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150 Cards in this Set
- Front
- Back
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What does the autonomic nervous system innervate? (7)
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It innervates visceral organs (smooth muscles), glands, blood vessels, heart, lungs, GI tract, and endocrine glands.
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What does the autonomic nervous system control?
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It controls the function of visceral ogans and regulates them.
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What is the function of the sympathetic system?
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It prepares and mobilizes the body in emergencies (fight or flight). It accelerates contraction of smooth muscle, mostly in the GI tract.
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Stimulation of the sympathetic system leads to? (7)
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Increased heart rate
Constriction of the arterioles of the skin and intestine, dialation of those of the skeletal muscle Raised blood pressure Dialation of the pupils Sphincters close Hair stands Sweating |
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What is the function of the parasympathetic system?
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It conserves and stores energy, normally during sleep.
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Stimulation of the parasympathetic system leads to? (7)
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Decreased heart rate
Pupil constriciton Increased peristalsis Increased glandular activity Sphincters open Bladder wall is contacted Increased motility of GI tract |
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Where are sympathetic ganglia located?
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In the paravertebral chain.
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Where are parasympathetic ganglia located?
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In or near the effector organs.
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What neurotransmitter does a preganglionic fiber produce?
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Acetylcholine.
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What neurotransmitter does a postganglionic fiber produce?
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Norepinephrine.
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What is the origin of the sympathetic or paravertebral ganglion?
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Cell bodies lie in the lateral horn of the spinal cord. T1-L2 or L3.
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What is the origin of the parasympathetic ganglion?
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CN III: occulomotor
CN VII: facial CN IX: glossopharengyl CN X: vagas S1, S2, and S3 (pelvic splanchnic nerves) |
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What neurotransmitter does an adrenergic receptor release?
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Norepinephrine.
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What neurotransmitter does a cholinergic neuron release?
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Acetylcholine.
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Where are alpha 1 receptors located? (3)
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On vascular smooth muscle, in the GI and bladder sphincters, and radial muscle of the iris.
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Do alpha 1 receptors produce excitation or inhibition?
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Excitation: contraction and constriction.
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Where are alpha 2 receptors located? (4)
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In presynaptic nerve terminals, platelets, fat cells, and walls of the GI tract.
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Do alpha 2 receptors producte excitation or inhibition?
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Inhibition: relaxation or dialation.
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Where are beta 1 receptors located? (3)
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In the sinoatrial (SA) node, atrioventricular (AV) node, and ventricular muscle of the heart.
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Do beta 1 receptors produce excitation or inhibition?
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Excitation: increased heart rate, increased conduction velocity, and increased contractility.
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Where are beta 2 receptors located? (3)
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On vascular smooth muscle of skeletal muscle, bronchial smooth muscle, and in the walls of the GI tract and bladder.
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Do beta 2 receptors produce excitation or inhibition?
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Inhibition: dialation of vascular smooth muscle, dialation of bronchioles, and relaxation of the bladder wall.
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Where are nicotinic receptors located? (3)
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In the autonomic ganglia of the sympathetic and parasympathetic systems, at the neuromuscular junction, and in the adrenal medulla.
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Do nicotinic receptors produce excitation or inhibition?
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Excitation.
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Where are muscarinic receptors located? (3)
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In the heart, smooth muscle, and glands.
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Where are muscarinic receptors excitatory?
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In smooth muscle and glands: increased GI motility, increased secretion.
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Where are muscarinic receptors inhibitory?
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In the heart: decrease heart rate, decrease conduction velocity in the AV node.
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In the parasympathetic system, what neurotransmitter is released by the postganglionic fiber?
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Acetylcholine.
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In the sympathetic system, what neurotransmitter is released by the postganglionic fiber?
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Norepinephrine.
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What autonomic centers are located in the medulla oblongata? (5)
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Vasomotor, respiratory, swallowing, coughing, and vomiting centers.
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What autonomic center is located in the pons?
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The pneumotaxic center: regulates respiratory rate.
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What autonomic center is located in the midbrain?
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The micturition center: controls urination and renal system.
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What autonomic centers are located in the hypothalamus? (3)
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Temperature, thirst, and food intake regulatory centers.
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Chronotropic
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Heart rate
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Dromotropic
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Contractility and conduction velocity
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Which system controlls the adrenal medulla?
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The symathetic system activates secretion of hormones and neurotransmitters.
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What neurotransmitters are secreted by the adrenal medulla?
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Epinephrine and norepinephrine.
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Which system controls ejaculation?
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Both sympathetic and parasympathetic.
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What are examples of mechanoreceptors? (5)
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Pacinain corpuscles, joint receptors, stretch receptors in muscles, hair cells in auditory and vestibular systems, and baroreceptors in carotid sinus.
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What are examples of photoreceptors? (2)
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In the rods and cones of the retina.
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Whatare examples of chemoreceptors? (4)
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Olfactory receptors, taste receptors, osmoreceptors, and carotid body O2 receptors.
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What receptor transmits extremes of temperature and pain?
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Nociceptors.
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What is the fastest type of fiber?
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A-alpha: large alpha-motorneurons.
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What are the medium speed fibers?
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A-beta: touch and pressure
A-gamma: gamma-motorneurons to intrafusal fibers A-delta: touch, pressure, temperature, and pain B: preganglionic autonomic fibers. |
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What is the slowest type of receptor?
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C: postganglionic autonomic fibers; slow pain.
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What is the receptive field?
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An area of the body that, when stimulated, changes the firing rate of a sensory neuron.
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If the firing rate of a sensory neuron is increased, what happens to the receptive field?
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The receptive field becomes excitatory.
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If the firing rate of a sensory neuron is decreased, what happens to the receptive field?
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The receptive field becomes inhibitory.
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How are sensory receptors activated?
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By environmental stimuli.
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Where are primary afferent neurons located? What do first order neurons do?
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Cell bodies are in the dorsal root or spinal cord ganglia.
They receive the transduced signal and send the information to the CNS. |
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Where are second order neurons located? Where does sensory information go from here?
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In the spinal cord or brain stem.
They receive information from one or more primary afferent neurons in the relay nucleus and transmit it to the thalamus. |
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Where are third order neurons located? Where does sensory information go from here?
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In the relay nuclei of the thalamus.
From here, sensory information ascends to the cerebral cortex. |
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Where are fourth order neurons located? What do forth order neurons do with the sensory information?
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In the sensory area of the cerebral cortex.
The information received results in a conscious perception of the stimulus. |
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What does the somatosensory system do?
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It processes information about touch, pain, and temperature.
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What kinds of receptors are in the somatosensory system? (3)
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Mechanoreceptors for touch, thermoreceptors for temperature, and nociceptors for pain.
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What are the somatosensory pathways? (2)
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Dorsal column system
Anterolateral system |
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What does the dorsal column system do?
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Processes sensations of fine touch, pressure, two-point discrimination, and vibration.
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What does the anterolateral system do? What does it primarily consist of?
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Processes sensations of temperature, pain, and light touch.
It consists primarily of fibers which enter the spinal cord and terminate in the dorsal horn. |
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What happens when the thalamic nuclei is destroyed?
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Loss of sensation on the contralateral side of the body.
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Where are pain receptors located?
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In free nerve endings in the skin, muscle, and viscera.
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What is the neurotransmitter for nociceptors?
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Substance P. Inhibition of the release of substance P is the basis of pain relief.
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What fibers carry fast pain?
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A-delta fibers. Fast pain has a rapid onset and offset, and is localized.
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What fibers carry slow pain?
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C fibers. Slow pain is characterized as aching, burning, or throbbing that is poorly localized.
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Which cranial nerves transduce the sense of taste? (3)
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CN VII: anterior tow thirds of tongue and soft palate
CN IX: posterior one third of the tongue CN X: back of the oral cavity Dendrite endings of these nerves are located around the taste buds and relay sensations of touch and temperature. |
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From the taste buds, where are taste sensations relayed to?
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The medulla oblongata.
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Where on the tongue can salty flavors be transduced by taste buds?
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Around the edges of the tongue.
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Where on the tongue can sour flavors be transduced by taste buds? What does sour taste indicate?
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On the sides of the tongue.
Sour taste signals the presence of acidic compounds. |
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Where on the tongue can bitter flavors be transduced by taste buds?
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At the back of the tongue.
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Where on the tongue can sweet flavors be transduced by taste buds?
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On the tip of the tongue.
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Ageusia
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Loss of taste from damage to the facial nerve (CN VII)
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Hypogeusia
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Decreased taste sensitivity.
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Hypergeusia
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Increased taste sensitivity.
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What might cause a sore tongue?
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Trauma, such as biting your tongue or eating hot foods. If teeth don't fit together properly, tongue trauma is more likely. It can also occur because of teeth grinding (bruxism).
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Glossodynia
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A condition characterized by a burning sensation on the tongue.
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Benign Migratory Glossitis
(Geographic Tongue) |
Irregular and inflamed patches on the tongue surface that have white borders. The tongue may be generally swollen, red, and sore.
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Where are olfactory receptor cells located?
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In the olfactory epithelium.
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Where does sensory information go from the olfactory receptor cells?
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To the olfactory bulb
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What kinds of fibers are the olfactory nerves made of?
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Unmyelinated C fibers; they are among the smallest and slowest in the nervous system.
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What does the trigeminal nerve (CN V) innervate in the olfactory epithelium?
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CN V detects noxious or painful stimuli, such as ammonia.
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What might a fracture to the cribriform plate cause?
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It could sever input to the olfactory bulb and reduce or eliminate the sense of smell because the olfactory nerves pass through the cribiform plate.
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What are second order neurons of the olfactory bulb called?
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Mitral cells. Output of the mitral cells forms the olfactory tract.
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Anosmia
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Lack of olfaction, or a loss of the sense of smell.
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Phantosmia
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The phenomenon of smelling odors that aren't really present.
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Dysosmia
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When things smell differently than they should.
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What is the sclera?
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A tough, white, fibrous layer that maintains, protects, and supports the shape of the eye.
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What is the cornea?
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The transparent front portion of the sclera, which refracts light rays.
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What is the choroid?
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The thin middle layer of the eye. It is the vascular layer between the retina and the sclera. It contains a nonreflective pigment that acts as a light shield and prevents light from scattering.
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What cells are within the retina?
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Photoreceptors known as rods and cones.
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What kind of light is interpreted by rods?
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Rods are sensitive to light and do not see color.
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What kind of light is interpreted by cones?
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Cones are sensitive to different wavelengths of light, they see colors.
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What is the optic disc?
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The area where the optic nerve leaves the eye. Also known as the blind spot because it has no photoreceptors.
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What is the fovea centralis?
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A small area where light focuses and cone cells are densely packed. It has the highest visual acuity and contains no rods.
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What are the layers of the retina? (6)
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1. Pigment epithelial cell (absorbs stray light and prevents light scattering)
2. Receptor cells (rods and cones) 3. Bipolar cells 4. Horizontal cells 5. Amacrine cells 6. Ganglion cells (output cells of the retina) |
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Color Blindness
(Color Vision Deficiency) |
The inability to perceive differences between some or all colors that other people can distinguish.
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Night Blindness
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The most common cause is retinitis pigmentosa, a disorder in which rod cells gradually lose their ability to respond to the light.
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Glaucoma
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An eye condition that develops when too much fluid pressure builds up inside of the eye. When Schelemn's canal is blocked, fluid builds up and causes intraocular pressure which can damage the optic nerve. Without treatment, glaucoma can cause permanent blindness.
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Visual Agnosia
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The inability of the brain to make sense of or make use of some part of otherwise normal visual stimulus. The inability to recognize familar objects or faces.
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Emmetropia
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Normal vision where light focuses on the retina.
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Hypertropia
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Farsightedness where light focuses behind the retina. Corrected with a convex lens.
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Myopia
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Nearsightedness where light focuses in front of the retina and is corrected with a concave lense.
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Astigmatism
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The curvature of the lens is not uniform and is corrected with a cylindric lens.
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What fluid is found in the scala vestibuli and scala tympani?
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Perilymph, which has a high sodium concentration.
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What fluid is found in the scala media?
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Endolymph, which has a high potassium concentration.
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Where is the organ of corti located?
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Inside the scala media, between the basilar membrane and the tectorial membrane.
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How does sound travel through the ear?
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Tympanic membrane --> malleus, incus, stapes --> oval window --> scala vestibuli --> scala tympani --> scala media and organ of corti
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Otitis Media
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An inflammation of the middle ear segment from a buildup of fluid. Untreated could lead to meningitis.
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What part of the ear detects linear and rotational movement?
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The vestibular apparatus detects linear acceleration. Utricle for horizontal and saccule for vertical. The semicircular canals detect rotational movement.
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What fluids are found in the semicircular canals?
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Both endolymph and perilymph.
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Which way does the stereocilia of a hair cell bend for depolarization or excitation?
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The stereocilia bend towards the kinocilium. When the stereocilia are bent away from the kinocilium, the hair cell hyperpolarizes or is inhibited.
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Where do afferent nerves from the vestibular hair cells terminate?
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In the vestibular nuclei of the medulla.
Superior and medial nuclei: CN III and CN IV Inferior nuclei: brain stem and cerebellum Lateral nuclei: spinal cord motorneurons |
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Nystagmus
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When the head is roatated it causes the eyes to move slowly in the opposite direction to maintain visual fixation. When the limit of eye movement is reached, the eyes to rapidly snap back in the same direction as the head rotation.
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Vertigo
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Dizziness associated with a problem in the inner ear balance mechanisms, in the brain, or with the nerve connections between the two organs.
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Where are neurons located? What do they do?
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Neurons are found in grey matter of the central nervous system and ganglia.
They transmit electrical signals. |
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What are neuroglial cells?
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They are support cells that surround and wrap neurons. They are nonexcitable.
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What are the characteristics of neurons? (6)
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Conduct electrical impulses along the plasma membrane
Produce nerve impulse Produce action potential Can live and function for a lifetime Do not divide Require abundant oxygen and glucose |
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What is another name for the cell body of a neuron?
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Perikaryon.
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What is the initial segment of an axon?
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It is the most exicitable site and the site of action potential.
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What is the function of supporting cells?
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To provide supportive functions for neurons and cover nonsynaptic regions of neurons.
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What are Schwann cells?
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They are cells which form myelin sheaths around peripheral axons.
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What are satellite cells or ganglionic gliocytes?
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They support neuron cell bodies within the ganglia of the peripheral nervous system.
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What are oligodendrocytes?
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Small cell bodies which form myelin sheaths around axons of the central nervous system.
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What are microglia?
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Small neurological cells which migrate through the CNS and phagocytose foreign and degenerated material, during times of inflammation or degeneration of the CNS.
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What are ependymal cells?
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A single layer of cuboidal cells that line the ventricles of the brain and the central canal of the spinal cord.
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What are astrocytes?
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Small cell bodies which help to regulate the external environment of neurons in the CNS.
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What molecules do astrocytes absorb? (4)
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Glucose, glutamate, potassium, and GABA.
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What do astrocytes do when a neuron dies?
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They proliferate and fill the spaces previously occupied by neurons.
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What is gliosis?
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Hyperplasia (increase in cell numbers) and hypertrophy (increase in the volume of an organ's component cells) of astrocytes that occurs in response to a CNS injury.
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What accounts for 50% of intracranial tumors?
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Tumors of neuroglia (glioma) such as astrocytomas and glioblastomas.
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Multiple Sclerosis
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An unknown disease causes demyelination in the CNS that usually starts with the optic nerve, spinal cord, and cerebellum. Axonal degeneration is part of the disability.
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What forms white matter of the brain?
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Areas of the CNS that contain a high concentration of axons. The myelin sheaths around axons of the CNS give the tissue a white color.
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What forms gray matter of the brain?
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High concentrations of cell bodies and dendrites that lack myelin sheaths.
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What happens when the axon of a peripheral nerve is cut?
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The severed part degenerates and is phagocytosed by Schwann cells, which then form a regeneration tube.
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What happens when the axon in the central nervous system is cut?
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No extensive regeneration occurs because of the inhibitory environment produced by oligodendrocytes and astrocytes. Glial scars form, and axons cannot grow across them.
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What growth factors do neurotrophins release? (4)
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Nerve growth factor (NGF)
Brain-derived neurotrophic factor (BDNF) Glial-derived neurotrophic factor (GDNF) Neurotrophin 3 |
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What is the blood brain barrier?
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The barrier between cerebral capillary blood and the cerebral spinal fluid, which is found in the ventricles of the brain and the subarachnoid space in the spinal cord.
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What substances travel freely across the blood brain barrier?
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Lipid soluble substances like carbon dioxide and oxygen, and water.
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Why can't neurotransmitters cross the blood brain barrier?
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So that they stay in their functional sites inside the CNS.
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CSF and blood have equal quantities of? (4)
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Na+
Cl- HCO3- Osmolarity |
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CSF has lower quantities of? (5)
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K+
Ca2+ Glucose Cholesterol Protein |
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CSF has higher quantities of? (2)
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Mg2+
Creatinine |
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What are the most common forms of synapses?
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Axodendritic and axosomatic.
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What is a chemical synapse?
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A synapse where neurotransmitters are released from a pre-synaptic neuron. The neurotransmitter becomes attached to a protein receptor at a postsynaptic membrane. Chemical synapses are unidirectional.
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Where is acetylcholine found?
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At neuromuscular junctions, in autonomic ganglia, and in parasympathetic nerves.
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Where is norepinephrine found?
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At sympathetic nerve endings and in the hypothalamus.
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Where is dopamine found?
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In basal ganglia and the hypothalamus.
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What happens to neurotransmitters after they are used?
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They are either destructed in the cleft or reabsorbed by the presynaptic part.
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What kind of junctions use electrical synapses?
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Gap junctions, which are bidirectional.
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What does serotonin regulate? (6)
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Levels of stress hormones, anger, mood, sleep, sexuality, and appetite.
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What disorders are associated with low serotonin levels? (4)
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Increase in aggressive and angry behaviors
Clinical depression Migrane Bipolar or anxiety disorders |
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If neurons of the brain stem that make serotonin are abnormal there is a risk of?
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Sudden infant death syndrome.
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