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Aim: How does the brain communicate with other parts of the body?. Do Now: Why is the spinal cord so important? Homework: Castle Learning Assignment #8 quarter 2. Nervous System. Nervous system. The nervous system is composed of two types of cells
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Aim: How does the brain communicate with other parts of the body? Do Now: Why is the spinal cord so important? Homework: Castle Learning Assignment #8 quarter 2
Nervous system • The nervous system is composed of two types of cells • Glial cells Non-conducting cells that serve as support cells in the Nervous System and help to protect Neurons • Neurons cells that transmit nerve signals. • A human has about 100 billion neurons inside the brain.
Parts of the nerve cells • The dendrites pick up messages from other cells and send them into the cell body.
Nerve Cells • The cell body contains all of the organelles of the cell (mitochondria, nucleus, etc….) • Is also called the cyton • Axon takes the messages away from the cell body and to the next cell. (almost like electrical wires) • Synapse is the gap or space between the axon and the dendrites of another cell. • Impulses are sent.
Nerve Cells • Wrapped around the axon of the nerve cell are these myelin sheaths. • The myelin sheath wraps around to help insulate and speed up nerve impulses. • The myelin sheath is made up of these cells call Schwann cells. • There are also gaps between clusters of Schwann cells called nodes.
Aim: How do the peripheral and the central nervous systems differ? Do Now: Complete Question Sheet Homework: Text Book Pg 563 – 566 Questions 1-5
The Human Nervous System • How many parts make up the nervous system? • There are two main parts • The central nervous system (CNS) which includes the spinal cord and brain. • The peripheral nervous system (PNS) which includes all of the nerves that connect to muscles and sensory organs.
Types of Neurons • Sensory neurons – these have long dendrites and short axons and carry messages from the sensory receptors to the central nervous system • Motor Neurons – Have long axons and short dendrites, transmits messages from the central nervous system to muscles or glands. • Interneurons – found only in the central nervous system and connect neuron to neuron.
Questions: • Name the two types of cells that make up the nervous system. • What are the parts of the neuron called? • State the different types of neurons present within the body. • What are the two main parts of the nervous system? • What is the myelin sheath made up of?
How many different divisions are the motor neurons broken into? • There are two different divisions • The somatic nervous system which controls voluntary movement. Ex- walking, running, etc • The autonomic nervous system which regulates involuntary muscle movements. Ex- heart beating, blood pressure, muscles of the digestive system.
Areas of the brain • Forebrain o Developed into Cerebrum & diencephalons (thalymus & hypothalymus) • Midbrain o Developed into Midbrain region of brainstem • Hindbrain o Developed into Medulla oblongata (part of brainstem)
Aim: why is a reflex arc so important to our bodies ability to protect itself? Do Now: State the three different types of neurons and their function. Homework: Text Book Pg 567 – 571 Questions 1-5
Brain • Major control center of the body. • Has 3 main parts. • Cerebrum: the largest part is the center for thinking, memory, emotions, and all voluntary activities. • Cerebellum: is responsible for coordination of muscles and is the center for balance. • Medulla: the area that controls respiration, heartbeat, and other involuntary activites. • Also known as the “brainstem”
Behaviors • There are two types of behaviors • Involuntary behavior: this is a movement that occurs without conscious control, it can be both learned or inborn. • Voluntary Behavior: requires thinking these are learned behaviors. Examples picking up a book, building a model airplane.
Reflex Arc • SRSIMER remember this. • Stimulus • Receptor • Sensory Neuron • Interneuron • Motor Neuron • Effector • Response
Reflex Arc • Brain is not used during this. • Goes from sensory neurons to interneuron's. • Signals do not go up the spine to the brain. • This speeds up reaction time.
List of Neurotransmitters • ACETYLCHOLINE CHLOINE • A-ENDORPHIN • DOPAMINE • GABA • CLYCINE • HISTAMINE • HISTIDINE • KRYPTOPYRROLE • L-DOPA • L-GLUTAMIC ACID • MALVIN • NITRIC OXIDE • NOREPINEPHRINE • OCTOPAMINE • ORTHOMETHYL SEROTONIN • PHENYLETHYLAMINE • PYRIDOXINE • SEROTONIN • TAURINE • TYRAMINE • TRYPTOPHAN Do not copy these down in your notes
Aim: How do disorders in the nervous system interrupt homeostasis? Do Now: why do nerve cells use neurotransmitters? Homework: Nervous System Worksheet
Sodium Potassium Pump • A nerve impulse is sent down the axon. • This is transmitted by sodium and potassium ions that are lined up on either side of the axon. • When a signal comes the sodium and potassium switch sending the charge down the axon.
Nerve Transmissions • When a nerve signal has come to the end of the nerve but must move along to another nerve the signal must jump. • The two nerves are not connected but they are very close together. • The space in between the two nerves is called the synapse.
Nervous System Disorders • Multiple Sclerosis (MS) • Deterioration of the myelin sheath is a sign of MS. This will cause the nerve impulses to slow.
Nervous system Disorders • Cerebral Palsy • Congenital disorder of the muscle and speech center of the brain. • The person loses motor function • Happens from damage to the brain of the fetus or child during or after birth