* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download 9d. Know the functions of the nervous system and the role of
Action potential wikipedia , lookup
Psychoneuroimmunology wikipedia , lookup
Premovement neuronal activity wikipedia , lookup
Patch clamp wikipedia , lookup
Neural coding wikipedia , lookup
Central pattern generator wikipedia , lookup
Signal transduction wikipedia , lookup
Caridoid escape reaction wikipedia , lookup
Resting potential wikipedia , lookup
Clinical neurochemistry wikipedia , lookup
Endocannabinoid system wikipedia , lookup
Feature detection (nervous system) wikipedia , lookup
Neural engineering wikipedia , lookup
Development of the nervous system wikipedia , lookup
Nonsynaptic plasticity wikipedia , lookup
Electrophysiology wikipedia , lookup
Circumventricular organs wikipedia , lookup
Evoked potential wikipedia , lookup
End-plate potential wikipedia , lookup
Neuromuscular junction wikipedia , lookup
Microneurography wikipedia , lookup
Single-unit recording wikipedia , lookup
Neurotransmitter wikipedia , lookup
Synaptogenesis wikipedia , lookup
Synaptic gating wikipedia , lookup
Molecular neuroscience wikipedia , lookup
Chemical synapse wikipedia , lookup
Neuropsychopharmacology wikipedia , lookup
Biological neuron model wikipedia , lookup
Neuroregeneration wikipedia , lookup
Nervous system network models wikipedia , lookup
9d. Know the functions of the nervous system and the role of neurons in transmitting electrochemical impulses. 9e. Know the roles of sensory neurons, interneurons, and motor neurons in sensation, thought and response. You are such a Neuron! • Neurons: Basic Units of the Nervous System: – __________________: conducts impulses throughout the NS • Made up of dendrites, a cell body, axon • ____________________: branchlike cytoplasmic extension of a neuron – Transports impulses toward the cell • ___________________: a single cytoplasmic extension of a neuron – Carries impulses away from a nerve cell Neuron Neurons Neuron Background Info • 3 types of neurons: • __________________: carry impulses from the body to the spinal cord and brain • _______________________: found w/in the brain and spinal cord. – They process incoming impulses and pass response impulses on to motor neurons • ___________________: carry response impulses away from the brain and spinal cord to a muscle or gland. The Spinal Cord • The Spinal Cord • The spinal cord is the main communications link between the brain and the rest of the body. • Certain information, including some kinds of reflexes, are processed directly in the spinal cord. • A __________________ is a quick, automatic response to a stimulus. The Peripheral Nervous System • The Peripheral Nervous System • The peripheral nervous system is all of the nerves and associated cells that are not part of the brain and the spinal cord. • The peripheral nervous system includes cranial nerves, spinal nerves, and ganglia. • Ganglia are collections of nerve cell bodies. Central Nervous System Peripheral Nervous System The Peripheral Nervous System – What are the two divisions of the peripheral nervous system? • The sensory division of the peripheral nervous system transmits ________________ from sense organs to the central nervous system. • The motor division transmits impulses from the central nervous system to the ________________ or __________________. The Peripheral Nervous System • The motor division is divided into the somatic nervous system and the autonomic nervous system. – The Somatic Nervous System • The somatic nervous system regulates activities that are under conscious control, such as the movement of skeletal muscles. • Some somatic nerves • A ______________ _________ includes a sensory receptor, sensory neuron, motor neuron, and effector that are involved in a quick response to a stimulus. Sensory neuron Motor neuron Interneuron Spinal cord • Reflex Arc The peripheral nervous system transmits impulses from sense organs to the central nervous system and back to muscles or glands. When you step on a tack, sensory receptors stimulate a sensory neuron, which relays the signal to an interneuron within the spinal cord. The signal is then sent to a motor neuron, which in turn stimulates a muscle in your leg to lift your leg. Effector (responding muscle) Sensory receptors The Peripheral Nervous System – The Autonomic Nervous System • The autonomic nervous system regulates ___________________ activities. • The autonomic nervous system is subdivided into two parts: – _______________________ nervous system – ______________________________ nervous system The Peripheral Nervous System • The sympathetic and parasympathetic nervous systems have opposite effects on the same organ system. • These opposing effects help maintain _________________________. The Nerve Impulse – The Resting Neuron • When resting, the outside of the neuron has a net _________________ charge. • The inside of the neuron has a net ______________________ charge. • The cell membrane is electrically charged because there is a difference in electrical charge between its outer and inner surfaces. The Nerve Impulse • The sodium-potassium pump in the nerve cell membrane pumps sodium (_____) ions out of the cell and potassium (____) ions into the cell by means of active transport. • As a result, the inside of the cell contains more K+ ions and fewer Na+ ions than the outside. • Sodium-Potassium Pump The Nerve Impulse • More K+ ions leak across the membrane than Na+ ions. This produces a negative charge on the inside and a positive charge on the outside. • The electrical charge across the cell membrane of a neuron at rest is known as the __________________ ________________. The Nerve Impulse • How is a nerve impulse transmitted? – The Moving Impulse • An impulse begins when a neuron is stimulated by another neuron or by the _______________________. The Nerve Impulse • At the leading edge of the impulse, gates in the ________________ channels open allowing positively charged Na+ ions to flow inside the cell membrane. The Nerve Impulse • The inside of the membrane temporarily becomes more ________________ than the outside, reversing the resting potential. The Nerve Impulse • This reversal of charges is called a nerve impulse, or an _______________ ______________. The Nerve Impulse • As the action potential passes, gates in the __________________ channels open, allowing K+ ions to flow out restoring the negative potential inside the axon. The Nerve Impulse • The impulse continues to move along the __________________. • An impulse at any point of the membrane causes an impulse at the next point along the membrane. The Nerve Impulse – Threshold • A stimulus must be of adequate strength to cause a neuron to transmit an impulse. • The minimum level of a stimulus that is required to activate a neuron is called the ___________________. • A stimulus that is stronger than the threshold produces an impulse. • A stimulus that is weaker than the threshold produces no impulse. The Synapse • The Synapse • At the end of the neuron, the impulse reaches an axon terminal. Usually the neuron makes contact with another cell at this site. • The neuron may pass the impulse along to the second cell. • The location at which a neuron can transfer an impulse to another cell is called a _______________________. The Synapse • A Synapse The Synapse • The synaptic cleft separates the axon terminal from the ____________ of the adjacent cell. Synaptic cleft The Synapse Vesicle • Terminals contain vesicles filled with neurotransmitters. • ________________ are chemicals used by a neuron to transmit an impulse across a synapse to another cell. Neurotransmitter The Synapse • As an impulse reaches a terminal, vesicles send neurotransmitters into the synaptic cleft. • These _____________ across the cleft and attach to membrane receptors on the next cell. Receptor The Synapse • Sodium ions then rush across the membrane, stimulating the next cell. • If the stimulation exceeds the cell’s threshold, a new impulse begins. • Moments after binding to receptors, neurotransmitters are released from the cell surface. • The neurotransmitters may then be broken down by enzymes, or taken up and recycled by the axon terminal. Summary The __________________ ________________ controls and coordinates functions throughout the body and responds to internal and external stimuli. Neurons transmit electrochemical impulses throughout the body. Sensory neurons carry impulses from the sense organs to the spinal cord. Motor neurons carry impulses from the brain and spinal cord to muscles and glands. ___________________ connect sensory and motor neurons and carry impulses between them.