Unit 7 Nervous System
Schwann cells
Schwann cells are specialized cells that myelinate the fibers of neurons found in the PNS.
Sensory Division
Sensory Division is made up of the PNS and divided into sensory, or afferent, neurons that convey information to the CNS from sensory receptors that monitor the external and internal environment.
Sensory Input
Sensory input is Information gathered by sensory receptors about internal and external changes.
Axon terminals
Axon terminals are bulb like structers at end of axon contain neuro transmitters that carry neuron message into synapse.
Axons
Axons are a part of a neuron that carries impulses away from the cell body.
Satellite cells
Satellite cells are a type of neuroglia, surround soma of neurons in ganglia of PNS. Mostly unknown function, but thought to be linked to regeneration.
Bipolar neuron
A bipolar neuron is a neuron with two processes, one axon and one dendrite.
Cerebrospinal fluid
A clear fluid the circulates around through the brain and spinal cord that helps to physically support the brain and act as a shock absorber, and that also exchanges nutrients and wastes with the brain and spinal cord.
choroid plexus
A highly vascular tissue that protrudes into the ventricles and produces cerebrospinal fluid.
limbic system
A loosely connected network of structures located roughly along the border between the cerebral cortex and deeper sub cortical areas.
Neural tube
A neural tube is formed when the neural folds meet at the midline and fuse.
medulla oblongata
A portion of the brain that is the control center of various unconscious bodily functions and via the autonomic nervous system.
Lumbar tap
A procedure in which a needle is carefully inserted into the spinal canal low in the back, or in the lumbar area, and samples of CSF are collected.
Blood-brain barrier
A specialized capillary arrangement in the brain that restricts the passage of most substances into the brain, thereby preventing dramatic fluctuations in the brain's environment.
pineal body
A structure in the brain that separates the two cerebral hemispheres. It produces the hormonelike substance melatonin that appears to influence the body like biological clock.
synapse
A synapse is a junction between two neurons or a neuron and another cell where electrical or chemical signals are relayed.
Synaptic Cleft
A synaptic cleft is a space between nerve cells where chemical transmitters act to move impulses from one neuron to the next.
Action potential
Action potential is a brief electrical impulse by which information is transmitted along the axon of a neuron.
Astrocytes
Astrocytes are star-shaped supporting cells in the CNS that are the most abundant & versitile; assists in exchanges between blood in capillaries and neurons
Cauda Equine
Cauda equine is a Collection of dangling nerve roots past the terminal end of the spinal cord.
Cerebral hemispheres
Cerebral hemispheres are the nearly symmetrical left and right halves of the cerebral cortex.
Dendrites
Dendrites are short fibers that branch out from the cell body and pick up incoming messages
Depolarization
Depolarization is the movement of an electrical charge within a cell in a more positive direction.
Neurilemma
Neurilemma is an additional sheath external to myelin that is formed by schwann cells and found only on axons in the peripheral nervous system.
Dorsal root ganglion
Dorsal root ganglion is a group of sensory neuroon cell bodies found just posterior to the spinal cord, and part of the peripheral nervous system.
Ependymal Cells
Ependymal cells are a type of neuroglial cell found in the ventricles, circulate cerebrospinal fluid
Ganglia
Ganglia are cell bodies outside the CNS that carries impulses to the involuntary muscles and glands.
Glia
Glia are supporting cells that are essential for the structural integrity of the nervous system and for the normal functioning of neurons.
Glioma
Glioma is a cancer that arises from the glial cells of the nervous system.
Gray Matter
Gray matter is the tissue within the central nervous system. It consists of unsheathed or uncovered nerve cell bodies and dendrites.
Gyri
Gyri are elevated ridges of brain tissue, separated by shallow grooves called sulci.
Neuroglia
Neuroglia are cells within both the CNS and PNS, which, although they are external to neurons, form an essential part of nerve tissue.
Neurons
Neurons are the long, thin cells of nerve tissue along which messages travel to and from the brain.
parietal lobe
Lobe at the upper middle of the cortex. Contains the somatosensory area where feeling sensations are processed.
Microglia
Microglia are very small neurons that remove waste materials and microorganisms from the central nervous system
Motor Division
Motor divisions carry signals from the CNS to gland and muscle cells that carry out the body's response.
Motor Output
Motor output is the conduction of signals from a processing center in a central nervous system to effector cells.
Multipolar Neuron
Multipolar neurons are the most common structural type of neuron, that has many dendrites and a single axon.
Myelin
Myelin is a fatty material that forms a sheathlike covering around some axons.
Myelin Sheath
Myelin sheath are insulating membrane surrounding the axon in some neurons.
cerebral aqueduct
Narrow passageway that carries cerebrospinal fluid between the third ventricle and the fourth ventricle
Nerve Impulse
Nerve impulses are message that travels from the dendrites of a neuron to the axon.
Neurotransmitter
Neurotransmitters are chemicals that are released by a neuron for the purpose of carrying information across the gaps (synapses) between neurons.
Nodes of Ranvier
Nodes of Ranvier are breaks in the myelin sheath that allow ions to flow in and out of the cell, causes the message to move down the axon.
Oligodendrocytes
Oligodendrocytes are supporting cells in the CNS that wrap their cytoplasmic extensions around the nerve fibers, producing insulating covering called myelin sheaths.
Reticular activating system
Part of brain stem involved in arousal and attention, sleep and wakefulness, and control of reflexes.
Polarized
Polarized is possessing a membrane potential or resting state.
Posterior Horns
Posterior horns are two dorsal horn projections of gray matter that form columns of gray matter that run the entire length of the spinal cord.
Receptors
Receptors are parts of the cell membrane that receive the neurotransmitter and initiate a new electric signal
Reflex arc
Reflex arc is a nerve pathway, consisting of a sensory neuron, interneuron, and motor neuron, that forms the structural and functional bases for a reflex.
Reflexes
Reflexes is an action that happens before the brain has time to think about it.
Stimuli
Stimuli is information in the environment that activates the nerves in a sense organ.
Autonomic Nervous System
The autonomic nervous system is a division of the peripheral nervous system that regulates involuntary functions; made up of sympathetic and parasympathetic nervous systems
Nervous System
The body system of nervous tissues is organized into the brain,spinal cord, and nerves, that send and receive messages and integrate the body's activities.
Central Nervous System
The central nervous system is the portion of the vertebrate nervous system consisting of the brain and spinal cord.
epithalimus
The epithalmus has the pineal gland that regulates wake and sleep cycles, which is a part of diencephalon.
fissures
The large, deep groves in the cerebral hemispheres.
brain stem
the part of the brain that controls functions including heart rate, breathing, and body temperature. It includes the midbrain, pons, and medulla oblongata.
Dura mater
The outermost of the three meninges that surround the brain and spinal cord.
Parasympathetic Nervous System
The parasympathetic nervous system is a subdivision of the autonomic nervous system that calms the body after action and also retains the body functioning at is normal state (homeostasis)
Peripheral Nervous System
The peripheral nervous system the sensory and motor neurons that connect the central nervous system to the rest of the body.
diencephalon
The portion of the brain that contains two of the most critical areas of the brain, the thalamus and the hypothalamus.
Somatic nervous system
The somatic nervous system is the division of the peripheral nervous system that controls the body's skeletal muscles.
Spinal Cord
The spinal cord is composed of nerves that run down the length of the back and transmit most messages between the body and the brain.
Sympathetic Nervous System
The sympathetic nervous system involves the division of the autonomic nervous system that is concerned primarily with preparing the body in stressful or emergency situations.
Arachnoid mater
The web-like threads between the two other meninges, which contains cerebrospinal fluid in the spaces.
Unipolar neuron
Unipoliar neuron is a neuron with one process extending from its cell body.
Ventral Horns
Ventral horns are two anterior projections of the gray matter of the spinal cord that surrounds the central canal of the cord.
Ventral root
Ventral root is a bundle of motor neuron axons that emerge from the ventral spinal cord and joins sensory fibers to form a spinal nerve. Ventral root axons carry information away from the spinal cord.
Ventricles
Ventricles are a series of interconnected cavities within the cerebral hemispheres and brainstem filled with cerebrospinal fluid.
White Matter
White matter is an areas of the nervous system rich in fat-sheathed neural axons that form the connections between brain cells.
pons
a brain structure located at the top of the brain stem that is involved in respiration, movement, and sleep.
hypothalamus
a structure found near the base of the forebrain that is involved in the regulation of basic biological needs
temporal lobe
an area on each hemisphere of the cerebral cortex near the temples that is the primary receiving area for auditory information
Brocas area
anterior speech area in the left hemisphere that functions with the motor cortex to produce the movements needed for speaking
basal nuclei
collections of neural cell bodies responsible in part for motor control, muscle relaxation -particularly important in rhythmic movements
tyramidal/icorticospinal tract
controls voluntary and skilled movement ability such as writing
cerebral peduncles
descending bundles of nerve fibers on the ventrolateral surface of the midbrain
Arachnoid villi
fingerlike projections of the arachnoid that act as valves projecting through the dura into the dural blood sinuses
Integration
integration is the process and interpretation sensory input and decide if action is needed
cerebral cortex
intricate fabric of interconnected neural cells that covers the cerebral hemispheres
pituitary gland
located at the base of the hypothalamusit is the gland that sends hormonal signals controlling the release of hormones from endocrine glands
frontal lobe
located in the front most portion of the brain, involved with motor movements, speech, and executive functions
corpora quadrigemina
nuclei scattered around white matter in midbrain; raise four domelike protrusions on the dorsal midbrain surface
mammillary bodies
pair of rounded nuclear masses located inferior to the hypothalamus which part of the limbic system. It function as a sense of smell.
occipital lobe
section of the brain located at the rear and bottom of each cerebral hemisphere containing the visual centers of the brain
sulci
shallow depressions on cortical surface of the cerebral hemisphere
lobes
shallow grooves in various regions that correspond to the major bones of the cranium
thalamus
the brain's sensory switchboard, located on top of the brainstem that directs messages to the sensory receiving areas in the cortex
Pia mater
the innermost of the layers of meninges, found in both the central and peripheral nervous systems
corpus callosum
the large band of neural fibers connecting the two brain hemispheres and carrying messages between them.
Meninges
three membranes that cover the brain and spinal cord, consisting of the sura mater, pia mater, and arachnoid mater
