Intro to The Brain

LIMBIC SYSTEM

The Limbic System is the area of the brain that regulates emotion and memory. It directly connects the lower and higher brain functions. It influences emotions, the visceral responses to those emotions, motivation, mood, and sensations of pain and pleasure. The Limbic System is comprised of the following parts.

LIMBIC System

Thalamus

Hypothalamus

Cingulate gyrus

Amygdala

Hippocampus

Basal Ganglia

LIMBIC System - THALAMUS

Thalamus means “inner room” in Greek, as it sits deep in the brain at the top of the brainstem.

The thalamus is called the gateway to the cerebral cortex, as nearly all sensory inputs pass through it to the higher levels of the brain.

LIMBIC System - HYPOTHALAMUS

The hypothalamus sits under the thalamus at the top of the brainstem. Although the hypothalamus is small, it controls many critical bodily functions: Controls autonomic nervous system Center for emotional response and behavior Regulates body temperature Regulates food intake Regulates water balance and thirst Controls sleep-wake cycles Controls endocrine system

The hypothalamus is shaded blue. The pituitary gland extends from the hypothalamus.

LIMBIC System - CINGULATE GYRUS

The Cingulate (to surround) Gyrus (fold), is part of the cerebrum gray matter surrounding and directly connected to the parts of the inner Limbic System. The Cingulate Gyrus serves as a conduit of messages to and from the inner Limbic System.

LIMBIC System - AMYGDALA

The Amygdala is important for making associations across stimulus modalities (a certain fragrance often elicits an associated visual image).

It appears to be responsible for the influence of emotional states on sensory inputs. This produces a spectrum of sensory perceptions from apparently identical stimuli (ex. the sound of one's own motorcycle is never perceived as noise). Thought to be responsible for face recognition.

LIMBIC System - HIPPOCAMPUS

The Hippocampus is very important in the transition of information from short to long term memory,   Since the Hippocampus is also part of the Temporal Lobe, damage to that portion of the brain can result in a loss of memory.

LIMBIC System - BASAL GANGLIA

The Basal Ganglia play an important role in planning and coordinating motor movements and posture. Complex neural connections link the Basal Ganglia with the Cerebral Cortex.

The major effect of the Basal Ganglia is to inhibit unwanted muscular activity and disorders of the Basal Ganglia result in exaggerated, uncontrolled movements.