The two divisions of the NS
Central NS & Peripheral NS
What systems are apart of the CNS
brain & spinal cord
average weight of the brain
1.3-1.4 kg/ 3lbs
how many neurons and glia are there?
8 billion nerve cells/ trillions of glia (support cells)
length of spinal cord
43cm (women)/ 45cm (men)
Weight of spinal cord
35-40g
length of vertebral column
around 70 cm
What systems are apart of the PNS
Automatic & somatic
what does the SNS do?
its consist of peripheral nerve fibers that send sensory info to the CNS and motor nerve
What does the SNS have?
fibers that project to the skeletal muscles
Where is the SNS cell body located and what does it do?
either in the brain or spinal cord & project to spinal cord
What are the 3 parts of the ANS
Sympathetic, parasympathetic, and enteric
What does the ANS do?
controls smooth muscle of internal organs (viscera) and glands
Where is the preganglionic neuron located?
brain/spinal cordd
What does the preganglionic neuron do?
projects to an automatic ganglion and then projects to a target organ (basically sends messages to other neuron the the organ)
What does the ENS do?
it is a meshwork of nerve fibers that inner rate the viscera (gastrointestinal, pancreas, gall bladder)
The 3 sections of the Brain
Forebrain, midbrain, hindbrain
The sections in the forebrain
telencephalon & diencephalon
Sections in the telencephalon
cerebral cortex, basal ganglia, hippocampus, amygdala
Sections in the diencephalon
Thalamus, hypothalamus
Section of the midbrain
Mescencephalon
sections of the mesencephalon
tectum, tegmentum
Section of the hindbrain
metencephalon & myelencephalon
Sections of the Metencephalon
pons, cerebellum
Section of the myelencephalon
medulla
How do the 2 hemispheres of the brain communicate
through the corpus callosum & smaller fiber bundle (anterior commissure)
What are the differences between the CNS and PNS
CNS= nuclei, PNS= ganglia
CNS= axons are tracts, PNS= axons are nerves
PNS through Sensory (afferent)
Carries info INTO CNS from SENSE organs
PNS through motor (efferent)
carries info AWAY from CNS (MUSCLE control)
PNS through cranial function
connects brain with periphery
PNS through spinal function
connects spinal with periphery
PNS through somatic function
connects skin or muscles with CNS
PNS through visceral function
connects organs with CNS
cerebral cortex
“bark”; a sheet of tissue that makes up outer layer of the brain, 2-6mm
Cerebral cortex function
thought, voluntary mov, lang, reasoning, preception
Cerebellum
“little brain”; behind the brain stem, has hemispheres and cortex that surrounds the hemispheres
Cerebellum functions
mov, balance, posture
Brain stem
area between thalamus and spinal cord
brain stem structures
pons, medulla, oblangata, tectum, reticular formation, tegmentum
Brain stem functions
breathing, heart rate, blood pressure, living basics
hypothalamus
located below thalamus in the base of the brain, 1/300 weight of the brain, controls pituitary
hypothalamus functions
body temp, emotions, hunger, thirst, circadian rhythm
limbic system
group of structures: amygdala, hippocampus, mammillary bodies, cingulate gyrus
limbic system functions
emotions and memory
hippocampus
part of limbic important for memory and learning
basal ganglia
group of structures: globus palidus, caudate nucleus, subthalamic nucleus, putamen, subterminal nigra
basal ganglia function
coordination of movement
mid brain
structures that are inferior and superior colliculi and rea nucleus
mid brain function
vision, audition, eye movement, body movement
What are the 4 lobes of the brain?
Frontal, temporal, occipital, parietal
the total surface area of the brain
324 in^2
Frontal lobe location
front of central sulcus
frontal lobe concentration
reasoning, planning, speech, mov, emotions, prob-solving
Temporal lobe location
below lateral fissure
what’s the difference between fissure, gyri, sulci
sulci=groove; gyri=bump; fissure= deepest groove
Temporal lobe concentration
perception, recognition of auditory stimuli, memory (hippocampus), vision
Parietal lobe location
behind central sulci
parietal lobe concentration
preception of stimuli, movement through somatosensory (pain, temp, touch, pressure,) x
Occipital lobe location
back of brain behind temporal and parietal
Occipital lobe concentration
vision
Prefrontal cortex/gyrus function
problem solving, emotion, complex thought
motor association cortex function
coordination of complex movpri
primary motor cortex function
initiation of voluntary mov
primary somatosensory cortex function
receives tactile info form the body
sensory association area function
processing of multisensory info
visual association area function
complex processing of visual info
visual cortex
detection of simple visual stimuli
wernicke’s area function
lang comprehension
auditory association area function
complex processing of auditory infoa
auditory cortex function
detection of sound quality
broca’s area
speech production articulation
How many cranial nerves are there? and what are they?
(hint): On Old Olympus Towering Top A Famous Vocal German Viewed Some Hops
12
1 cranial nerve
olfactory nerve
olfactory nerve function
smell
II cranial nerve
Optic Nerve
Optic nerve function
vision
III cranial nerve
Oculomotor nerve
Oculomotor nerve function
eye movement/ pupil constriction
IV cranial nerve
Trochlear nerve
Trochlear nerve function
eye mov
V cranial nerve
Trigeminal nerve
Trigeminal nerve function
somatosensory info form face to head muscles (chewing)
VI cranial nerve
Abducens nerve
Abducens nerve function
eye mov
VII cranial nerve
facial nerve
facial nerve function
taste (anterior 2/3 of tongue), somatosensory info (ear), controls facial exsp
VIII cranial nerve
vestibulocochlear nerve
vestibulocochlear nerve function
hearing/balance
IX cranial nerve
Glossopharyngeal nerve
glossopharyngeal nerve function
taste (posterior 1/3 of tongue), Somatosensory info (tongue), tonsil, pharynx, controls muscles (swallowing)
X cranial nerve
Vagus nerve
vagus nerve function
somatosensory automatic function of viscera
XI cranial nerve
spinal accessory nerve
spinal accessory nerve function
controls muscles in head mov
XII cranial nerve
Hypoglossal nerve
Hypoglossal nerve function
controls muscles of the tongue
What is CSF
Cerebrospinal fluid
What provides CSF
choroid plexus in the lateral 3rd and 4th ventricles
How does CSF flow
from lateral 1s t& 2nd ventricle through interventricular foramen; then through 3rd & 4th cerebral aqueduct; then to subarachnoid; then to foraming of Luschkla; then to formamen of magendie (1)
Where is CSF absorbed in the bllod stream?
Superior sagittal sinus through arachnoid villi structures