Brain And Nervous System Flashcards
Peripheral Nervous system contains:
Sensory and motor functions
Somatic, voluntary - sensory and motor components available consciously.
Automatic, involuntary - maintenance and control of our internal functions such as cardiovascular and digestive system
Central nervous system contains:
Storing information, send and receive messages to trigger responses from the brain and spinal cord
What is a dendrite and axon?
Dendrites are specialised for reception of information
Axons are specialised for transmission of information
Explain pre and post synaptic neutron
Pre synaptic neuron releases a chemical messenger called a neuro transmitter into the synapse, and the post synaptic neuron has receptors to receive this
Name some common neurotransmitters
Dopemine
Noradrenaline (norepinephrine)
Serotonin
GABA
Facts about glial cells
About 85% of cells in the brain are glial cells
Look similar to neurotransmitters but functionally quite different; they do not create action potentials the way neurotransmitters do
3 types:
Astrocytes
Oligodendrocyte - function different to Astrocyte, provides myelinisation
Micro-glials - repair damaged neuron tissue
MS damages myelinisation
Somatic NS - names for the crocodile diagram
Neuraxis - line from top to bottom Rostral or anterior - face Caudal or posterior - feet Dorsal - upper parts (tip of head front) Ventral - lower parts Lateral - extremeties Medial - midline parts
12 cranial nerves that exit the brain that serve sensory and motor fibres.
Supplemented by 31 spinal nerves, named according to the parts of the column they exit
Cervical (8 pairs), thoratic (12), lumbar (5), sacral (5), cocyceal (1)
43 pairs of cranial and spinal nerves join the CNS
See slide for image of spinal area – dorsal horn routes incoming sensory fibres, ventral horn routes outgoing motor fibres.
Muscles contracting
During depolarisation of muscle fibre calcium enters via voltage dependent calcium channels and causes a chemical reaction to produce tension between interleaved myosin and actin filaments, this causes contraction of the muscle fibre
Vestibular system
System that allows us to balance and movement within space
The ampullae of the semi-circular canals contain hair cells. Bending the cilia of the hair cells (such as during moving your head) causes transmitter release into the synapse with ampullary nerve.
The ultricles (floor) and saccules (on the wall) contain hair cells with cilia embedded in a gel which contains calcium carbonate crystals – otoconia.
Motion sickness can be caused by stimulation in the vestibular system.
Cutaneous receptors
Merkel’s discs and Riffini corpuscles – slow adaptation
Meissner’s and Pacinian corpuscles – rapid adaptation
Neurons that sense heat and cold
Menthol sensitive neurons sense cold
Capsaicin sensitive neurons sense heat
Autonomic nervous system
Parasympathetic pathways – vegetative states, long preganglionic fibres and short postganglionic fibres.
Sympathetic pathways – activate targets for physical responding, opposite fibres to parasympathetic.
Neural tube becomes the ventriculur system
During cortical development, Cells migrate out from the ventriculur zone: ‘moving like cable-cars on a network of wire’
6 distinct waves which result in 6 layers of cortex
Cells that migrate out first are on the inside of the brain
Number of layers between brain, spinal cord and bone
Dura mater, pia mater, arachnoid membrane
Subrachnoid space (cerebrospinal fluid)
Cerebrospinal fluid - Providing nutriets, removing waste products from the brain and providing a cushioning layer to protect the brain from the cortotions it would otherwise encounter.
