nervous system and brain Flashcards
the CNS consists of _____ and ______
brain and spinal cord
only 10% of CNS cells are neurons the rest are ______
neuroganglia
the CNS is supported by the ________
cerebral spinal fluid CSF
specific areas of neuronal bodies are called _____
nuclei
axons from multiple nuclei running parallel are called ______ (aka nerve tracts or white matter)
fibers
the neuron is the basic functional unit of the nervous system- responsible for ___________
sending and receiving nerve impulses or signals
________ are non neural cells that provide support and nutrition, maintain homeostasis, form myelin and facilitate signal transmission in the nervous system
glial cells
Brain is ___% of body weight and __% of the body oxygen and glucose consumption
2
20
forebrain
prosencephalon
midbrain
mesencephalon
hindbrain
rhombencephalon
the forebrain is subdivided into the telencephalon and diencephalon
telencephalon- cerebral hemishperes
diencephalon - thalamus and hypothalamus
Brain protection
Cranium
skull
Brain protection
meninges
shock absorbent
-prevents brain from contacting the skull
dura matter
arachnoid
pia matter
Brain protection
cerebrospinous fluid (CSF)
cushions the brain and spinal cord
Brain protection
blood brain barrier
tight junctions- prevent diffusion of materials between cells
only lip soluble compounds diffuse into the interstitial fluid
Meningeal Layers- Cranial meninges
- Dura matter
has 2 fibrous layers
1. periostea (fibrous outermost) - fused with periosteum lining of cranial bones
- Meningeal (innermost)
Meningeal Layers- Cranial meninges
- Arachnoid
delicate membrane located between meningeal dura and Pia matter, bridging both sulky and gyri
Meningeal Layers- Cranial meninges
- Pia matter
tightly attached to the surface contour of the brain and lines the sulci
epidural space located between
the skull and outermost dura
- middle meningeal artier runs in this space
subdural space located
between the inner dura layer and arachnoid
-bridging veins transverse it
subarachnoid space located between
the arachnoid and Pia matter
-CSF fills this space
longitudinal fissure
- separates the 2 hemispheres
- each hemisphere is divided into lobes named after the overlying bones of the skull
central sulcus
- deep groove extends laterally from longitudinal fissure
-frontal love anterior to central sulcus
lateral sulcus
-marks the inferior border of frontal lobe
region inferior to lateral sulcus is the temporal lobe
Pareto-occipital sulcus
-inferior border of parietal lobe
-parietal lobe: extends posteriorly from the central sulcus to the p-o sulcus
-region posterior to this is the occipital lobe
frontal lobe
primary motor cortex- conscious control of skeletal muscles
parietal lobe
primary somatosensory cortex- conscious perception of touch, pressure, vibration, pain, temperature and taste
temporal lobe
auditory and olfactory cortex- conscious perception of auditory and olfactory stimuli (hearing and smell)
occipital lobe
visual cortex- conscious perception of visual stimuli
lobes of the brain
Fibres: carry __________ within and between hemispheres
information
association fibers
connect areas of cerebral cortex within one hemisphere