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40 Cards in this Set
- Front
- Back
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What does the Nervous system do?
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Receives stimuli.
Processes information. Produces a response. All in 1/10 of a second. (relies on speed) |
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What does the nervous system consist of?
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1- Central Nervous system.
2- Peripheral Nervous system. |
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What is the Central Nervous System? (CNS)
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The CNS is the brain and the spinal cord.
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What is the Peripheral Nervous System?(PNS)
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The PNS is part of the nervous system that lies outside of the CNS.
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What does the PNS consist of? What are the functions?
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1) Sensory (input)
Carries information to the brain and spinal cord. 2) Motor (output) carries information from the brain and spinal cord to either: a) Somatic Division. which controls skeletal muscles. b) Autonomic Division, controls smooth muscles, cardiac muscles, and glands. The autonomis division consists of Sympathetic and Parasympathetic and they oppose each other. |
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What are neurons?
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Neurons are cells that communicate. They generate and conduct electrical impulses, also called potentials from one body part to another.
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How many types of neurons are there? What are they?
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There are 3 types: 1- Sensory 2- Interneurons 3- Motor neurons.
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What are the functions Sensory neurons?
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Sensroy neurons of the PNS are specialized to respond to stimulus like light and pressure. This info is transmitted to the CNS in the form of electrical impulses. Sensory neurons send input to the CNS.
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What are the functions of Interneurons?
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Interneurons within the CNS(brain & spinal cord) transmit impulses between brain and spinal cord. Interneurons receive input from sensory neurons.
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What are the functions of Motor neurons?
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Motor neurons of the PNS transmit impulses away from the CNS. They carry the electrical impulses to all the tissues and organs of the body.
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What are the parts of the neuron?
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1- cell body
2= One or more Dentrites. 3= Axons. |
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What are the functions of neuron parts?
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1) The cell body contains the nucleus and other organelles.
2)The dentrites are slender extensions in all three types of neurons, receive information of incoming impulses from other neurons. Interneurons and motor neurons dentrites are short and extend in many directions from the cell body. Sensory neurons dentrites connect directly to an axon. 3)Axons are long passage ways impulses are sent through, at the end of the axon there are terminals called Axon terminals and Axon bulbs. |
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What are Neuroglial cells?
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20% of cells in human nervous system are neurons.
80% are supporting cells called neouroglial cells. They protect and provide physical support to neurons. |
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What are the types of Neuroglial cells?
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Schwann cells.
In the PNS, Schwann cells produce Myelin sheaths(fatlike insulating substance) that is wrapped around axons leaving spaces inbetween called Nodes Of Ranvier. |
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What are the functions of Schwann cells?
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Schwann cells can regenerate damaged or severed cells.
Impulse travels down myelinated neurons at about 5mi/hr but the because of the gaps (Nodes of Ranvier) the speed increases to about 250 mi/hr in leaping patterns. |
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What happens to the Myelin Sheaths within the CNS that are destroyed?
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The myelin sheaths in the CNS called Oligodedrocytes once destroyed can not regenerate. This is why spinal cord injuries and CNS disorders result in permanent change or function loss.
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What is a nerve impulse?
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How neurons initiate and conduct an impulse within the axon.
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What goes on within the axon?
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The axon consists of plasma membrane and cytoplasm. Cells are passed through selectively permeable membrane with active transport. Protein Sodium-potassium pumps actively pump 3N+ (sodium)out and 2K+(potassium)in.(keeping cell volume). This creates a polarity of more positive on the outside then the inside.
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How does an impulse enter an Axon?
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At the moment of an impulse (graded potential)it enters through the membrane of the axon through a Sodium-potassium pump, 3 sodiums flow in and 2 potassiums rush out.
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What is Depolarization?
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When Sodium flows into the Axon.
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How is information transferred from neuron to target? pain to brain?
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Through chemical means, as impulse is traveling down an axon (travel potential) and reaches the end, channels will open up and release calcium in the axon bulb this triggers neourotransmitters to move toward membrane via exocytosis, through the space between the neurons(synapse) and toward protein channels triggering sodium-potassium pumps in the next neuron.
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How many neurotransmitters exist in our bodies?
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At least 50.
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What is the space in between the neuron cells called?
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Synapse.
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What types of neurotransmitters are there?
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1) Excitatory neurotransmitters impulse is continued and postsynaptic cell is depolarized.
2) Inhibitory neurotransmitters stop impulse and postsynaptic cell hyperpolarize. |
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In which ways are impulses sent?
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Action potential(impulse) of many neurons is received by one neuron it is called Convergence. When the action potential of one neuron is sent to many other neurons it is called Divergence.
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What are poisons?
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Poisons are neurotoxins.
Honeybees and Scorpians black Sodium channels (stopping electrical impulse) Poison Arrow frogs stop Potassium channels from opening. Tarantula blocks Calcium channels, stopping electrical impulse. |
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What are Psychoactive Drugs?
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Any substance that affects states of consciousness, emotions or behaviors. Affects neurotansmitters keeping them longer in the synapse.
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What is Dopamine?
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A drug that makes people feel good because neurotransmitters are in the synapse not allowing them to return. When this happens neurotransmitters are altered and very difficult to go back to natural state.
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What is the function of the PNS?
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It relays information between tissues and CNS.
Nerves are cable like bundles of neuron axons tightly wrapped in connective tissue. Facial nerves are cranial nerves. |
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What is the function of the Spinal cord in the Central Nervous System?
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It serves as a superhighway for impulses between the body and the brain (thickness of our thumb). The spinal cord is responsible for simple responses (i.e reflexes, first response to contact like stepping on a nail) automatic, not sent to brain until after.
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What is the brain?
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The brain is in the CNS. It is the master control center, the center of homeostasis, senses interpretation, emotion, intellect.
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What does the brain consist of?
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The skull is a bone that protects the brain.
Meninges is a cushion made up of 3 layers of connective tissue(specialized blood vessels) Cerebral Fluid, cushions, lays between meninges layers and brings oxygen and nutrients to brain. Blood-brain barrier. Consist of tight capillary blood vessels making it difficult for bacterias/virus to get through. |
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What are the 3 main parts of the brain?
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1) Hindbrain.
2) Forebrain 3) Midbrain. |
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What does the Hindbrain consist of?
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The Hindbrain
1)Pons. Just above and partly surrounds the medulla oblongata, connects to the spinal cord. It conducts data to and from other brain centers. Aids Medulla oblongata in regulating respiration. 2) Cerebellum. Coordinates body movement, learns and remembers motor response. 3) Medulla Oblongata. Controls automatic functions of internal organs. |
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What does the Forebrain consist of?
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The forebrain is the Cerebrum, Thalamus, and Hypothalamus.
1) Cerebrum is the most highly developed part of the brain. Controls memory, learning, speech. Controls emotions, behavior, concious thought. 2) Hypothalamus small region at the base of the forebrain, regulates homeostasis (body temperature, blood pressure, thirst, hunger, sex drive). 3) Thalamus, (secretary of the cerebrum), just above the hypothalamus, takes info and sorts it for the cerebrum, works for the cerebrum. |
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What is the barrier that divides the brain?
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The Corpus Callosum bridges the two cerebral hemispheres.
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What is the function of the Midbrain?
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Relays visual and auditory inputs, coordinates movements of skeletal muscles.
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