Limbic System, Hypothalamus, Brain Stem, and Thalamus Overview

This set of flashcards covers key concepts related to the limbic system, hypothalamus, brain stem, and thalamus from the lecture notes, designed to aid in vocabulary retention and comprehension for exam preparation.

Limbic System

A group of structures located on the medial aspects of the cerebral hemispheres and diencephalon involved in emotion and memory.

Amygdaloid body

Structure that recognizes angry or fearful facial expressions, assesses danger, and elicits fear responses.

Fornix

A fiber tract that links regions of the limbic system.

Cingulate gyrus

Part of the limbic system that plays a role in expressing emotions via gestures and resolving mental conflicts.

Hypothalamus

A structure located below the thalamus, responsible for homeostasis and various autonomic functions.

Mammillary bodies

Paired anterior nuclei in the hypothalamus that act as olfactory relay stations.

Infundibulum

The stalk connecting the pituitary gland to the base of the hypothalamus.

Homeostasis

The process through which the body maintains a stable internal environment.

Autonomic nervous system

Part of the peripheral nervous system that controls involuntary bodily functions.

Body temperature regulation

The hypothalamus regulates this by initiating sweating or shivering.

Hunger regulation

The hypothalamus regulates hunger in response to blood nutrient levels or hormones.

Circadian rhythms

Biological cycles that occur on a roughly 24-hour basis, regulated by the suprachiasmatic nucleus.

Endocrine system

The system responsible for hormone secretion, regulated by the hypothalamus.

Reticular Formation

A group of nuclei in the brainstem involved in regulating wakefulness and sleep.

Reticular activating system (RAS)

Part of the reticular formation that sends impulses to the cerebral cortex to maintain consciousness.

Brain Stem

The portion of the brain that connects the cerebrum with the spinal cord, consisting of midbrain, pons, and medulla oblongata.

Cerebral peduncles

Ventral bulges in the midbrain that contain pyramidal motor tracts.

Periaqueductal gray matter

Part of the midbrain that plays a role in pain suppression and the fight-or-flight response.

Cranial nerves

Nerves that emerge directly from the brain and brainstem, including those associated with the brainstem.

Thalamus

Bilateral egg-shaped nuclei that act as relay stations for sensory impulses to the cerebral cortex.

Cortical gray matter

The outer layer of the brain that localizes and interprets sensory inputs and controls voluntary muscle activity.

Basal nuclei (ganglia)

Subcortical motor centers that help regulate skeletal muscle movements.

Epithalamus

The most dorsal part of the diencephalon, containing the pineal gland.

Pineal gland

An endocrine gland in the epithalamus that secretes melatonin, influencing sleep-wake cycles.

Interthalamic adhesion

A connection between the two thalami in the brain.

Ascending input

Sensory information that is transmitted to the cerebral cortex.

Memory processing

The thalamus is involved in the integration and relaying of memory-related information.

Acts as a relay station

The main function of the thalamus is to sort, edit, and relay information to the cortex.

Visceral functions

Functions related to internal organs, regulated by the hypothalamus.

Sleep-wake cycle

Regulated by the suprachiasmatic nucleus and influenced by melatonin.

Emotional imbalance

A possible disorder caused by hypothalamic disturbances.

Homeostatic disturbances

Issues such as obesity or dehydration resulting from hypothalamic dysfunction.