Ch 2 Vascular Flashcards
What percentage of total cardiac output does the brain receive?
20% of total CO
What are the five pairs of arteries supplying the brain?
- Rostral cerebral
- Middle cerebral
- Caudal cerebral
- Rostral cerebellar
- Caudal cerebellar
How do the arterial supplies differ between dogs/humans and sheep/cats?
Dogs and humans have internal carotid artery and basilar artery supplying ventral arterial circle, while sheep and cats have maxillary artery supplying arterial circle.
What is the primary function of the blood-brain barrier (BBB)?
Limit CNS exposure to pathogens/toxins
What are the components of the blood-brain barrier?
- Continuous type endothelial cells with tight junctions
- Basement membrane made by endothelial cells and pericytes
- Foot processes by astrocytes
What is vasogenic edema?
Increased vascular permeability due to breakdown of tight junctions, leading to excess fluid in the CNS
What causes cytotoxic edema?
Disruption of Na/K pumps in endothelial and glial cells, leading to intracellular swelling
Fill in the blank: Ischemia is defined as _______.
decreased blood flow to a level incompatible with normal function
What is the first cell type affected by lack of oxygen during ischemia?
Neurons
What is the typical presentation of vascular lesions?
- Any age
- Peracute/acute onset
- Focal
- Nonprogressive
- Improvement with time
What are potential causes of ischemic brain infarct?
- Vascular obstruction (thrombosis, embolism)
- Vasculitis
- Atherosclerosis and arteriosclerosis
What are the types of infarcts mentioned?
- Territorial infarct
- Lacunar infarct
- Watershed infarct
What is the acute appearance of an ischemic infarct?
Pale, discrete area with acidophilic neurons amongst vacuolated parenchyma
What is the difference between acute and chronic ischemic encephalopathy?
Acute has few necrotic neurons, while chronic presents with global infarctions
What is feline ischemic encephalopathy associated with?
Migration of cuterebra larvae
What is hypertensive encephalopathy associated with?
- Systemic hypertension
- Renal failure
- Hyperthyroidism
- Left ventricular hypertrophy
What is the primary gross finding in hypertensive encephalopathy?
Cerebral edema
True or False: The spinal cord is more sensitive to ischemic injury than the brain.
False
What are the histopathological findings of fibrocartilaginous embolism?
- Tissue vacuolation
- Loss and cavitation
- Inflammatory response (neutrophils, edema, acute hemorrhage)
What is the role of astrocytes in the blood-brain barrier?
Provide foot processes that contribute to the barrier structure
Fill in the blank: Acidophilic neuronal necrosis is characterized by _______.
irreversible neuronal damage due to lack of O2
