Presentation on theme: "The Function of the Nervous System"— Presentation transcript:
1 The Function of the Nervous System Receives informationTransmits the informationSorts and interprets the incoming informationDetermines a responseTransmits the responseActivates the response.
2 Neuron Structure A. Parts of a Neuron: 1. Dendrites – short branches of a neuron that receives stimuli and conduct impulses to the cell body.2. Cell Body – the center of metabolic activity in a neuron, it is where the nucleus and much of the cytoplasm are located.3. Axon – the long fiber that carries impulses away from the cell body.DendritesSynapseAxonCell Body
3 Neuron Structure, cont.4. Synapse- is a small space between the axon of one neuron and the dendrites of an adjacent neuron.In order for an impulse to be carried on, the synapse must be crossed.Chemicals called neurotransmitters are released by the ends of the axons and are received by the dendrites to carry on the impulse.If the synapse is blocked in any way, the nerve impulse cannot be conducted.DendritesSynapseAxonCell Body
4 Types of NeuronsSensory Neurons – carry impulses from outside and inside the body to the brain and spinal cord.Motor Neurons – carry response impulses from the brain and spinal cord to muscles or glands.Interneurons - connect sensory neurons and motor neurons and carry impulses between them. They are concentrated in the brain and spinal cord.
5 2 divisions: Sensory (From sense organs to Brain) & Motor Divisions (From CNS to muscles or glands) Somatic Nervous SystemAutonomic Nervous SystemSpinal CordBrainMedulla oblongataReflex ArcBrainstemHypothalamusThalamus
6 CENTRAL NERVOUS SYSTEM Consists of the brain and spinal cord.It is the control center.It relays messages, processes information, compares and analyzes the information, and coordinates the body’s activities.
7 The BrainCerebruma. Cerebrum – Divided into two halves called hemispheres. Controls conscious activities, intelligence, memory, language, skeletal muscle movements, and senses.b. Cerebellum – Controls balance, posture, and coordination of muscle movements.Cerebellum
8 The Brain, cont.c. Medulla Oblongata – Controls involuntary functions such as breathing, blood pressure, heart rate, swallowing, and coughing.d. Thalamus – Passes information to proper region of cerebrum for further processing.e. Hypothalamus – Controls center for hunger, thirst, fatigue, anger, and body temperature.ThalamusHypothalamusPonsMedulla Oblongata
9 The Brain, cont.f. Pituitary Gland—the master control gland; the gland that triggers all other glands.Pituitary Gland
10 Spinal CordRelays information to and from the brain.
11 PERIPHERAL NERVOUS SYSTEM * consists of all nerves running to and coming from the brain and spinal cord.* makes contact with the body’s environment.* consists of all the nerves and associated cells that are not part of the brain and spinal cord.There are two parts of the peripheral nervous system: the autonomic nervous system and the somatic nervous system.
12 2 divisions: Sensory (From sense organs to Brain) & Motor Divisions (From CNS to muscles or glands) Somatic Nervous SystemAutonomic Nervous SystemSpinal CordBrainMedulla oblongataReflex ArcBrainstemHypothalamusThalamus
13 Somatic Nervous System regulates activities under conscious control such as movement of skeletal muscles.Reflexes—Receptors in the skin stimulate the sensory neurons to carry impulses to the spinal cord. Before the information is relayed to the brain, a group of neurons in the spinal cord called interneurons automatically activates motor neurons, causing the muscle to contract.Examples: Step on a tackTouch a hot objectReact to a loud noise
14 A “reflex arc” is the route followed by nerve impulses to produce an involuntary response to a stimuli (a reflex).
15 Autonomic Nervous System Regulates activities that are automatic.Carries impulses from the central nervous system (CNS) to the internal organs and is involuntary.
16 Sensory Divisiontransmits impulses from sense organs – such as the ears and taste buds – the CNS.
17 Motor Divisiontransmits impulses from the CNS to the muscles or glands.
18 What do all these pictures have in common? They are all controlled by hormones!
19 The Endocrine SystemFunction: Controls all of the metabolic activities of body structures; includes all of the glands in the body that secrete chemical messengers called hormones which travel in the blood stream to target tissues where they alter the metabolism of the target tissue.
20 The Endocrine SystemComparison to Nervous System: The endocrine system is slower and uses chemical messengers called hormones sent throughout the blood stream.The nervous system is faster than the endocrine system and operates by use of electrical impulses and neurotransmitters.
21 The Endocrine System Comparison to Nervous System: The hypothalamus and the pituitary glands are the major areas where the nervous system and endocrine system interact.The hypothalamus controls the secretions of the pituitary gland. The pituitary gland secretes hormones that affect other glands in the body. The level of hormones secreted by those glands signal the hypothalamus. By monitoring these signals, the hypothalamus maintains the correct level of hormones.
22 NAMELOCATIONHORMONESFUNCTIONSPituitaryUnder the hypothalamus at the base of the brain1. TSH – thyroid stimulating hormone2. GH – growth hormone3. FSH/LH- Reproduction Hormones4. ADH – antidiuretic hormoneRegulates thyroidStimulates growth of bonesRegulate reproduction cycleHelps kidneys reabsorb waterThyroidBase of neck1. Thyroxine1. Regulates metabolic rateAdrenalTop of the kidneys1. Adrenalin1. Regulates normal body functions, example:Increase sodium and potassium levels in bloodIncrease rate of metabolism of carbohydrates, fats and proteinsIncrease blood pressureIncrease blood sugar levels“fight or flight” responsePancreasBehind the stomachInsulinGlucagon1. 2. Regulates the release and storage of blood sugarsOvariesLower abdomen (see Fig. 42-3)EstrogenProgesterone1. Estrogen – female secondary sexual characteristics2. Progesterone – prepares the uterus for an embryoTestesLower abdomen1. Testosterone and other androgens1. Sperm production and male secondary sexual characteristics