Lecture 2- Intro to Nervous System Flashcards
What are the 2 cell types that make up the NS? (nevous tissue is comprised of these two cell types)
- neurons
- neuroglia
How many neurons are in the NS?
~ 100 billion neurons
What are the major components of the NS? (6)
- brain
- spinal cord
- cranial nerves
- spinal nerves
- ganglia
- sensory receptors
Cranial nerves
- 12 pairs of nerves
- emerge from base of brain
spinal nerves
- 31 pairs of nerves
- emerge from spinal cord
ganglia
- cluster of neuron cell bodies
- located outside CNS
- one nerve comes in…one nerve comes out
- relay station for neuron communication
sensory receptors
- monitor changes in environment
- in skin, eyes, nose, muscles, etc.
Functional organization of the NS
sensory function - integrative function - motor function
Sensory function (input)
- sensory receptors detect internal and external stimuli
- sensory (afferent) neurons transmit info to CNS
- part of PNS
Integrative function (control)
- interneurons analyze sensory info
- perception (conscious awareness) of stimuli
- located in spinal cord (CNS)
- part of CNS
Motor function (output)
- motor (efferent) neurons respond to integration
- initiate actions in effector organs (muscles, glands, etc.)
- part of PNS
What are the two divisions of the Nervous System?
Central (CNS) and Peripheral Nervous system (PNS)
What are the two divisions of the PNS
Somatic and Autonomic Nervous System
What are the two somatic neuron types?
- somatic sensory neurons
- somatic motor neurons
Somatic sensory neurons
- convey info to CNS from sensory receptors
- input of info to CNS for integration
Somatic motor neurons
- convey info from CNS to skeletal muscles (ONLY!!)
- output of info from CNS for muscular contraction
What does the somatic nervous system do?
regulates VOLUNTARY control of skeletal muscles
What are the 2 divisons of the autonomic nervous system?
sympathetic and parasympathetic nervous system
What does the autonomic nervous system do?
regulates INVOLUNTARY control
Sympathetic nevous system
- increase in activity and metabolic rate
- “fight or flight” response
- ex: dilate pupils, increase heartrate, inhibit intestinal activity
parasympathetic nervous system
- decrease in activity and metabolic rate
- “rest or digest” response
- ex: constrict pupils, decrease heartrate, stimulate intestinal activity
Neurons
- basic structural and functional units of thr nervous system
- form complex processing networks
- transfer and processing of info
Neuroglia
- smaller and more abundant
- support, nourish and protect neurons
- do not participate in transfer fo info
Cerebrum (telencephalon) (2)
- largest and most anterior part of brain
- consists of two hemispheres seperated by a fissure
What does the cerebrum do?
- initiates and manages conscious thoughts and actions
- provides ability to read, write, speak, logically make calculations, creatively make art, rememeber the past, plan for the future, imagine things that may not exist
What are the 4 main parts of the brain?
- cerebrum
- diencephalon
- brainstem
- cerebellum
What consists of the cerebrum? (4)
- white matter
- grey matter
- gyrus
- sulcus
what covers the cerebrum?
cerebral cortex
What are two features of the cerebrum?
- longitudinal fissure
- corpus callosum
what does the longitudinal fissure do?
sereprates the right and left hemispheres
what does the corpus callosum do?
- connects the right and left hemispheres which allows for communication between both hemispheres
- it is made up of white matter
What are the 5 lobes of the cerebrum?
- frontal
- parietal
- temporal
- occipital
- insular lobe
What is the frontal lobe’s main functions?
- planning
- determining
- executive functionning (boss)
- mood
What is the parietal lobe’s main functions?
- responds to stimuli from environment
- mental body map of where you are in relation to space
What is the temporal lobe’s main functions?
- communication:
- hearing
- speaking
What is the occipital lobe’s main functions?
- vision
What is the insular lobe’s main functions?
- autonomic processing
What fossa on the skull does the frontal lobe rest in?
anterior fossa
What fossa on the skull doe the temproal lobes rest in?
middle fossa
What fossa on the skull does the brain stem as well as the cerebellum rest in?
posterior fossa
What sulcus seperates the frontal and parietal lobes?
the central sulcus
What sulcus seperates the parietal and occipital lobes?
the parieto-occipital sulcus
What sulcus seperates the frontal and temporal lobes?
lateral sulcus
What features differentiate the sulci that seperate lobes and other sulci
they are deeper, more pronounced and travel until they reach another lobe
What are the features of the cerebellum?
- folia (gray matter)
- arbor vitae (white matter)
what does arbor vitae mean and why is it good to know that?
- it means the tree of life
- it looks like a tree in the cerebellum
What are the main functions of the cerebellum? (2)
- coordinates voluntary movement
- regulates posture and balance
What are the three structures of the cerebellum?
- cerebrallar hemispheres
- vermis (seperates both hemispheres)
- cerebellar peduncle
What seperates the cerebellum and the occipital lobe?
the transverse fissure
