lab 5: nervous system Flashcards
name and briefly describe subdivisions of nervous system
Peripheral nervous system (PNS) - all nervous tissue outside CNS
Central nervous system (CNS) - brain and spinal cord
describe dendrites and axons
Dendrite = carry nerve impulse towards cell body
Axon = transmit nerve impulses onwards to other connecting neurons
Both make synaptic connections with other nerve cells
what are nissl granules
seen in cell body represent aggregations of RNA on endoplasmic reticulum
what are brain and spinal cord protected by
skull and vertebrae
what does central spinal canal contain
cerebrospinal fluid
what shape is grey matter in spinal cord
butterfly shaped
outer areas of white matter of spinal cord is made up of
ascending and descending myelinated fibre tracts
what are meninges (spinal cord)
tough outer covering protects cord
3 layers = outer dura mater, arachnoid and inner pia mater
Between arachnoid and pia mater is the subarachnoid space where cerebrospinal fluid circulates
what is dorsal root
pathway by which afferent (sensory) neurons enter the cord
what is ventral root
efferent motor pathway
what is dorsal root ganglion
contains cell bodies of afferent neurons
what is ventral horn
where cell bodies of the efferent neurons are located
Afferent and efferent pathways are connected by interneurons
what do neurons together form
reflex arc
Pathway linking the sensory receptor to the effector (response) mechanism
Reflex may be mediated at the spinal cord level (knee jerk) OR higher centers of brain
describe brain cut longitudinally
Grey and white matter of the cortex - representing cell bodies
cerebellum - representing myelinated fibre tracts
what is corpus callosum
connects right and left hemispheres
