Insula lays where?
beneath lateral fissue
Insula is important for?
relays somatosensory info and important for language function and swallowing
Parietal lobe is bounded by...
central sulcus and end of lateral sulcus
Functions of parietal lobe?
Spatial orientation, perception and sensation and language comprehension
What does the post central gyrus contain?
The somatosensory area, primary sensory cortex BA 1-3
What is adjacent to the post-central gyrus in the parietal lobe?
Angular and supramarginal gyrus
Superior means
above
Inferior means
Below
Rostral means
toward the beak
Caudal means
toward the tail
Frontal lobe is bounded by
Central gyrus and lateral sulcus
Temporal lobe is bounded
by the lateral fissue and the occipital lobe
Functions of temporal lobe
Auditory processing, learning, and memory
Heschi's gyri
Houses the primary auditory cortex BA 21
Where is Wernicke's area?
In the temporal gyrus
Medial temporal lobe contains
hippocampus
Function of hippocampus
memory
The occipital lobe is bounded by
small area behind parietal lobe
Function of occipital lobe?
Visual processing
Important landmarks in the occipital lobe?
Parietal-occipital sulcus and calcarine sulcus
Limbic lobe boundaries?
Located on the medial surface of the two hemispheres
function of limbic lobe?
Emotion, motivation, and memory
Parts of the limbic system
Thalamus, hypothalamus, amygdala, and hippocampus
Association cortices are...
not otherwise defined as primary motor cortex or primary sensory cortex
make up a majority of the cerebral cortex
Have different cellular makeup than the primary cortexes
Point of association cortices
To organize information that comes from various other areas of the brain and mediate higher mental functions
Association cortices can be divided up into:
Unimodal and multimodal association areas
Association fibers are... (location)
within the same hemisphere
What are the two association fibers?
a. longitudinal fasciculus
b. arcuate fasciculus
Commissural fibers (location)
arise from the opposite hemisphere
What are the two commissural fibers?
a. corpus callosum
b. anterior and posterior commissure
Projection fibers go from... (location)
cortex to nervous system
What is the one project fiber?
a. internal capsule
What are the basal ganglia?
Collection of cell bodies
Important for selecting and initiating motor plans
Diencephalon
thalamus and hypothalamus
What are the dorsal and ventral horns of the spinal cord?
The dorsal horns contain secondary sensory nerve cells receiving information from the dorsal root ganglion
The ventral horns contain motor nerve cells which project through anterior roots to activate muscles, glands, and cells
Two ways in which neural tube forms
Primary and secondary neurulation
What happens in primary nerurlation?
The cells of the neural plane invaginate and pinch off to form the tube
What happens in secondary neurulation?
The cells of the neural plate form a cord-like structure that migrates inside the embryo and hollows to form the tube
When does primary neurulation turn into secondary?
When the causal neuropore undergoes final closure
Ventricle pathway
lateral ventricles narrow into the intraventricular foramen which go to the 3rd ventricle which narrows into the cerebral aqueduct which flows into the 4th ventricle which is wedged in between the cerebellum and the brainstem. There are openings in the 4th ventricle which leads the CSF to flow in the subarachnoid space and also through the central canal which houses the spinal cord
What's in the subarachnoid space?
External arteries and veins run in this space
Arachnoid trabeculae
CSF
Arachnoid villi which are protrusions that poke through the dura into the sinuses where CSF is dumped into the venous sinus
What happens if a meningeal artery ruptures?
Epidural hematoma
What happens if there is bleeding between the dura and the arachnoid if a vein tears near a venous sinus
Subdural hematoma
What is hydrocephalus?
Abnormal enlargement of cerebral ventricles
What are the two types of strokes?
Hemorrhagic strokes which are rupture of blood vessels and ischemic strokes which is restriction of blood supply
_______ is the condition where tangled dilated arteries become connected in a local area
arteriovenous malformation
What can stimulate neuron channels?
Electrical activity
Ligands
In some, heat and mechanical stimulation
At rest, there are more ______ ions outside the cell body than inside meaning that the voltage inside the cell body is _____ relative to the outside
positive; negative
What contributes to the -70 mV?
Negatively charged mostly inside the cell
NA+ mostly outside the cell whereas more K+ inside the cell
Membrane is leakier to K+ than Na+ so more positive ions leave the cell interior than get in
What causes release of neurotransmitters in synapse?
Electrical change at axon terminals
Multiple sclerosis occurs because...
Myelin sheath are attacked by immune system leading to failure of action potentials
Temporal summation
Repeated stimuli can have a cumulative effect and can produce a nerve impulse when a single stimuli is too wear
Spatial summation
Synaptic input from several locations can have a cumulative effect and trigger a nerve impulse
Spontaneous firing rate
The periodic production of action potentials despite synaptic input
Brainstem consists of...
medulla, pons, and midbrain
Function of medulla
contains centers for cardiac, respiratory, vomiting, and vasomotor for dealing with heart rate, breathing, and blood pressure
Function of pons
contains tracts that carry signals from the cerebrum to the medulla and cerebellum, and also tracts that carry sensory signals to the thalamus
Function of midbrain
Associated with vision, hearing, motor control, sleep/wake, alertness, and temperature regulations
How to remember the ventral side of the brainstem?
The V-shape
What tracts travel the dorsal side of the brainstem?
Sensory
What tracts travel the ventral side of the brainstem?
Motor
What are the bumps of the dorsal brainstem?
Colliculus
What structures go through the medulla?
CST (motor), STT (sensory), and posterior column or medial lemniscus (sensory)
What information travels through the corticospinal tract?
Motor
What information travels through the spinalthalamic tract?
Pain, temperature and crude touch
What information travels through the medial lemniscus?
Conscious proprioception, vibration and fine touch
How do you identify the caudal medulla?
By the central canal in which CSF travels through
What structures are seen in a cross-section of the caudal medulla?
Central canal, pyramids, ML, inferior olivary nucleus, and STT
When does the ML or PC cross?
At the spinal cord
When does the STT cross?
At the level of the spinal cord
How can you identify the rostral medulla?
The floor of the 4th venticle
What important landmarks do you see in a cross-section of the rostral medulla?
Inferior olivary nucleus which is snake like, ML, pyramid, STT, and floor of fourth ventricle
Pinna need to know info
Made of cartilage
Shape in important in funneling and localization of sounds
Muscles
External auditory canal need to know info
Slightly s-shaped
Outer is 1/3 cartilage, inner is 2/3 bone lined with thin skin
Main function is to protect air drum and amplify certain frequencies
Function of middle ear
Transmitting sounds to the cochlea, pressure equalizer, and amplification of sound
Importance of eustachian tube
Normalizing pressure in middle ear
Importance of middle ear muscles
Protect our ear from loud sounds
Peri- meaning
Surrounding
Cochlea anatomy from uppermost chamber to lowermost chamber
Scala vistibuli, scala media, and scala tympani
The concentration of different ions in the perilymph and endolymph in similar to neuron true or false
true
Organ of corti need to know info
In scala media
Rests on top of basilar membrane
Includes hair cells
Function: converting mechanical vibrations/sound waves into electrical sigals
Two types of hair cells
OHCs and IHCs
Which group of hair cells have 12,000 and which have 3000?
12000-OHCs 3000-IHCs
What is the function of outer hair cells?
Causes the basilar membrane to vibrate
What is the function of inner hair cells?
Determine which frequencies are present
The endocochlear potential is the _____ in the body
laregest difference
How do action potentials occur due to the hair cells?
1. Sound waves cause the stereocilla to move, which opens channels
2. Opening of channels changes the hair cell potential with K+ entering the cell
3. In the inner hair cells, the change in potential causes neurotransmitters to be released at the synapses with auditory nerve fibers
4. The release of NTs at the synapses initiates action potentials in the nerve fibers
What are the 3 neural outputs?
Frequency, pitch of the sound and how often the nerve is firing
Intensity, energy carried by the sound, how many neurons are firing
Timing, when the firing is occuring
Anatomy of the eye need to know info
Eyeball divided into small anterior and large round posterior cavity
Anterior cavity contains the iris, cornea, and lens; also contains aqueous humor simlar to CSF
Posterior cavity contains vitreous humor, a jellylike substance that maintains pressure which prevents the eyeball from collapsing, it's never replaced
Importance of cornea
protection, keeps humor in place, and starts to bend light to direct it to your pupil
Importance of iris
Helps regulate the amount of light going through your pupil
Importance of pupil
Where the light enters the eye
Importance of the lens
Focuses light into the retina
Importance of retina
Back lining of eye, light will not get into the brain without this structure
Which cells sense the light?
Photoreceptors and then the bipolar cells transmits signals to the ganglion cells
What are the two photoreceptor cells?
Rods and cones
Limbic system is known as the
emotional brain
Motor control is really ______
sensorimotor control
What are the three types of movement?
Reflexes, central pattern generators, and skilled learned movements
What information does the dorsal column pathway carry and when does it cross?
Proprioception and fine touch; crosses at medulla
What information does the STT carry and when does it cross?
Pain and temperature; crosses at level of spinal cord
Where does the corticospinal tract cross?
Pyramids
What info does the CST carry?
Motor info to the arms and legs
What is the dorsal root ganglion?
Sensory nerve cell bodies of the PNS
White matter and gray matter placement in the CNS
Gray inside, outer ring of white matter
Dorsal horns contain _____ sensory nerve cells receiving info from the dorsal root ganglion
secondary
Lower motor neurons are the _______
final common pathway to muscles
Lower motor neurons are made up of _____ and ______ nerves
cranial and spinal
A motor unit contains ____ motor nuerons
1
Myasthenia Gravis is a _________ dysarthria condition
flaccid
Myasthenia Gravis
Decrease ability of ACh to act as a nuerotransmitter which leads to reduced efficieny in muscle contraction
Lower motor neurons control contralateral muscles. True or false
False, they control ipsilateral muscles because the crossing already happened
Lower motor neurons synapse with upper motor neurons in the brainstem or spinal cord. True or false
True
Do LMNs receive activity from multiple sources or just the upper motor neuron?
Multiple sources such as PNS, direct activation system and indirect activation system
What are effects of damage to LMNs?
Weakness, may result in paralysis, hyporeflexia, atrophy, fasciculation, and fibrillation
Where do upper motor neurons have their cell bodies?
The cerebral cortex
Corticobulbar need to know info
Fibers originate from the cerebral cortex, travel down through the internal capsule and cross midline at the brainstem at the level of CN nuclei they innervate
Control muscles of the head and face through cranial nerves
What are the effects of damage from UMN?
Weakness (spastic), increased muscle tone, hyper-reflexia
Direction action pathways, also known as pyramidal tract need to know info
Go through pyramids, corticispinal or corticobulbar tracts, and damage causes loss of or reduction of skilled movements like walking
Indirect pathways need to know info
Other pathways that synapse onto LMNs
Functions are to regulate reflexes, posture, background muscle activity, and helps direct pathways accomplish skilled, discrete actions
Importance of premotor cortex
Mediates skilled and goal-directed movements
Importance of supplemental motor cortex
Mediates planning and sequencing of actions e.g. clapping
What three structures have no direct contact with LMNs?
Thalamus, basal ganglia, and cerebellum
Functions of basal ganglia
Regulates background muscle activity, supports goal-directed movements, and helps initiate movements
Major output of the basal ganglia?
Striatum
Major input of the basal ganglia?
Globus pallidus internal segment
True or false. The substantia nigra is not a part of the basal ganglia
False, it is
Glutamate is excitatory. true or false
True
GABA is inhibitory. True or false
True