Chapter 15- The brain and cranial nerves

What does the longitudinal fissure separate?

The right and left hemispheres with the cerebral cortex

What does the precentral gyrus the primary cortex of?

Primary motor cortex

What does the post central cortex the primary cortex of?

Primary somatosensory cortex

Where is the insular lobe?

Inside the frontal lobe (sort of) and in front of the precentral gyrus

What does the telencephalon give rise to?

The cerebrum (consciousness)

What does the diencephalon give rise to?

The thal- structures (epithalamus, thalamus, hypothalamus)

What does the lateral sulcus separate?

Temporal lobe from parietal lobe

What does the mesencephalon (midbrain) give rise to?

The corpora quadrigemina - superior and inferior colliculi

What does the metencephalon give rise to?

The cerebellum and pons

What does the myelencephalon give rise to?

Medulla oblongata

Thalamus 

Relay center for all info coming in (sensory) and all motor going out

What sensory does not go through the thalamus?

Smell information

What layers are beneath the level of consciousness?

Diencephalon, mesencephalon, metencephalon, myelencephalon

What is known as the emotional cortex?

Cingulate gyrus

Hypothalamus

Eating, drinking, sex, sleeping, centers controlling emotions, autonomic functions, and hormone production

Where is the choroid plexus in relation to the thalamus?

Superior and on the border

Pineal Body

Where serotonin is metabolized to melatonin

Hippocampus

Learning and memory

Amygdala 

Sex, fear, and aggression

Where are mammillary bodies located?

anterior tip of the hypothalamus

Corpus callosum

Where the left and right hemisphere connects

What ensures that the response of the brain can vary to meet changing circumstances?

Excitatory (depolarizing) and inhibitory (hyperpolarizing) interactions in the 20 billion neurons among the extensively interconnected neuronal pools ensure

What creates false memories?

Neural nets

Cerebrum

• Conscious thought processes, intellectual functions

• Memory storage and processing

• Conscious and subconscious regulation of skeletal muscle contractions

Mesencephalon/midbrain

• Processing of visual (superior colliculi) and auditory data (inferior colliculi)

• Generation of reflexive somatic motor responses

• Maintenance of consciousness

Pons

• Relays sensory information to cerebellum and thalamus

• Subconscious somatic and visceral motor centers

Medulla oblongata

• relays sensory information to thalamus and to other portions of the brain stem

• Autonomic centers for regulation of visceral function (cardiovascular, respiratory, and digestive system activities)

What two brain structures are essential for life?

Pons and medulla oblongata

Cerebellum

• Coordinates complex somatic motor patterns

• Adjusts output of other somatic motor centers in brain and spinal cord

What are the primary brain vesicles filled with?

CSF in the hollow tube which is how the brain begins (causes the ventricles of the brain)

What do the 1st and 2nd ventricles become?

Lateral ventricles

What do you poke through to get to the thalamic center?

Third ventricle 

Where is the fourth ventricle?

In between the pons and cerebellum in the brainstem

What does the fourth ventricle tie into?

The central canal of spinal cord

What is CSF called?

The “urine” of the brain

What ties together the 3rd and 4th ventricle?

Cerebral aqueduct

Does CSF flow through the head?

Yes, it does flow

What causes hydrocephalus?

Too much CSF in the ventricles causing them to be against the skull

If you cut the brain in half, what do you cut into?

Well, first the corpus callosum, then the thalamic nucleus

What does the protection, support, and nourishment of the brain involve?

• Bones of the skull

• Cranial Meninges

  • Dura Mater

  • Arachnoid mater

  • Pia mater

• CSF

• BBB

• Vessels of cardiovascular system

What does dura mater mean?

Tough mother 

What does arachnoid mater mean?

Spider mother

Is there an epidural space in the skull?

No, there is not

Where is CSF found in the brain?

Subarachnoid space and CSF

What is the major brain drain?

Dural sinus

What does the dura mater separate into?

Meningeal layer and endosteal layer

From superficial to deep how does the dura mater and dural sinus go

Dura mater endosteal layer

Dural sinus

Dura mater meningeal layer

Where does venus blood with CSF come from?

Subarachnoid space

Where does the Pia mater attach to in the anterior part of the brain?

Crista galli of the ethmoid bone

Where does the pituitary gland insert in the skull bones?

Sella turcica of the sphenoid bone

Which sinus attaches to the crista galli?

Superior sagittal sinus

What do the two layers of the dura mater split to create?

Superior sagittal sinus

Does the pia mater go into fissures/sulci?

Yes, it goes down, the rest of the layers do not

What is the choroid plexus?

Worm that floats around to each ventricle (it is really long) to produce CSF that is made of modified epithelial cells that are ependymal cells to produce CSF

What products go into the choroid plexus?

Waste products

Ions

Amino acids

What leaves the choroid plexus?

Ions (Na+, K+, Cl-, HCO3-, Ca2+, Mg2+)

Vitamins

Organic nutrients

Oxygen

What type of junctions are in the choroid plexus?

tight junctions

Does CSF circulate all the time?

Yes, it is constantly moving

What is anastomosis?

For most of the structures in our body, we have an alternate way to get to the cells that need to be nourished, this is an alternate way to get blood to where it needs to go

Hydrocephalus

Very dangerous because fluid will push brain and skull - the fontanelles will damage neurons themselves

What is the largest, most superior portion of the human brain?

Cerebrum (think consciousness)

Do we have almost identical folding of human brains?

Yes, all foldings are very similar

Where is the gustatory cortex?

Inside the frontal lobe and insula

Where is the auditory cortex?

Cute through the external acoustic meatus and temporal bone

Frontal lobe primary motor cortex

Conscious control of skeletal muscles

Parietal lobe primary sensory cortex

Conscious perception of touch, pressure, vibration, pain, temperature, and taste

Occipital lobe visual cortex

Conscious perception of visual stimuli

Temporal lobe auditory and olfactory cortex

Conscious perception of auditory and olfactory stimuli

All lobes association areas

Integration and processing of sensory data; processing and initiation of motor activities

Are all of the functions of the cerebral cortex conscious or unconscious?

Conscious

Are there connections throughout the brain with axons?

Yes, there are longitudinal fasciculi throughout the whole brain

What is the primary comissual tract of the cerebrum?

The corpus callosum

What is the internal capsule of the brain known as?

The corona radiata and the brain stem up and down

What are the two commissural fibers and what do they do as a key structure?

Anterior commissure and corpus callosum that interconnect corresponding lobes of different hemispheres

Where is the thalamus located by the caudate nucleus?

Deep and within the caudate nucleus

What is the claustrum known for?

What we think is causing the slow time moving during accidents (allows decisions to be made during that time)

Plays a role in the subconscious processing of visual information

What is within the lentiform nucleus?

Putamen and globus pallidus

What is the putamen known for?

Dopaminergic neurons

Where can we spot early dementia?

Basal ganglia (caudate nucleus, lentiform nucleus (with putamen and globus and pallidus)

Caudate nucleus, lentiform nucleus (with putamen and globus and pallidus)

What is today, tomorrow, or 2 weeks ago

Subconscious adjustment and modification of voluntary motor commands

Where is the fornix?

From the mamillary bodies to the temporal lobe

Is fear sensed?

Yes, it is

If something is off, avoid them and it is determined with the frontal lobe

Where is our powerful responses to threat (where fear is sensed)?

Parahippocampal gyrus and amygdala

Who’s job is it to form new memories?

Hippocampus 

Epithalamus

Controls circadian rhythm (the light and dark cycles)

** you can change your circadian rhythm but it is very hard to do

Where is the epithalamus located?

With the pineal body (the pinecone where serotonin and melatonin are synthesized)

Where is the hypothalamus located to the thalamus?

Inferior and rostral to the thalamus

What is the main function of the hypothalamus?

Homeostasis - coordinates the nervous and endocrine systems

Superior colliculus

Visual reflex 

When you hear a loud noise what type of reflex is it?

A collicular reflex

What does corpora quadrigemina mean?

4 twins or 2 sets of twins

Inferior colliculus

Auditory reflex

What splits the third ventricle?

The thalamus (right and left) in a coronal section

CN 1

Olfactory, sensory, olfactory foramina on crista galli

CN II

Optic nerve, sensory, optic canal

CN III 

Oculomotor nerve, motor, S.O.F.

CN IX

Trochlear nerve, motor, S.O.F.

CN V

Trigeminal (V1, V2, V3), both, V1- S.O.F, V2- foramen rotundum, V3- foramen ovale

What 4 cranial nerves go through the S.O.F.?

CN III, CN IV, CN V V1, CN VI