HERS 468 exam 2 - Pathophysiology

What are the 3 layers of the meninges? What is the most superficial to the deepest?

dura mater, arachnoid mater, pia mater

How does the cerebral spinal fluid (CSF) located relative to the meninges?

made in the choroid plexus and then flows through the ventricles and out of the brain through the formina of luschka and magendi in the roof of the 4th ventricle.

Relate this to communicating (external) and (internal) non-communicating hydrocephalus?

Outside the brain CSF fills and flows through the arachnoid space.

What are the main functions of the hypothalamus, pituitary gland, medulla oblongata, tentorium, and internal capsule?

Pituitary: the endocrine systems most influential gland. Under the influence of the hypo, the pituitary regulates growth and other endo glands
Hypothalamus: Brain region controlling the pituitary gland.
Medulla: the base of the brain stem

What part of the brain is most susceptible to damage due to lack of blood flow and why?

The white mater of the brain, because when you get older blood flow slows.

How many cranial nerves are there, and what is there basic function?

12 cranial nerves

Which of these nerves is most susceptible to cancer?

the 8th cranial nerve is most susceptible to cancer.

What is the functional cell of the nervous system?

neuron

Cerebrum

Largest part of the brain; has left and right side. responsible for voluntary muscular activity, vision, speech, taste, hearing, thought, and memory.

Brainstem

midbrain, pons, medulla oblongata

occipital lobe

Allows you to see and process stimuli and assign meaning to remember visual perceptions

subarachnoid space

Beneath the arachnoid where CSF is contained

choroid plexus

produces CSF collection of vascular projections in the ventricles

white matter

myelinated axons

pre-central gyrus

controls voluntary movement of concentrated side of the body

post central gyrus

controls involuntary movements

corpus callosum

ensures both sides of the brain can communicate and send signals to each other

Broca's area

speech production

blood-brain barrier

Cells that only allows certain molecules through to protective mechanisms for the brain.

symapthetic nervous system

fight or flight, raises heart rate, uses more energy, causes more problems than it helps

parasympathetic nervous system

Slows the heart rate, dilates blood vessels and lowers blood pressure

Oligodendrocytes

Type of glial cell in the CNS that wrap axons in a myelin sheath.

Axon

the extension of a neuron, ending in branching terminal fibers, through which messages pass to other neurons or to muscles or glands

myelin sheath

allows electrical impulses to travel quickly and efficiently along nerve cells

Astrocytes

Provide structural and metabolic support for neurons. (glue cells)

microglial cells

macrophages of the CNS

Saggital

divides body into left and right

Tentorium

extension of the dura mater that separates the cerebellum from the inferior portion of the occipital lobes

Grey Mater

Collections of neurons cell bodies

basal ganglia

a set of subcortical structures that directs intentional movements, executive functioning and behavoirs

spina bifida occulta

small defect in posterior vertebral arch

Ancephaly

most severe neural tube defect, rare and fatal, underdeveloped brain and incomplete skull, multifactorial inheritance, supplementation of mother with folate can reduce risk.

cerebral palsy

permnant, non-progressive motor problems that arise owing to an insult to the brain before it reaches a certain maturity. 3/4 from unknown prebirth conditions, 1/4 from injury after birth.

guillan-barre

acute autoimmune disease caused by anti myelin antibodies. motor weakness.

Name the three levels of spina bifida.

Spina bifida Meningocele, spina bifida occulta, spina with myelomeningocele

What is cerebral palsy?

permanent, non-progressive motor problems that arise owing to an insult to the brain before it reaches certain maturity. 3/4 from unknown prebirth conditions. 1/4 from injury after birth.

Tonsillar herniation

Herniation of the lower cerebellum through the foramen magnum. Obstructs the venous and arterial blood flow in the brain stem and can produce hemorrhage or infarction of the midbrain

What are the causes of Tonsillar Herniation?

Brain tumor, sudden hemorrhage, brain abscess, brain edema

Define at least 5 different outcomes of increased intracranial pressure

-High intracranial pressure is dangerous because it can force brain tissue to herniate (protrude) through any available opening.
-May undergo direct pressure necrosis or may impede vascular flow that results in brain hemorrhage or infection.
-Hydrocephalus. In patient flow of CSF was obstructed (non-communicating between the 3rd and 4th ventricle.
-Intracranial hemorrhage

Which type of bleeding over the surface of the brain is associated with rapid bleeding of arterial blood?

Epidural Hemorrhage

What is the most common cause of subarachnoid hemorrhage

A ruptured berry brain aneurysm

what is a white stroke?

caused by infarct of the brain tissue from lack of oxygen.

what is a red stroke?

caused by chronic hypertension, coagulation defects, anticoagulation therapy.

What is the treatment for white stroke?

treatment for white stroke is anticoagulants, heparin, thrombolytic medication

What are the first cells in the CNS to typically suffer ischemia?

Neurons because they consume the most oxygen. Most sensitive to oxygen deprivation are those of superficial cerebral cortex and Purkinje cells of the cerebellum.

what is laminar cortical necrosis?

if hypoxia is relieve, the rest of the brain may recover, leaving in the superficial cerebral cortex a layer of necrotic.

Define Coup brain injury.

when a moving head meets an immobile object, injury occurs at the site of the blow.

Define Countercoup brain Injury.

the rebound site in the brain directly opposite from the initial point of contact, usually more sever and produces more tissue damage.

define concussion.

no anatomic lesions (10% unconscious)

Define contusion.

Superficial hemorrhage (bruise)

What is septic meningitis?

bacterial, Neisseria meningitis

what is Aseptic meningitis?

viral meningitis (acute lymphocytic meningitis) no bacteria, normal glucose, high lymphocytes, no neutrophils.

What are CNS infections?

Acute infections
Chronic infections

What is an acute infection?

anaerobic bacterial abscess, Viral (syphilis) encephalitis. Can have infected sinuses, lungs, and bacterial endocardium.

What is a Chronic infection?

Viruses: Viral encephalitis (herper, cytomegalovirus, measles)

Prion: spongiforms encephalitis, is a chronic degenerative disease brain disease. (Creutzfeldt-Jacob disease: similar to mad cow, its a rare fatal brain disorder, characterized by rapidly progressive dementia)

What is Creutzfeldt-Jakob disease?

(similar to mad cow) rare fatal brain disorder, characterized by rapidly progressive dementia

What are the degenerative diseases of the CNS Gray matter?

-Dementia
-Alzheimer Disease
-Parkinsonism
-Amyotrophic Lateral Sclerosis
-Huntington Disease

What is dementia?

deterioration of mental abilities

Alzheimer's disease

>half of all cases of adult dementia
-1% early 60s -> nearly 33% of 85 yo

What is parkinsonism?

caused by motor control abnormalities in the basal ganglia of the midbrain. Affected cells do not transmit signals properly; they do not release normal amounts of neurotransmitters dopamine.

What is Amyotrophic Lateral Sclerosis (ALS)?

Microscopy cross section of spinal chord myelin is stained black. Lateral corticospinal tracts (LCS in the section) are pale due to loss of myelin. Degenerative condition of motor neurons in the gray matter of the Cerebral cortex.

What is Huntington's disease?

an Autosomal dominant (chromosome 4 effected degeneration of basal ganglia)

What are the degenerative diseases of the CNS white matter?

Demyelinating Disease, MS, Leukodystrophies

What is a demyelinating disease?

Degenerative disease of white matter cause loss of myelin sheath of the neural axons. May be acquired or hereditary.

What is multiple sclerosis?

Probably autoimmune triggered by unidentified microbe. Acquired chronic demyelinating disease that affects the myelin sheath of both motor and sensory neurons.

What is Leukodystrophy?

an autosomal recessive demyelinating disease, DNA defect encoding for enzyme producing myelin, Disease of infancy and childhood, uniformly fatal.

What is beriberi?

Lack of thiamine (B1), motor weakness because of peripheral neuropathy and general weakness because of CHF.

What is hepatic encephalopathy?

Brain syndrome of personality changes, confusion, depressed level of consciousness because of accumulated metabolic products, especially ammonia, that cannot be metabolized by the liver. Alcoholics.

what is werkickes encephalopathy?

Cerebellar atrophy (d/t malnutrition) in a patient with chronic alcoholism. Ataxia, tremors, confusion, and paralysis of extra ocular muscles. If untreated leads to Korsakoff.

What is Korsakoff's psychosis?

permanent defect of short- and long term memory that leads to patients having explanations that get nowhere.

What is lead poisoning?

numbness, weakness, seizures

what is Vitamin B12 deficiency?

Demyelination

What is cretinism?

(infantile hypothyroidism) a congenital form of hypothyroidism, severe mental and physical developmental delays.

What are genetic defects?

Phenylketonuria and Wilson Disease

what is Phenylketonuria?

Neuronal storage diseases, toxic accumulation of phenylalanine which causes mental problems and seizures.

What is Wilson Disease (Hepatolenticular degeneration)?

neuronal storage diseases, (hepatilentricular degeneration) inherited disease of copper metabolism characterized by mental instability and parkinson's like motor symptoms.

What is the main problem associated with benign tumors of the brain?

May produce severe debility or death of the confined space and the critical anatomy of the brain. Difficult to remove.

Glioma: tumors of glial cells and are the most common primary brain tumors.

MOST COMMON is ASTROCYTOMA.

Describe the neoplasm of the different types of CNS cells.

-Traumatic Neuroma
-Ganglioneuroma
-Neurofibromas
-Schwannoma
-Glioblastoma

What precent of CNS neoplasms are brain cells?

60%

What precent of CNS neoplasms are cranial nerve and meninges?

20%

What precent of intracranial tumors?

50%

what precent of neoplasms originate in the cranium?

50%

What is a glioma?

tumors of glial cells and are the most common primary brain tumor.

What is a traumatic Neuroma?

ends of separated parts of the neuron are too far separated. The sprouting fibers and scar tissue may accumulate into a nodule.

What are ganglioneuroma?

Benign tumor of nerve cells.

what is Neurofibromas?

Contain both schwann cells and nerve sheath fibroblasts.

What is von Recklinghausen disease?

Multiple neurofibromas

what is a Schwannoma?

tumor of the myelin sheath

What is a glioblastoma?

malignant brain tumor arising from glial cells

what is neuropathies?

any non-neoplastic disease of peripheral nerves.

what is the most common neuropathy?

Diabetes

What is Guillian Barre disease?

autoimmune, anti-myelin antibody. Motor weakness.

What is shingles?

"chicken pox" painful infection of sensory nerves

What is Bell's Palsy?

paralysis of facial muscles (7th cranial (facial) nerve, unknown etiology, viral)

what is trauma disease of the peripheral?

neuromas from sprouting axonal fiber and scar tissue following trauma (mortons neuroma)

Where does blood cell production occur in a fetus? After birth?

In fetus: Liver
After Birth: bone marrow

What do blood cells arise from?

Totipotent stem cell: breaks into myeloid and lymphoid.

what is the process of Hematopoiesis and how are different cells are created?

the lymphoid cell line differs from myeloid cell line. Each derived from a primitive stem cell.

the process by which the body creates new blood cells, starting with specialized cells called hematopoietic stem cells (HSCs) in the bone marrow, which then divide and differentiate into various mature blood cell types like red blood cells, white blood cells, and platelets, through a series of steps involving cell division and specialization depending on the required cell type; essentially, it's the body's way of constantly replenishing its blood supply.

How long does a red blood cell live for?

120 days

How long does a lymphocytes and monocytes live for?

1-2 weeks