nervous system CNS Flashcards
what is the CNS
the central nervous system. it is composed of the brain and spinal cord and is responsible for the integrative functions of the nervous system.
what does the CNS do
it receives and processes information from the internal and external environment of the body, coordinating and controlling body activities in response
CNS controls integrative functions
how does the CNS carry out functions such as memory, learning, personality and intelligence
through communication networks of neurons within the brain and spinal cord and through the connection of nerve cells in these regions with nerve cells of the peripheral nervous system PNS
what is the cerebrum
the most dominating structure of the brain, divided into left and right hemispheres. the hemispheres are connected by a white matter tract called the corpus collosum which allows communication between the 2 hemispheres
what is the cerebrum covered in
bumps called gyri and grooves called sulci. they increase the surface area of the brain, allowing more neurons to be contained within the skull
what is the cerebral cortex
the outermost gray matter covering the cerebrum, forming the functional areas of the brain
what are the 3 functional areas of the brain
sensory areas, motor areas and association areas
what are sensory areas
they are areas responsible for conscious perception and interpretation of somatic senses, some of the visceral senses and the special senses
what are the motor areas
involved in deciding, planning and initiating somatic motor signals
- pre frontal cortex- decide
- pre motor cortex- plan
- primary motor cortex- initiate
what are association areas
they are multimodal areas receiving input from multiple senses and sending output to multiple areas. they integrate (combine) motor, sensory and higher cognitive functions such as memory, learning and emotion to produce a response
what is the primary somatosensory cortex (sensory area) and where is it located
located on the parietal lobe. identifies location, type and intensity of somatic senses
what is the somatosensory association area and where is it located
located behind the primary somatosensory cortex within the parietal lobe. interprets details of somatic sensations using memory
visual cortex (special sense)
located in the occipital lobe. interprets visual signals from the eyes
auditory cortex (special sense)
located on the temporal lobe. interprets auditory signals from the ears for hearing
vestibular cortex (special sense)
located on the insula. interprets signals from the inner ear for balance
gustatory cortex (special sense)
loacted on the insula. interprets signals from the taste buds
olfactory cortex (special sense)
located on the the temporal lobe. interprets signals from the nose for smell.
visceral sensory cortex (special sense)
located on the insula. receives signals front the viscera of the body and provides conscious perception of visceral sensations e.g. an upset stomach
what are motor areas and where are they located
located on the frontal lobe and is responsible for deciding, planning and initiating motor signals to be sent to skeletal muscles. all parts of the motor cortex communicate with each other
primary motor cortex
located on the frontal lobe. initiates the movement by sending signals down the spinal cord towards skeletal muscle
premotor cortex
located in the frontal lobe. planning of skeletal muscle movements
brocas area
small cortical area within the premotor cortex of the left hemisphere. responsible for coordinating the movements of muscles related to speech
frontal eye field
another small area within the motor cortex that controls the voluntary movements of the eye
association area of the cortex
they are involved in sending and receiving input to and from the CNS and integrate (combines) motor and sensory functions as well as higher cognitive functions
prefrontal cortex (association area) of cerebral cortex
- responsible for deciding which skeletal muscle movements are required
- deciding higher cognitive functions such as intelligence, cognition, recall and memory, reasoning and planning etc
posterior association area of the cerebral cortex
recognition and interpretation of sensations and understanding of language
basal ganglia
- recieves input from numerous areas of the brain
- help in the planning of motor movements
- starting and stopping skeletal muscle movements
thalamus
role in movement, role in emotions, relay station for incoming sensory information to cerebral cortex
hypothalamus
autonomic NS control center, emotional response center, control of appetite and thirst, endocrine control center, thermoregulation, control of sleep-wake cycles
limbic systems
regulating and interpreting emotional responses, emotional memory recall, assessment of danger
brainstem gray and white matter
gray matter areas in the brainstem produce the autonomic behaviours for survival as-well as influencing some of the communication between other CNS areas.
The white matter is arranged into tracts that provide a pathway of communication between the spinal cord, cerebellum and higher brain centers.
what is the diencephalon
located in the middle of the basal ganglia. it is divided into the thalamus and the hypothalamus
brainstem (midbrain, medulla and pons) functions
midbrain- pain suppression and coordination of auditory and visual senses
medulla- regulation of respiratory functions, cardiac functions and other automatic actions (sneezing, coughing)
pons- major connections pathway to cerebellum
what does the spinal cord do
it is a 2 way conduction system providing neuronal pathways to and from the brain. it is where synapses occur between neurons of the CNS and PNS and is the site for integration of involuntary reflexes below the head.
what are the functional areas of the spinal cord
dorsal (back) horns-receive incoming sensory information of sensory neurons via peripheral nerves
ventral (front) horns- send motor signals out of the body structures via peripheral nerves
what is the anatomy of the spinal cord
the gray matter forms a H shape with two posterior dorsal horns and two anterior ventral horns
outline the protection of the CNS
they are surrounded by multiple tissue layers in order from superficial to deep
- bone
- dura mater
- arachnoid mater
- CSF
- pia mater
what does bone and meninges do in the protection of the CNS
the brain is surrounded by cranial bones and the spinal cord is surrounded by the vertebrae. the meninges are 3 connective tissue layers that surround the brain and spinal cord. they also protect blood vessels of the CNS and provide space for cerebrospinal fluid to form partitions in the fissures of the the brain.
what does cerebrospinal fluid do in the protection of the CNS
- it lines the spaces of the brain
- ensures the protection of the CNS from mechanical shocks and vibrations
- regulation of inter cranial pressure
what part of the brain receives and processes somatic sensory impulses for touch, pain and temperature
parietal lobe
what part of the brain processes and initiates motor signals
frontal lobe
what part of the brain is the primary visual cortex on that allows the interpretation of colour and shape
occipital lobe
what part of the brain receives impulses for smell
temporal lobe
