64 terms

Terms	Definitions
Nervous System	Along with the endocrine system, this system regulates and maintains homeostasis
Neurons	Carry information along their membrane extensions via electrical signals to allow cell communication Very long cells with membrane extensions Secrete neurotransmitters (chemical signals) to communicate with other cells
Neuron Cell Body	Contains the nucleus of the cell is the biosynthetic center of the cell producing neurotransmitter chemicals
Dendrites	some neurons have one, most have many Provide a large surface area for the reception of signals from other neurons. Carry signal towards cell body. Some are actually sensory receptors
Axon	Efferent Neuron will only have one. -Conduct the impulse, action potential, away from cell body -release neurotransmitter chemical that carries signal from axon to dendrite of following neuron
Which way does a does a signal travel in a neuron?	Signal always travels from dendrite to axon, which releases neurotransmitter to carry the signal to next dendrite
Neurologlial cells	AKA Schwann Cells (neurolemmocytes) wrap around the axons of neurons in nerves. They form the Myelin sheath, a whitish fatty sheath that insulates and aids repair. More importantly, It speeds the rate of the impulse. a) white matter = myelinated cells (where fast conduction occurs) b) gray matter = unmyelinated cells (where decisions are made)
White Matter	Myelinated cells (where fast conduction occurs)
Gray Matter	Unmyelinated cells (where decisions are made)
Myelin Sheath	a layer of fatty tissue segmentally encasing the fibers of many neurons; enables vastly greater transmission speed of neural impulses as the impulse hops from one node to the next
Neurologlial Cells in brain ventricles produce	CSF (Cerebrospinal fluid) that acts to transport nutrients throughout the CNS (Central Nervous System)
Central Nervous System (CNS)	Acts as control centers to regulate many organ functions. Contains the Brain and Spinal Cord
Peripheral Nervous System (PNS)	Monitors sensory information (receptors) and sends it to CNS (Sensory Neurons) As well as carries signals from CNS (motor Neurons) to organs (effectors)
Somatic Nervous System	Provides Voluntary Control of the Skeletal Muscle Cells (effectors) Uses Acetylcholine for neurotransmitter to activate effectors
Effectors	are outside the nervous system and include muscles that contract and glands that secrete when stimulated by nerve impulses
Autonomic Nervous System	Involuntary control of effectors that includes: smooth muscle (in blood vessels, digestive and respiratory system); cariac muscle (heart rate); endocrine glans (including adrenals that secrete adrenaline); sweat glands and digestive glands. uses Epinephrine (adrenalin) as neurotransmitter to activate/inhibit effectors
Sympathetic Division of Nervous System	Fight or Flight division Combined effect of many control centers on many effectors that results in: Increased heart rate; increased repiratory rate; increased blood glucose; decreased urine output; decreased digestive activity including apetite
Parasympathetic Division of Nervous System	Rest and Digest aka feed and breed that results in decreased heart rate, decreased respiratory rate; increased storage of energy; increased urine output, increased digestive activity and absorption of nutrients
Organization of Nervous Tissue In the CNS	Nuclei are clusters of cell bodies that provide control centers (gray) Tracts are groups of myelinated neuron processes that carry information (white)
Organization of Nervous Tissue in the PNS	Ganglia are clusters of cell bodies that provide control centers (Gray) Nerves are groups of myelinated neuron processes that carry informaation (white)
Feedback Loops	Consist of neurons that communicate (along membrane by electrical signals) and between cells (by Chemical signals by neurotransmiter) Control Organ Function)
Feedback Loops Consist of	Sensory Receptors, Sensory Neurons, Association Nuerons, Motor Neurons and effectors. Signal always travels from dendrite to axon, which releases neurotransmitter to carry the signal to the next dendrite.
The Two Primary Functions of The Spinal Cord include	1. Communication between receptors and brain (sensory information) and between brain and effectors (motor information). White matter spinal spinal tracts 2. Acts as reflex center (association neurons in gray matter)
Cross-sectional anatomy of spinal cord
Nervous Reflex pathway	(receptor-sensory neuron-association Neuron-motor neuron-effector) is imposed on structures of spinal cord: Posterior root of spinal nerve with ganglion - get sensory input from receptors. go to association neurons in gray matter (decision making part of spinal cord White matter (myelinated neurons going vertically, also known as spinal tracts) carry information to and from brain anterior root of spinal nerve - motor then shoots the output to the effectors.
Cross section of vertebral column	Structures and fluids provide protection a. Vertebrae Bone b. Epidural Space - filled with adipose provides cushion c. Dura Mater - tough protective layer d. Arachnoid mater e. Subarachnoid Space -filled with cerebrospinal Fluid providing nutrient/gas transport. f. Pia Mater g. Spinal Cord (gray and white matter = neural tissue)
Cerebrospinal fluid	blood-derived (plasma) fluid that surrounds, protects against infection, nourishes, and cushions the brain and spinal cord Produced by choroid plexus which are clusters of thin walled capillaries in the ventricles. Choroid plexus are also known as the blood/brain barrier
Gross Anatomy of A Spinal Cord	Extends from the Foramen Magnum to L1 or L2 Cervical and lumbar enlargements (plexuses) contain the cell bodies of the many spinal nerves to the limbs Cauda Equina The Nerve roots of lumbar and sacral Spinal nerves. Ascending and descending white matter tracts carry information to/away from brain
Cauda Equina	"horse's tail", a fan of nerve fibers below the spinal cord
Spinal Nerve Structure	Similar to that of a muscle with fascicles and membranes. 1. Axon 2. Myelin Sheath around Axon 3. Endoneurium: Surrounds each myelinated axon 4. Perineurium: Forms each fascicle (A group of Myelinated axons) 5 Epineurium: tough fibrous sheath surrounding the nerve, enclosing all the fascicles
Spinal Nerve Function	Supply all parts of the body except the head and some parts of the neck. All are mixed nerves, having both motor and sensory neurons They originate as the anterior and posterior roots meet laterally and just distal to the posterior root ganglion. Plexuses: These branching networks of the spinal nerves found at spinal cord. Usually associated with appendages.
3 Meninges	Pia matter (inner most) Arachnoid (middle) Dura mater (outer) Same as spinal cord in general
Ventricles	Chambers within the brain filled with CSF which is produced there. Continuous - the subarachnoid space and the central canal of the spinal cord.
Brain Stem	the part of the brain continuous with the spinal cord and comprising the medulla oblongata, pons, midbrain and parts of the hypothalamus Some gray (control centers) and white matter (carry information towards /away from brain) all functions autonomic and involuntary
Medulla Oblongata	Continuous with spinal cord at Foramen Magnum -Heart Rate regulation -Respiratory Rate Regulation -Blood Pressure (vasodilation and vasoconstriction) regulation -vommitting, coughing, sneezing, swallowing
Pons	Inferior to midbrain and anterior to cerebellum -secondary respiratory control center to medulla oblongata. Relays impulses from one side of the cerebellum to the other and between the medulla and midbrain. Pneumotaxic area and apneustic area, together with the medulla, help control breathing. Contains nuclei of origin for cranial nerves V, VI, VII, and VIII.
Midbrain	inferior to the thalmus Control center for visual and auditory "startle" reflexes (rapid movement of head/neck in response to bright lights/loud sounds)
Diencephalon	Almost all gray matter , located between the midbrain and the cerebrum and consists of the thalamus, hypothalamus, optic chiasma, and pineal body
Thalmus	- Relay station for sensory impulses to the cerebral cortex -Memory Processing
Hypothalamus	acts as control center for regulating : -Body Temperature -Food Intake (hunger) -Water balance and thirst -Reproduction -Metabolism -Growth
Pituitary Gland	An extension of the hypothalamus found below the hypothalamus. Triggered by Hypothalamus to produce hormones that regulate reproduction, metabolism and growth.
Cerebellum	maintains posture and ensures smooth coordinated movements
Cerebrum	largest percentage of total brain mass
Cerebral Cortex	Gyri = ridges or 'hills' Sulci = grooves or "valleys Fissures: very deep grooves that separate lobes from each other and other brain parts cortical functions are generally voluntary and conscious and fall in one of three functional categories: Motor, Sensory and Association
Lobes of the Cerebral Cortex	Prefrontal Frontal Parietal Occipital Temporal
Prefrontal Lobe	Intellect, Cognition, Mood, Personality, Judgement, Reasoning.
Frontal Lobe	Conscious skeletal muscle control of muscles on opposite side (=primary motor area) voluntary eye movements motor speech (voluntary movements for speaking)
Parietal Lobe	Body sensory information (touch and position) from skin and muscles (=primary somatosensory cortex) -Gustation/taste
Somato Sensory Cortex	picks up feeling from skin, internal organs, interprets feeling
Occipital Lobe	Sensory Vision
Temporal Lobe	Auditory Olfaction/Smell Balance
Corpus Callosum	A white matter tract that allows communication between hemispheres of cerebral cortex
Crainal Nerves	12 Pairs, Olfactory, Optic, Oculomotor, Trochelar, Trigeminal, Abducens, Facial, Vestibulocochlear, Glossopharyngeal, Vagus, Accessory, Hypoglossal Oh, Oh, Oh, To Touch And Feel Viginia's Gucci Vest. Ah, Heaven
Olfactory Nerve I	Smell Sensory Input
Optic Neve II	Vision sensory Input
Oculomotor III	Eye Movement Note (three nerves work together on this.)
Trochlear IV	Eye Movement
Trigeminal V	Chewing movements, facial sensation (of the skin) sensory input
Abducens VI	Eye movement
Facial Nerve VII	Movement of facial expression muscles, taste (from anterior 2/3 of tongue)
Vestibulocochlear VIII	Hearing (hence "cochlea"), Equilibrium sensory input
Glossopharyngeal IX	Reception of blood pressure, blood gas levels, taste (from posterior 1/3 of tongue)
Vagus Nerve X	Reception of blood pressure and blood gas chemistry, controls smooth movements in digestive system, decreases cardiac muscle contractions, increases secretion of digestive juices
Accessory Nerve XI and Hypoglossal XII	Head and neck movement, tongue movements

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