Human Nervous System Bombick 7 th Grade Science

Outline of Presentation A. Nerve Cell Biology 1. Anatomy 2. Physiology B. Parts of Nervous System 1. Brain 2. Spinal Cord 3. Peripheral Nerves C. Nervous System Physiology 1. Brain Physiology 2. Autonomic System D. Human Psychology E. Pharmaceuticals and Psychotropic agents

Nerve Cell Biology

Nerve Cell Physiology Nerve impulse (think of it as a wave) travels down the axon Nerve impulse at a synapse releases a chemical Chemical crosses the synapse and starts another impulse on another nerve cell Large number of drugs and biochemicals interact with this physiological mechanism

Nervous System Anatomy Nervous system can be divided into two major parts—central and peripheral nervous system Central nervous system is comprised of the brain and spinal cord Peripheral nervous system is comprised of nerves that come off the brain (cranial) or spinal cord

Brain Anatomy Brain contains many folds and convolutions to increase surface area Brain can be separated into three principle regions—forebrain, cerebellum, and brain stem

Brain Functions-Brain Stem Brain stem is comprised of medulla, pons, and midbrain The medulla is the center for respiration, cardiovascular, and digestive functions The pons has inhibitory control centers for respiration and interacts with the cerebellum The midbrain is involved with the regulation of walking and posture; and of reflexes for head and eye movements

Brain Functions-Cerebellum Cerebellum is located behind the brain stem Cerebellum is involved in movement coordination Involved in the vestibular (balance) apparatus

Brain Functions-Forebrain Forebrain is comprised of two principle organized regions The forebrain controls body temperature, blood sugar, hunger and satiation, and sexual behavior The forebrain also controls sensory signals and relays them to other parts of the brain The forebrain is also involved in motor control

Frontal Lobe-Specific Regions Frontal lobe is involved in learning, planning, speech, other psychological functions, and some sensory and motor functions Parietal lobe is involved in some sensory functions (e.g., skin senses); important in certain cognitive and intellectual processes Occipital lobe is involved in visual functions Temporal lobe is involved in hearing functions and associated speech centers; important involvement in memory

Important Note about Brain Function Even though many functions can be localized to specific regions of the brain, there are many connections via fiber pathways throughout the brain resulting in the brain working as a whole. This is true for the “global functions” of the brain such as learning, memory, and consciousness.

Autonomic Nervous System The autonomic nervous system and the endocrine (hormone) system control the body’s internal organs. It innervates smooth muscle, cardiac muscle, and glands, controlling the circulation of blood, the activity of the gastrointestinal tract, body temperature, and a number of other body functions. Most of this control is not conscious.

Autonomic Nervous System (cont.) The autonomic nervous system is divided into two parts, the sympathetic and parasympathetic nervous systems, whose actions are mostly antagonistic. Many organs are supplied by nerves from each division, but some are not. The sympathetic nervous system is activated in times of crisis (fight or flight) while the parasympathetic nervous system operates in ordinary times.

Autonomic Nervous System (cont.) Autonomic nervous system also stimulates the secretions of the adrenal gland The principle secretion of the adrenal gland is epinephrine (adrenalin) Epinephrine further effects other parts of organ systems in the autonomic nervous system response (fight or flight)

Sympathetic Parasympathetic

Psychopharmacotherapy Antipsychotics (Neuroleptics)-Gradually reduce psychotic symptoms such as hallucinations, delusions, paranoia, disordered thinking, and incoherence. Examples include Haldol, Mellaril, Thorazine, and Clozapine Antidepressants (Thymoleptics)- Designed to relieve symptoms of depression. Examples include Tofranil, Elavil, Prozac, Anafranil, and Nardil

Psychopharmacotherapy (cont.) Antianxiety Drugs (Anxiolytics)- Commonly called tranquilizers, these mood-altering substances are calming, reduce anxiety and stress, and lower excitability. They are the mose widely prescribed of all legal drugs. Examples include Librium, Valium, Xanax, BuSpar, Equanil, Miltown, and Tranxene. Antimania Drugs (Lithium)-If taken regulary, lithium carbonate can be effective in preventing both the depression and mania associated with bipolar disorder. Examples include Lithium carbonate and Eskalith.