chapter 6 - MA certificate

Brain

Composed of the cerebrum, cerebellum, and the brain stem. The ___ receives information from and relays info to all the organs and body systems. It consumes 20% of the total body oxygen.

Cerebrum

Highest + largest component of the brain.

Divides into two hemispheres by a longitudinal fissure. Verbal functions (reading, writing, speaking, and calculating) are the domain of the left hemisphere, while artistic or creative activities (drawing and creating rhythm) is the domain of the right hemisphere.

Corpus Callosum

The element that joints the two hemispheres together is the ___ ___. It is composed of white matter (the largest in the brain) and has high myelin content for faster neural transmission.

Cerebellum

The cerebellum is located at a spot just inferior to the cerebrum’s occipital lobe.

Balance control, equilibrium, posture, and muscle coordination.

Brain stem

Regulates vital functions such as respiration, HR, BP, and consciousness and serves as a relay center. It works as a relay station receiving inputs from the body to the brain + sensory and motor pathways.

Spinal Cord

Extends from the inferior part of the brain stem to approx. the level of the first or second lumbar vertebra (L1-L2) in adults. Its main function is to carry messages between the spinal nerves and the brain.

Spinal nerves exit the ___ ___ through openings (intervertebral foramina) between the vertebrae.

Spinal nerves supply nerves to different organs or areas in the body.

The ___ ___ caries messages between the spinal nerves and the brain.

Meninges

The brain is surrounded by three membranes called ___, which protect the brain and spinal cord.

Dura mater

A tough membrane and the outer layer of the meninges.

dura mater

Below the ___ ___ is the subdural space, and above it is the epidural space.

Arachnoid

The middle membrane that looks like a spider web.

Subarachnoid space

Present below the arachnoid membrane that allows CSF to circulate. CSF contains glucose, proteins, and chloride.

Pia Mater

The innermost, thinnest layer of the meninges. It is highly vascular and supports the brain’s blood vessels.

Cranial Nerves

Begin from the brain’s underside portion.

Connect to the sensory organs and muscles of the face and neck to transmit information back and forth.

Spinal Nerves

Use spaces between the vertebrae as pathways to enter and leave the spinal canal.

Transmit to and from the brain using the pathway through the spinal cord.

Consist of sensory (stimuli transmission from skin and organs to CNS) and motor fibers (stimuli transmission from CNS to skeletal muscles)

Autonomic nerves regulate important body functions such as breathing and digestion.

Autonomic Nervous System (ANS)

Carries info to and from the brain through the spinal cord.

Manages homeostatic processes (body temp control, etc.)

Sympathetic Nervous System

Promotes geared responses i.e., “fight or flight”

Increases the HR

Increases blood glucose levels and BP

Decreases peristalsis

Allows more oxygen to enter the body quickly by widening the bronchioles.

Parasympathetic Nervous System

Promotes rest or reduction effects

Decreases the HR

Increases digestive system function

Narrows the bronchioles.

Cerebrovascular disease (CVD)

A type of CNS disorder; The blood vessels that supply blood to the brain are affected. It involves disorders of the blood vessels supplying the brain, such as blockage or rupture, which can impair blood flow.

Transient Ischemic Attack (TIA)

A type of CVD in which there is a temporary reduction in blood supply to a part of the brain without permanent damage. Also known as a mini stroke. The symptoms include numbness in the face, arm, or leg or on one side of the body. Patients may also experience difficulty while communicating or understanding others, diplopia, difficulty in walking, and vertigo.

Cerebrovascular accident (CVA)

Caused by a rupture or occlusion of a blood vessel in the brain. Symptoms include slurred speech, unexplained confusion, sudden and severe headaches, and difficulty swallowing. Can also cause paralysis on one side of the body.

Migraine

Characterized by sudden, recurrent episodes of headache associated symptoms including nausea or vomiting, increased sensitivity to light and sound, throbbing pain on one side of the head.

Underlying cause of this condition is unknown, researchers believe it is connected to a combination of trigeminal nerve issues along with brain chemical imbalances (neurotransmitter serotonin)

Patients report the following as triggers leading to the migraine: hormonal imbalance, caffeine, alcohol, and monosodium glutamate (MSG), increased stress levels, weather changes.

Dementia

A chronic disorder of the mental processes caused by brain disease.

Symptoms include progressive memory loss, disorientation about person, time, and place, neglect of personal hygiene, nutrition, and safety, personality changes, and inability to follow simple directions.

Alzheimer’s Disease

A common disorder categorized under dementia and mainly affects the older population. Symptoms include slow and progressive loss of recent memory'; inability to recognize people, places, and events; and disorientation.

Epilepsy

Characterized by recurrent abnormal electrical impulses in the brain called seizures.

Seizure

A temporary disturbance in the brain’s electrical activity.

Partial seizures

Divides into simple and complex seizures, and result from abnormal electrical activity in one part of the brain.

Generalized seizures

Types of seizures that involve more parts of the brain.

Simple partial seizures

Do not cause loss of consciousness, but may cause the patient to repeat certain actions, such as shaking a leg or arm, resembling a twitch or tremor.

Complex Partial Seizures

Cause staring and repeated movements, like swallowing or lip smacking.

Absence epilepsy

A form of epilepsy in which the patient stares with the eyes open, while being conscious.

Encephalitis

The inflammation of the brain most commonly caused by viral infections. The patient may experience stiff neck, headache, muscle aches, malaise, and flu in the mild stage. Severe conditions bring about symptoms including fever, delirium, seizures, and coma.

Meningitis

The inflammation of the meninges that may be due to bacterial, viral, or fungal infections. Symptoms include headache, flu-like symptoms, nuchal rigidity, and seizures.

Concussion

A mild brain injury. It is associated with loss of consciousness that can last from seconds up to several minutes. This may be followed by disorientation.

Contusion

Caused by a more severe brain injury. Symptoms include headache, nausea, vomiting, vision disturbances, and sensitivity to light.

Closed injury

There is an internal brain injury without fracture to the skull.

Open brain injury

Occurs when the skull is fractured or displaced; an object may penetrate into the skull, resulting in the fractured skull.

Shaken baby syndrome

Refers to a severe head injury in infants.

Spinal Cord Injury

Refers to any damage to the spinal cord. Traumatic accidents may cut across the spinal cord, which would then cause CNS stimulation activity below the injury to stop, paralyzing areas below the injury section. May lead to paralysis.

Multiple Sclerosis (MS)

Autoimmune disease affecting the myelin sheath, resulting in inflammation and deterioration leaving nerve fibers exposed and scattering the NS message as it travels down the axon.

Causes damage to nerve cell bodies and axons in the brain, spinal cord, and optic nerve.

Symptoms include numbness, paresthesia, diplopia, ataxia, and bladder control problems.

Parkinson’s Disease

A chronic, progressive, and debilitating condition, affects more women and accounts for tens of thousands of new cases annually.

A deficiency of the neurotransmitter dopamine in the brain, caused by a combination of genetic and environmental factors, is believed to cause this disorder.

Symptoms include tremors of the extremities, jaw, and face; slow movements; impaired coordination; and a mask-like expression.

Comprehensive medical history and neurologic examination help to diagnose this condition.

Brain Tumors

Signs + Symptoms depend on location and type of the tumor. Initial symptoms include headaches, dizziness, and diplopia.

May cause increased intracranial pressure.

History, neurologic examination, and imaging studies help to identify.

Amyotrophic Lateral Sclerosis (ALS)

Also known as Lou Gehrig’s disease

Cause not known; results in destruction of motor neurons that control voluntary muscles.

Symptoms include small, local, involuntary muscle contraction in the forearm and hands.

Bell’s Palsy

Temporary facial paralysis.

Occurs due to inflammation and edema of cranial nerve VII (caused by a viral infection, such as herpes simplex)

Symptoms include facial twitching, eyelid drooping, and excessive tearing of the affected eye.

Peripheral Neuropathy

Idiopathic (unknown cause) and a condition of peripheral nerve dysfunction.

May be caused by conditions such as diabetes mellitus, human immunodeficiency virus (HIV) infection, and nutritional deficiencies.

Symptoms include muscular weakness, pain, and sensory disturbances such as burning, numbness, and tingling.

Biceps reflex

to assess the flexion of the elbow.

triceps reflex

to assess the extension of the arm.

patellar reflex

to assess the extension of the leg.

Achilles reflex

to assess the flexion of the foot.

Arteriography

Helps in the detailed viewing of vertebral and carotid arteries, cerebral arterial circulation.

Highlights presence in leaking vessels, aneurysms, and occludes blood vessels.

Performed through injection of a contract medium into the artery through a catheter.

Computed Tomography Scan

Creates visuals of multiple, serial, radiographic sections; differentiates between bones and soft tissue.

Uses X-rays to visualize the multiple transverse sections of the test structure.

Electroencephalography

Records the brain wave activity to diagnose seizure types and determine effectiveness of seizure-related pharmaceutical treatment.

Performed by attaching electrodes to the scalp to record the brain’s electrical activity.

Lumbar Puncture

A lumbar puncture measures CSF fluid pressure and helps detect increase intracranial pressure, infection, or bleeding.

Checks for infection of inflammation of CNS or to detect increased intracranial pressure or bleeding.

Invasive process; requires insertion of a special needle into the subarachnoid space to collect the CSF for analysis.

Magnetic Resonance Imaging (MRI)

Aids in viewing of multiple, serial, and radiographic sections; produces detailed images of brain, spinal cord, and surrounding tissue.

Uses magnetic fields and radio waves to produce detailed images of the brain and spinal cord.

Positron Emission Tomography (PET)

Identifies the areas of increased metabolic activity, vascular abnormalities, and space-occupying lesions.

Involves injecting a radioactive isotope and scanning the brain.

X-Ray Studies

Identifies bone fractures of the skull; limited use for evaluating brain tissue.

Uses X-ray film to create the images of the bone structure.