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Nervous System
Chapter 10 Nervous System.
Question | Answer |
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Nervous System | Consists of the Brain and Spinal Cord and Nerves. |
Synapses are composed of 3 pain parts | The presynaptic ending that contains neurotransmitters. The synaptic cleft between the two nerve cells. The postsynaptic ending that contains receptor sites. |
Neurotransmitter | Bridges a very narrow gap to carry the message from the first neuron to t he next. |
Ganglion | Cell bodies of the dorsal neurons are clustered in a knot-like structure. |
Sciatic Nerve | A thick nerve that arises in the lower part of the spine and passes through the pelvis on it's way to the back of the leg. |
Phrenic Nerve | One of a pair of nerves that arises from cervical spinal roots and passes down the thorax to innervate the diaphragm and control breathing. |
Ventricles | The brain contains four chambers. Lateral -- Third -- Fourth -- ?? |
Meninges | Layer of fibrous connective tissue covering the brain and spinal cord. |
Divisions of the Nervous System | Contains 2 main divisions. CNS and PSN |
CNS | Central Nervous System- Consists of the brain and spinal cord |
PSN | Peripheral Nervous System- Consist of the vast network of nerves throughout the body. The PSN consists of everything outside of the brain and spinal cord. |
Autonomic Nervous System (ANS) | Provides autonomic activities such as control of blood pressure and heart rate. |
Somatic Motor | Allows voluntary movements of skeletal muscles |
Somatic sensory | Carries signals from skin, bones, joints, and muscles |
Visceral Sensory | Carries signals from viscera of heart, lungs, stomach, and bladder. |
Sensory (afferent) Division | Carries signals from nerve endings to CNS |
Motor (efferent) Division | Transmits information from the CNS to the rest of the body |
Sympathetic Division | Arouses the body for action |
Parasympathetic Division | Has a calming effect. |
Cell Body | Also called Soma- Is the control center of the neuron and contains the nucleus. |
Dendrites | Which look like bare branches of a tree, receive signals from the neurons and conduct the information of the cell body. Some neurons have only one, others have thousands. |
Axon | Which carries nerve signals away from the cell body, is longer than the dendrites and contains few branches. Nerve cells have only one axon; however, the length of the fiber can range from a few millimeters to as much as a meter. |
Myelin Sheath | They form Schwann Cells |
Nodes of Ranvier | Gaps in the Myelin Sheath, occur at evenly spaced intervals. |
Synaptic Knob | The end of the axon branches |
What is a Synapse | Small gap at the end of a neuron that allows information to pass from one neuron to the next |
How many pairs of spinal nerves are in the body | 31 8 cervical 12 thoracic 5 lumbar 5 sacral 1 coccygeal |
Cervical Plexus | Contains nerves that supply the muscles and skin of the neck, tops of shoulders, and part of the head. |
Phrenic nerve | Stimulates the diaphragm for breathing is located in the cervical plexus |
Brachial plexus | Innervates the lower part of the shoulders and the arm Key nerves traveling into the arm from this region include the axillary nerve. the radial nerve the ulnar nerve and the median nerve. |
Lumbar plexus | Derived from the fibers of the first four lumbar vertebrae- supplies the thigh and leg. A key nerve in this region is the large femoral nerve. |
Sacral plexus | Is formed from fibers from nerves :4,L5, and S1 through S4. Contains the largest nerve in the body. Runs down the back of the thigh. |
Skull has 3 layers of meninges covering the brain | Dura mater- Contains 2 layers (outer layer) Arachnoid Mater- Is the middle layer Pia Mater- clings tightly to the surface of the brain. |
Reflexes | Are quick involuntary, predictable responses to a stimulus. |
Somatic Reflexes | Protects the body against hard such as causing you to withdraw your hand from a hot stove. |
Frontal Lobe | Voluntary movement, memory, emotion, social judgment, decision making, reasoning, and aggression. Also the site for certain aspects of one's personality. |
Temporal Lobe | Hearing, smelling, learning, memory, emotional behavior, and visual recognition. |
Parietal Lobe | Touch, pressure, temperature, and pain. |
Occipital Lobe | Analyzing and interpreting visual information. |
Olfactory | Smell |
Optic | Vision |
Oculomotor | Eyelid and eyeball movement |
Trochlear | Innervates superior oblique turn's eye downward and laterally. |
Trigeminal | Chewing; face and mouth touch and pain |
abducens | Turns eye laterally |
Facial | Controls most facial expression, secretion of tears and saliva, taste. |
Vestibulocochlear (auditory) | Hearing, Equilibrium sensation |
Glossopharyngeal | Taste, Pharynx contraction |
Vagus | Heart, Lung, and Viscera |
Accessory | Contracts the neck and shoulder muscles |
Hypoglossal | Controls tongue movements. |
MS | Multiple Sclerosis- chronic disease of the central nervous system. Thought to be autoimmune disorder. |
Meningitis | Infection or inflammation of the meninges. |
Hydrocephalus | if the flow of CSF becomes blocked anywhere on its route, the fluid accumulates in the brain's ventricles. "Water on the brain" |
Brain Lesions | Symptoms that may occur following trauma or stroke to specific brain regions Parietal Lobe Lesion Temporal Lobe Lesion Frontal Lobe Lesion |
Parietal Lobe Lesion | Dysfunction in this part of the brain causes people to ignore objects on the opposite side of the body- even their own arm and leg. Patients may dress only half their body and even deny that the opposite arm or leg belongs to them. |
Temporal Lobe Lesion | An injury here can impair the ability to identify familiar objects. Some may not even recognize their own face. In other instances, the person may lose the ability to differentiate between sounds, causing him to lose any appreciate for music. |
Frontal Lobe Lesion | A lesion or injury here can result in severe personality disorders and cause socially inappropriate behavior. |
Cerebellum | Receives information from the sensory system. |
Medulla Oblongata | Attaches the brain to the spinal cord. Perform functions vital to the human life. Cardiac center. Vasomotor center. Two respiratory centers. |
Cardiac center | Regulates heart rate |
Vasomotor Center | Controls blood pressure |
Respiratory Center | Controls breathing. |
Where does Synapse occur | Cardiac muscle cells and certain types of smooth muscle. |
Acetylchoiline | A substance that is released at the junction between neurons and skeletal muscle fibers, at the nerve endings of parasympathetic nervous system, and across synapses in the central nervous system, where it acts as a neurotransmitter. |
Epinephrine | A hormone that is secreted by the adrenal gland in response to physical or mental stress, as from fear, and is regulated by the autonomic nervous system. Increases heart rate, blood pressure and respiratory rate. |
Norepinephrine | A hormone that is released by the adrenal medulla and by the sympathetic nerves and functions as a neurotransmitter. It is also used as a drug to raise blood pressure. |
What is contained in the white matter | It contains bundles of axons (called tracts) that carry impulses from one part of the nervous system to another |
What is contained in the gray matter | Contains mostly the cells bodies of motor neurons and interneurons. This H-shape mass is divided into two sets of horns Posterior (dorsal) horn and the ventral (anterior) horn. |
Corpus Collosum | Most of the tracts that pass from one hemisphere to the other travel through large "bridge". This arrangement allows the brain's two hemispheres to communicate with each other. |
Blood brain barrier | Serves to restrict what substances can pass from the bloodstream into the tissue fluid of the brain |
How many pairs of Cranial Nerves are there | 12 pairs |
Trigeminal Neuralgia | Eating, drinking, tooth brushing, shaving or even changing temperatures can trigger brief episodes of intense pain. |
Bell's Palsy | Dysfunction of facial nerves causes paralysis of the facial muscles on one side. Suspected to be viral. Can last 3-5 weeks. |