00:00 / 00:00
Generalized anxiety disorder
Social anxiety disorder
Major depressive disorder
Major depressive disorder with seasonal pattern
Premenstrual dysphoric disorder
Neuroleptic malignant syndrome
Lewy body dementia
Attention deficit hyperactivity disorder
Autism spectrum disorder
Disruptive, impulse control, and conduct disorders
Fetal alcohol syndrome
Body dysmorphic disorder
Body focused repetitive disorders
Cluster A personality disorders
Cluster B personality disorders
Cluster C personality disorders
Female sexual interest and arousal disorder
Genito-pelvic pain and penetration disorder
Male hypoactive sexual desire disorder
Somatic symptom disorder
Alcohol use disorder
Physical and sexual abuse
Post-traumatic stress disorder
Amnesia, dissociative disorders and delirium: Pathology review
Anxiety disorders, phobias and stress-related disorders: Pathology Review
Childhood and early-onset psychological disorders: Pathology review
Dementia: Pathology review
Developmental and learning disorders: Pathology review
Drug misuse, intoxication and withdrawal: Alcohol: Pathology review
Drug misuse, intoxication and withdrawal: Hallucinogens: Pathology review
Drug misuse, intoxication and withdrawal: Other depressants: Pathology review
Drug misuse, intoxication and withdrawal: Stimulants: Pathology review
Eating disorders: Pathology review
Malingering, factitious disorders and somatoform disorders: Pathology review
Mood disorders: Pathology review
Personality disorders: Pathology review
Psychiatric emergencies: Pathology review
Psychological sleep disorders: Pathology review
Schizophrenia spectrum disorders: Pathology review
Trauma- and stress-related disorders: Pathology review
0 / 18 complete
0 / 5 complete
Jim's story: The dementia guide
5 A's of Alzheimer's Disease
Alzheimer's Disease Assessment (Early Symptoms)
Alzheimer's Disease Assessment (Late Symptoms)
Alzheimer's Disease Interventions
Alzheimer Disease & Dementia
Alzheimer disease p. 566
amalyoidosis in p. 214
Down syndome and p. 61
drug therapy for p. 239, 566
labs/findings p. 730, 736
neurotransmitters for p. 508
ventriculomegaly with p. 538
for Alzheimer disease p. 566
Alzheimer disease drugs p. 566
Dementia isn’t technically a disease, but more of a way to describe a set of symptoms like poor memory and difficulty learning new information, which can make it really hard to function independently.
Usually dementia’s caused by some sort of damage to the cells in the brain, which can be caused by a variety of diseases. Alzheimer’s disease, now referred to as Alzheimer disease, is the most common cause of dementia.
Alzheimer disease is considered a neurodegenerative disease, meaning it causes the degeneration, or loss, of neurons in the brain, particularly in the cortex. This, as you might expect, leads to the symptoms characteristic of dementia.
Although the cause of Alzheimer disease isn’t completely understood, two major players that are often cited in its progression are plaques and tangles.
Alright, so here we’ve got the cell membrane of a neuron in the brain. In the membrane, you’ve got this molecule called amyloid precursor protein, or APP, one end of this guy’s in the cell, and the other end’s outside the cell. It’s thought that this guy helps the neuron grow and repair itself after an injury.
Since APP’s a protein, just like other proteins, it gets used and over time it gets broken down and recycled.
Normally, it gets chopped up by an enzyme called alpha secretase and it’s buddy, gamma secretase.
This chopped up peptide is soluble and goes away, and everything’s all good.
If another enzyme, beta secretase, teams up with gamma secretase instead, then we’ve got a problem, and this leftover fragment isn’t soluble, and creates a monomer called amyloid beta.
These monomers tend to be chemically “sticky”, and bond together just outside the neurons, and form what are called beta-amyloid plaques—these clumps of lots of these monomers.
These plaques can potentially get between the neurons, which can get in the way of neuron-to-neuron signaling.
If the brain cells can’t signal and relay information, then brain functions like memory can be seriously impaired.
It’s also thought that these plaques can start up an immune response and cause inflammation which might damage surrounding neurons.
Amyloid plaque can also deposit around blood vessels in the brain, called amyloid angiopathy, which weakens the walls of the blood vessels and increases the risk of hemorrhage, or rupture and blood loss.
Here’s an image of amyloid plaque on histology, these clumps are buildups of beta amyloid, and this is happening outside the cell.
Latest on COVID-19
Nurse Practitioner (NP)
Physician Assistant (PA)
Create custom content
Raise the Line Podcast
Copyright © 2024 Elsevier, its licensors, and contributors. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
Cookies are used by this site.
Terms and Conditions
USMLE® is a joint program of the Federation of State Medical Boards (FSMB) and the National Board of Medical Examiners (NBME). COMLEX-USA® is a registered trademark of The National Board of Osteopathic Medical Examiners, Inc. NCLEX-RN® is a registered trademark of the National Council of State Boards of Nursing, Inc. Test names and other trademarks are the property of the respective trademark holders. None of the trademark holders are endorsed by nor affiliated with Osmosis or this website.