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Anatomy: Ch.7 Vocab
The Nervous System (Vocab)
Term | Definition |
---|---|
Nervous System | fast-acting control system that employs nerve impulses to trigger muscle contraction or gland secretion |
Sensory Input | Receptors monitor change inside and outside of the body and send info to integrating center. |
Integration | A function in the nervous system which processes and Interprets sensory input and then makes decisions. |
Motor Output | Dictates a response by activating effector organs. |
Central Nervous System (CNS) | the part of the nervous system made up of the brain and spinal cord |
Peripheral Nervous System (PNS) | Outside the CNS |
Sensory (Afferent) Division | signals picked up by sensor receptors; carried by nerve fiber of PNS to CNS. |
Motor (Efferent) Division | Signals are carried away from CNS; Innervate muscles and glands. |
Somatic (Voluntary) Nervous System | |
Autonomic Nervous System (ANS) | nerves that control involuntary body functions of muscles, glands, and internal organs |
Involuntary Nervous System | |
Neuroglia (glia) | these fill spaces, support neurons, provide structural frameworks, produce myelin, and carry on phagocytosis |
Astrocytes | Star shaped cells found throughout the CNS, cleaning up debris in the extracellular space and removing neurotransmitters from the synaptic cleft, connects neurons to nearby cappilaries, components of the blood-brain barrier |
Microglia | type of neuroglial cell that phagocytizes bacterial cells and debris |
Ependymal Cells | atypical epithelial cells that line chambers and passageways filled with cerebrospinal fluid in the brain and spinal cord. assist in producing, circulating and monitoring CSF |
Oligodendrocytes | type of neuroglial cell that produces myelin in the CNS wrap there cell processes around the axon in the CNS. |
Schwann Cells | Supporting cells of the peripheral nervous system responsible for the formation of myelin. |
Neurons | (Nerve Cells) the basic building block of the nervous system |
Nissl Substance | the material consisting of granular endoplasmic reticulum and ribosomes that occurs in nerve cell bodies and dendrites. |
Processes (Fibers) | |
Dendrites | branching extensions of neuron that receives messages from neighboring neurons |
Axons | long, thin fibers that transmit signals away from the neuron cell body to other neurons or to muscles and glands |
Neurotransmitters | chemical messengers that traverse the synaptic gaps between neurons. When released, travel across the synapse and bind to receptor sites on the receiving neuron, influences whether that neuron will generate a neural impulse. |
Synaptic Cleft | the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron. The tiny gap at this junction is called the synaptic gap or cleft. |
Myelin Sheath | insulate axons & increase rate of impulse conduction and are fatty layers. |
Neurilemma | the outer nucleated cytoplasmic layer of the schwann cell, which encloses the myelin sheath and can regenerate- found in the PNS only |
Nodes of Ranvier | gaps between the myelin wrappings along the axon |
Multiple Sclerosis (MS) | a chronic, typically progressive disease involving damage to the sheaths of nerve cells in the brain and spinal cord |
Ganglia | masses of nerve cell bodies, usually outside the CNS |
White Matter | In The Spinal cord; located on the outer layer of the spinal cord. Only contains Myelinated axons running between different parts of the axon |
Gray Matter | contains mostly nerve cell bodies and un-myelinated fibers. Gray area of the central nervous system; contains neuronal cell bodies and their dendrites |
Interneurons | (Association Neurons) Central nervous system neurons that internally communicate and intervene between the sensory inputs and motor outputs |
Multipolar Neuron | Neurons whose bodies lie in the brain and spinal cord |
Bipolar Neurons | Neurons whose bodies lie in specialized parts of the eyes, ears and nose. |
Unipolar Neurons | Neurons whose bodies are located outside of the brain and spinal cord; found in basal ganglia |
Polarized | |
Depolarization | |
Local Depolarization | |
Repolarization | |
Reflexes | |
Meningitis | inflammation of the meninges caused by viral or bacterial infection |
Encephalitis | inflammation of the brain, caused by infection or an allergic reaction |
Hydrocephalus | a condition in which fluid accumulates in the brain, typically in young children, enlarging the head and sometimes causing brain damage |
Alzheimer's Disease (AD) | progressive mental deterioration that can occur in middle or old age, due to generalized degeneration of the brain. |
Cerebral Palsy | a condition marked by impaired muscle coordination (spastic paralysis) |
Anencephaly | the absence of a major portion of the brain, skull, and scalp that occurs during embryonic development. |
Spina Bifida | a congenital defect of the spine in which part of the spinal cord and its meninges are exposed through a gap in the backbone |