What is in the Brain?

Study Notes

Basic Description of the Brain

The brain resembles a small, wrinkled melon, weighing around 1,350 grams (less than 3 pounds).
It has a pinkish-white color and a firm, JELL-O-like consistency.
Composed of approximately 1 trillion cells, including about 900 billion glial cells and 100 billion neurons.
Fully develops by age 25 and primarily relies on glucose for energy.
Wrinkles increase surface area, allowing for more neural connections.

Functions of Glial Cells

Provide structural support for neurons during development and maturation.
Insulate neurons to prevent electrical signal interference.
Release chemicals that influence neuron growth and functionality.
Remove dead neurons and pathogens from the brain environment.
Some types of glia are capable of transmitting electrical impulses; malfunctions can lead to neuron dysfunction and contribute to neurodegenerative diseases.

Neurons

Neurons serve as the basic building blocks of the nervous system, involved in receiving and transmitting electrical signals.
Structure includes:
- Soma (cell body): Egg-shaped, containing DNA, fuels the neuron, and produces essential proteins.
- Dendrites: Branch-like structures that receive signals and expand with communication.
- Axon: Passageway for electrical impulses.
- End bulbs (terminal buttons): Located at the axon's end, sending signals to other neurons.
Neurogenesis refers to the formation of new neurons, occurring during prenatal development and to a limited extent in adults, primarily in the hippocampus and olfactory bulb.
Antioxidants and omega-3 fatty acids may promote neurogenesis, while zinc deficiencies can inhibit it.

Synaptic Pruning

A process where extra neurons and synaptic connections are eliminated to enhance neural efficiency.
Learning strengthens specific neural networks, while others are pruned away over time.

Effects of Exercise on the Brain

Reduces stress and anxiety while combating and preventing depression.
Lowers the risk of dementia and Alzheimer’s disease.
Can increase IQ and enhance mood through promoting new brain cell growth.

Alzheimer's Disease

The most prevalent type of dementia, characterized by cell death in the cerebral cortex, leading to memory and cognitive decline.
Causes brain shrinkage (atrophy) and affects approximately 5.8 million people in the US.
Diagnosis involves a combination of behavioral, neurological, physical, and psychological assessments.
Onset: 10% occur after age 50; 90% after age 65.
Risk factors include stress, age, genetic predisposition, faulty glial cells, and abnormal accumulation of amyloid beta and tau proteins.

Description

This quiz explores the fascinating structure and function of the human brain. Learn about its unique shape, weight, and composition, including the different types of cells. Discover the importance of brain development and its energy requirements.