The (neuro)vascular system as a key brain-body interface Flashcards
How is the connection of the CNS to the wider world usually considered?
In simple terms –> sensory input and motor output
How are the connections between the CNS and the wider world implemented?
By the peripheral nervous system
What are the divisions of the peripheral nervous system?
Sensory (afferent) division + motor (efferent division)
Motor division divides into autonomic and somatic nervous system
Autonomic nervous system divides into sympathetic division and parasympathetic division
What is the function of the autonomic nervous system?
Controls involuntary responses
What is the function of the somatic nervous system?
Controls voluntary movement
What is the function of the sympathetic division?
Mobilises body systems
Fight or flight response
What is the function of the parasympathetic division?
Conserves energy
Rest and digest responses
How else does the brain and body communicate?
The vascular system and the blood brain barrier
What is meant by the hungry brain?
The brain is a highly demanding organ which is very costly to maintain
Brain uses 1.5 pints of blood per minute
Brain is 2% of body mass but demands approx 20% of cardiac output
Limited storage capacity so therefore need an excellent supply chain - each neuron effectively has its own supply capillary
How does the brain manage supply with changing demands?
Neurovascular coupling
== Delivery of nutrients to the brain tissue, removal of waste products
What is the neurovascular unit?
A group of closely related cells and extracellular matrix components that function in the homeostatic haemodynamic response of NVC
Provides the blood-brain barrier
What cells are in the neurovascular unit?
Neurons
Astrocytes
Pericytes
Vascular cells (endothelial cells)
What molecules can pass through the BBB through simple diffusion?
SMALL MOLECULES
Water
Oxygen
Carbon dioxide
Ammonia (NH3)
Ethanol
LIPOPHILIC SUBSTANCES
Steroid hormones
What molecules require special transport proteins to travel across the BBB?
Glucose (GLUT-1)
Amino acids
What is a hormone?
A signalling molecule that is transported between organs of the body by the vascular system and coordinate different functions in your body
What are hormones essential for?
The regulation of development, physiology and behaviour