5.4 Structure & Function of the Human Brain

Gray Matter

The cortex of the human brain that is composed of the neurons that form the thin outer covering

Cerebral Cortex

Provides us with our distinctly human qualities, allowing us to look to the plan, to reason, and to create

Left Hemisphere, Right Hemisphere, & Lobes

Parts of the Cerebral Cortex

Left Hemisphere

Hemisphere responsible for verbal and other cognitive processes

Right Hemisphere

Hemisphere responsible for perceiving the world around us and creating images

Prefrontal Cortex

Located in the very front of the cortex that regulates the amygdala and is responsible for higher cognitive functions

White Matter

Made up of large tracts of myelinated (sheathed) fibers that connect cell bodies in the cortex with those in the spinal cord and in other areas of the brain

Ventricles

Cavities filled with cerebrospinal fluid deep within the brain

Cerebrospinal Fluid

Circulates through the brain through these ventricles, which are connected with the spinal cord

Brain Stem

Lower part of the brain essential for autonomic functions

Hindbrain

Contains the medulla, pons, & cerebellum that regulates many autonomic activities

Cerebellum

Controls motor coordination abnormalities associated with autism

Thalamus & Hypothalamus

Involved in regulating behavior, emotions, and hormones

Limbic System

Located around the edge of the center of the brain

Hippocampus, Hypothalamus, & Amygdala

Subcortical Structures

Hippocampus

Associated with memory

Hypothalamus

Regulates metabolism, temperature, perspiration, blood pressure, sleeping, and appetite

Amygdala

An important area for attention to emotionally salient stimuli

Basal Ganglia

Base of the forebrain, related to Parkinson’s

Pruning

When a number of synaptic connections begin to be eliminated

Brain Networks

Clusters of brain regions that are connected in that activation in these regions is reliably correlated when people perform certain types of tasks or are at rest

Somatic NS

Controls muscles

Autonomic NS

Innervates the endocrine glands, the heart, and the smooth muscles that are found in the walls of blood vessels, stomach, intestines, kidneys, and other organs

Sympathetic NS

In charge of the fight or flight response

Parasympathetic NS

Helps to calm down the body

Endocrine System

Composed of glands that produce hormones which are released into the bloodstream

Pituitary Gland

Master gland that regulates vital body functions—such as growth, metabolism, stress response, and reproduction

Thyroid Gland

Gland that controls metabolism and growth

Parathyroid

Gland that controls the levels of calcium

Adrenal

Gland that accounts for metabolism, blood pressure, sex development, stress

Pineal

Gland that regulates your circadian rhythm and produces melatonin

Pancreas

Produces insulin

Testes

Produces testosterone

Ovaries

Produces estrogen, progesterone, & testosterone

HPA Axis

Central to the body’s response to stress and figures prominently in many of the disorders

Hypothalamus releases Corticotropin-Releasing Factor (CRF) which then communicates to the pituitary gland that releases the adrenocorticotropic hormone which travels to the adrenal cortex

How does the HPA Axis work?

Cortisol

Often referred to as the “stress hormone”

Temperament

Refers to a child’s reactivity and characteristic ways of self-regulation

Permissive Hypothesis

Hypothesis that states that when serotonin levels are low, other neurotransmitters are permitted to range more widely, become dysregulated,