Divisions of the Nervous system Flashcards
What are the 2 main divisions of the Nervous system? What makes up this 2 divisions?
The two main divisions are the central and peripheral nervous systems. The CNS is made up of the brain and spinal cord. The PNS is made up of the autonomic, somatic and enteric systems. The autonomic system is made up of the parasympathetic (cholinergic, calming down) and sympathetic (adrenergic, fight or flight) nervous systems. The somatic system consists of the motor and sensory systems.
What are the 5 main divisions of the CNS?
The Cerebrum - made up of the Telencephalon (the cerebral hemispheres and the basal ganglia)
The diencephalon - hypothalamus and thalamus
The Brainstem - midbrain, pons and medulla
The cerebellum
The spinal cord.
The brain is protected by meninges (covering of the brain) - what are these?
The duramater (outer layer of the skull)
Arachnoid - contains blood vessels
Subarachnoid space - contains CSF
Pia mater - layer of the brain
If you were to drill into the skull and brain, what is the order of layers you would see from outside to in?
Skin - periosteum - skull - duramater - arachnoid - subarachnoid space - pia mater.
Where is the thalamus located?
Superior to the pons, inferior to the corpus collosum, posterior to the basal ganglia
Where is the basal ganglia located?
Anterior to the thalamus, continuous with the corpus collosum in the frontal lobe
Where is the Cerebellum located?
Posterior the pons, inferior to the temporal and occipital lobes.
Where is the spinal cord located?
From the temporal lobes, is continuous with the brainstem and runs to the L1/2 spinal level
What are the 4 lobes of the brain and where are they located?
Frontal lobe - anterior to the central sulcus
Parietal lobe - posterior to the central sulcus and
frontal lobe
Occipital lobe - inferior and posterior to the parietal lobe
Temporal lobe - inferior to the central sulcus
What is the function of each lobe?
Frontal lobe - thinking, reasoning, planning, decision making and problem solving
Parietal lobe - Perception and recognition of sensory stimuli, orientation (beliefs)
Occipital lobe - Perception and recognition of visual stimuli
Temporal lobe - Perception and recognition of auditory stimuli, memory, speech
What are the ventricles?
A set of 4 interconnected cavities in the brain parenchyma that are lined with ependymal cells and produce cerebral spinal fluid.
The 3rd ventricle joins to the 4th ventricle via the cerebral acqueduct - here CSF drains into the subarachnoid cisterns which bathe the brain.
What are the 3 main roles of cerebral spinal fluid (CSF)?
Protection - cushions the brain in the skull
Buoyancy - decreases the net weight of the brain by 20g, decreasing the pressure on the base of the brain against the skull
Chemical stability - maintains a low extracellular potassium concentration for synaptic transmission
Define afferent
Sensory neurones relaying information towards the dorsal horn of the spinal cord to a higher level of the CNS
Define efferent
Motor neurones relaying information from the anterior horn cell in the CNS towards an effector
Define ascending tracts
Carry sensory information from the dorsal horn of the spinal cord to the brain
