Hard :( Flashcards
what is ganglia
Ganglia is where axon meets another axon
this is where there is a collection of dendrites and allow collection of synapses
what is endogenous
Sometimes the neurotransmitter is the ANS is not caused by classic neurotransmitters but is caused by non adrengeric and non cholinergic transmission
Electrical stimulation of post ganagolic parasymapethic fibre to vessel
Acetylcholine and Nictonic oxide produce rapid relaxation
Vasoactive intestinal peptide can produce a slow delayed reponse
Electrical stimulation of post ganagolic symapethic fibre to vessel
ATP produce as a fast contraction in smooth muscle
Noradrenaline produces a moderately fast response
Neuropeptide Y produces a slow reponse
Potency
a adrenceptors -> noradrenaline -> adrenaline -> isoprenaline
B adrenoreceptors -> isoprenaline -> adrenaline -> noradrenaline
example of an antagonist
biceps branchii and brachilias are antgonist branchii and anceoneous
different muscles and examples
Axial muscle ~ trunk
Proximal muscle ~ Shoulders
Distal muscle ~ hands and feet
Upper motor units infuelnce
Upper motor units influence activity of lower motor units
Lower motor units
stimulate contraction
exit spinal cord
supply
Lower Motor units - neurons synapse to stimulate contraction allowing contraction from the spinal cord
exit spinal cord in spinal nerves - sensory and motor supply
Relationship between motor unit vs contraction
Increase Motor Units increase the force of contraction
Size Principle
Fixed order to recruit to increase activity - size principle
what does control of motor function involves
Control of motor function involves integration of sensory and motor inputs / outputs
what is extrafusal
Extrafusal - bulk of skeletal fibres which generate force and innverated by motor neuorns
what is intrafusal
Intrafusal - remaining specialised fibres - muscle spindles and are innverated by y motor neurons and sesnory afferent
What afferent have sesnory and motor afferent
Sensory and motor innervation is provided by la and II afferent
Muscle spindle sense chnages in what
Muscle spindle sense changes and respond to changes in muscle length to return skeletal muscle to resting state after they have been used
Mid Diastole
Ventricles contain most of the volume
atrial and ventricular pressures are low and aortic is high
Aortic and Pulmonary valves are closed
Late diastole
Late Diastole is the p wave and blood enters the ventricles from the atria
both atrial and ventricle is increased
aortic and pulmonary are clsoed
End Diastole and early systole
End Diastole and early systole - QRS ventricular depolarisation and ventricular rapidly increases and aortic is shut
Ejection Peroid
Ejection Period - blood is ejected into aorta and pulmonary
ventricular > Aterial
Aortic and Pulmonary is open
End of Ventricualr systole
End of ventricular systole - ventricular repolarisation Ventricular < Aortic
both Aortic and pulmonary are shut
Filling Peroid
Filling peroid - ventricualr volume increases
Ventricular < Atrial pressure
AV is open
First coincides
First coincides with the beginning of systole produced by closure of the AV valve
Second Coincides
Second begins with the onset of diastole - closure of the aortic and pulmonary valves
strucrture of a scarmoere
Scarmoere consits of a single A band and two I band
I band is only thin filament from 2 adjacent scarmoeres
Alkaline chain
Alkaline chain is stability and regulatory action for ATPase and activity of chain is regulated via phosphorylation by kinase
Ca modulate what
Ca modulates contraction and regulatory proteins rather than interacting directly with contractile proteins
Troponin moving to allow cross bridge cycle
Troponin I shift permitting tropomyosin molecule to move
Troponin T tropomyosin is moved away from myosin binding site on actin
Transverse tubules
Transverse tubules action potential spread through muscle fibre
Maximal muscle current to penetrate into fibre to separate myofibrils and transmission of action potential along transverse tubules
what is smooth muscle
Smooth Muscle - individual Muscle fibres are relatively small spindle shaped one nuclei
what is cardiac Muscle
Cardiac is individual muscle fibres are large cylindrical with many nuclei
What is skeletal muscle
Skeletal multi-nuclei individual muscle fibres are large elongated cylindrical
Tonic
Tonic is constanlty engaged and stronger reponses when stimualted by neurons that innervate them
helps control spinters periodically and are individual neurons and have electrical isolation of cell
Phasic
Phasic operates together with small number of neurons that innervate a cell
gap junction allowing coordinated contraction as they all communicate together
what are contractile protiens
contractile proteins are anchored in the cytoplasm on the cell membrane on dense bodies and dense plaques - net like structure
factors affecting striated muscles are stretch
factors affecting striated muscles are stretch and intracellular calcium
factors affecting smooth muscle cross-bridge
factors affecting smooth muscle cross-bridge are increased intracellular calcium, phosphorylation of MLCK and inhibition of myosin light chain phosphate
How do Ca leave the SR
Membrane bound Ca2+ ATPase and Na Ca2+ exchanger expel calcium from the cell and calcium is sequestered into stores by SR calcium ATPase
what is pharmochemical coupling
Pharmaochemical is the change in smooth muscle tone without a change in membrane potential and a production second messengers for contraction or relaxation (IP3 causing contraction and cAMP causing relaxation)
What is the electrochemical coupling
Electrochemical is the opening plasma membrane voltage activated L type Ca2+ channels and response to depolarisation with or without potential generation
Na Ca exchanger
Na Ca exchanger utilises the Na electrochemical graident to pump Ca out of the cell
Ca2+ ATPase
Ca2+ ATPase utilises ATP hydrolysis to actively pump Ca2+ out of the cell
SERCA Ca2+ ATPase
Ca2+ ATPase (SERCA) utilises ATP hydrolysis to actively pump Ca2+ ATPase
How does gas change state going into the alveolus
moves from gas phase in the avoleous into liquid that lines alveous so when gas is inhaled it mixes with gas inside the lung
how oxygen moves around the body
diffuses through blood gas barrier into the pulmonary vein into the heart and around the body and makes its way to the mitochondria where it is converted to water in the process of oxidative phosphorylation to generate ATP
Branching has two consequences:
Increase surface area for gas exchange
Dissipates resistance to airflow as airway diameter narrows towards the respiratory zone
number of airways increase what else increase
when the number of airways increases the number of cross sectional area increases and airflow resistance factor decreases
what is bulk flow
Bulk flow of gas into conductive zone is driven by
difference is net pressure caused by expansion and relaxation of the chest cavity
how does gas moves
Gas will only move into the lung if we decrease the pressure of lungs
as expands the chest pressure will go under atmospheric pressure and goes into the lungs due to decrease pressure gradient
what does relaxation for lung
relaxation put pressure on the walls of the avolei
raising partial pressure above the atmospheric pressure so gas goes out the lung conversion
what is the sum of alveolar pressure
alveolar pressure is the sum of elastic recoil pressure and plural pressure
muscle movement expiration and inspiration
inspiration - upwards and outwards
expiration - backwards and downwards
how does diffusion and convention work
Convention is gas movement through conducting airways
diffusion is the gas exchange across the blood gas barrier in the alveolus
what is content and satuation
Content - is determined by the amount of Hb of O2 in blood
saturation in the proportion = oxyhemoglobin / O2 carrying capacity of Hb
Dissociation curve
For the oxyhemoglobin dissociation curve the p50 value gives PO2 required for half maximal Hb saturation
Left shift = increase HbO2 affinity and reduced O2 offloading to tissues
Right shift = decrease HbO2 affinity raised O2 offloading to tissues
what is the Bohr Effect
The amino terminus of the haemoglobin a subunit binds to the carboxy-terminal histidine in the b subunit this stabilises hb structure
This interaction is pH and O2-sensitive
Acidosis decreases pH favours ab subunit interaction and reduces the binding of O2 to heme
how can you carry CO2
Plasma Soluble CO2 and Bicarbonate Ion and Carbamino hemoglobin - carbonate reaction at N terminal amino acid groups of Hb a subunit
What is the calculation showing
Tells us that alveolar PO2 is significantly affected by amtopheric PO2 and arterial carbon dioxide
If arterial PCO2s increases so alveolar PO2 decreases
If RQ increases
Conserve pAO2
For climbers
Increasing breathing frequency - paCO2 decreases
High carbohydrate diet
Climb when barometric pressure high
Poor ventilation and good ventilation
Poor ventilation and large blood flow
Reduce perfusion - hypoxia constricts pulmonary arterioles
Good ventilation and poor blood flow
Reduce ventilation - low CO2 constrict bronchioles
what is plueral sacs linked to
Pleural sac links elastic forces in the chest wall and lung
what is fluid filled
The pueral sac is a fluid fullied cavity which tethers the lung to the movement of the rib cage
lierteral outer wall
the plueral cavity acts to oppose what
the pleural cavity acts to oppose elastic recoil of ribs
tethers the lung to the thoracic wall
holds to the lungs out and open and allows inspiratory movement
Aveolar pressure
Avolaolr pressure
Inspire alveolar pressure decreases below atmospheric pressure
End of inspiration the pressure equalises and goes to 0
Exhalation - increase in alveolar pressure which goes back to 0 at the end of the expiration
Compliance varies with lung Disease
Emphsema has a is higher than normal and fibrosis is lower than normal
Pulmonary compliance is produced by what
Pulmonary compliance is produce by elastin connective fibres and alveolar surface tension
surface tension in an alveolus resists stretch
surface tension in an alveolus resists stretch tends to become smaller and tends to recoil after stretch contributes to elastic recoil pressure
effect of air liquid interface on lung compliance
Inflating with liquid overcomes recoil effect by dissipating surface tension
Lungs requires greater transpulmonary pressure to inflate with air in order to overcome surface tension + elastic recoil effect
the law of laplace
The law of laplace is the small diameter bubbles have higher surface tension than large diameter one
variation in alveolar size would cause small alveoli to collapse into the other
What is the calculation of laplace
P = 2T / r
Pressure = 2 x Surface tension / radius of bubble
Pulmonary surfactant
Pulmonary surfactant stabilised alveolar structure by reducing surface tension
effect of surfactant on the surface tension
Surfactant reduces tension by decreasing density of water molecules at air water interface
Because the hydrophobic tail pulls the surfactant molecule upward the resultant vector is minimal
Redcues surface tension in alveoli
to effect surface tension
Composed of DPPC packed around surfactant protiens AD
secreted by type II alveolar epithelial cells
Redcues surface tension in alveoli
Prevent collapse of alveoli during lung expansion and contraction
Reduces pressure required to infalte lungs
Effect on surface tension varies with alveolar surface area
Laplace law as r fall
stabilised by what
As r falls surfactant molecules croded together surface tension reduced smaller alveolous stabilises
alveoli also stabilised by mechanical interactions between neighbouring alveoli prevents alveolar collpase
two specialised types of cardiac cell
There are two specialised types of cardiac cell
contractile cells and autorhythmic cell
what is pacemaker acitvity
cardiac autorhythmic cell do not have a resting membrane potential - they display pacemaker activity
what is pacemaker potential
pacemaker potential is when an autorhythmic cell membrane slow drift to threshold
what initiate Action potential
Autorhythmic cells cyclically initiate APs which then spread through the heart to trigger contraction without any nervous stimulation
AV Node
AV forms only conducting pathways between atrial and bundle of his
AV node introduces considerable delay to spread of excitation - allowing blood to move from the atria to the ventricles
AV node has a latent power
what is cardiac output
Cardiac output is the volume of blood pumped by each ventricle per minute
CO is the product of heart rate and stroke volume
CO = HR x SV
What is stroke volume
stroke volume is the volume of blood ejected per contraction
SV = EDV - ESV
How CO is controlled
CO is controlled according to physiological requirements
via control of HR and SV and control of HR
The strength of cardiac muscle contraction and, accordingly SV can be graded by
The strength of cardiac muscle contraction and, accordingly SV can be graded by:
1. Varying the initial length of the cardiac muscle fibres, which in turn depends upon EDV(intrinsic control)
2. Varying the extent of sympathetic stimulation(extrinsic control)
The strength of cardiac muscle contraction and, accordingly SV can be graded by
The strength of cardiac muscle contraction and, accordingly SV can be graded by:
1. Varying the initial length of the cardiac muscle fibres, which in turn depends upon EDV(intrinsic control)
2. Varying the extent of sympathetic stimulation(extrinsic control)
Frank Starling Law
The heart normally pumps out during systole the volume of blood returned to it during diastole; increased venous return results in increased stroke volume
what is arteries
Arteries - low resistance vessels and acts as pressure reservoirs for maintaining blood flow between ventricular contraction
what is arterioles
Arterioles - major site of resistance to blood flow , responsible for the pattern of blood flow distribution and participate in the regulation of arterial blood pressure
what is flow
flow is always from a region of higher pressure to one of lower pressure
pressure exerted by a fluid is often termed the hydrostatic pressure
what is resistance
Resistance is the measure of how difficult is for blood to flow between two points at any given pressure difference
what is teh calculation of blood flow
blood flow through vessels depends upon the pressure gradient and vascular resistance
the driving force is the pressure generated by contraction of the heart
F = ^P / R
resistance to blood flow depends upon 3 factors
resistance to blood flow depends upon 3 factors
viscosity of the blood
vessel length
vessel radius
what is contraction adn relaxation
Contraction=decreased radius, increased resistance=decreased local blood flow =vasoconstriction
Relaxation=increased radius, decreased resistance=increased local blood flow =vasodilation
two factors reponsible for vascular tone
Two factors are responsible for vascular tone
myogenic activity
sympathetic activity
what does chnage in contractility of arteriolar
Any change in contractility of arteriolar smoothmuscle will substantially change resistance to flow inthese vessels
