| question | answer |
|---|
| Nervous system- | the system of nerves in an animal including the brain, spinal cord, nerves, and ganglia. |
| What is the main purpose of the nervous system? | Coordinate the bodily functions of animals and to aid the animals in interacting with the environment. |
| Neural coordination occurs in all but… | the simplest of animals |
| What coordinates movement in cnidarians (like jellyfish and hydra)? | A nerve net |
| What is the Nervous system in annelids and arthropods composed of? | A ventral nerve cord with segmental ganglia, a brain and well-developed sensory receptors |
| In some arthropods like cockroaches, where is the brain located? | It is located throughout the body consisting of several ganglia. |
| Nervous system in flatworms consists of… | widely separated ventral nerve cords |
| Who has the most complex nervous systems of all invertabrates? | Chephalopods like squid with highly developed brains and very large nerve cells or neurons |
| Dendrite- | branched extension of nerve cell that conducts impulses toward cell body |
| Axon- | the appendage of the neuron that transmits impulses away from cell body |
| Neurons- | any of the impulse conducting cells that constitute the brain, spinal column and nerves consisting of a nucleated cell body with one or more dendrites and a single axon. |
| What makes squid neurons so popular in neurophysiology research? | The large size of their neurons |
| What are the two subdivisions of vertebrate nervous systems? | The central nervous system and the peripheral nervous system |
| What is the central nervous system composed of? | The brain and spinal cord |
| Brain- | the part of the CNS enclosed in the cranium of humans and other vertebrates serving to control and coordinate the mental and physical actions |
| What is the peripheral nervous system composed of? | Cranial and spinal nerves |
| Spinal cord- | connecting link between brain and spinal nerves all over the body/the cord of nerve tissue extending through the spinal canal of the spinal column |
| Central nervous system | -the part of the nervous system comprising the brain and spinal cord |
| Peripheral nervous system- | the portion of the nervous system lying outside the brain and spinal cord |
| Cranial nerves- | any of the nerves arising from the brainstem and exiting to the periphery of the head through skull openings like olfactory nerve, optic nerve etc.) |
| Where are cranial nerves located? | The extend from the spinal cord to all parts of the body except the head. |
| Spinal nerve- | any of a series of paired nerves that originate in the nerve root of the spinal cord and emerge from the vertebrae on both sides of the spinal column, each branching out to a region in the neck, trunk or limbs |
| What has the most advanced nervous system of all animals? | mammals |
| What does the nervous system provide? | Rapid coordination and control of body function by transmitting impulses over neuron processes |
| Impulse- | a progressive wave of excitation over a nerve or muscle fiber having an either stimulating or inhibitory effect |
| Where do the impulses originate? | Either the brain or receptors |
| Receptors- | a specialized cell or group of nerve endings that responds to sensory stimuli |
| Where are the effectors carried to? | Effectors |
| Effectors- | where the action occurs (muscle and glands) |
| What two basic type of cells make up the neural system? | Neurons and neuroglial cells |
| What do neurons do? | Transmit impulses |
| What do neuroglial cells provide? | Support and prevent contact of neurons except in certain sites |
| Nerves- | bundles of many neurons |
| Cell body- | (integrates incoming signals and generates signal to axon)enlarged portion of the neuron that contains the nucleus |
| Dendrites- | (collect electrical signals)receive impulses from receptors or other neurons and carry them toward the cell body(many can exist on neuron) |
| Axons- | (passes signals to dendrites of another cell or to an effector)carry impulses away from cell body (usually only one) |
| What are neuron processes of the peripheral nervous system enclosed by? | A covering of Schwann cells |
| What is different in larger processes ? | There’s a inner mycelin shealth and outer neurilemma |
| Shwann cells- | provide a pathway for the regeneration of neuron processes and are essential for regrowth |
| Are there Schwann cells in CNS? | No but neuroglial cells called oligdendrocytes form myelin sheath |
| Inner myelin sheath- | a fatty insulating material in composed of multiple wrappings of Schwann cells in larger processes. |
| Myelin sheath- | serves as insulator that speeds nerve impulses to muscles and effectors |
| Nodes of Ranvier- | minute spaces between Schwann cells where the neuron process is exposed |
| Are impulses transmitted more rapidly with myelinated or unmyelinated fibers? | Myelinated |
| Invertebrates have what kind of fiber and what do they do because of having unmyelinated fibers? | Unmyelinated, so the impulses go slow. To compensate this, invertebrates have much larger neurons to speed up transmission. |
| Synapse- | junction of an axon tip of one neuron and a dendrite of another neuron |
| Neurotransmitter- | any chemical substance that transmits impulses across synapse to muscle, nerve, or gland and triggered by impulses passing along the axon |
| Synaptic knob- | axon tip |
| Synaptic cleft- | minute space between the neurons |
| What does the neurotransmitter bind with and what does this produce? | Receptor on photo synaptic membrane, and this produces stimulation or inhibition of impulse formation |
| What inactivates the neurotransmitter immediately after stimulation or inhibition of impulse? | Enzyme, which prevents continuous stimulation or inhibition. |
| How does the direction of neural impulses across a synapsis go? | Axon to dendrite because only axon tips can release neurotransmitters onto another neuron. |
| Name 2 stimulating neurotransmitters- | acetylcholine and nor epinephrine |
| Name 2 inhibiting neurotransmitters- | GABA and glycine |
| Spinal cord- | the cord of nerve tissue extending through the spinal canal of the spinal column |
| What is the spinal cord covered by? | Meninges |
| Meninges- | 3 layers of protective membranes |
| Where is spinal cord located? | Extends from brain stem down to the vertebral canal |
| What does the spinal cord act as? | The connecting point of the brain and spinal nerves |
| Gray matter- | located in interior of spinal cord and composed of neuron cell bodies and unmyelinated neuron processes |
| White matter- | located around gray matter and composed of myelinated neuron processes |
| What makes it a white color? | Myelin |
| What happens in the white matter? | Impulses are carried up and down the spinal cord by neuron fibers. |
| How many spinal nerves o humans have? | 31 |
| What does spinal nerve carry(2 things)? | Sensory neuron fibers and motor neuron fibers |
| Sensory neuron fibers- | carry impulses from sensory receptors to the spinal cord |
| Motor neuron fibers- | carry impulses from the spinal cord to an effector |
| How do spinal nerves join the spinal cord? | Via a dorsal root and ventral root |
| Dorsal root- | the more posterior of the two nerve fiber bundles of a spinal nerve that carries sensory info to the central nervous system |
| Ventral root- | part of spinal nerve consisting of motor fibers that arises from the anterior section of the spinal cord |
| Dorsal root ganglion- | a swelling on the dorsal root that contain sensory neuron cell bodies |
| Where are the motor neuron cell bodies located? | In the gray matter of the spinal cord |
| Brain- | control center of the nervous system |
| What is the brain covered with? | menings |
| Cerebrospinal fluid- | fluid between the brain and menings which provides cushion to absorb shock |
| How many cranial nerves are attached to the brain? | 12 all but one innervates (supplies) structures in head and neck |
| What nerves innervate internal organs? | Vagus nerves |
| Cerebrum- | largest part of the brain |
| What does cerebrum consist of? | Right and left cerebral hemispheres separated by a median of longitudinal fissure |
| Longitudinal fissure- | deep groove that divides the cerebrum into right and left hemispheres |
| Corpus callosum- | mass of neuron fibers which enables impulses to pass between the 2 hemispheres |
| Cerebral cortex- | outside portion of cerebrum that is gray matter composed of neuron cell bodies with unmyelinated neuron processes |
| Gyri- | ridges on cerebral cortex that inc surface area |
| Sulci- | grooves on cerebral cortex that inc surface area |
| What does the cerebrum initiate? | Voluntary action and interpretation of sensations (in humans its for will memory and intelligence) |
| Cerebellum- | below cerebrum which is for muscle tone and muscular coordination (subconscious) and divided into left and right hemispheres by a shallow fissure |
| What is spinal cord covered by? | Meninges (three layers of protective tissue) |
| What is the spinal cords purpose? | Connects the brain and spinal nerves |
| What makes the white matter white? | Myelin |
| Where are impulses carried up and down through? | The spinal cord by neuron fibers in white matter |
| How many pairs of spinal nerves are there? | 31 |
| Where do sensory neuron fibers enter? | The spinal cord via the dorsal root |
| Where are sensory neuron cell bodies located? | Dorsal root ganglion |
| How do motor neuron cell bodies exit? | Via the ventral root |
| Where are motor neuron cell bodies located? | In gray matter of spinal cord |
| What is the mammalian brain covered by? | Menings |
| How many pairs of cranial nerves are there in the brain? | 12 |
start learning | start learning |
All but one pair of cranial nerves innervate (stimulate) structures in the head and neck except this one. Vargus nerves that stimulate the internal organs
edit
favorite
combine tables
