NERVOUS SYSTEM Its function is to control and co-ordinate the parts of the body.

Slides:

Advertisements

Similar presentations

“If I Only Had a Brain” H-15 Answers to homework.

Advertisements

B1- Understanding organisms.

How and why do organisms respond to changes in their environment? Can you list what is required for a coordinated response? What makes up the CNS? Can.

Nervous System.

The Nervous System *.

What is the function of the nervous system? Sensory Input: action of getting information from the surrounding environment. Things are being sent to the.

NERVOUS SYSTEM.

Neurons and the Nervous System

Nervous System.

How Nerve Signals Maintain Homeostasis

Nervous System 06/01/12 pages Know: What are the 3 functions of the nervous system?

An Introduction to the Nervous System

The Nervous System Chapter 36.

How Nerve Signals Maintain Homeostasis

9 How Nerve Signals Maintain Homeostasis

NERVOUS SYSTEM Its function is to control and co-ordinate the parts of the body.

National 5 Biology Course Notes Unit 2 : Multicellular Organisms Part 3 : Control and communication.

THE NERVOUS SYSTEM. The Nervous System Central Nervous System Peripheral Nervous System BrainSpinal cord Cranial Nerves Spinal Nerves Ganglia.

Nervous System. Learning Outcomes Understand the role of the Nervous System Understand what Stimuli, Receptors and Effectors are Understand what the role.

Chapter 13.1 Pages The Nervous System. Introduction The Organization of the Nervous System.

The Nervous System.

Nervous System.  1. Function – Receives and sends out info from and to the outside and inside your body.

Movie: Nervous System (27:00min)

Main Function: This communication system controls and coordinates functions throughout the body and responds to internal and external stimuli. Our nervous.

THE NERVOUS SYSTEM Schaefer Hedgepeth. Divisions of the Nervous System Central Nervous System Peripheral Nervous System Somatic Nervous System Autonomic.

The Nervous System.  The function of the nervous system is to allow the animal to quickly detect, communicate and co- ordinate information about its.

Understand the language – understand the process.

SBI 4U: Metablic Processes

Vocabulary Review The Nervous System. Peripheral nervous system Cranial and spinal nerves outside the central nervous system Central nervous system Consists.

Neuron Structure and Function. Nervous System  Nervous system is composed of specialized cells called neurons.  Neurons have long “arms” called axons.

Nervous System & Neurons

Nervous System & Senses. Neuron A neuron is the basic unit of the Nervous System. Carry messages in the form of electrical impulses.

The Nervous System. Key Concepts Muscle Motor Neuro n Interneuron Skin receptors Sensory Neuron Brain Know the function and divisions of the nervous system.

The Human Body The Nervous System

Chapter 11: Nervous System NS Organization Neurons Reflex Arcs.

-read the Summaries at the back of each section (example pg.414) -read the Summaries in the KEY and do practice questions -you should read your textbook.

The Nervous System Control and coordinate the body parts and processes. It receives sensory stimuli from internal and external environments. It responds.

The Nervous System Chapter 6

Nervous System. NERVOUS SYSTEM Two Parts Central (CNS) Peripheral (PNS)

The Nervous System Control Center for Maintaining Homeostasis.

Unit 3: Chapter 9 How Nerve Signals Maintain Homeostasis Section 9.1 (pages )

Biology 30 The Nervous System Chapter 11 and 12 Intro Animation.

Chapter 15 Nervous & Chemical Control (sec. 1 & 2)

The Nervous System Vocabulary Review.

The Nervous System Miss Charney Northville Central School Miss Charney Northville Central School.

Nervous communication IGCSE Biology: The Human Nervous System and the Eye.

Nervous Control Simplest type of response controlled by the nervous system is a reflex arc. To be able to understand how a reflex arc works, it is first.

The Nervous System 1.Control center for all body activities 2.Responds and adapts to changes that occur both inside and outside the body (Ex: pain, temperature,

Tri-teach The nervous system. Responding to change Our bodies have 2 ways of responding to change: The nervous system for fast, short term responses.

Nervous System (Overview)

 Organisms must be aware of what is happening around them, as this affects their survival chances. The Nervous System  A nervous system allows an organism.

 What organ coordinates most of the activities of the nervous system?  Through what part of the body do most messages reach or leave the brain?  The.

The Nervous System.

Regulation: Nervous System. A World Without Pain Perry Goldberger, 15, can't distinguish between hot and cold and cannot feel pain Four-year-old Roberto.

Our electrochemical controls

An introduction to the Nervous system From:

Nervous System. Function of the nervous system Transmits stimuli to the brain (sound, sight, taste, smell, feel) Processes information (thinks) Responds.

The Nervous System. Functions of the Nervous System 1. Monitors internal and external environment 2. Take in and analyzes information 3. Coordinates voluntary.

 Elaborate communication system that contains more than 100 billion nerve cells in the brain alone  Control the actions of the body  Makes adjustments.

Coordination and Response in Plants and Animals Receptors, Effectors and the Central Nervous System.

Coordination and Response Explain the role of the nervous and hormonal systems in coordinating the activities of the body. Describe the structure and function.

3 kinds of neurons: Sensory, Interneuron, and Motor neurons. Explain what each neuron does:  Sensory neurons --- picks up stimuli from the environment.

Receives information about environment and what happens inside your body Directs how body responds to information Maintains homeostasis.

Chapter 24 Regulation. Why do you respond to changes around you? Your responses are controlled by your nervous and endocrine system. Together these 2.

The Nervous System Nervous Regulation – Allows you to respond to changes (STIMULI) in the environment (MAINTAIN HOMEOSTASIS)

Topic: 6.5 Option A. Nerve Signals Maintain Homeostasis Both the nervous system and the endocrine system control actions of the body and maintain homeostasis.

Neurons and Neurotransmitters. Nervous System –Central nervous system (CNS): Brain Spinal cord –Peripheral nervous system (PNS): Sensory neurons Motor.

The Nervous System (Peripheral Nervous System).  Peripheral nervous System (PNS): all the parts of the nervous system except for the brain & spinal cord.

Lesson Overview Lesson Overview The Peripheral Nervous System Lesson Overview 33.4 The Peripheral Nervous System.

Biology SL Ms. Ragsdale.  Central Nervous System (CNS) – the control center of your brain  Receives all the impulses from your body and coordinates.

Presentation transcript:

NERVOUS SYSTEM Its function is to control and co-ordinate the parts of the body.

CENTRAL NERVOUS SYSTEM(CNS) PERIPHERAL NERVOUS SYSTEM (PNS) BRAIN receives and sends out messages. SPINAL CORD connects the brain to the rest of the body. CRANIAL NERVES carry messages directly to and from the brain. SPINAL NERVES carry messages to and from the spinal cord. Coordinating center for incoming and outgoing information Carry info. between organs such as skin, heart, eyes, ears and the CNS.

Peripheral Nervous System Somatic Nervous System Sensory and motor neurons under conscious control VOLUNTARY e.g. controls skeletal muscles Autonomic Nervous System Motor neurons that function without conscious control INVOLUNTARY e.g. controls heart rate, blood pressure, digestive muscles, breathing

NERVE CELLS (NEURONS) There are two types: 1.Glial cells – non-conducting / important for structural support and Schwann cells make myelin 2.Neurons - Specialized cells that can carry electro-chemical messages called NERVE IMPULSES Sensory neurons Interneurons – link neurons Motor neurons

Direction of impulse ReceptorDendrite Cell body Axon Branches forming synapse These sense and relay info. from the environment to CNS Baroreceptors (detect pressure) Chemoreceptors (detect chemicals) Photoreceptors (detect light) Osmoreceptors Thermoreceptors SENSORY NEURONS

MOTOR NEURONES These carry impulses from the CNS to an EFFECTOR (a muscle or a gland or an organ). Direction of impulse DendritesCell body Axon Nerve endings on a muscle Both sensory and motor neurons are very long (up to 1m in a human). This helps to reduce the synapses (connections) needed.

The importance of myelin Many neurons have axons that are covered in a fatty substance called myelin. This insulates the axons so it stops impulses jumping from one axon into others next to it. The myelin sheath also increases impulse speeds. Direction of impulse Myelin sheath

NERVES NERVE CELLS (FIBRES) NERVE A nerve is a bundle of nerve fibres (cells). Most nerves carry a mixture of sensory and motor fibres.

SYNAPSES Nerve impulses can travel at up to 100m per sec but when they reach the end of a cell they have to cross a gap called a SYNAPSE. IMPULSE Impulse arrives at the end of first neuron. TRANSMITTER chemical is released from vesicles. TRANSMITTER diffuses across the gap When TRANSMITTER reaches second neuron it starts a new impulse.

The synapse The gap between neurones is called a synapse. Messages are sent across this gap using chemical messengers. End of neurone (Axon terminal) Chemical is released by one neurone and detected by the next Impulse travels along axon to the terminal An impulse travels through the neurone

NERVE PATHWAY STIMULUSRECEPTOR SENSORY NEURON C.N.S. (interneurons) MOTOR NEURON EFFECTORRESPONSE

REFLEXES These reactions are:- Fast Automatic Unlearned Do not involve the brain Often designed to protect the body

Examples :- COUGHINGRemoves particles from breathing system PUPIL REFLEX Automatically adjusts the eye to light intensity WITHDRAWAL REFLEX Removes arm or leg from a painful stimulus to prevent damage.

Motor neurone Sensory neurone Effector (Biceps) Receptor in skin Spinal cord REFLEX ARC The path taken by an impulse during a reflex eg Withdrawing hand from a painful stimulus.

Reflex arc Finger touches hot object Receptor in skin detects stimulus Sensory neurone sends impulse to spinal cord Motor neurone picks up impulse from sensory neurone and sends impulse to the effector Effector (muscle) moves hand away from danger Gap between neurones is called synapse

REFLEX ARC IN SPINAL CORD Grey matter White matter Sensory neuron Motor neuron Interneuron Synapse Dorsal root of spinal nerve

SEQUENCE OF EVENTS 1. Skin of hand touches a hot surface. 2. Temperature receptors in the skin start an impulse 3. Impulse travels up the spinal nerve of the arm in a sensory neuron. 4. Impulse passed to relay neurone in spinal cord 5. Impulse travels down the spinal nerve of the arm in a motor neuron. 6. Impulse causes BICEPS muscle to contract bending the arm and pulling the hand away NB Although the brain is informed it does not have time to stop the reaction.

The reflex is fast because:- The impulse does not need to travel through the brain so it only involves two synapses. Synapses delay a reaction because of the time taken for transmitter to diffuse across the gap between neurones.