Motor nueruone + Medulla oblugunta

Long conductive fibre that carries the nerve impulse along neurone

Wwrap around the axon to form the myelin sheath-lipid rich membranes (Charged particles can not pass as it is lipid)

They allow ions to diffuse in and out of the neurone membrane. This means depolarisation only occurs at the nodes, so the action potential “jumps” from node to node — a process called saltatory conduction. This makes the conduction of impulses much faster than in non-myelinated neurones.

Nodes of Ranvier are gaps between Schwann cells where the axon membrane is exposed, allowing saltatory conduction of the action potential.

The CNS is made up of the brain and spinal cord and coordinates responses.

The peripheral nervous system is the part of the nervous system consisting of the nerves outside the brain and spinal cord, which transmit impulses to and from the central nervous system.

Unconcious part of nervous system Heart rate Breathing Digestion

Concious part of nervous sytsem Running Picking things up

Active when body at rest

Activated during stress fight/flight

A group of cells in the wall of the right atrium, often referred to as the pacemaker that release electrical impulse to the atria and AVN

conductive tissue that links the atria and ventricles and releases electrical impulse down bundle of his

conductive fibres that carry waves of depolarisation down the septum to the base of the ventricles

conductive fibres that carry waves of depolarisation from the base of the ventricles into the ventricle wall

1) SAN releases a wave of depolarisation across atrium causes atria to contract simultaneously and the wave of depolarisation travels to AVN (Atrial systole) 2) AVN releases wave of depolarisation. There is non-conductive layer between the atria and the ventricles preventing wave of depolarisation going straight to ventricles allows for a delay so maximum blood can be transferred from atria to ventricles before ventricular contraction 3) Depolarisation travels down conductive tissue in septum known as bundle of his down to ventricular walls 4) Depolarisation passed to purkyne fibres 5) Apex contracts first and rest of the ventricle contract to force maximum blood out of heart 6) During diastole cells repolarise and cardiac muscles relax

Bottom tissue of ventricles

Chemoreceptors and Baroreceptors

pH of blood (CO2) and are located in aorta and carotid artery

Blood pressure and are located in aorta and carotid artery

Nerve system route that decreases heart rate when stimulated

Nerve route system that increases heart rate when stimualte

High blood pressure is detected by baroreceptors in aorta/carotid artery Baroreceptors send more electrical impulses to medulla oblugunta by sensory neurone Medulla sends more impulses down parasympathetic nerve to sinoatrial node Sinoatrial node decreases frequency of waves of depolarisation so less muscle contraction in atrium and ventricles Decreases rate of heart beat so blood pressure decreases

Myogenic - Muscle cells can contract without nervous stimulation / input from nervous system