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A & P chap. 11
Nervous System
Question | Answer |
---|---|
Central Nervous System Peripheral Nervous System Spinal Cord | Brain and spinal cord. Cranial and Spinal nerves Connects brain with PNS |
Nerve Sensory (afferent) division of PNS Motor (efferent) division of PNS | Organ of the PNS. Consists of bundles of axons, connective tissue sheaths and blood vessels. Detects changes in environment and transmits them to CNS. Relays motor information from CNS to muscle and glandular tissues. |
Functions of nervous system Functions of CNS Functions PNS | Controls perception of the world. Directs voluntary movement. Homeostasis-respiratory rate, blood pressure, body temp, sleep/wake, blood pH. Integrate information. Link CNS to rest of body; perform motor and sensory functions. |
Somatic Sensory division Visceral Sensory division | Carries signals from muscles, bones, joints, and skin from PNS to CNS Carries signals from organs from PNS to CNS |
Somatic Motor division Autonomic Nervous system (ANS) of Motor division | Carries signals to skeletal muscles from CNS to PNS Carries signals to smooth muscle, cardiac muscle and glands. |
Sensory Functions Integrative Functions Motor Functions | Gathering information about the internal and external environments. Analyze and interpret incoming sensory information and determine an appropriate response. Actions performed in response to integration. |
Effectors Viscera Neurons | Organs that carry out the effects of the nervous system Organs an excitable cell. Responsible for sending and receiving signals in the form of action potentials. |
Cell body Dendrite (branch or tree) | Central portion of a neuron. Contains nucleus and bulk of organelles. Typically short, highly forked processes. They receive input from other neurons, which they transmit in the form of electrical impulses toward the cell body. |
Axon Axon terminal | Extension of a neuron. Generates action potentials; carries away. Knob-like structure at the end of an axon. Contains synaptic vesicles with neurotransmitters. |
Neurogllial cells (glia means glue) | Maintain environment around neurons, protect them, and assist in their proper functioning. Mitotic. fill in the gaps when neurons die. 4 in CNS: astrocytes, oligodendrocytes, microglia, and ependymal. 2 in PNS: schwan and satellite |
Astrocyte (star-shaped) | neuroglial. Most numerous and largest in CNS. End-feet. Functions: Anchor neurons and blood vessels in place. Regulate the extracellular environment. Facilitate the formation of the blood-brain barrier. Repair damaged tissue. |
Oligodendrocyte (few) Microglial | Few radiating processes which myelinate axons in CNS by wrapping processes around. Most numerous in CNS. Act as phagocytes by "cleaning-up" |
Ependymal | Ciliated neuroglial that line fluid filled cavities in the brain and spinal cord. Functions; Line cavities. Cilia circulate fluid around brain and spinal cord Some secrete cerebrospinal fluid. |
Schwann (similar to oligodendrocytes in CNS) Satellite Myelin sheath (develops in early childhood) | Myelinates axons in PNS by wrapping around them. Flat cells that surround the cell bodies of neurons in PNS. Surround & support cell bodies. layers of plasma membrane of the neuroglial. Phospholipids, other lipids and proteins. Keeps charge in. |
3 functional regions of neurons | Receptive- dendrites-receive signals, monitor environment via sensory receptors. Conducting-Axon Secretory-axon terminal-secrete chemicals that trigger changes in target cells. |
Nissl bodies Axolemma Axoplasm | Neural version of rough ER. Why you can't see nuclei in stained neuron. Membrane of axon. cytoplasm of axon. |
Axon hillock Unmyelinated 3 structural classifications | Where axon leaves neuron and action potentials are generated. less myelin. Moves signal slower. Mylinated is 150% faster. Multi, bi, and pseudouni-polar neurons |
Multi-polar Bipolar | 99% single axon and multiple highly branched dendrites. Motor and inter-neurons. Most of the neurons in PNS. motor in CNS 1 axon and 1 dendrite. Sensory neurons. Special sense organs in PNS. Retina and Olfactory epithelium. |
Psuedounipolar 3 functional groups | Single short process that splits to 2 axons.Sensory neurons in PNS associated with touch, pain and vibration. Sensory (afferent)-to CNS, (association) relay messages within CNS between Sensory and motor, motor (efferent)-away from CNS. |
Nuclei (CNS) Tracts (CNS) Ganglia (PNS) Nerves (PNS) | Clusters of neuron cell bodies (gray matter) Bundles of axons (white matter) Clusters of neuron cell bodies (gray matter) Bundles of axons (white matter) |
Krabbe disease Multiple Sclerosis | Recessive (rare) gene with mutation for building myelin in CNS. Symptoms appear by 1-2. Die by 4-5. FATAL!! Autoimmune - against myelin producing cells. Imaging used for diagnosis. Scar tissue grows where myelin should be. Women 20-30 |
Node of Ranvier Internode Regeneration | A gap between internodes. Depolarization only needs to happen here. Segments of an axon that are covered by neuroglia. PNS only. Growth factors are not present in CNS. Only if cell body is intact. |
Gliomas and Astrocytomas | Primary brain tumors. Astrocytomas are gliomas in astrocytes. Responsible for most brain tumors. Aggressive, quick, readily matasticize. |
Axon Collaterol Increases speed of transmission of Action potential | Branches away from axon at 90. Causes reffed pain Allows neuron to talk to another area. more myelin, more ATP, needs vesicles, needs motor proteins |