Neuroanatomy Flashcards
medial
middle
anterior
front
-frontal or rostral
ventral
below or belly sometimes called inferior
lateral
side
posterior
tail
- caudal
Dorsal
above
-superior
Contralateral
opposite side
Ipsilateral
same side
Unilateral
on one side only
Bilateral
on both sides
Proximal
close to the body
Distal
further away from the body
Efferent signal
away from the CNS
send signal down to the foot from CNS
Afferent signal
towards the CNS(stub your toe pain goes up to CNs)
What can the PNS be divided into?
sympathetic and parasympathetic branches
Parasympathetic
REST OR DIGEST: INHIBITORY constricts pupils - stimulates saliva production - constricts bronchi - slows heart - stimulates stomach pancreas and intestines -stimulates urination - promotes erection of genitals - involved in arousal
sympathetic divison
STIMULATION: FLIGHT OR FIGHT
- dilates pupils
- inhibits saliva production
- dilates bronchi
- accelerates heart
- stimulates epinephrine and norepinephrine responses
- stimulates glucose release
- inhibits stomach and pancreas
- inhibits urination
- stimulate sweating
- hair standing up on arms
- increase muscle strength
- promotes ejaculation and vaginal contractions(orgasm)
What are the meninges?
outer covering of the brain through the CNS
duramater – Latin for “tough mother”
arachnoid layer – Greek for “like a spider’s web”
piamater – Latin for “soft mother”
All offer forms of protection
meningitis
infection of the meninges increases pressure on the brain.(all this stuff is in the skull the skull doesn’t increase or decrease if you get an infection white puss builds up and puts pressure on the brain which damages the brain)
encephalitis
infection of the brain itself.
Cerebrospinal fluid (CSF)
Brain is surrounded by CSF.
Ventricles (filled with CSF and produce it) are continuous with the outer supply of CSF.
(bathes the brain) supports or ‘cushions’ the brain. (Like a waterbed for the brain) (could protect against minor injury
Provides nutrients, removes waste, helps maintain the blood-brain barrier.
Where is the CSF produced and circulated around?
produced by the choroid plexus and circulated around the subarachnoid space
Where does CSF get reabsorbed?
reabsorbed by the arachnoid granulations.
How does the CNS communicate with the body?
communicates with the body via nerves that connect with the brain (cranial nerves) or the spinal cord (PNS
Medulla Oblongata
12 cranial nerves – many attached to medulla.
reticular activating system – arousal, attention and sleep-wake cycle.
motor fibres cross to contralateral side.(right side of the brain controls left side of the body)
controls reflexes, respiratory and heart rate.
damage can be fatal – swelling of other brain regions following injury can also affect the medulla.
Cerebellum
precise or fine motor control
balance
neuroimaging suggests a role for the cerebellum in many cognitive processes – a ‘mini-brain’?
Ipsilateral(right cerebellum activates when the right side of the body moves) motor organization
Pons
main connection between cortex and cerebellum.
vestibular functions (e.g., balance).
sleep and arousal.
contains superior olive
What are two important midbrain structures:?
superior colliculus (rapid eye movements)
- inferior colliculus
auditory equivalent of SC
- This area is also known as the tectum.- roof
What is the Hypothalamus?
- group of nuclei.
- maintain equilibrium or homeostasis.
- ventromedial lesions affect regulation of food intake.
- regulate body temperature (anterior and posterior nuclei).
- regulates hormones (involved in sexual behavior, biological rhythms, fight or flight responses, etc.).
Thalamus
group of nuclei.
sensory and motor relay centre.
Lateral geniulate nucleus
medial geniulate nucleus
lateral geniculate nucleus
relays information from the retina to visual cortex.
medial geniculate nucleus
relays information from auditory pathway to cortex
Basal Ganglia
group of nuclei – functionally related.
primarily involved in motor control.
Caudate nucleus, Globus pallidus, Putamen
What can damage to the basal ganglia cause?
Parkinson’s disease, Huntington’s disease, Tourette’s syndrome
Describe the Limbic System
Originally thought to be solely involved in emotional regulation.
This is partly true but only tells half the story.
- learning and memory
- emotional memories
- recognition of emotions in other people
List the structures part of the limbic system
Amygdala
Hypothalamus Cingulate cortex Anterior thalamus Mammilliary bodies
Hippocampus
Neural tube
serves as the origin of the central nervous system.
Preformation
Seneca (Roman philosopher) – suggested embryo was just a miniature person.
Claims made that microscopic horses be seen in horse semen
theres a striking similarity in embryos across all species
What do all vertebrates share?
All vertebrates share the same CNS structures:
- Forebrain
- Brainstem (midbrain and hindbrain)
- Neural tube (spinal cord)
In humans these structures are evident at 28 days gestation
When do wrinkles in the brain form?
“wrinkles” in the brain don’t start forming until about 7 months
What are the major divisions of the brain?
Forebrain
Midbrain
Hindbrain
Name the ventricles located in each major division?
Forebrain- Lateral, Third
Midbrain- Cerebral aqueduct
Hindbrain- Fourth
Name the different subdivisions and principle structures in each
Forebrain; Lateral; Telencephalon; Cerebral cortex Basal ganglia Limbic system
Forebrain; Third; Diencephalon; Thalamus, Hypothalamus
Midbrain; Cerebral aqueduct; Mesencephalon; Tectum tegmentum
Hindbrain; Fourth; Metencephalon; Cerebellum; Pons
Myelencephalon; Medulla oblongata
Origins of Neurons and Glia
lining of neural tube – neural stem cells.
extensive capacity for self-renewal.
in the adult stem cells line the ventricles – ventricular zone.
Growth and development
- Cell birth (neurogenesis, gliogenesis)
- Cell migration
- Cell differentiation
- Cell maturation (axon and dendritic growth)
- Synaptogenesis (formation of synapses)
- Cell death – synaptic pruning
Cell migration
road map provided by radial glial cells.
layers of the cortex are added on from the inside out.
Synaptic pruning
cell death (apoptosis) can’t completely account for synaptic pruning.
instead reinforcing functional circuits may lead to synaptic pruning of non-functional circuits.
Cell death and synaptic pruning
unnecessary connections are killed off.
up to 100,000 synapses per second!
neuron relies on its target for survival.
neurotrophin promotes survival - without successful contact the dendrite will not receive enough
Neural maturation
dendritic arborization (growing branches) and growth of dendritic spines.
axons grow faster (mm per day) than do dendrites (micrometers per day) – so axons may play a role in dendritic differentiation as they reach their target before the dendrites are fully formed.
Cell migration – path finding
normally particular neurons from the retina migrate to specific sites on the optic tectum
if the neurons are severed and the eye rotated in its socket 180 degrees, they continue to seek out the preprogrammed sites on the optic tectum!
a remapping occurs that is maladaptive.
horizontal plane
Take a brain and cut straight across
by slicing the brain perpendicular to the long axis of the body, and thus parallel to the floor in a person that is upright.
sagittal plane
Take a brain and go right thru the midline
divides the right and left side of the brain into parts.
coronal plane
Take the brain and cut thru the sides
divides the brain into an anterior and posterior portion. It is created by slicing the brain parallel to the long axis of the body, and thus perpendicular to the floor in a person that is upright.
cerebral aqueduct
connects the third and fourth ventricle
subarachnoid space
space filled with CSF
- area between arachnoid layer and pia matter
Choroid Plexus Papilloma
type of ventricular tumor
- brain tissue will die away
- surgeries can help prevent it from happening
Hydrocephalus
excessive CSF
can cause pressure in the brain
ventricles are blown out
end up having cell death & brain damage
Contrecoup injury
if in car accident your brain will slosh and hit the front part of the and the back part of the brain
damage on front & back part of brain bc of a violent collision
superior olive
– point at which information from both ears converges – important for localization
- located in the pons
- realizing which side the sound is coming from)
Describe gross development
- neural plate
- neural groove
- neural grove closes to make neural tube
- neural tube
