neurology Flashcards
purpose
Senses changes in internal and external environments, processes them and responds to maintain homeostasis.
Coordinates all voluntary and involuntary actions of the body.
2 types of cells
Neurons
Neuroglia
neurons
Cells that transmit impulses.
Identified by direction impulse travels:
Sensory (afferent) neurons transmit stimuli to the brain and spinal cord.
Motor (efferent) neurons transmit impulses from brain or spinal cord to muscles & glands.
Most nerves contain both types of fibres and are called mixed neurons.
cell body
Contains nucleus and organelles of the cell.
dendrites
Branched projections that receive impulses from other neurons and carry impulses to cell body.
axons
Long, single projections that carry impulses from cell body to muscles, glands, and other dendrites.
myelin sheath
Covering on many axons that acts as an electrical insulator.
Accelerates impulse transmission along axon.
Insulates axons to reduce chance of an impulse stimulating adjacent nerves.
schwann cell
Covering for axons formed by neuroglial cells.
Wraps tightly around axon to form the neurilemma, or neurolemma.
Space between Schwann cells is called the Node of Ranvier.
Space helps with nerve impulse conduction.
synapse
Small space found between the axon terminal of one neuron and the dendrite of another.
Neurotransmitters released from an axon terminal travel across synapse to receptor sites on the dendrite of the next neuron.
neuroglia
Means “nerve glue”.
Support neurons and bind them to other tissues.
Play a role if the nervous system is injured and immune response.
Forms blood-brain barrier.
Helps develop myelin.
two main divisions
Central Nervous System (CNS).
Peripheral Nervous System (PNS).
central nervous system
Brain and spinal cord.
Enclosed by protective membranes called meninges.
Surrounded by Cerebrospinal Fluid (CSF)to protect.
brain- Main control centre for all body functions.
spinal cord- Main pathway for information transmission between brain and body.
cerebrum
Largest portion.
Functions: Sensory perception, interpretation, language, voluntary movement, emotional aspects of behaviour, memory.
cerebellum
Second largest portion.
Functions: Movement, equilibrium, balance.
diencephalon
Composed of thalamus and hypothalamus.
Functions: Thalamus receives sensory info to send to rest of brain. Hypothalamus integrates autonomic nerve impulse, body temperature, endocrine functions.
brain stem
Composed: Midbrain, medulla oblongata, and pons.
Functions: Attaches to spinal cord; pathway of message transmission from brain to spinal cord; pathway of cranial nerves; origin of the beginning of life.
spina bifida
Types: Myelomeningocele or cleft spine; spina bifida occulta; meningoceles
Birth defect - backbone and/or spinal canal do not close before birth
Newborn has a sac sticking out of the mid to lower back that is opaque when shining a light behind it.
Loss of bladder or bowel control
Partial or complete lack of sensation and/or paralysis of the legs
Weakness of the hips, legs, or feet of a newborn
Abnormal feet or legs, such as clubfoot
Build up of fluid inside the skull (hydrocephalus)
Dimpling of the sacral area
multiple sclerosis
Inflammatory disease that damages the myelin sheaths around the axons of the brain and spinal cord
Leads to demyelination and scarring as well as a broad spectrum of signs and symptoms
cerebral palsy
Disorder of movement, muscle tone or posture that is caused by injury or abnormal development in the immature brain, most often before birth
Cerebral palsy is caused by an abnormality or disruption in brain development, usually before a child is born
spinal cord injury
Damage to any part of the spinal cord or nerves at the end of the spinal canal
Often causes permanent changes in strength, sensation and other body functions below the site of the injury
Ability to control limbs after spinal cord injury depends on two factors:
Place of the injury along your spinal cord
Severity of injury to the spinal cord
The lowest normal part of your spinal cord is referred to as the neurological level of your injury
The severity of the injury is often called “the completeness“ (quadriplegia or paraplegia)
cerebrovascular accident
Sudden death of some brain cells due to lack of oxygen when the blood flow to the brain is impaired by blockage or rupture of an artery to the brain Aka: Stroke Causes: Thrombus/Embolism Aneurysm Head trauma/bleeding in the brain Atherosclerosis
epilepsy
Disorder that results from the surges in electrical signals inside the brain, causing recurring seizures Causes: Genetic Head trauma Medical disorders Dementia Diseases such as meningitis, AIDS and viral encephalitis can cause epilepsy Prenatal injury Developmental disorders
sleep apnea
Potentially serious sleep disorder in which breathing repeatedly stops and starts
You may have sleep apnea if you snore loudly and you feel tired even after a full night’s sleep.
Causes:
Obstruction of the airway
Muscles of the throat relaxing too much
parkinsons
Progressive disorder of the nervous system that affects your movement Develops gradually Causes: Idiopathic Possible gene mutations Possible environmental triggers
tumours
There are 120 different types of brain tumours and many different types of tumours of the nervous tissue
Includes: nervous tissue, brain tissue, glandular tissue and glial tissue
Both benign and malignant
See textbook for definitions
encephalitis
Inflammation of the brain Cause: Viral infections are the most common cause of the condition Can also be caused by: Bacteria, fungi, parasites Tx: Antiviral medications Analgesic and antipyretic medications Bed rest Supportive therapy Follow up therapy (PT, OT, Speech, etc.)
shingles
Viral infection that causes a painful rash
Rash most often appears as a single stripe of blisters that wraps around either the left or the right side of your torso
Causes:
Varicella-zoster virus — same virus that causes chickenpox
After you’ve had chickenpox, the virus lies inactive in nerve tissue near your spinal cord and brain and the virus may reactivate as shingles years later
concussion
A traumatic brain injury that alters the way your brain functions
Effects are usually temporary, but can include problems with headache, concentration, memory, judgment, balance and coordination
Causes:
Blow to the head
Blow or shaking of any upper body part
contrecoup injury
A head injury, occurring on the side opposite the area that was impacted
thrombosis/embolism
Thrombosis = Blood clots
Embolism = Blood clots that move from the original location
Causes a stroke or TIA if the clot is in the brain
coma
A state of prolonged unconsciousness that can be caused by a variety of problems
Causes:
Traumatic head injury
Stroke
Brain tumor
Drug or alcohol intoxication
An underlying illness, such as diabetes or an infection.
meningitis
Inflammation of the membranes (meninges) surrounding your brain and spinal cord
Causes:
Mostly viral infection, but can also be bacterial or fungal
Tx:
Bed rest – may heal itself
Treat underlying cause
cerebral contusion
Form of traumatic brain injury
A bruise of the brain tissue
Associated with multiple microhemorrhages
Small blood vessel leaks into brain tissue
Occurs in 20–30% of severe head injuries
hemiplegia
paralysis of half the body
quadriplegia
paralysis from neck down
paraplegia
paralysis from waist down
insomnia
Disorder that can make it hard to fall asleep, hard to stay asleep, or both
You usually awaken feeling unrefreshed
tremor
Essential tremor is a nervous system disorder (neurological disorder) that causes a rhythmic shaking
Most often in your hands
