Topic 4 Circulation: Brain Structure and Blood Brain Barrier

Study Notes

Circulation of the Brain

The brain receives 15-20% of the total blood supply despite being only 2% of the total body weight.
The brain requires a steady flow of blood to deliver oxygen, glucose, vitamins, amino acids, minerals, and other nutrients.
Cerebral blood circulation also removes waste products, such as CO2, toxins, and metabolic waste.

Importance of Blood Flow to the Brain

Blood flow to the brain is critical, as it keeps the brain hydrated (more than 70% water) and maintains a constant temperature and pH.
Brain cells suffer and can lead to brain damage or death when circulation is restricted.

Cerebral Circulation

Cerebral circulation is the movement of blood through a network of cerebral arteries and veins supplying the brain.
The rate of cerebral blood flow in an adult human is typically 750 ml per minute, which is about 15% of cardiac output.

Blood Supply to the Brain

The brain receives blood from two sources: the internal carotid arteries and the vertebral arteries.
The brain stem controls circulation.

Cerebrospinal Fluid (CSF)

CSF plays a crucial role in cushioning and protecting the brain from major shocks.
CSF also plays a role in the homeostasis and metabolism of the CNS.

Symptoms of Poor Blood Flow to the Brain

Poor focus and concentration
Dizziness
Frequent headaches
Mental fatigue
Memory loss
Cold nose, feet, or hands
Needing to wear socks to bed
Cramping in feet and hands
Unhealthy nails (fungus or white nail beds)

Causes and Risk Factors for Impaired Blood Flow to the Brain

Sedentary lifestyle
Underlying health conditions

Improving Blood Flow to the Brain

Engage in regular physical exercise
Eat the right foods
Practice mind-body techniques like meditation
Partake in mentally stimulating activities
Aerobic exercise is particularly effective in increasing blood flow to the hippocampus, a region crucial to memory.

Blood-Brain Barrier (BBB)

The BBB is a unique feature of the microvasculature of the CNS that controls the passage of substances from the blood into the CNS.
The BBB is formed by microvascular endothelial cells lining the cerebral capillaries.
The BBB restricts movement of substances between endothelial cells and uses specific transport proteins to determine which substances can cross the barrier.

Description

Explore the circulation of the brain structure, understand the blood brain barrier, and learn about physical dysfunctions caused by circulation disturbances. Dive into the essential topic of how the brain receives its disproportionate amounts of energy and nutrients from the body's blood supply.