Phase One: Week Seven Flashcards
What is the origin of the sympathetic nervous system?
T1-L2
What is the origin of the parasympathetic nervous system?
Cranial nerves: 3, 7, 9, 10
S2-4
Where are beta-one recepotrs located?
These are located in the heart and they increase contraction and heart rate
Where are beta-2 receptors not found?
Heart and vascular vessels
Where are beta-2 receptors found and what is there affect?
These are on uterus, lungs, gut, bladder and eye. They cause smooth muscle relaxation.
What is the mechanism of action and use of Isoprenaline?
This is used to treat bradycardia and is a agonist of beta-one recepotrs.
What is the parasympathetic response of cranial nerve three?
Pupil constriction
What is the parasympathetic response of cranial nerve seven?
Vasodilates mucous membranes in nasopharynx
What is the parasympathetic response of cranial nerve nine?
Increases salvia
Where are M2 recepotrs found?
The heart
Where are M3 recepotrs found?
Salivary glands, gut, bladder and vessels
Where are M1,3,5 recepotrs found?
The Brain
Where are N1 recepotrs found?
Motor neurons
Where are N2 recepotrs found?
ANS
What is the test for cranial nerve 2,3?
Light response
What is the test for cranial nerve 3,4,5,6,8?
Loss of occulovestibular response
What is the test for cranial nerve 5,7?
Painful face stimuli and corneal reflex
What is the test for cranial nerve 9?
Loss of gag reflex
What is the test for cranial nerve 10?
Loss of cough reflex
How is brain death caused?
When there is no blood/oxygen supply to the brain
What is the difference between PR segment and PR interval?
The PR interval starts at the beginning of the P wave and ends at the beginning of the R wave.
The PR segment starts at the end of the P wave and ends at the beginning of the R wave
How is the SA node connected to the AV node?
Internodal pathways
What is the function of the Bachmann’s bundle?
Transmits impulses from the SA node to the left atrium
What branch is responsible for conduction an impulse from the right atrium to the left atrium?
Bachmann’s bundle
What is the correct order of the heart’s conduction pathway?
SA node - Internodal pathways - AV node - Bundle of HIS - Purkinje fibres
How do auto-rhythmic cells depolarise?
There is a gradual depolarisation due to a slow inward current of calcium channels. An action potential is imitated at -40mV and, at this moment, fast calcium channels open and cause rapid depolarization to +10mV. Reversal of this is done by potassium channels.
When is an action potential initiated in auto-rhythmic cells?
-40mV
What positive charge do auto-rhythmic cells reach when undergoing depolarisation?
+10mV
What is the resting membrane of cardiac contractile cells?
-90mV
When is an action potential initiated during depolarisation of cardiac contractile cells?
-40mV
Explain the process of cardiac contractile cells depolarization
Depolarization of adjacent autorhythmic cells causes fast sodium channels to open and this causes the potential to reach +25mV in the cardiac contractile cells. There is a period of plateau, where there is a balance of calcium flowing into the cell and potassium flowing out of the cell.
The membrane potential is reversed by potassium channels.
What is the refractory period?
The membrane will not respond to a second stimuli
What are the six stages of the cardiac cycle?
- Atrial systole
- Ventricular systole (phase one): isovolumetric contraction
- Ventricular systole (phase two)
- Ventricular diastole: early (isovolumetric relaxation)
- Ventricular diastole late
What happens during the two stages of ventricular systole?
The first stage is also known as isovolumetric contraction. This is where atrial diastole begins and the ventricle contract. The Ventricular is enough to close the AV valves but the pressure is not enough to open the semi-lunar valves.
During phase two, Ventricular pressure rises and exceeds the artery pressure, causes the semi-lunar valves to open.
What is the effect of hydrostatic pressure on fluid transport?
Hydrostatic pressure refers to pressure that any fluid in confined spaces exerts. The force of blood hydrostatic pressure in the capillaries means that blood fluid will move out into the interstitial space. The pressure will decrease as it reaches the venous end.
What is the effect of oncotic pressure on fluid transport?
Due to the high plasma concentration in blood, the plasma proteins displace some water and create a low water concentration. Therefore, due to the low blood water, water from the interstitial space (higher oncotic pressure) is pulled in.
Why does oncotic pressure not change along the length of the capillary?
Plasma proteins are too big to pass through the vessel wall.
What is the most reliable evidence collecting?
Systemic review
What is the lest reliable evidence collecting?
Expert’s opinion
What is single blinding?
The study participate doesn’t know
What is double blinding?
The study participate and investigator (Doctor) do not know
What is triple blinding?
The study [participate, investigator (Doctor) and statistician do no know
What is the P-value?
Probability that an outcome would arise by chance
What would a low P-value indicate?
There is enough evidence to reject the null hypothesis
What is the absolute risk?
The risk of developing disease over a period of time
What is relative risk?
Comparing the risk of two different groups of people
What is observational study?
Observations made without interventions
What is experimental study?
One or more factors altered and the effects and examined.
What is a systemic review?
This answers a defined research questions by collecting and summaringin all empirical evidence that fits the criteria.
What is meta-analysis?
Use of statistical methods to summarise results
What is reliability?
Refers to the repeatability of findings
What is validity?
The credibility of research. It is how accurate an instrument is at measuring something.
What is internal validity?
This is established when research demonstrates a casual relationship between two variables. The experiment is free from error and any difference is due to a independent variable.
What is external validity?
Extent to which research can be inferred to world at large
What is the role of astrocytes?
Nutrient supply to the neurons of CNS
What does the CNS consist of?
Brain and Spinal nerves
What does the PNS consist of?
Spinal Cranial nerves
What are the five divisions of the brain?
- Telencephalon
- Diencephalon
- Mesencephalon
- Metencephalon
- Myelencephalon
What brain division makes up the cerebrum?
Telencephalon
What brain division makes up the thalamus and hypothalamus?
Diencephalon
What brain division makes up the forebrain?
Telencephalon and Diencephalon
What brain division makes up the midbrain?
Mesencephalon
What brain division makes up the hindbrain?
Metencephalon and Myelencephalon. These two divisions make up the rhombenecephalon.
What is the function of the frontal lobe?
The frontal lobes are involved in motor function, problem solving, spontaneity, memory, language, initiation, judgement, impulse control, and social and sexual behaviour.
What is the function of the parietal lobe?
Integration of sensory functions
What is the function of the occipital lobe?
Visual processing
What is the function of the temporal lobe?
Primary auditory cortex
What covers nerve fibres?
Endoneurium
What covers nerve fascicles?
Perineurium
What covers the nerve?
Epineurium
What is another name for adrenaline?
Epinephrine
What is the definition of Blood Pressure?
The pressure of the circulating blood on the walls of the blood vessel
What is autonomic Dysreflexia?
Autonomic Dysreflexia is an uninhibited sympathetic nervous system response to a variety of noxious stimuli occurring in people with spinal cord injury at the thoracic six (T6) level and above.
What affect does blood volume have on blood pressure?
A decrease in blood volume (if greater than 10%) will cause a decrease in blood pressure. An increase in blood pressure will cause an increase in blood pressure.
What three factors affect vascualr resistance?
Lumen size, blood viscosity and blood vessel length
What affect does lumen size have on blood pressure?
The smaller the lumen, the greater the resistance and hence the blood pressure increases.
What affect does blood viscosity have on blood pressure?
The higher the viscosity, the higher the resistance and hence the higher the blood pressure.
What affect does dehydration have on blood viscosity?
Increases viscosity
What affect does blood vessel length have on blood pressure?
The longer the vessel length, the greater the resistance and hence the higher the blood pressure.
N.B: Obese people will most often have a high blood pressure because they have additional blood vessels in their fat that contributes to a longer blood vessel length.
What affect does blood velocity have on blood pressure?
This is the speed in which blood flows. Each time an artery branches, the cross-sectional area decreases and hence the velocity decreases. This means that blood pressure decreases.
Where is the cardiovascular centre located?
The medulla oblongata
What is the role of the baroreceptors when there is low blood pressure?
These detect wall stretch from pressure changes. The less stretched, the less impulses they send through their parasympathetic nerves. The medulla responds to this by increasing the rate of the sympathetic response and their results in increases heart rate and vasoconstriction.
Where are baroreceptors located and what are their associated nerves?
The carotid sinus: Glossopharyngeal nerve
The aortic arch: Vagus nerve
What is the role of proprioceptors with regards to blood pressure?
These monitor limb position and they produce input during physical activity.
Where is ADH secreted and stored?
ADH is made in the hypothalamus and stored in the posterior pituitary
What is the function of ADH?
ADH is released when there is low blood pressure. It acts on the collecting duct to promote water retention
Where is aldosterone secreted?
Adrenal cortex
What is the function of aldosterone with regards to blood pressure?
This acts on the PCT and CD and promotes sodium retention and potassium secretion.
What is the function of angiotensin II?
This a vasoconstrictor and raises BP by increasing vascualr resistance. It also increases secretion of Aldosterone and increases the thirst sensor.
Where is ANP secreted?
Right atrium
What is the function of ANP?
This promotes sodium/water loos and results in decreased blood volume, hence reducing blood pressure. It also blocks the release of ADH, NA and aldosterone.
What is vasopressin?
ADH
What channels does ADH insert?
Aquaporin-2 channels in the collecting duct principle cells to increase water reabsorption.
Where is adrenaline and noradrenalin secreted?
Adrenal medulla
What is the correct order of the meninges layers, superficial to deep?
- Dura
- Arachnoid
- Pia