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Nervous System
Physiology
Question | Answer |
---|---|
What is Glioma? | Form of brain tumor that is formed from Glia cells. |
Blood-Brain Barrier (BBB) Functions? | (BBB) Separates the blood tissue and nervous tissue to protect vital brain tissue from harmful chemicals that might be in the blood. |
Define astrocytes? | (Star cells) 1. Thread like branches attach to neurons and to small blood vessels holding these structures close together. 2. Along with the walls of the blood vessels, astrocyte branches form two-layer structure called (BBB) blood-brain barrier |
What does "Glia" mean in Greek | Glue |
Name the types of cells in the nervous system? | 1.Neurons 2.Glia |
What are the 3 parts the each neuron consists of? | 1. cell body 2. dendrites 3. axon |
Define cell body? | The main part of a neuron |
define dendrites? | One or more branching projections. |
Define axon | One Elongated Projection |
Name the three types of neurons? | 1.Sensory neurons 2. Motor neurons 3. Interneurons |
Define Sensory neurons? | Transmit impulses to the spinal cord and brain from all parts of the body. A.K.A ( Afferent neurons) |
What are Afferent Neurons/ | Just another name for Sensory Neurons |
Define motor neurons? | -Transmit impulses in the opposite direction. away from the brain and spinal cord. -They do not conduct impulses to all parts of the body only to 2 kinds of tissue muscle and glandular epithelial tissue. |
What are Efferent Neurons/ | Another name for motor neurons |
Define Interneurons? | Conduct impulses from sensory neurons to motor neurons |
What is Myelin? | White fatty substance formed by Schwann cells that wrap around some axons outside the central nervous system. |
What Is Myelinated fibers? | Fibers that are wrappenin myelin are said to be myelinated |
Define Central Nervous system (CNS)/ | Contains the brain and spinal cord |
Define peripheral nervous system (PNS) ? | All other nerves connecting the brain and spinal cord to other parts of the body. |
Autonomic Nervous System (ANS) | Division of the human nervous system that regulates involuntary actions. |
Define Glia cells? | Support cells bringing the cells of nervous tissue together structurally and functionally. |
3 main types of Glia cells of the CNS/ | 1.Astrocytes 2.Microglia 3.oligodendrocytes |
what is Microglia? | Small cells that move in inflamed brain tissue carrying on phagocytosis. |
What is Oligodendrocytes? | form Myelin sheaths on axons in the CNS |
Define a nerve? | Bundle of peripheral axons. |
Define Tract? | Bundle of central Axons. |
Define White Matter? | Tissue composed primarily of myelinated axons ( nerves or tracts) |
Define Gray Matter? | Tissue composed primarily of cell bodies and unmyelinated fibers... |
Name the 3 nerve coverings? | 1. Endoneurium 2. Perinurium 3. epineurium |
Define Endoneurium? | surrounds individual fibers within a nerve. |
Define Perineurium? | Surrounds a group ( Fascicle) of nerve fibers |
Define Epineurium? | Surrounds the entire nerve! |
Define nerve Coverings? | fibrous connective tissue |
What is nerve Impulses? | conducted from receptors to effectors over neuron pathways or reflex arcs; conduction by a reflex arc results in a reflex( That is contraction by a muscle or secretion by a gland) |
What is the Simplest Reflex Arcs? | Two-neurons arcs-consisting of sensory neurons synapsing in the spinal cord with motor neurons. |
What is a Three- neuron arc? | consist fo sensory neurons synapsing in the spinal cord with interneurons that synapse with motor neurons. |
Define nerve Impulses? | Self propagaing wave of electrical disturbance that travels along the surface of a neuron membrane |
Nerve Impulses Mechanism? | 1.Stimulus triggers the opening of NA+ channels in the plasma membrane of neuron. 2. Inward movement of positive sodium ions leaves a slight excess of negative ions outside at a stimulated point; marks the beginning of a nerve impulse. |
Define Synapse? | Chemical compounds released from axon terminals of a persynaptic neuron into a synaptic cleft. |
Define Neurotransmitters/ | Bind to apecific receptor molecules in the membrane of a postsynaptic neuron, opening ion channels and thereby stimulating impulse conduction by the membrane. |
The Division of the Brain? | 1.Brainstem 2. Diencephalon 3. Cerebellum |
Structure of the brainstem? | made of three parts of brain: medulla oblongata , pons,and midbrain. white matterwith bits of gray matter acattered through it. |
Functions of the Brainstem? | Gray matter in the brainstem functions as reflex centers example: heartbeat,breathing and blood vessels diameter. |
Define Sensory Tracts in the Brainstem? | Conduct impulses to the higher parts of the brain. |
Define Motor tracts in the Brainstem? | Conduct from the higher parts of the brain to the spinal cord! |
Hypothalamus consists of..? | Mainly of the posterior pituitary gland, pituitary stalk and gray matter. |
Hypothalamus Acts as? | major center for controlling the ANS; therefore it helps control the functioning of most internal organs. |
Hpothalamus Controls? | Hormone secretion by anterior and posterior pituitary glands; therefore it indirectly helps control hormone secretion by most other endocrine glands. |
Hypothalamus Contains? | centers for controlling body temperature.appetite,wakefulness and pleasure. |
Structure Of the Thalamus? | Dumbbell shaped mass of gray matter in each cerebral hemisphere. |
Function of the Thalamus? | -Relays sensory impulses to cerebral cortex sensory areas -in some way produces the emotions of pleasantness or unpleasantness associated with sensations. |
Define Cerebellum? | 1. Second largest part of the human brain 2. Helps control muscle contractions to produce coordinated movements so that we can maintain balance move smoothly and sustain normal postures. |
What is the largest part of the brain? | Cerebrum. |
Structure of the Cerebrum? | 1. outer layer of gray matter is the cerebral cortex. made up of lobes; composed mainly of dendrites and cell bodies of neurons. 2. Interior of the cerebrum composed mainly of white matter |
Cerebrum functions? | mental processes of all types including sensations, consciousness, memory, and voluntary control of movements |
Spinal Cord Functions? | functions as the center for all spinal cord reflexes; sensory tracts conduct impulses to the brain and motor tracts conduct impulses from the brain. |
Coverings of the brain? | Dura mater, pia mater, arachnoid mater. |
Fluid spaces of the brain? | subarachnoid spaces of meninges, central canal inside cord, and ventricles in brain. |
Cranial nerves? | 1 Twelve pairs- attached to undersurface of the brain. 2. connect brain with the neck and structures in the thorax and abdomen. |
Spinal nerves structure? | contain dendrites of sensory neurons and axons of motor neurons. |
Spinal nerves Function? | Conduct impulses necessary for sensations and voluntary movements. |
Autonomic neurons are? | Preganglionic autonomic neurons conduct from spinal cord or brainstem to an autonomic ganglion; postganglionic neurons conduct from autonomic ganglia to cardiac muscle, smooth muscle, and glandular epithelial tissue. |
autonomic or visceral effectors are? | Tissues to which autonomic neurons conduct impulses. |
The divisions of the autonomic nervous system? | Sympathetic nervous system and Para-sypathetic nervous system. |