Nervous system Flashcards
What parts of the nervous system is divided to?
CNS- divided into the brain and spinal cord
PNS- consists of nerves, cranial attached to the brain and the spinal attached to the spinal cord
What are the 2 main types of cells in the nervous system?
nerve cells(neurones)- transmit information fast over long distances
glial cells- in which the nerve cells are protected, supported and insulated
What are the 3 type of neurones?
sensory, motor, relay
What do the types of neurones do?
sensory- transmit impulses from sensory cells, have their cell bodies in swellings on nerves just outside the CNS, terminate on connector neurones within the CNS
motor- transmit impulses from the cns to effectors such as muscles and glands, have their cell bodies within the CNS
relay- transmit impulses from sensory to motor neurones, found entirely within the CNS
What does myelin do?
insulates the neurone membranes from the tissue fluid as ions cannot diffuse through thick layer of phospholipid
What is action potential?
is the net effect of ion flow across the neuron membrane, in unmyelinated neurones they occur in neurones, in myelinated they occur at the nodes of ranvier
What is resting potential?
is the result of an unequal distribution of ions across membranes
What are factors the contribute to resting potential?
the impermeability of the membrane to ions, the presence of organic anions inside the cells, sodium potassium pumps that pump out 3 sodium ions for every 2 potassium ions pumped in
What is the role of synapses?
transmission of impulses, integration of impulses, summation
