week 13 and workshop 6 Flashcards
liquefactive necrosis
disease explaination
- Liquefactive necrosis is a form of tissue death where cells are digested by enzymes, turning the affected tissue into a viscous liquid mass.
- This type of necrosis is most commonly seen in the brain due to ischemic injury (such as a stroke), where a lack of blood flow leads to cell death. In the brain, cells are rich in enzymes and lack a strong supporting matrix, which is why liquefactive necrosis occurs.
- Infections (like bacterial abscesses) can also lead to liquefactive necrosis, where neutrophils and enzymes digest tissue.
- this necrosis can also be seen in liver and lungs n other severe infections
-stroke symtoms and cognitive impairment - no cure - thrombolysis
Histological Differences:
Normal Cortex (Right Side):
The brain cortex shows normal, well-defined neuronal cells and glial cells in a uniform, structured arrangement.
There is clear cortical organization, with intact tissue and no evidence of cellular damage or destruction.
Liquefactive Necrosis (Left Side):
The area shows disorganized and disrupted tissue architecture.
The affected tissue has undergone liquefaction, meaning it has lost its normal cellular and structural integrity.
There are cystic spaces filled with cellular debris, where cells have died and been broken down into a semi-liquid state.
Inflammation and macrophages (which engulf dead tissue) may also be present.
berry aneurysms - in brain
types of aneurysms
Aneurysm Effects
motor
* sensory
* perceptual
* cognitive
* affective
Relates to location of injury - part of brain = dif function
- Describe the utility of cerebral haemodynamics
- Cerebral blood flow (CBF) is crucial for delivering oxygen and nutrients to brain tissue.
- Normal CBF is 45-55ml/100g brain tissue per minute.
- Autoregulation helps maintain consistent CBF within a wide range of mean arterial pressure (MAP).
- It prevents ischemia or hyperperfusion, which can cause brain damage
what is cva?
A CVA, or stroke, occurs when there is a disruption of blood flow to part of the brain, causing tissue damage.
Types of CVA:
Ischaemic (80-85%): Caused by thrombotic or embolic occlusion of cerebral arteries.
Haemorrhagic (15-20%): Caused by ruptured blood vessels, often associated with hypertension.
Pathogenesis of cva
Ischaemic: Thrombosis or embolism leads to infarction.
Haemorrhagic: Blood vessel rupture causes intracerebral or subarachnoid haemorrhage, increasing intracranial pressure (ICP).
Manifestations of cva
Manifestations include sudden weakness, loss of speech, facial drooping, or severe headache (for haemorrhagic stroke)
Types of Cerebrovascular Accident:
Ischaemic:
Thrombotic: Blockage forms within the brain’s arteries.
Embolic: Clots form elsewhere (e.g., heart) and travel to the brain.
Haemorrhagic:
Intracerebral haemorrhage: Bleeding within the brain tissue.
Subarachnoid haemorrhage: Bleeding in the subarachnoid space, often due to an aneurysm
Types of Peripheral Nerve Injury:
Neuropraxia: A mild injury where the nerve is compressed but not severed.
Axonotmesis: The axon is damaged, but the surrounding connective tissue is intact.
Neurotmesis: A complete severance of the nerve, the most severe type
Responses During Nerve Repair
Axonal Degeneration: After injury, the distal segment of the axon degenerates.
Schwann Cell Response: Schwann cells help by clearing debris and guiding regeneration.
Nerve Regeneration: Axons can regrow, especially if the myelin sheath and endoneurium remain intact
Neurodegenerative Diseases?
Alzheimer’s Disease:
Characterized by amyloid plaques and neurofibrillary tangles.
Symptoms include memory loss, cognitive decline, and personality changes.
Parkinson’s Disease:
Degeneration of dopamine-producing neurons in the substantia nigra.
Symptoms include tremors, rigidity, and bradykinesia (slow movement).
Huntington’s Disease:
An autosomal dominant disorder leading to motor dysfunction and cognitive decline, typically presenting in mid-adulthood
Crohn’s Disease. Histological Features: Transmural inflammation: Unlike ulcerative colitis, Crohn’s disease involves inflammation through all layers of the bowel wall.
Granulomas: Non-caseating granulomas are often seen in biopsy samples of Crohn’s patients.
Cobblestone appearance: The mucosal surface becomes uneven due to deep ulcerations and inflammation.
Fissures and fistulas: Result from deep inflammation through the entire wall thickness.
- neoplastic disease, specifically involving a benign or malignant tumor of the epithelial tissue, possibly adenocarcinoma or adenoma 2. adenocarcinoma (if malignant) or adenoma (if benign) of the gastrointestinal tract. The villous appearance suggests a tumor arising from the epithelium of the GI tract, possibly in the colon or stomach.
- Proliferation of glandular structures: These suggest an epithelial origin for the tumor.
Villous or papillary growth pattern: These structures are typical in adenomas or adenocarcinomas, indicating abnormal growth.
Disrupted normal architecture: Loss of normal epithelial structure suggests a neoplastic process.
Lack of a clear demarcation may indicate invasive growth, characteristic of adenocarcinoma. 4. There is a lack of normal glandular structures or crypts in the mucosa, which is indicative of an abnormal proliferation of cells, consistent with a neoplastic process.
The basement membrane may also be compromised or missing, which could indicate invasive carcinoma if the tissue shows signs of invasion beyond the mucosal layer.
what is shown by the red circle?
The red circle highlights glandular hyperplasia of the mucus-secreting glands in the bronchi. This is a characteristic feature of Chronic Bronchitis.
Hyperplasia of mucus glands and increased goblet cells contribute to excess mucus production, one of the hallmark features of chronic bronchitis.
This glandular enlargement and over-secretion of mucus obstructs airways, leading to difficulty breathing.
Diagnosis: Chronic Bronchitis (COPD)
Pathology of Chronic Bronchitis:
Histological Features:
Hyperplasia of mucus-secreting glands in the bronchi (as seen in the circled area).
Increased goblet cells in the respiratory epithelium.
Chronic inflammation of the airways leading to bronchial wall thickening.
Loss of ciliated pseudostratified epithelium in severe cases, leading to impaired mucociliary clearance.
Tuberculosis (TB). The chest X-ray shows cavitary lesions, which are characteristic of pulmonary TB.
The CT scan shows areas of lung destruction (yellow circles), likely representing cavities where the TB bacteria have caused lung necrosis.
The histological image shows a granulomatous reaction with central necrosis surrounded by epithelioid cells, which is typical for TB (caseating granulomas).
In the CT scan, what are the yellow circles indicating?
The yellow circles in the CT scan likely indicate cavitary lesions.
These are areas of lung tissue that have been destroyed by the infection, forming open spaces or cavities.
Cavitation is a hallmark of reactivation TB, where large necrotic areas develop within the lung tissue. disease = tuberculosis.
organ? disease?
lung, tuberculosis. 1. Structure of the Tissue:
Lungs: The presence of alveolar spaces or bronchioles is a strong indicator of lung tissue.
- Type of Cells:
Certain cell types are specific to organs:
Respiratory epithelium (ciliated, pseudostratified) and alveolar structures are found in the lungs.
In this slide, you can see granulomatous inflammation, which is a typical reaction in tuberculosis and often involves the lungs. TB tends to affect the lungs due to airborne transmission but can also affect other organs.
