Aqa a level Biology - Topic 6 - survival and response

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Cards (100)

During high blood pressure, ....................... detect it, send impulses along sensory neurones to the .................., this then sends impulses along ...................... neurones, these secrete ................. which binds to receptors on the .................. and the heart rate slows down
Baroreceptors
Medulla
Parasympathetic
Acetylcholine
SAN
Which receptors are found in the aorta, carotid arteries and the medulla which monitor oxygen levels in the blood
Chemoreceptors
Which pressure receptors are found in the aorta and carotid arteries that are stimulated by high and low blood pressure?
Baroreceptors
What are internal stimuli detected by?
Pressure and chemical receptors
The rate of which the SAN fires is .................... controlled by a part of the brain called the .....................
Unconsciously
Medulla
What is purkyne tissue? 
Muscle fibres from bundle of His which carries waves of electrical activity into the muscular walls of the left and right ventricle causing them to contract simultaneously from the bottom up
What is the bundle of His? 
Group of muscle fibres responsible for conducting the waves of electrical activity between the ventricles and apex of the heart. Splits into finer muscle fibres in left and right ventricle called purkyne tissue
What does AVN stand for and what is it?
Atrioventricular node- responsible for passing the waves of electrical activity to the bundle of His , slight delay before it reacts to make sure the atria have emptied
What does SAN stand for and what is it?
Sino-atrial node - small mass of tissue in the wall of the right atrium which sets the rhythm of the heartbeat by sending out regular waves of electrical activity to the atrial walls
What are the 4 main points in order in the route of waves of electrical activity in the heart? 
SAN (sinoatrial node)
AVN (atrioventricular node)
Bundle of His
Purkyne fibres
Explain what is meant by " cardiac muscle is myogenic"
It can contract and relax without receiving signals from nerves
Explain the movement of sodium and potassium in resting neurones
Sodium potassium pumps move sodium ions out of neurone, this creates a sodium ion electrochemical gradient because there are more positive ions outside, sodium potassium pumps also move in potassium. When cell is at rest most potassium ion channels are open which means the membrane is permeable to potassium ions.
What do potassium ion channels do?
Allow facilitated diffusion of potassium ions out of the neurone down their concentration gradient
What do sodium potassium pumps do?
Use active transport to move 3 sodium ions out of the neurone for every 2 potassium ions moved in
What creates and maintains the resting potential?
Sodium-potassium pumps
Describe the resting membrane potential
Polarised- Outside of membrane is positively charged compared to inside so there's a difference in charge across it. Voltage is about 70mv
The movement of which ions causes transmission of electrical charges?
Sodium and potassium
During low blood oxygen, high co2 or low blood ph, ...................... detect it, send impulse along sensory neurones to the ........... which sends impulses along .................. neurones which secretes ................ binds to receptors on the ,.............. and heart rate ............... in order to return levels back to normal
Chemoreceptors
Medulla
Sympathetic
Noradrenaline
SAN
Increases
During high oxygen , low co2 or high ph levels, ....................... detect it , send impulses along sensory neurones to the .............. which sends impulses along .................... neurones which secrete ........................ this binds to receptors on the ........... and causes heart rate to ................ in order to return levels back to normal
Chemoreceptors
Medulla
Parasympathetic
Acetylcholine
SAN
Decrease
During low blood pressure, .......................... detect it and send impulses along sensory neurones to the .............. which sends impulses along ........................ neurones, which secrete ................ which binds to receptors on the .......... causing the heart rate to speed up
Baroreceptors
Medulla
Sympathetic
Noradrenaline
SAN
During high blood pressure, ....................... detect it, send impulses along sensory neurones to the .................., this then sends impulses along ...................... neurones, these secrete ................. which binds to receptors on the .................. and the heart rate slows down
Baroreceptors
Medulla
Parasympathetic
Acetylcholine
SAN
Which receptors are found in the aorta, carotid arteries and the medulla which monitor oxygen levels in the blood
Chemoreceptors
Which pressure receptors are found in the aorta and carotid arteries that are stimulated by high and low blood pressure?
Baroreceptors
What are internal stimuli detected by?
Pressure and chemical receptors
The rate of which the SAN fires is .................... controlled by a part of the brain called the .....................
Unconsciously
Medulla
What is purkyne tissue? 
Muscle fibres from bundle of His which carries waves of electrical activity into the muscular walls of the left and right ventricle causing them to contract simultaneously from the bottom up
What is the bundle of His? 
Group of muscle fibres responsible for conducting the waves of electrical activity between the ventricles and apex of the heart. Splits into finer muscle fibres in left and right ventricle called purkyne tissue
What does AVN stand for and what is it?
Atrioventricular node- responsible for passing the waves of electrical activity to the bundle of His , slight delay before it reacts to make sure the atria have emptied
What does SAN stand for and what is it?
Sino-atrial node - small mass of tissue in the wall of the right atrium which sets the rhythm of the heartbeat by sending out regular waves of electrical activity to the atrial walls
What are the 4 main points in order in the route of waves of electrical activity in the heart? 
SAN (sinoatrial node)
AVN (atrioventricular node)
Bundle of His
Purkyne fibres
Explain what is meant by " cardiac muscle is myogenic"
It can contract and relax without receiving signals from nerves
Which nervous system is involved in the control of the heart rate?
The autonomic nervous system
What is the parasympathetic system?
Rest and digest system that calms the body down
What is the sympathetic nervous system?
fight or flight gets you into action
What does the autonomic nervous system control and what 2 systems does it split into?
Unconscious activities such a digestion
Sympathetic and parasympathetic nervous systems
What does the somatic nervous system control?
Conscious activities eg running
What are the 2 systems of the peripheral nervous system?
Somatic nervous system
Autonomic nervous system
What is the peripheral nervous system made up of?
The neurones that connect the central nervous system to the rest of the body
What is the central nervous system made up of?
Brain and spinal cord
The nervous system is split into two different systems called.....
The central nervous system
The peripheral nervous system