Pathology Flashcards
What is neuromuscular disease?
Damage at any one of the levels in the passage of a message from a nerve to the final contraction of a muscle.
Impairs normal function.
What are some causes of peripheral neuropathies?
medications (esp. chemotherapy for cancer)
diabetes mellitus (adult onset, likely high blood sugar)
infections (viral or bacterial infections) i.e. shingles, epstein-barr virus, hepatitis C, leprosy, diptheria and human immunodeficiency virus (HIV)
autoimmune diseases i.e. lupus, rheumatoid arthritis
What are some symptoms of peripheral neuropathies?
temporary numbness, tingling, pricking
sensitivity to touch, burning pain especially at night
atrophy, paralysis, organ or gland dysfunction
exhaustion
What is Wallerian degeneration?
damage to nerve axons leading to failure of nerve impulse transmission
if the axon is completely transected, it is unlikely that it can regenerate
What is Charcot Marie Tooth (CMT) disease?
a disease affecting the nerves outside of the CNS resulting in problems with feet, hands, and balance. It is the most common inherited peripheral neuropathy.
Clinical presentation:
- chronic muscle weakness & atrophy in limbs
- sensory loss in feet & hands
- foot & hand deformity
What is Guillain-Barre syndrome?
an autoimmune reaction following a viral illness which affects nerve roots and myelin degeneration
paralysis begins distally and ascends to involve the respiratory muscles requiring ventilation
clinical presentation:
- a tingling or prickly sensation in fingers/toes
- muscle weakness in legs that travels proximally
What is poliomyelitis?
a highly infectious viral disease that invades the nervous system (targets and destroys lower motor neurones)
can cause total paralysis in hours
clinical presentation:
- fever
- fatigue
- headache
- vomiting
- neck stiffness
- limb pain
What is Duchenne & Becker muscular dystrophy?
x-linked (seen in boys)
progressive weakness seen by age 5 with the inability to walk by early 20’s
caused by an abnormality in dystrophin gene that normally maintains sarcolemmal cell membrane integrity
muscle fibres degererate and are replace by fat
Duchenne= full loss of gene Becker= patrial loss of gene
What is myotonic dystrophy (MD)?
a disease that affects the muscles and other body systems
most commonly begins in adulthood
characterized by loss of muscle and weakness
What is the difference between MD 1 & MD 2? (myotonic dystrophy)
MD 1 affects the legs, hands, neck and face (more severe symptoms)
MD 2 affects the neck, shoulders, elbows and hips (more mild symptoms)
What is myasthenia gravis (MG)?
a disease of the neuromuscular junction in which antibodies develop to the acetylcholine receptors
most common MG is ocular myasthenia gravis (OMG) affecting the muscles around the eyes
What are some causes of physiological atrophy?
hormone withdrawal, ageing, lack of exercise
What are some causes of pathological atrophy?
ischaemia (reduced blood flow), endocrine disorders, nerve damage, lack of nutrition
What is hypertrophy?
increase in cell & tissue size
What is hyperplasia?
increase in cell numbers (cell division)
What is atrophy?
decrease in cell size, numbers & tissue size
What is metaplasia?
change in cell differentiation, better equipped for environmental stress
What is dysplasia?
distorted growth pattern, pre-neoplastic, often increased mitoses
What is the difference between labile, stable and permanent cells?
labile: continuous cell proliferation i.e. skin, gut, resp tract
stable: do not normally proliferate but are able to i.e. liver, kidney, smooth muscle
permanent: no capacity to divide i.e. neurons, cardiac muscle
What are some causes of cell injury/cell death?
lack of oxygen & ischaemia, chemicals/drugs toxicity, mitochondrial damage, free radical formation, build-up of intracellular calcium
What is gouty arthritis?
metabolic products like urate crystals form in the joints resulting in pain and loss of function
What is the difference between apoptosis and necrosis?
apoptosis= programmed cell death necrosis= lysis of cell
What are some general signs of inflammation?
heat, reddness, swelling, loss of function
systemic signs: fever, increased leukocyte count, sleepiness, hypotension
What is meningitis?
acute inflammation from a bacterial infection resulting in neutrophils (pus) filling the subarachnoid space, vessels become engorged with blood. This can lead to vessel occlusion and ischaemic damage in the brain
What is laryngitis?
acute inflammation from a viral or bacterial infection resulting in oedema and airway obstruction
What is a macrophage’s role in wound healing?
activated by blood monocytes, macrophages increase in size, ingest and kill microbes, and digest cell debris
macrophages produce pro-fibrotic messenger molecules called cytokines
neutrophils have a similar role but are not as efficient as macrophages and have a shorter life span
What is granulation tissue (in regards to wound healing)?
new connective tissue and blood vessels that form during wound healing
What is fibrosis?
the development of fibrous connective tissue as a reparative response to injury
results from chronic inflammation
What is rickets disease?
also known as osteomalacia
deficiency of vitamin d resulting in softening of bone and failure to replace calcium and phosphorus in the organic matrix of bone
