NROB60 Lec 1-2

ectoderm

the top plate of the embryo that becomes the neural plate

What happens at 18 days of neural tube development?

Notochord forms and the ectoderm becomes the neural plate

What happens at day 20 of neural tube development?

Floorplate comes up form the neural plate above the notochord and the neural crest emerges in the lateral margins of the neural plate

What happens at day 22 of neural tube development?

Neural tube completes when the edges of the neural plate meet in the midline and somites begin to form in the mesoderm which becomes the skeleton

somites

form in the mesoderm around the neural tube and develop into the skeleton

What does the Prosencephalon divide into?

Telencephalon and diencephalon (thalamus and hypothalamus)

Neurulation

the process of developing the neural tube from the ectoderm of the embryo, leads to brain and spinal cord development

Notochord

A long rod structure that develops into ventral (beneath) the neural tube

Olfactory nerve (CN I)

Carries information about smell

Optic nerve (CN II)

Carries vision

Vestibulocochlear nerve (CN VIII)

Carries information about hearing and balance

Oculomotor nerve (CN III)

Controls eye movement

Trochlear nerve (CN IV)

Controls eye movement

Abducens nerve (CN VI)

Controls eye movement

Spinal accessory nerve (CN XI)

Controls neck muscles

Hypoglossal nerve (CN XII)

Controls the tongue

Trigeminal Nerve (CN V)

Transmits facial sensation and controls chewing

Facial Nerve (CN VII)

Controls facial muscles and receives taste sensation

Glossopharyngeal nerve (CN IX)

Receives taste sensation and sensation from posterior end of throat/tongue, and also controls muscles of the throat

Vagus nerve (CN X)

Receives sensation and controls many visceral organs

Bell's palsy

Sudden weakness or paralysis of the muscles on one side of the face

Vestibular neuritis

Inflammation of the vestibular portion of CN VIII

Vestibular schwannomas

Slow-growing benign tumor arising from Schwann cells of the vestibular nerve

Chronic traumatic encephalopathy

Degenerative brain disease associated with repeated hits to the head

Anterior fossa

Ventral aspect of the frontal lobe

Middle fossa

Much of the temporal lobe

Posterior fossa

Brainstem and cerebellum

Dura mater

Outermost protective membrane of the brain and spinal cord

Arachnoid mater

Middle protective membrane of the brain and spinal cord

Pia mater

Innermost protective membrane of the brain and spinal cord

Falx cerebri

Crescent-shaped fold that separates the two hemispheres of the brain

Major venous sinuses

Formed by a separation of the inner and outer layers of the dura mater

Subarachnoid space

Space filled with cerebrospinal fluid (CSF) and major cerebral arteries, and space where CSF flows after exiting the fourth ventricle

Brain hemorrhage

Localized bleeding in the brain

Meningiomas

Benign tumors arising from the dura mater

Meningitis

Infection and inflammation of the meninges

Cerebrospinal fluid (CSF)

Clear, colorless fluid that flows in and around the brain and spinal cord

Ependymal cells

Specialized cells in the choroid plexus that produce CSF

Ventricles

Cavities in the brain that contain CSF

Fourth ventricle

Space between the dorsal brainstem and cerebellum

Ventriculoperitoneal shunt

Surgical procedure to relieve buildup of CSF by draining it into the peritoneal cavity

Alzheimer's Disease (AD)

Neurodegenerative disease that causes shrinkage of the brain and ventricles

Blood supply

Elaborate vascular system crucial for neurological diagnoses

Embolic Stroke

Blockage due to blood clots formed elsewhere in the body

Internal Carotid Arteries

Arteries ascending up the sides of the neck, branching into external and internal carotid arteries

Neurodegenerative Diseases

Diseases causing neuron death and shrinkage

Thrombotic Stroke

Blockage due to fatty plaque build-up on cerebral vessels

Transient Ischemic Attack (TIA)

Temporary blockage of blood supply to the brain

Stroke Risk Factors

High blood pressure, high cholesterol, diabetes, age, race, sex, sleep apnea, obesity, sedentary lifestyle, high alcohol or drug use

Stroke Symptoms

Numbness or weakness of face, arm, or leg; confusion, trouble speaking, or understanding speech; blurred vision; dizziness, loss of balance or coordination, difficulty walking; severe headache with no known cause

Blood Supply of Brain

Internal carotid arteries and vertebral arteries supplying oxygenated blood

Brain Atrophy

Shrinking of brain size due to neuron loss

Prediction of AD Ventricles

Larger ventricles due to atrophy of neurons

Stroke

Blockage or bleeding in the brain resulting in functional deficits

Ischemic Strokes

Blocked blood vessels in the brain

Hemorrhagic Stroke

Ruptured blood vessel causing bleeding in or around the brain

Vertebral Arteries

Arteries ascending up each side of the cervical vertebrae, fusing together to form the basilar artery

Anterior Circulation

Supplies forebrain (cerebral hemispheres and diencephalon)

Posterior Circulation

Supplies brainstem, cerebellum, and upper portion of the spinal cord

Circle of Willis

Ring formed by major cerebral arteries at the base of the brain, providing an alternate route if a main artery is damaged or blocked

Major Cerebral Arteries

Internal carotid artery, posterior cerebral artery, anterior cerebral artery

Anterior Cerebral Artery (ACA)

Artery supplying anterior regions of basal ganglia and internal capsule

Middle Cerebral Artery (MCA)

The artery that supplies an extensive region of the central and lateral cerebral hemispheres; supplies the internal capsule, anterior hypothalamus, amygdala, hippocampus, thalamus, and basal ganglia

Posterior Cerebral Artery (PCA)

Artery supplying posterior hypothalamus, thalamus, and regions in the parietal and occipital lobes

Lenticulostriate Arteries

supplies most of basal ganglia, main body of the internal capsule, anterior hypothalamus

Dural Venous Sinuses

Sinuses formed between the inner and outer layers of dura mater, draining venous blood from the brain and returns blood from the brain back to the heart via the internal jugular veins

Blood-Brain Barrier (BBB)

Barrier that restricts movement of substances from blood vessels into brain cells

Endothelial Cells

Cells forming tight junctions in the BBB

Astrocyte End Feet

Surrounding structures that contribute to the BBB

BBB Permeability

Only allows substances soluble in lipids or transported via specific transporters

Importance of BBB

Maintains stable ionic milieu, prevents infections and blood-borne toxins from reaching the brain

Challenges of BBB

Hurdle for developing drug therapeutics to treat CNS disorders

Drug Delivery Strategies

Mimic natural substances, temporarily disrupt BBB, intranasal administration, use of nanoparticles

Glymphatic System and Sleep

During sleep, glymphatic flow increases, aiding waste removal

Glymphatic System and Alzheimer's

Disruption of glymphatic system may contribute to AD onset/progression

Bilateral anosmia

(loss of smell) can occur following head trauma that causes shearing forces on olfactory nerves

Bell's palsy

a condition that causes sudden weakness or paralysis of the muscles on one side of the face

Vestibular neuritis

results from inflammation of just the vestibular portion of CN VIII

Vestibular schwannomas

a slow-growing benign tumor that arises from Schwann cells of the vestibular nerve

Chronic traumatic encephalopathy

a degenerative brain disease associated with repeated hits to the head

Foramen magnum

a large, oval-shaped opening in the occipital bone of the skull that the spinal cord passes through when exiting the cranial cavity

meninges

three protective membranes that surround the brain and spinal cord

Dura mater

Outermost layer of the meninges

Tentorium cerebelli

a U-shaped which that runs between the occipital lobe and the cerebellum, separate the cerebrum from the cerebellum

tentorial notch

provides space for the brainstem to pass

Falx cerebelli

a small midline fold that runs in the space between the two cerebellar hemispheres

How the venous sinuses is formed

a separation of the inner and outer layers of the dura mater

Epidural hemorrhage

collection of blood between the dura mater and the skull

Subdural hemorrhage

a collection of blood between the dura mater and arachnoid mater

subarachnoid hemorrhage

Bleeding into the subarachnoid space, where the cerebrospinal fluid circulates.

Intracerebral hemorrhage

bleeding within the brain tissue itself

Meningiomas

typically benign tumors arising from the dura mater

Functions of the ventricular system

Protects brain, Provides buoyancy, and Provides a medium for the exchange of materials between blood vessels and brain tissue

cerebrospinal fluid (CSF)

produced by specialized ependymal cells in the choroid plexus of the ventricles

Lateral Ventricles

Large, C-shaped spaces in each cerebral hemisphere

Interventricular foramen of Monro

a short conduit that connects the lateral ventricles to the third ventricle

Third Ventricle

a narrow midline space between the right and left diencephalon (thalamus + hypothalamus)

cerebral aqueduct

connects the third and fourth ventricles

Fourth Ventricle

found between the dorsal brainstem and cerebellum

choroid plexus

Modified vascular structure lining the ventricles that produces CSF by filtering blood