Term | Definition |
Central Nervous System consist of | Brain and Spinal Cord |
Peripheral Nervous System consist of | Everything outside of the brain and spinal cord |
Roles of the nervous system | Sensing, Integrating, Responding |
Sensing | Detect changes both inside and outside the body |
Integrating | Process the information received, relate it to past experience, and determine what response is appropriate |
Responding | Issues commands to muscles and glands to initiate changes based on its information |
Somatic Sensory | Carries signals from skin, bones, joints, and muscles |
Neuroglia | Supportive cells of the nervous system |
Astrocytes | Form blood-brain barrier |
Blood- brain barrier | protects the brain from foreign substances, formed as astrocytes wrap around capillaries |
Sensory (afferent) Neurons | Detect stimuli and transmit info to CNS |
Motor (efferent) Neurons | Relay messages from the brain to the muscle or gland cells |
Multipolar Neurons | One axon and multiple dendrites, most common type of neuron of the brain and spinal cord |
Cell body (soma) | the control center and contains the nucleus |
Dendrites | Receive signals from other neurons and conduct the information to the cell body |
Axon | Carries nerve signals away from the body |
Myelin sheath | Insulates the axon |
Nodes of Ranvier | Gaps in the myelin sheath that occur at the evenly spaced intervals |
Synaptic Knob | End of the axon branches, inside are vesicles containing neurotransmitters |
Neurilemma | Outer layer of sheath only in PNS, essential for an injured nerve to regenerate |
Myelin blocks the... | Free movement of ions across the cell membrane. |
Electrical changes occur.. | At the Node of Ranvier |
Cervical | Innervates the chest, head, neck, shoulders, arms, hands, and diaphragm |
White Matter | appears white because of its abundance of myelin fibers |
Gray Matter | Appears gray because of its lack of myelin, it contains mostly neuron cell bodies |
Central Canal | Carries cerebrospinal fluid through the spinal cord |
Epidural Space | Lies between the outer covering of the spinal cord and the vertebrae |
Dorsal Nerve Root | Carry sensory information into the spinal cord |
Spinal Nerve | A single nerve that contains both motor and sensory fibers |
Ventral Nerve Root | Carry motor information out of the spinal cord |
Pia mater | Innermost layer |
Subarachnoid Space | Lies between the arachnoid mater and the pia mater, filled with cerebrospinal fluid |
Dura Mater | Tough outer layer |
Tracts | serve as the routs of communication to and from the brain |
Ascending Tracts (Sensory) | takes information to the brain |
Descending Tracts (Motor) | takes information to muscles |
Spinal Cord Tracts... | Cross from one side of the body to the other in the brainstem, this is why someone suffers from a stroke |
Pairs of Spinal Nerves | 31 pairs |
Cervical Plexus | Contains phrenic nerve, which stimulates the diaphragm for breathing |
Sacral Plexus | Contains the sciatic Nerve runs down the back of the thigh, irritation of this nerve cause severe pain down the back of this leg |
Cerebrospinal Fluid is reabsorbed into the venous bloodstream by.... | Projections of the arachnoid mater into the Dural sinuses, called arachnoid villi |
Medulla Oblongata | Contains cardiac center, vasomotor center, and two respiratory centers |
Cerebellum | Monitors body movement and send messages for balance, coordination and posture |
Cerebellum | Stores the information necessary for muscle groups to work together to preform smooth, efficient, and coordinated movements. |
Cerebellum | Evaluates sensory input, such as, touch, spatial perception, and sound |
Thalamus | Resides on top of the brainstem, acts as a gateway for nearly every sensory impulse |
Hypothalamus | Controls the autonomic nervous system; contains centers for hunger, thirst and temperature regulation |
Frontal Lobe | Governs voluntary movements, memory, emotions, social judgment, decision making, reasoning, and aggression |
Limbic System | The "Emotional Brain" |
Hippocampus | Converts short term memory into long term memory |
Autonomic nervous system | Innervates glands, smooth muscle, and cardiac muscle; Consist of two nerve fibers that synapse at a ganglion before reaching target, secretes both acetylcholine and norepinephrine as neurotransmitters, May excite or inhibit target cells , Involuntary |
Sympathetic Nervous System | Prepares the body for activity, increases alertness, heart rate, sweat, inhibits intestinal motility ( Fight or Flight) |
Parasympathetic Nervous System | Calms body functions, has calming effect, decrease heart rate, constricts bronchial tubes, stimulates intestinal motility |
sympathetic division | Neurons Arise from thoracic and lumbar regions of spinal cord |
Sympathetic ganglia | exist in chains along both sides of the spinal cord |
Parasympathetic division | Neurons arise from the cranial and sacral regions of the spinal cord |
Parasympathetic ganglia | Reside in or near target organs |
Myelination of nerves begins during the.... | 14th week and isn't completed until late adolescence |
Type of stimulus | Cold receptors respond only to cold, light receptors only respond to light |
Location of stimulus | Responds to stimuli in a certain area, sensitive areas contain many receptors |
Intensity of stimulus | The stronger the stimulus, the more nerve fibers fire |
Adaptation | When stimulus is continuous, the firing frequency of the nerve slows, causing the sensation to diminish |
Chemoreceptors | React to chemicals, including odor and taste |
Mechanoreceptors | Respond to factors such as pressure, stretch, and vibration that change the position of receptor |
Thermoreceptors | Activated by a change in temperature |
Nociceptors | Respond to tissue damage from trauma as well as heat, chemicals, pressure, or a lack of oxygen |
Photoreceptors | Respond to light, only found in eyes |
Proprioceptors | Provide information about body movement, muscle stretch, and the general orientation of the body |
In Pain, nociceptors | consist of free nerve endings that carry impulses to the brain |
Fast | Abundant in the skin and mucous membrane; produce a sharp, localized, stabbing type pain at the time of injury |
Slow | Congregated on deep body organs and structures; produced a dull, aching pain |
Impulses bypass the thalamus and travels to the hypothalamus and limbic system.... | these area trigger emotional and behavioral responses to pain |
Referred pain | pain originating in a deep organ may be sensed as if it is originating from another area on the body surface |
Papillae | taste results when chemicals come in contact with taste buds, most of which are located in protrusions |
taste cranial nerves | facial nerve, glosspharyngeal nerve, and vagus nerve |
Smell | Incoming odor molecules bind to cilia projecting from the ends of olfactory receptor cells |
Tympanic membrane | Separates the outer from the middle ear, vibrates freely in response to sound waves;transmits sound waves from outer to middle ear |
Cochlea | Contains the structures for hearing |
The ripples in the peri lymph travel to the organ of corti, hairs of the organ of corti are stimulated and send impulses along the cochlear to brain..... | Where sound is perceived |
Vestibule and semicircular canals.... | Play a key role in balance |
Conjunctiva | Consist of transparent muscous membrane that lines inner eyelid and covers anterior surface of eyeball, secretes a thin mucous film to keep eye moist |
Cranial nerves associated with eye movement | Oculomotor, trochlear, and abducens |
Sclera | Outermost layer |
Cornea | Transparent extension of the sclera in the anterior part of the eye; sits over the iris and admits light |
Iris | Ring of colored muscle that adjust the diameter of the pupil to control the amount of light entering the eye |
Ciliary body | Forms a collar around the lens, secretes fluid called aqueous humor |
Chorid | Highly vascular layer of tissue that supplies oxygen and nutrients to the retina and sclera |
Retina | Thin layer of light sensitive cells |
Optic nerve | Transmits signals to the brain |
Fovea centralis | Where most cones are concentrated, making this the area that produces the sharpest vision |
Anterior cavity | Lies between the lens and cornea |
Posterior cavity | Lies posterior to the lens; large cavity filled with vitreous humor |
Lens | Transparent disk just behind the pupil |
Vitreous Humor | A jelly like substance that fills the posterior cavity of the eye |
Ciliary Body | Secrets aqueous humor |
Canal of schlemn | Drains aqueous humor from the anterior cavity; if becomes obstructed, pressure in the anterior cavity would rise |
Refraction | Light rays entering the eye must be bent so they focus precisely on the retina, bending of light rays |
Accommodation | The curvature of the lens changes to allow the eye to focus on a near object |