Week 8 Flashcards
Nervous system functionS?
- communication: between areas of the body
- behviour: personality by frontal lobe
- regulation: bresthing, HR, movement, temperature
- stores information: memories
- sensation: pain, touvh, feelings
- emotions
what is the central nervous system composed of?
brain and spinal cord
what is the peripheral nervous system composed of?
spinal and cranial nerves
how many spinal nerves are there?
31 pairs
how many pairs of cranial nerves are there?
where do they come from?
where do they supply?
12
brain and brainstem
head and neck structures bar vagus nerve
what does somatic mean?
cell of the body, not germ line cell
what does visceral mean?
internal organs in main cavities of body
what does afferent mean?
arrives into spinal cord and brain
why does efferent mean?
exits brain and spinal cord
what does motor mean?
supplies muscle
what does autonomic nervous system mean?
involuntary part of body functions
what are somatic efferents supplying?
skeletal muscle
what do visceral efferents supply? difference between them and other neuronal pathways?
smooth muscle, glands, cardiac muscle
2 neurons in pathway, usually 1
what do longitudinal fissure seperqte?
2 cerebral hemispheres
what are the 2 layers of brain matter?
outer grey matter, inner white matter
what are gyri vs sulci? purpose?
gyri - brain ridges, stick out
sulci - spaces between grooves
increases surface area
when does brain folding happen?
embryological development
structure and function of brainstem?
midbrain, pons and medulla
breathing and HR control
what is brain coning?
swelling in brain presses on brainstem and impacts respiratory and cardiac systems
cerebellum fucntion?
controls movement and coordination
what is the telencephalon?
cerebrum
what is the diencephalon?
thalamus, hypothalamus
thalamus function?
relay station of sensory/motor systems
regulates sleep, consiousness, awakeness
hypothalamus function?
regulates endocrine system via pituatry gland
thermoregulation
what is the forebrain?
telencephalon and diencephalon
what is the mesencephalon, function?
midbrain
vision, hearing, motor function, arousal
what is the hindbrain or rhombencephalon?
part of developing brain
function of frontal lobe?
executive functions
long term memory, speech, movement, personality
what is the parietal lobe function?
sensory integration, language interpretation, spatial/visual perception
occipital lobe function?
visual processing - colour/light
temporal lobe function?
auditory cortex, memory, understanding language
function of cell body in neuron?
contains nucleus/mitochondria
interprets information around it via dendrites
function of dendrites in neurons?
take information from periphery and communicate with nerves around it
function of axons in neurons?
conducting portion
function of myelin sheath in neuron, what makes it? structure?
encases neuron, allows faster propogation of nerve impulses
produced by schwann cells/oligodendrocytes
made iof fat
function of node of ranvier?
between myelin sheaths
allows rapid transmission of nerve impulses
function of axon terminals?
allows communication with other axon terminals
function of astrocytes? how?
nutrient supply to neurons in CNS
link to blood vessels
also form blood brain barrier
structural support
function of microglia?
defence role (phagocytic)
function of ependymal cells?
produces CSF and circulate it
function of oligodendrocytes?
neuronal support
myelin formation in CNS
function of schwann cells?
neuronal support
myelin formation in PNS
what cells surrpund central canal?
ependymal cells
function of corpus callosum? what does crossing of fibres mean?
links cerebral hemispheres
crossing meand R brain controls left body, L brain controls R body
what does FAST stand for?
F - face drooping
A - arm weakness
S - speech difficulty
T - time to call emergency services
used in strokes
areas of glasgow coma sclae?
eye opening -4
verbal response - 5
motor response - 6
what is the conus medullaris?
lower end of spinal cord at L1/2
what is the cauda equina? where found?
nerve rootlets at L2-5
sits in space called lumbar cistem, formed by subarachnoid spaces from conus medullarys to S2
where can CSF be extracted?
subarachnoid space in cauda equina
Where does afferent sensory information from brain enter first in spinal cord?
dorsal root ganglion, then dorsal horn
where are aautonomic efferent nuclei found? function?
lateral grey horn
mediate sympathetic nervous system
how do efferent signals get to muscles?
via ventral root
what are meninges? 3 layers?
3 layers wrapping rounf brain and spinal cord
dura, arachnoid, pia
structure of dura mater?
thick membran made of dense irregular connective tissue
2 layers - periosteal, meningeal
joined directly to skull bone
structure of arachnoid mater?
…
structure of pia mater?
innermost layer
delicate
allows blood vessels to pass through annd nourish brain
where are falx cerebri found? function?
longitudinal fissure, prevents brain movement
how many different types of spinal nerves are there?
8 cervical
12 thoracic
5 lumbar
5 sacral
1 coccygeal
which axons are found in each spinal nerve?
sensory and motor axons
what are dermatomes?
individual region of skin supplied by sensory neurons
what are myotomes?
blocks of muscle supplied by motor axons
why doesnt C1 have a dermatome?
doesnt have dorsal root, only motor root supplying head/neck muscles
what are v1/v2 dermatomes associated with?
trigeminal nerve
function of dermatomes clinically?
helps locate whats wrong if theres pain in a certain area
structure of psudounipolar neuron?
1 extension from cell body splits into 2 branches - one goes to PNS, one to CNS
Structure of multipolar neuron? found in?
single axon and many dendrites, usually motor neurons
structure of autonomic multipolar neurons? what does it supply?
synapse between 2 neurons, supplies glands, heart, gut
name 12 cranial nerves and their functions.
- olfactory: smell
- optic: vision
- oculomotor: eye movements
- trochlear: eye movements
- trigeminal: motor to muslces of mastication and general sensory to face
- abducens: eye movements
- facial: muscles of facial expresiion
- vestibococchlear: hearing and balance
- glossopharangeal: swallowing, taste
- vagus: wandering nerve supplying heart, lungs, gut
- spinal accessory: neck muscles
- hypoglossal: tongue muscles
2 parts of somatic nervous system?
sensory and motor system
2 fibres of autonomic nervous system?
visceral afferent and visceral efferent
2 types of visceral efferent fibres?
sympathetic and parasympathetic
where are sympathetic fibres found?
T1-L2
where are parasymapthetic fibres found?
S2-S4
what do nociceptive fibres detect?
pain sensation
how many neurons are in the effector pathway of the autonomic nervous system?
2
what does caudal mean in regards to the brain?
below or towards the back
what does dorsal and ventral mean in the brain?
dorsal is above longitudinal axis of forebrain
ventral below
what does rostral mean in the brain?
towards the front
where are unipolar neurons usually found?
sensory neurons
where are bipolar neurons usually found?
interneurons
where are multipolar neurons usually found?
motorneuron/interneuron
where are pyramidal neurons usually found?
forebrain e.g. cerebral cortex
the dysfunction of which glial cell can cause multiple sclerosis?
oligodendrocytes
the dysfunction of which glial cell can cause guillan-barre syndrome?
schwann cell
what is a glioma? what is a glioblastoma?
glioma is brain tumor
glioblastoma i grade IV glioma. aggressive form
which cell types are found in grey matter?
cell bodies
dendrites
axon termini
glial cells e.g. astrocytes
blood vessels
which cell types are found in white mater?
myelinated axons
glial cells - oligodendrocytes
blood vessels
what is the deep lobe of the brain?
limbic lobe
which cranial nerves arise from the brainstem?
CN III - XII
which system has functions in the medulla?
autonomic nervous system
where are reflex centres found in the brain? what does this require?
medulla e.g. vomiting
nuclei
what is another name for grey matter?
cerebral cortex
what functions are in the prefrontal corteX?
cognition
personality
behaviour
mood
what happens if brocas area is damaged? where is this area?
speech impaired but can comprehend speech
towards front of brain between frontal and parietal lobe
what happens if wenickes area is damaged? where is this area?
fluent speech but no meaning, cant comprehend speech
towards back of brain between temporal and parietal lobes
what is contained in limbic system?
amygdala and hippocampus
function of amygdala?
emotions and emotional behaviour
function of hippocampus?
learnign and memory
function of basal ganglia?
controls movement
function of corpus callosum?
communication between brain parts
where is language production and comprehension usually in the brain?
left hemisphere
what happens if your brain is split down the corpus callosum?
cant verbally describe image shown in left visual field as fibres cross over between hemispheres in CC
what is the spinal cord an extension of?
brainstem
what spinal nerves control diaphragm?
C345 keep the diaphragm alive
which spinal nerves cotrol knee and foot movement
L3-S1
which spinal nerves are involved in sympathetic activity?
T1-12
which nerves are involved in parasympathetic activity?
Cranial nerves and S4
function of the filum terminale?
suspends spinal cord in CSF
what is the conus medullaris?
end of spinal cord
what are spinal cord tracts?
bundles of nerve fibres running up and down spinal cord
function of spinothalamic tract? ascending or descending?
ascending, sensory, pain and temperature
function of corticospinal tract? ascending or descending?
descending
motor
voluntary movement
what does decussate mean? when is it used?
cross over
spinal cord tracts
meaning of ipsilateral and contralateral in relation to spinal cord tracts?
ipsilateral: same side
contralateral: opposite side
What are partial spinal cord injuries? Where is function lost?
damage to specific spinal tracts
loss of function below level of injury
if tracts decussate below, lose function on contralateral side
if none, ipsilateral side
why do the 2 dura mater layers seperate?
to form venous sinuses
when does the epidural potential space occur?
when meningeal artieries supplying dura rupture, causes haematoma, space fills with blood
when does the subdural potential space occur?
when bridging veins connecting to venous sinuses rupture, causes haematoma, space fills with blood
what is within the subarachnoid space?
csf
cerebral arteries/veins
connective arachnoid trabeculae
what is different about the meninges at the spinal cord?
one layer of dura mater
epidural space contains fat and venous plexus
what is meningitis an inflammation of?
pia and arachnoid mater and subarachnoid space
which infections cause meningitis?
viral and bacterial
what is seen in a lumbar puncture when someone has meningitis?
increased WBCs in CSF +/- bacteria
where do you do a lumbar puncture?
between L4-5
Which parts of the brain does CSF fill?
ventricles and subarachnoid space
how much csf is there in total?
125-150ml
functions of CSF?
cushions brain against movement and own weight
provides stable chemical environment for brain e.g. electrolyte levels
nutrient and waste exchange between nervous tissue and blood
how might neurodegenerative disease be related to CSF?
reduced CSF turnover = metabolic waste buildup
what is the daily turnover of csf?
500ml/day
where is CSF produced?
chorid plexus - lateral and 4th ventricles
what is circulation of CSF driven by?
new production
what is caused by excess CSF levels?
hydrocephalus
what is different in CSF compared to plasma?
few cells
lower protein
different electrolyte levels
what is the blood brain barrier?
several features preventing harmful substances getting into brain and spinal cord from blood
how do capillaries in nervous tissue act as a blood brain barrier?
- tight junctions between endothelial cells restrict movement
- thick continuous BM
- astrocytes processes cover vessel
how do ependymocytes act as a blood brain barrier, where do they line?
line ventricles and spinal canal
- tight junctions restrict movement
which areas of the blood brain barrier have higher permeability?
area postrema in medulla: toxin detection for vomiting
pituatry gland in endocrine system secretes hormones
what happens when the blood brain barrier is diseased?
toxins can get into CNS and cause problems
functions of blood brain barrier?
- keeps out toxins, pathogens etc.
- stops fluctuation of ions, nutrient, metabolite concentrations in CNS
what would happen if the blood brain barrier was defective and increased potassium leaked into the CNS?
it would affect nerve impulses
what is the blood brain barrier permable to?
- water, small lipophilic molecules, gases by diffusion
- glucose, amino acids by active transport
what exactly is a signal?
ion movement or movement of electrical charge
examples of signals?
gap junctions between cardiac myocytes
nerve cells along cell membrane
how quickly do neurons transmit signals? what does speed depend on?
up to 120m/s
type of neuron
which system has slow signalling?
endocrine
what is the longest neuron in the body?
base of spine to big toe
what is an impulse/action potential?
wave of altered charge along nerve cell membrane that sweeps along axon
what is the membrane potential maintained by?
ion pumps in plasma membrane
whta is usually the electrical potential difference across neuron plasma membrane
-70mV
when is an action potentual generated?
when nerve cell is stimulated
what happens in an action potential?
depolarisation: voltage gated sodium channels open and flow into the cell, membrane potential increases
repolarisation: potassium channels open at 30 mV and flow out of the cell, sodium channels close
hyperpolarisation: potassium channels close, sodium channels reset and return to rest
what is hyperpolarisation?
too many
what is hyperpolarisation?
too many potassium leave cell so the cell becomes very negatuve
how does the membrane return to resting potential after hyperpolarisation?
ion diffusion
how is an impulse prevented from going backwards along a neruon?
refractory period
what is a refractory period?
time immediately following AP when new AP cannot be initiated in same area of membrane
what is the absolute refractory period?
sodium channels close and cannot be activated for short period of time
what is the relative refractory period?
sodium channels could open but harder to reach ap due to hyperpolarisation
which 4 ion channels are present in the hydrophobic membrane?
leakage, voltage ligand and mechanically gates
what is the stimuli for opening leakage channels?
randomly opens
what is the stimuli for opening voltage gated channels?
changes in membrane potential
what is the stimuli for opening ligand gated channels?
specific ligand binding to receptor
what is the stimuli for opening mechanically gated channels?
tension in the membrane
what is the distribution of sodium and potassium ions at rest?
more sodium ions on outside of cell
more postassium ions on inside
where does the sodium potassium pump get energy to pump ions across a conc gradient?
energy from the hydrolysis of ATP
what happens in the sodium potassium pump?
3 sodium out, 2 potassium in
which ion channels are open at rest? what does this do?
leakage channels for sodium and potassium
keeps resting potential at -70
what membrane potential figure causes an AP?
-55mV
what happens if the membrane does not reach -55mV?
sodium potassium pump restores membrane potnetial
what is a graded potential?
small changes in membrane potential
which inputs to dendrites starts an AP?
excitatory pre-synaptic potentials
inhibitory pre-synaptic potentials
what do excitatory pre-synaptic potentials do?
increase chances of AP initiation
what do inhibitory pre-synaptic potentials do?
decreases chances of AP initiation
what is spatial summation?
summation of inputs from different areas of cell e.g. from different dendrites
what is temporal summation?
input occurs multiple times from same dendrites, repeated inputs in short time = summation
does Ap frequcny or magnitude vary?
ap frequcency varies
magnitude stays the same
what is the signal intensity in a neuron caused by?
AP frequency
what do APs cross at the end of a neuone?
synapse
what is a signal reflex arc?
neural pathways containing multiple nerve cells such as relay neuron
function of neurotransmitters in signalling?
can help transmit signal across a synapse
when are neurotransmitters released, where do they bind?
when AP reaches pre-synaptic neuron termini
bind to receptors of post synaptic neuron
which type of signal are neurotransmitters?
chemical
which type of chemical signal can be excitatry or inhibitory?
neuotransmitters - promote/inhibit formation of AP in receiving neuron
example of amino acid neurotransmitter?
glutamate: excitatory
gaba: inhibitory
example of monoamine neurotransmitter?
dopamine, serotonin
where is acetycholine derived from? function in signalling?
choline
neurotransmitter
example of peptide neutrotransmitters?
substance P
endorphins
which type of receptor is GABA-A?
ion channel
what happens when GABA ligand binds to GAPA-A?
conformation change opens ion channel
ions flow along conc gradient
AP happens in pre synaptic neuron
triggers release of vesicles contianing GABA
diffuse actoss synapse and binds to gaba a
what flows into the cell when GABA binds? what happens?
negative chlorine
hyperpolarisation
which medcines use GABA and why?
benzodizepines, ethanol, some anaesthetic
inhibition of APs causes sedative action
how is GABA switched off?
reuptake into presynaptic cell by transporters
enzymes degrade neurotransmitters
which type of receptor is nAChR?
sodium ion channel receptor
what happens when ACh binds to nAChR at neuromuscular junction?
sodium entry causes depolarisation of muscle cell membrane which intiates contraction
how is ACh effects switched off?
acethylcholinsterase removes ACh
what is the cause of myasthenia gravis?
muscle weakness:
autoimmune antibodies attach ACh receptors at neuromuscular junction
treatment for myasthenia gravis?
AChE inhivitors enhances NMJ transmission
what excatly is the heartbeat?
electrical impulse travels along heart tissue causes contraction of heart muscle via gap junctions
which cells spread charge throughout the heart? which order? how?
purkinje fibres
atria first then ventricles
ions flow between adjacent myocytes via gap junctions
which cells have the alpha globin gene?
all, only some make alpha globin protein through
what is transcription?
turning DNA to RNA
what is translation?
turning RNA to protein
which RNA doesnt translate?
tRNA
rRNA
miR
what is a genome?
sequence of all DNA in an organism
what is a gene?
unit of inheritance, some code for proteins
difference between exons and introns?
exons - excellent, keep in
introns, intruder, keep out
what is the UTR?
untranslated region, end of transcript that doesnt get translated
which way is rna translated?
5’ to 3’ end
what is the cap addition site?
adds protective nucleotide to RNA
what is PolyA addition site?
adds protective nucleotide to RNA
3 steps of transcription?
initiation: RNA polymerase pulls DNA strands apart
Elongation: RNA gets longer forming transcription bubble
Termination: RNA synthesis stops
what is splicing, what does this?
removes introns
spliceosome
where is mRNA translates?
cytoplasm
where do transcription factors bind and what do they do?
bind to short but specific DNA sequences
affect rate of transcription by turning genes on or off, activates or represses
what are master regulators?
transcription factors determining how much protein will be made from a gene
examples of transcription factors?
p53 and E2F
nuclear hormone receptors e.g. oestrogen/testosterone receptors
where do steroids act on?
transcription factors
how does RNA polymerase 2 bind to DNA as it cannot do it itself?
general/basal TFs act as a bridge between DNA and RNA polymerase
where do transcription factors bind to?
TATA box and CAT box
what is the promoter?
transcription factors bind here to influence how much protein is expressed
what happens when the TATA box is muatted in beta globin gene promoter?
thalassaemia - severe anaemia
what happens when the CCR5 promoter is mutated?
affects rate that HIV progresses to aids
what happens when there are mutations in the factor IX promoter?
haemophilia b
what happens when there are mutations in the LDLR promoter?
familial hypercholerolemia
what stabilises the transcription intitiation complex?
TFs on upstream enhancer elements
what can make it more or less likely to activate a promoter?
enhancer/silencer
how is p53 an activator and repressor?
activates transcription of p21, cell cycle arrest and DNA repair
respressor of transcription of surviviv, apoptosis
how is E2F an activator?
activates transcription of genes needed for S phase
how is Oct-1 a repressor?
respresses transcription of TSH in all cells
where is TSH transcribed?
thyrotrophs in pituatry
what does snail repress?
e cdherin in epithelial cancers, less cell-cell adhesion, more inhasive ability
what mutations are frequently found in enhancers or silencers?
single nucleotide polymorphisms
what keeps DNA closed to TFs?
nucleosomes
what are locus control regions?
super enhancers
open chromatin spanning several genes
example of super enhancer?
globin genes
TF binds to globin LCR in erythrocytes
opens DNA of all globin genes
gene expression possible
what happens when LCR are mutated? disease?
locus stays closed
globin expression very low
hispanic thalassaemia
what is consititutive gene expression?
genes that are expressed in all cells all the time at the same levels
housekeeping genes: maintain basic cell function
examples of housekeeping/constitutive genes?
beta-actin for microfilaments
ribosomal proteins
GAPDH in glycolysis
general/basal transcription factors
what promoter do constitutive genes have?
constitutive promoter
what are inducible genes?
genes only expressed in certain tissues or cells at certain times
examples of inducible genes?
protein coding genes
cell specific: CD4,CD8, Collagen I and II, globin, myelin
time specific: cyclins, melatonin, inflammatory cytokines
clinical significance of time specific expression?
teratoma, cancer, hereditary persistence of fetal hemoglobin
what is splicing?
removal of introns by spliceosome
what is an isoform?
different mRNAs from same gene
what can affect splicing?
single nucleotide polymorphisms
what happens when there is a snp in beta globin first intron?
thalassaemia
what happens when dysstrophin is alernative spliced?
duchennes muscular dystropy
what happens when cftr is alternative spliced?
modifies severity of cystic fubrosis
what happens when tau is alternativrly spliced?
frontotemporal dementia with parkinsonism
what are microRNAs? function?
short rna sequencecs
complementary binding to mRNA to initiate its destructuin
can reduce gene expression post translationally
what are microRNAs involved in pathogenically?
cancer
what is the genome?
sequence of all the DNA in an organism
what is the transcriptome? what can it be used for?
all mRNAS in given tissue or cell at a given time
differentiate between diseases
what is the proteome?
all the proteins in a cell/tissue/tumor
what increases antibiotic resistance?
selection pressure from repeated exposure to antibiotics
what folows the emergence of antibiotic resistance?
a novel agent
how does clostridium difficile cause damage to the body?
lives in the gut and colonises the bowel where it releases toxins
can cause ibs
what is the increased numbers of c diff cases linked to?
increased antibitotic resistance
what is antibiotic stewardship?
- reduce antibitoic consumption
- restrict worst offender agents
-promote logical antibioticc choices - limit co-lateral damage
what is guided antibiotic therapy?
- identifying cause of infection and selecting agent based on sensitivity testing
what is empirical antibiotic therapy?
best educated guess therapy based on clinical acumen
when therapy cannot wait for culture
what is prophylactic antibiotic therapy?
preventing infection before it begins
which infections wuld you use guided therapy for?
mild ones that can wait a few days
cystitis, mild wound infecions
which infections would you use empirical therapy for?
severe infection
sepsis/meningitis
when would you use prophylactic therapy?
healthy people exposed to: surgery, injury, infected material
immunocompomised individuals: hiv, transplants, splenectomy
what are the target effects of antibiotics?
- highly toxic to bacteria causing infecion
- penetrate body area affected by infection
- limit release of toxins from bacteria
- convenient administration
what co-lateral damage should be limited with antibiotics?
- non-toxic
- limited effect on colonising bacteria
- low potential for bacteria to escape treatmet through resistance
what needs to be achieved with narrow spectrum/guidedtherapy antibiotics?
- use antibiotic which has limited action to the bacteria causing infection
- limit penetration to site of infection
- cure patient with as little impact on colonisation and resistance as possibel
what needs to be achieved with broad spectrum/empirical therapy antibiotics?
- use antibiotic which has extensive action against ant bacteria which may be causing infection
- need to penetrate broadly throughout the body
- accept that impact on colonisation and resistance may be greater
what do bactericidal antibiotics do to achieve sterilisation? what can this cause?
directly kill bacteria
release of toxins and inflammatory material
how do bacteriostatic antibiotics work? what do they require to clear bacteria? what is this called?
suppress growth but dont directly sterilise infected site
requires additional factors to clear bacteria from immune system
immune mediated killing
4 antibiotic targets?
cell wall
metabolism
DNA/RNA
ribosome
why are penicillin good antibiotics?
rapidly kill bacteria
low toxicity
how do penicilins/beta lactam antibiotics work?
insert beta lactam ring into peptidoglycan cell wall to inhibit cell wall synthesis
cell lysis will occur
what can a penicillin allergy result in?
rash or anaphylaxis
how many people report penicilin alergy compared to how many people actually have a penicillin allergy?
10 percent
1 percent
why is penicillin allergy label associated with poorer clinical outcomes?
they are effective antibiotics in many diseases e.g. cancer and alternatives dont work as well
name 3 beta lactam drugs? where do they target?
penicllin
cephalosporins
cerbapenems
cell wall
where do vanomycin antibiotics work and what are they useful against? where do they target?
large molecule cannot penetrate gram negative cell wall so gram positive
useful against penicillin resistant drugs e.g. mrsa
cell wall
what are doxycycline and clarithromycin effective against? where do they target?
intracellular pathogens as they are highly concentrated there
infections caused by both gram positive and negative organisms e.g. chest infections
ribosomes
what are ciprofloxacin effective against? where do they target? issue with them?
broad spectrum
damage dna
resistance is now widespread
what is trimethoprim used for? where do they target? problem?
non severe uti
target metabolism
resistance is widespread
first antibiotic
what are antibiotics derived from?
micro organisms
what are 3 primary mechanisms of resistance?
mutation of target site
inactivating enzymes
limmiting acces - reduced permability
how can beta lactams be inactivated?
beta- lactamase destrosy beta lactam ring
how can beta lactamases be overcpme?
beta lactamase inhibitors
beta lactamase stable drugs
what is the somatic nervous system?
part of peripheral nervous system
carries motor and sensory information to CNS
part of body which you can control
what is the autonomic nervous system?
part of nervous system controlled uncounsciously
what are the two parts of the peripheral nervous system?
sympathetic and parasympathetic
which part of peripheral nervous system is fight or flight?
sympathetic
what is the origin of sympathetic output? exception?
thoracolumbar spinal cord
cervical ganglia - extension of sympathetic chain, supplies head and neck e.g. to dry mouth and dilate pupils
what is the sympathetic neurotransmitter at the preganglionic synapse?
acetycholine
what is the sympathetic neurotransmitter at the post ganglionic synapse?
noradrenaline
what does the sympathetic nervous system do when it encounters a threat?
pupils dilate to see more
mouth dry to provide moisture in organs
adrenaline release from adrenal glands to speed up heart and increase contraction
inotropy: strength of heart contractions increase
chtonotropy: rate of cardiac contraction increases
vasodilation: in skeletal muscles so more oxygen delivered, in skin so heat is lost
reduced blood supply to gut to induce constipation
urinary/fluid retention
sweating
what does the renal system do in symapthetic response?
vasocontriction - reduced blood supply to kidneys as you want blood in muscles
increased renin to promote further vasocontriction
what is the post ganglionic neurotransmitter in sweat glands and deep muscle vessels?
acetycholine
function of alpha 1 receptor?
arteriole constriction: causes increased blood pressure, increased flow around the body, more oxygen to blood vessels/organs
function of alpha 2 receptor?
coronary/venous vasoconstriction
function of beta 1 receptors?
increase heart rate and contractility of the heart
function of beta 2 receptors?
smooth muscle relaxation:
uterus - so you dont give birth
gut - constipation
bladder - fluid retention
lungs- bronchodilation
eye - dilation
skeletal blood vessles - more o2 to muscles
what happens when the parasympathetic nervous system is activated?
pupillary constriction to improve near vision
nasal engorgement - maximise sensory absoprtion
excess salivation to eat
increased gastric secretions and blood flow
slow heart rate
bronchoconstrition
urination/defecation
origin of parasympathetic nervous systen?
craniosacral outflow
where is parasymapthetic ganglia? where do they diffuse?
near site of action
vagus
what are the ganglionic neurotransmitter in parasympatheric nervous system?
acethycholine pre and post
where is sympathetic ganglia?
next to spinal cord
what cranial and sacral nerves are the origins of parasympathetic nervous system?
c - 3,7,9,10
s - 2,3,4
2 types of parasympathetic receptors?
muscarinic receptors
nicotinic receptors
function of m2 receptor?
slow heart rate to normal rhythym
function of m3 receptor?
increase salivary production
increase blood supply to gut
increase bladde contraction
constrict pupils
function of muscarinic receptors antagonists?
reduce affect of ach on heart
increases heart rate
what is the lung m3 receptor agonists?
tiotropium/ipratropium
what is the bladder m3 receptor agonists?
oxybutinin
what is the gut m3 receptor agonists?
mebervine
what is the eyes m3 receptor agonists?
pilocarpine
muscarinic receptors in brain?
m1
m4
m5
what are n1 receptors involved with?
motor neurons
what are n2 receptors involved with?
autonomic nervous system
functions of the brain stem?
cranial nerve function
conduit function - connects brain to rest of body
integrative functions
what does coning of the brain cause?
raised pressure
cerebellar tonsillar herniation
ischaemia of brainstem
what can brain stem death cause?
paralysis/unconsiousness
apneoea
loss of cranial nerve function
how can you test brain stem death?
known irreversible cortical death
excluson criteria met
unconscious, apneic
the gene for which protein would be constitutively expressed?
translation initiation factor
which gene would be repressed in a neuron?
keratin
in which part of the cell is the splieosome found?
nucleus
