Presentation on theme: "Coordinates all the body’s activity"— Presentation transcript:
1 Coordinates all the body’s activity The Nervous SystemCoordinates all the body’s activity
2 The Nervous System 1. Two main divisions a. Central Nervous System (CNS) – consists of brain and spinal cordb. Peripheral Nervous System (PNS) – includes nerves extending from brain and spinal cordc. The CNS receives messages from the PNS, interprets them, and then sends out a response.
3 Neurons2. Neurons - nerve cells that transmit messages to and from the spinal cord and braina. Sensory Neurons – carry messages FROM body TO CNSex. Playing games in computer lab. When light switches to green, a sensory neuron transmits a message from your eye to your brain
4 Neurons b. Motor Neurons – carry message TO body FROM CNS ex. Your brain sends a signal through a motor neuron to tell your finger to click the mouse.c. Interneurons – connect neurons
5 3. Structure and Functions of Neurons 1. Dendrites – receive information and transmit impulses toward cell body2. Cell Body – large area which contains cell nucleus or power plant3. Nucleus – command center of the neuron
6 4. Axon – transmit impulses away from cell body and toward axon terminal 5. Axon Terminals – branched structures at the ends of neurons.6. Myelin Sheath – insulating coat which covers the axon. This helps messages relay faster.
11 The Central Nervous System 2. The Cerebruma. largest, most complex part of brainb. right and left sides communicate with each other to coordinate movement. Right controls left side and vice versa.c. left hemisphere is for language, reasoning, and critical, concrete thinkingd. right hemisphere is for abstract thinking
12 The Central Nervous System 3. Four lobes (parts) of the cerebruma. Frontal Lobe –use of languageb. Parietal Lobe – sensory information, including feelings of heat, cold, pain, touchc. Occipital Lobe – Controls sense of sightd. Temporal – sense of hearing and smell
14 The Central Nervous System 4. The Cerebelluma. second largest part of brainb. maintains body’s posture and balancec. coordinates complex muscle movements like serving a volleyball or playing violin
15 The Central Nervous System 5. The Brain Stema. 3 inch long stalk of nerve cells that connect the spinal cord to the rest of the brain
16 The Central Nervous System b. five parts1. Medulla Oblongata – regulates heartbeat, breathing rate2. Pons – controls muscles of eye and face.3. Midbrain – controls pupil size4. Thalamus – relays incoming information from the eyes, ears, and pressure receptors in skin5. Hypothalamus – regulates body temp, appetite, sleep
18 The Peripheral System 1. Broken into two parts a. Autonomic Nervous System – controls involuntary functions such as digestion and heart rate- you cannot control this; it is automatic! (autonomic)b. Somatic Nervous System – voluntary responses that are under your control- feeling and itch on your skin and scratching it
19 The Peripheral System 2. Autonomic Nervous System a. Broken down into two smaller networksb. Sympathetic nervous system – kicks in when you are startled. Messages are sent that increase your heart rate. Also, blood vessels dilate to allow for greater blood flow.- “Fight or flight response”- Example… you are riding in a car and a deer jumpsout in front of you. Think about how you feel. Your body prepares you to make a sudden reaction.
20 The Peripheral Systemc. Parasympathetic nervous system – opposite of sympathetic nervous system- slows heartbeat, relaxes blood vessels, lowers blood pressure
21 Problems of the Nervous System 1. Headaches – caused by muscle tension, eyestrain, sinus infection, dehydration, or food allergies2. Head injuriesa. concussion – a temporary loss of consciousness
22 Problems of the Nervous System 3. Spinal Injuriesa. swelling of spinal cord tissue can result in temporary loss of nerve functionb. if spinal cord is severed, you may become paralyzed.
23 Problems of the Nervous System 4. Meningitis – inflammation of the spinal and cranial meninges caused by a virus or bacteriaa. symptoms include fever, headache, light and sound sensitivity, and neck stiffness.b. can result in death
24 How to care for/prevent these problems: 1. Eat a well-balanced diet, exercise regularly, get lots of sleep!2. Wear protective devices – helmet, seat belt3. Stay away from drugs and alcohol!!!