12 yearsexcreted via biliary tract
characteristics of aminoglycosides
mainly active against gram negative aerobic organisms (coliforms and pseudomonas aeruginosa)damage of kidney and CN VIII - vestibulochlearexcreted in urine
what are the antibiotics which act on bacterial DNA
metronidazoletrimethoprim fluoroquinolones
characteristics of metronidazole
causes strand breakage of bacterial DNAtreat true anaerobic infectionsinteracts with alcohol
characteristics of trimethoprim
inhibits bacterial folic acid synthesis some activity against some gram negative and some gram positive
examples and characteristics of fluoroquinolones
CIPROFLOXACIN (can cause tendonitis) LEVOFLOXACINprevent supercoiling of bacterial DNAbactericidal restricted (c diff)weakens tendons, causes seizuresexcreted in urine
which antibiotics are to be avoided in pregnancy
trimethoprim and metronidazole avoid in first 3 months gentamicin, tetracycline and fluoroquinolones avoided!!
what is the mechanism of antibiotic resistance
changes in bacterial DNA cause change in gene product which is target of antibiotic (MRSA)bacteria can code for enzymes which degrade of inactivate antibiotic efflux pumps actively export antibiotics out of bacterial cell - genetic change may result in increased efflux
what are the stages of viral replication
1) attachment (ligand > receptor)2) entry (endocytosis) 3) uncoating (release nucleic acid from capsid)4) nucleic acid and protein synthesis (host ribosomes and polymerases used)5) assembly (nucleic acid and proteins packaged together)6) release by budding (viral released with host envelope) or lysis (accumulate until cell bursts)
how can antibodies be used in prevention of viral infection
neutralising antibodies (IgG and IgM) prevent virus binding to cellular receptors
how can viruses be detected
PCR, antigen detection
what is necrosis
no energy, death of tissues, pathological, elicits adjacent tissue response
what is coagulative necrosis
proteins coagulate, preservation of cell outline eg MI
what is colliquative necrosis
necrotic material becomes softened and liquefied (pus), no cell structure remains eg in brain
what is gangrenous necrosis
cell death by necrosis then infection on top of it - anaerobic bacteria may grow
what is fibrinoid necrosis
fibre deposition eg damage to blood vessel in malignant hypertension
what is the role of p53 protein
if lost, it can lead to development of cancer p53 can be spellchecker at G1, if mistakes are found cell cycle paused and repair attemptedif cant be repaired, p53 stimulates caspases and indices apoptosis
what is the role of telomeres
cap chromosomes to prevent degradation and fusionadds on TTAGGG after its lost to prevent cells dying
how can free radicals (chain reaction leading to lipid peroxidation) be formed?
drugs, O2 toxicity, reperfusion injury, inflammation, intracellular killing of bacteria
what is phenylketonuria?
metabolic disorderaccumulation of phenylalanine caused by deficiency in enzyme which converts phenylalanine to tyrosine guthrie test
what is the beneficial effects of acute inflamation
toxin dilution, entry of antibodies, fibrin formation, drug transport, oxygen and nutrient delivery and immune response stimulation
what are the harmful effects of acute inflammation
digestion of normal tissues, swelling and inappropriate inflammatory response - type 1 hypersensitivity
what is chronic inflammation
subsequent and often prolonged tissue reactions follow initial response cells: plasma, lymphocytes and macrophages
what is the fluid exudate in inflammation
proteins including immunoglobulins fibrinogen - fibrin on contact with ECM, acutely inflamed organ surfaces commonly covered in fibrin
what is margination
loss of intravascular fluid and increased plasma viscosity allowed neutrophils into plasma (only occurs in venules)
what increases surface adhesion molecule expression
complement C5aleukotriene b2TNF
what increases endothelial cell expression of adhesion molecules
IL1endotoxinsTNF
what releases histamine (chemical mediator) which causes vascular dilation
released by mast cells, eosinophils, basophils and platelets release stimulated by C3a, C5a and lysosomal proteins (released by neutrophils)
what does serotonin (chemical mediator) do and where is its receptors found
increased vascular permeability 5HT (receptors) present in high concentration in platelets
what is the role of chemokines (chemical mediator)
attract various leukocytes to site of inflammation
role of leukotrienes (chemical mediator)
type 1 hypersensitivity
role of prostaglandins (chemical mediator)
increase vascular permeability, stimulate platelet aggregation
how are micro-organisms recognised
when coated in opsonins (Fc fragment of IgG, C3b or collectins)
what is suppuration
formation of pus - neutrophils, bacteria and cellular debris
what is the macroscopic appearances of chronic inflammation
chronic ulcer (breach in mucosa, base lined by granulation tissue and fibrous tissue extends through muscle layer)chronic abscess cavity thickening of wall by fibrous tissue granulomatous (crohns, TB)fibrosis
what kinds of damage are reversible
reduced aerobic respiration / increased anaerobicmembrane pumps failcell swellingaccumulation of lipid
what kinds of damage are irreversible
severe damage to cell membranes and mitochondrialeakage of enzymes nuclear changes - ATP changes, cell membrane damage
what is a granuloma
in chronic inflammationcollection of macrophages (response to foreign bodies eg bone, asbestos, TB, parasites, syphilis and malignancy)
what causes wound contraction
myofibroblasts
what is metaplasia
one type of cell becomes another form of cell in response to stress (at risk site for cancer)barrett’s oesophagus
characteristics of a benign neoplasia
no necrosis N:C ratio normal minimal pleomorphism (change in size/shape)eg adenoma and papilloma
characteristics of a malignant neoplasia
necrosis common N:C ratio increased pleomorphic (alter shape/size)aneuploid eg carcinoma (cancer of epithelial cell), carcinoma in situ (not invading other tissues) or sarcoma (cancer of mesenchymal cell - MALIGNANT)
what is dysplasia
disordered growth pre-malignant process
what is angiogenesis
formation of new, abnormal blood vessels (successful tumours)
what are the different routes for metastasis
lymphatic route - carcinomahaematogenous route - sarcoma
what is the double hit hypothesis
one faulty gene puts person at increased risk two faulty mutated genes will result in functional problem
what are some examples of oncogenes (turn up genes that promote growth) which can be effected by mutations?
RAS (GTP binding) eg colon, lung, pancreatic, bladder, renal and melanomaBRAF - 50% melanoma RAF mutated - some colonic malignancies Myc eg lymphoma, neuroblastoma, small cell carcinoma of lungP13K must common mutated kinase in cancer eg haematological malignancies
why is the PTEN gene significant
without it, p27 cells can proliferate in uncontrolled fashion
example of DNA repair genes effected by mutation
BRCA 1 + BRCA 2 (breast cancer)
what is Bcl2
anti apoptotic gene usually switched off for purpose of getting rid of self reactive lymphocytes
what is an epithelial cancer called
carcinoma
what is glandular cancer called
adenoma v adenocarcinoma (malignant)
what is squamous cancer called
papilloma v squamous cell carcinoma (malignant)
what is a paraneoplastic syndrome
rare disorders that are triggered by an altered immune system response to a neoplasm (new growth)non-metastatic systemic effects that accompany malignant disease
what is the biochemical complications of diabetes
ketoacidosisnon-enzymatic glycosylationhypoglycaemia lactic acidosis
what is the cause of an atheroma
response to endothelial injury recruitment of macrophages and platelets lipid accumulation smooth muscle proliferation
what are the complications of atheroma
thrombosis, aneurysm, dissection, embolism and ischaemia
what is the results of left ventricular hypertrophy
increased LV loadpoor perfusioninterstitial fibrosismicro-infarcts diastolic dysfunction
what is the virchows triad (3 things thought to contribute to thrombus)
vessel wall (loss of endothelial surface, inflammation)blood flow (stasis, turbulence)blood constituents (platelets, coagulation proteins, viscosity)
what is the difference between thrombus and embolism?
thrombus - solid mass of blood constituents formed within blood vesselembolism - mass of material in vascular system moving from its site of origin to lodge in vessels in distant site
what is a infarction and how is it caused
zonal necrosis due to sudden occlusion of blood supply due to lack of O2 and nutrient supply re-perfusion injury possible due to formation of free radicals
what is pharmacodynamics
what drug does to body
what is pharmacokinetics
what body does to drug
what is affinity
strength of association between ligand and receptor
what is efficacy
ability of an agonist to evoke cellular response
what is the difference between competitive and non competitive antagonism on a graph
competitive - cause parallel rightward shift of agonist concentration with no depression in maximal responsenon competitive - depress the slope and maximum response curve - no shiftPICTURE ON DOC
how does the degree of ionisation effect the absorption of a drug
only unionised forms readily diffuse across bilayer depends on pKa (pH at which 50% of drug is ionised and 50% unionised)
what is henderson-hasselbalch equation
pH - pKa = log (A-/AH) = acidallows you to determine how active drug may be in body in blood stream or acidic stomach
what is the oral availability of a drug
fraction that reaches systemic circulation after oral ingestion
what is the systemic availability of a drug
fraction that reaches systemic circulation after absorption
what is the volume of distribution (Vd)
apparent volume in which a drug is dissolved (distributed with concentration equal to that of plasma)IV: Vd = dose/plasma concentration
what is the therapeutic ratio of a drug
MTC/MEC (max tolerated conc and max effective conc)higher the TR, safer drug
what is the half life of drug eliminated at first order kinetics
half life is inversely proportional to elimination rate constant t1/2 = 0.69/Kel
how to work out the rate of elimination of a drug
clearance (volume of plasma cleared of drug in unit time) x plasma concentration
what is the characteristics of a drug which is eliminated at zero order kinetics
initially eliminated at constant rate then return to first order
which factors influence drug disposition
ADME - absorption, distribution, metabolism and excretion
what is the role of drug metabolism
converts drugs to more polar metabolites not readily absorbed in renal tubules, facilitating excretionconvert drugs to metabolites that are less active than parent compound
what is the first phase of drug metabolism
RHS of liver - oxidation, reduction and hydrolysisthis makes drug more polar, adds chemically reactive group permitting conjugation
what is the second phase of drug metabolism
LHS of liver - conjugationthis adds an endogenous compound, increasing polarity
what happens to the membrane potential in depolarisation
becomes less negative (opposite for hyperpolarisation)
what is the characteristics of sodium channels
Na flows inwardly conc 140mm outside cell, 10-15mm insidedriving force - Vm - ENanegative driving force - inward movement of sodium
what is the characteristics of potassium channels
K flows outwardlydriving force - Vm - Ekwhen positive, outward movement of K
what are the ion channels responsible for action potential in neurons
voltage activated Na channels - depolarising voltage activated K channels - hyperpolarising
what is the effect of the activation of voltage activated Na channel (activated by depolarisation)
opening of a few channels causes further depolarisation positive feedback (upstroke of graph)
what is the effect of the activation of voltage activated K channel (activated by depolarisation)
outward movement of K causes repolarisation which turns off stimulus negative feedback (downstroke of graph and undershoot)
what happens during an absolute refractory peroid
no stimulus, however strong, can elicit a second action potential
what happens during a relative refractory period
stronger than normal stimulus may elicit second action potential
what is the role of oligodendrocytes
produce myelinated cells in CNS (schwann cells do PNS)
what is the role of astrocytes
star shaped, support homeostasis and maintain BBB
what is the role of microglia
immune surveillance, macrophages of CNS
what are the preganglionic and post ganglionic neurones in sympathetic NS
pre - AChpost - usually noradrenaline
what are neurones in parasympathetic
both pre and post - AChcontrols cranial nerves 3/7/9/10
sympathetic and parasympathetic role in male reproduction
sympathetic - ejaculationparasympathetic - erection
what is the steps in neurochemical transmission
1) precursor taken up2) transmitter synthesised and stored3) action potential depolarises4) calcium influx through voltage activated channels5) calcium induced release of transmitter6) receptor activation7) enzyme mediated inactivation of transmitter or reuptake of transmitter
characteristics of ligand-gated ion channels
consist of separate glycoprotein subunits forming a central, ion conducting channel allow rapid changes in permeability of membrane to certain ionsrapidly alter membrane potential
what is the structure of receptor in GPCR
integral membrane protein 7 transmembrane spans joined by 3 extracellular and 3 connecting loops
what is the structure of G protein in GPCR
peripheral membrane protein3 polypeptide subunits (alpha binding site)contains guanine nucleotide binding site which can hold GTP
what happens when there is no signalling in GPCR
receptor unoccupiedG protein binds GDPeffector not modulated
what happens when the signal is turned on in GPCR
agonist activates receptorG protein couples with receptorGDP dissociated from and GTP binds to alpha subunitG protein dissociatedalpha subunit combines with and modified activity of effectoragonist may dissociate from receptor, but signal persists
what happens when signal is turned off in GPCR
alpha subunit acts as enzyme to hydrolyse GTP -> GDPG protein alpha subunit recombines with By subunit completing G protein cycle
what are nicotinic acetylcholine receptors (ligand gated)
consist of 5 glycoprotein subunitsalpha 1-10, beta 1-4, gamma, delta, epsilonbinding of transmitter opens gate
what is role of M1 GPCR muscarinic ACh receptor at parasympathetic neuroeffector junctions
Gg - stimulates phospholipase C which increases stomach acid secretion
what is role of M2 GPCR muscarinic ACh receptor at parasympathetic neuroeffector junctions
Gj - inhibition of adenylyl cyclase and opening of K+ channels which decreases HR
what is role of M3 GPCR muscarinic ACh receptor at parasympathetic neuroeffector junctions
Gg - stimulates phospholipase C which increases saliva secretion and bronchoconstriction
what stimulates the re-uptake of NA at sympathetic neuroeffector junctions
transporters U1/U2
what stimulates the metabolism of NA at sympathetic neuroeffector junctions
MAO and COMT
what is the role of B1 GPCR adrenoreceptor at sympathetic neuroeffector junctions
Gs - stimulation of adenylyl cyclase which increases HR and force
what is the role of B2 GPCR adrenoreceptor at sympathetic neuroeffector junctions
Gs - stimulation of adenylyl cyclase which causes relaxation of bronchial and vascular smooth muscle
what is the role of A1 GPCR adrenoreceptor at sympathetic neuroeffector junctions
Gg - stimulation of phospholipase C which causes contraction of vascular smooth muscle
what is the role of A2 GPCR adrenoreceptor at sympathetic neuroeffector junctions
Gj - inhibition of adenylyl cyclase which causes the inhibition of NA release
how does amphetamine work
U1 substrate inhibits MAOdisplaces NA into cytoplasmNA accumulates in synaptic cleft causing increased adrenoceptor stimulation
how does prazosin work
selective, competitive antagonist of a1vasodilator used as anti-hypertensive
how does atenolol work
selective, competitive antagonist of B1used as anti-anginal and anti-hypertensive agent
how does atropine work
competitive antagonist of muscarinic ACh receptors, does not block nicotinic Ach receptorsblocks parasympathetic division of ANSused to reverse bradycardia post MI and in AchE poisoning
what is the difference between muscarinic and nicotinic receptors
muscarinic - G-protein coupled receptors (GPCRs) that mediate a slow metabolic response via second messenger cascadesnicotinic - ligand-gated ion channels that mediate a fast synaptic transmission of the neurotransmitter
what is the role of cholesterol
contributes to fluidity and stability stiffens membrane
where are docking marker acceptor proteins and where are they found
found in inner membrane surfaceinteract with secretory vesicles leading to exocytosis of vesicle contents
what is the role of cadherins (cell adhesion molecule)
hold cells within tissues together
what is the role of integrins (cell adhesion molecule)
span membrane acting as link between extra and intra cellular environments
what is the function of carbohydrates
self-identity markersrole in tissue growth
what does the ficks law of diffusion relate to
magnitude of conc gradientsurface area of membrane across which diffusion taking placelipid solubility of substancemolecular weight of substancedistance through which diffusion must take place
what is osmolarity
concentration of osmotically active particles in solution osmoles/litrebody fluids approx 300mOsm
what is tonicity
effect a solution has on cell volume
what is secondary active transport
energy not used directly, stored in form of an ion concentration (usually Na+)
what are the two mechanisms of secondary active transport
symport (co transport) - solute and Na move in same directionantiport (exchange / countertransport) - solute and Na move in opposite direction
what mechanism of transport is Na+K+ATPase
primary active 3 Na out and 2 K inbut, conc gradient for Na+ is inwards and outward for K+
what is the role of Na+K+ ATPase
establish Na and K conc gradient across plasma membrane regulate cell volume by controlling conc of solutes inside cellenergy used to drive pump indirectly serves as energy source for secondary active transport
what happens in endocytosis
membrane pinches off to engulf substance
what happens in exocytosis
vesicle fuses with membrane, releasing contents to ECF
what is membrane potential
Emseparation of opposite charges across membraneunits mV
at resting potential, the membrane is 100x more permeable to what ion
K+
what is the equilibrium potential for K+
when conc gradient and electrical gradient balance each other membrane potential at Ek is -90mV
what is the equilibrium potential for Na+
membrane potential at ENa is +61mV
what is the Nernst equation
Elon = 61log10 [ion]o / [ion]i
what is the resting potential for a typical nerve cell
-70mVK+ gradient most important factor in setting Em
what is the Goldman-hodgkin-katz equation and what is it used for
Em = 61log10 Pk+ [K+]o + PNa+ [Na+]o / Pk+ [K+]I + PNa+ [Na+]Icalculates overall membrane potential p is relative permeability
what is hyperpolarisation
change that makes cell membrane potential more negative
what is depolarisation
change that makes cell membrane potential more positive
what hormones control glucose during starvation
cortisol (adrenal gland)growth hormone (pituitary)
what are the pancreatic islets of langerhans (endocrine glands)
alpha cells - glucagonbeta cells - insulindelta cells - somatostatin
what does insulin convert (favours anabolism - build up)
glucose -> glycogenfatty acids -> triglyceridesamino acids -> protein
what is the effect of insulin
lowers glucose by stimulating uptake from blood and activating liver enzymes
what is the role of ANS on glucose
parasympathetic activity - promoting secretionsympathetic activity - inhibiting secretion
what is the effects of glucagon
raises glucose by increasing glycogenolysis, inhibiting liver glycogen synthesis, promoting liver gluconeogenesis, lipolysis
what is the effect of sympathetic nerve activity on glucagon
stimulates release
what is the effect of adrenaline
raises glucosestimulates glycogenesisstimulates gluconeogenesis(cortisol also does all of above plus lipolysis)released during short term emergencies
where is growth hormone located and what is its response to starvation
anterior lobe of pituitary decreases glucose uptake by musclemobilises glucose from liverpromotes lipolysis in fat cells
what are baroreceptors
located in aortic arch and carotid sinussensitive to stretch, firing rate increases when MAP increasesonly respond to acute changes (firing decreases if HBP sustained)
what is the systolic pressure
when heart is contracting (<140mmHg)
what is diastolic pressure
when heart is relaxed (<90mmHg)
what is MAP
average arterial BP during single cardiac cycle (70 - 105mmHg)MAP = [(2xdiastolic) + systolic] divided by 3MAP = cardiac output x total peripheral resistance
what is cardiac output
stroke volume x heart rate
what is feedforward control
responses made in anticipation of a change
what is negative feedback control
primary typeopposes initial change components: sensor, control centre and effectorpromotes stability by regulation of controlled variable through flow information along closed loop
what is positive feedback control
not as often as negative amplifies initial change
how is heat gained in body
metabolic heat - increased by hormoneradiation - emission of heat energy in form of electromagnetic waves (1/2 is loss)convection - transfer of heat energy by air currents, combines with conductionconduction - transfer of heat between objects in contact
how is heat lost in body
convection - air next to skin warmed by conduction so less dense and rises whilst cooler air moves next to skinconductionradiationevaporation - passive (water diffuses from skin etc) or active (sweating by sympathetic NS)
How does negative feedback control maintain temperature
sensor detects change sends signal to hypothalamuseffectors (skeletal muscles, skin arterioles, sweat glands) triggered and respond to restore variable
what does the posterior hypothalamic centre respond to
coldvasoconstrictionincreased muscle toneshivering
what does the anterior hypothalamus centre respond to
warmth vasodilationsweating (sympathetic NS)decreased muscle tone
how is a fever caused
macrophages release chemicals which act as endogenous pyrogenstimulates hypothalamus to release prostaglandinsthis resets thermostat higherhypothalamus initiates mechanism to heat body thermostat reset to normal if pyrogen release is reduced
what is defined as fever
38-40 oC
what is defined as hyperthermia
> 40 oC
what is defined as hypothermia
35 or below oC
vascular smooth muscles are partially constricted at rest (vasomotor tone) - how is this achieved?
tonic discharge of sympathetic nerves resulting in continuous release of noradrenaline
what is the exception to “there is no parasympathetic innervation of arterial smooth muscle”
penis and clitoris
what is gametogenesis
germ cell formation (oogenesis > oocyte, spermatogenes > spermatozoa)
what is cleavage
period of rapid cell division which leads to blastomereswhen 8 cells, compaction takes place so zygote becomes blastocyst
what is gastrulation
formation of germ layerectoderm (outer)mesoderm (middle)endoderm (inner)
what is the process in fertilisation
sperm binds to zona pellucida glycoprotein acrosomal enzymes released from sperm head digest way into eggegg and sperm plasma membrane fuse and sperm contents enter effect sperm entry triggers completion of meiosis 2 and release of cortical granules by oocyte
what is the fate of the ectoderm
epidermis of skin, nervous system
what is the fate of the mesoderm
subdivided into 3 partsparaxial - axial skeleton, voluntary muscle, parts of dermisintermediate - urogenital systemslateral plate - somatic part (lining of body wall) or visceral part (CV system, mesothelial covering of organs etc)
what does the incomplete closure of the embryonic foramen oval in the septum lead to
atrial septal defect (ASD)orventricular septal defect (VSD)
what is a meta-analysis
a statistical analysis that combines results of multiple scientific studies
what are the phases of clinical trials
I - clinical pharmacology (dosage, safety)II - initial clinical assessment (likely effectiveness, common adverse effects)III - randomised controlled trialIV - post marketing surveillance (less common adverse effects)
sagittal
separated left to right
coronal
separated front to back
axial
chopped in half
what is the two types of surface of the wrist
dorsal or volar
what is the two types of surface of hand
dorsal or palmar
what is the two types of surface of tongue
dorsal or ventral
what is two types of surface of foot
dorsal or plantar
what is flexion (opposite is extension)
decreasing angle between bones at a joint
what is abduction (opposite is adduction)
movement away from medial plane
what is internal/medial rotation (opposite is lateral rotation)
anterior surface rotates towards median plane
what is circumduction
circular motion at joint
what is movements made by foot
eversion or inversion
what is movement made by forearm
pronation (palm down) or supination (palm up)
what is pulmonary circulation
from right side of heart, to lungs and back to left side
what is systemic circulation
from left side of heart, to capillary beds of organs etc back to right side
where does the heart lie and what is it surrounded by
lies deep to costal cartilages and between lungs (in inferior middle mediastinum) and is surrounded by pericardium
what is the layers of pericardium
visceral serous pericardium covers the heart whilst parietal serous pericardium lines fibrous pericardium
what is bicuspid (mitral valve)
between left atrium and left ventricle
what is tricuspid valve
between right atrium and right ventricle
what is the crux
fibrous cardiac skeleton in septum which acts as electrical insulator
what is anastomosis
connection between arteries without capillary network - provide alternative route of blood flow called collaterals
what is end arteries
when there is only arterial blood supply to area - occlusion result in infarction and irreversible cell death
what does the arch of the aorta branch into
brachiocepallic trunk (bifurcates into right common carotid and right subclavian arteries)left common carotid (bifurcates into external and internal carotid)left subclavian
what nerve innervates carotid sinus
glossopharyngeal
where does the vertebral artery (travels through vertebral foraminae of cervical vertebrae then through foramen magnum to supply brain) branch from
subclavian artery
where is lymph drained
central veins in root of neck at venous angles
what is ossification
process in which initial, small, hyaline cartilage grows into bone
what is the periosteum
connective tissue sleeve which is vascularised and well innervated (pain when torn during fracture)
what are examples of bony features
greater tubercle of humerusstyloid process of radius
what are the 33 bones of the vertebrae
7 cervical 12 thoracic 5 lumbar 5 sacral (fuse to form 1 sacrum)4 coccygeal (fused to form 1 coccyx)
what is the intervertebral foramen
between adjacent vertebrae and spinal nerves emerge through here
what is the facet joint
between articular processes of 2 adjacent vertebrae
what is special about C1 atlas
does not have body of spinous process
what is special about C2 axis
has odontoid process
what is special about C7
first palpable spinous process in 70% of people
what bones are in the hand
carpal bones (wrist) metacarpals (palm)phalanges (fingers)
what bones are in the foot
tarsal bones (mid foot)metatarsals (forefoot)phalanges (toes)
example of circular muscle
orbicularis oculi
example of fusiform muscle
biceps brachii
example of pennate muscle
deltoid
example of quadrate muscle
rectus abdominus
what is the role of a tendon
attach muscle to bonean aponeurosis is a flattened tendon
what is role of posterior fibres of deltoid
extension of shoulder
what is role of middle fibres of deltoid
abduction of shoulder
what is role of anterior fibres of deltoid
flexion of shoulder
what is the role of shallow socket of glenoid fossa of scapula
circumduction of shoulder
what is paralysis
muscle without functioning motor nerve so cannot contract and would have reduced tone
what is spasticity
muscle has intact motor nerve but descending controls from brain not working - increased tone
what is compartment syndrome
increased pressure caused by swelling and affects functions of muscles of nerves (fasciotomy to relieve pressure in emergency)
what is a fibrous joint
limited mobility, stable syndesmoses (unites bone with fibrous sheet)sutures (between bones of skull)fontanelles (wide sutures in neonatal skull)
what is a cartilaginous joint
fairly limited mobilityprimary - joins bones e.g. epiphyseal growth platesecondary - fibrocartilage e.g. intervertebral disc
what are the features of a synovial joint
2 or more bones articulating articular surfaces covered in hyaline cartilage a capsule wraps around jointcontains joint cavitysupported by ligamentsassociated with bursae (prevents friction)other special features (articular disc in TMJ joint)
what are the types of synovial joint
pivot (Atlanto-axial joint - turns neck)ball and socket (hip)plane (acromioclavicular joint)hinge (elbow)biaxial (fingers)
what is subluxation
reduced area of contact between articular surfaces
what is dislocation
complete loss of contact between surfaces
what happens in the dislocation of TMJ
head of condylar process of mandible becomes stuck anterior to articular tubercle of temporal bone
what forms the pelvic roof
parietal peritoneum (lining of abdominal cavity)
what is the most inferior part of the part of the peritoneal cavity in an upright female patient
rectouterine pouch
what is the three layers of the uterus wall
perimetrium, myometrium and endometrium
how is an unfertilised ovum expelled
contraction of myometrium
how is testes developed
originate on posterior wall of abdominal cavity then descent into scrotum via inguinal canal
what produces sperm
seminiferous tubulessperm pass to rete testis into head of epididymis which becomes vas deferens
what does the spermatic cord (passes through abdominal wall) contain
vas deferens, testicular artery and pampiniform plexus of veins
what is the role of the seminal gland
produces seminal fluid connects with vas to form ejaculatory duct containing semen (sperm and fluid)
how does an erection form
3 cylinders of erectile tissue become angorged with blood at arterial pressure
which muscle prevents drooling
orbicularis oris
what is tonsils at back of mouth called
palatine tonsils
what are the extrinsic muscles of the mouth
4 pairs which attach tongue to bony skeleton and moves tongue around during mastication, speech and swallowing
what are intrinsic muscles of the mouth
4 pairs in various directions which change shape of tongue during friction
what are the three major saliva glands
parotid (near ear)submandibular (under mandible)sublingual (under tongue)
what are the 3 parts of the pharynx
nasopharynx, oropharynx and laryngopharynx - last 2 used in resp and GI pathway to risk of aspirating material into respiratory tract
what is role of oesophagus and at which vertebrae does It pierce diaphragm
transmits food etc from pharynx to stomachgradual transition of skeletal to smooth muscleT10 vertebrae
what is role of small intestine and what is the three parts
transit, digestion and absorption (proximal to distal) duodenum, jejunum and Ileum
what is role of large intestine
transit, reabsorption of H2O and electrolytes stool formation
what kind of pain does a patient with GI tract obstruction experience
colicky pain - comes and goes response is increased peristalsis proximal to site of obstruction
what is the role of cricopharyngeal sphincter
junction between laryngopharynx and oesophagus - prevent regurgatation
what is role of pyloric sphincter
junction between stomach and duodenum - control relieve of chyme from stomach
what is role of external anal sphincter
control release of stool
what is components of the foregut and what artery supplies it
oesophagus to mid-duodenumliver and gall bladderspleen1/2 of pancreascoeliac trunk of abdominal aorta
what is components of midgut and what artery supples it
mid duodenum to proximal 2/3rds of transverse colon1/2 of pancreassuperior mesenteric artery
what is components of handgun and what artery supplies it
distal 1/3 of transverse colon to proximal 1/2 of anal canalinferior mesenteric artery
what is a peripheral nerve
bunch of axons wrapped in connective tissue
CN I and location
olfactory nerve - forebrain
CN II and location
optic nerve - forebrain
CN III and location
oculomotor nerve - midbrain
CN IV and location
trochlear nerve - midbrain
CN V and location
trigeminal nerve - pons
CN VI and location
abducent nerve - junction (pons and medulla)
CN VII and location
facial nerve - junction (pons and medulla)
CN VIII and location
vestibulocochlear nerve - junction (pons and medulla)
CN IX and location
glossopharyngeal nerve - medulla
CN X and location
vagus nerve - medulla
CN XI and location
spinal accessory nerve - spinal cord
CN XII and location
hypoglossal nerve - medulla
how are spinal nerves named
according to vertebrae above it except in cervical region when named according to vertebrae below e.g. c8 exists between c7 and t1
what is conus medullaris
L1/L2 IV disc level where spinal cord ends
what is cauda equine
lumber and sacral spinal nerve roots descending in vertebral canal to their respective intervertebral foraminae - horse tail
what is a dermatome
area of skin supplied by both anterior and posterior rami
what is at T4 dermatone
male nipple
what is at T10 dermatone
umbilicus
what is a nerve plexus
network of intertwined anterior rami
what nerves are in brachial plexus C5-T1
axillary nerve, median nerve, musculocutaneous nerve, radial nerve and ulnar nerve
how are sympathetic nerve signals passed
originate from brain, exit spinal cord with T1-L2, travel to sympathetic chains, pass into all spinal nerves and hitch a ride to splanchnic nerves where they supply organs
how are parasympathetic nerve signals passed
leave CNA via cranial nerves III, VII, IX and X via sacral spinal nerves
what does vagus nerve supply
organs of neck, chest and abdomen
what is role of sacral spinal nerves
carry parasympathetic axons to hindgut, pelvis and perineum
what does the somatic NS supply
body wall and external environment
what does the autonomic NS supply
supplies visceral motor system and internal environment
what do mechanoreceptors sense
course touch, fine touch, vibration and proprioception
what do nociceptors sense
pain
somatic sensation is linked with posterior nerves and is 3 neurone chain. What are these 3 neurones?
primary somatosensory area, sensory homunculus and motor homunculus
what is motor innervation associated with
anterior nerves before they synapse onto skeletal muscle of lower limb and muscles contract
characteristics of upper motor neurone
opposite side from movement, axons cross at brainstem, upper motor neurone lesion
characteristics of lower motor neurone
same side as movement, connect to skeletal muscle, lower motor neurone lesion
what is ischaemia
problem in which there is reduced blood flow
what is cockily pain
obstruction, will be dull, achy and poorly localised
test sensitivity
proportion of those who have disease who are correctly identified with positive test (same as negative predictive value)
test specificity
proportion of those who do not have disease who are correctly identified by negative test (same as positive predictive value)
1-Negative predictive value
% of people with negative result who have health problem
prevalence
number of cases of a disease present in a population at a specific point in time / number of persons at risk of having the disease at that point in time
incidence rate
number of NEW cases of a disease occurring in population during specific period of time / number of persons exposed to risk of developing disease during that period