PCB3743 EXAM 2 STUDY GUIDE SP14Chapter 8 Central Nervous System (p. 204-209, 231-235)1. Know the very basic anatomy of the CNS as mentioned in lecture: spinal cord, brainstem, cerebellum, cerebrum, cerebral cortex, gryus, sulcus, ventricles & CSF, spinal nerves vs. cranial nerves. a. Central nervous system (CNS) - receive sensory inputs, coordinate response of the organs & functions of the body (spinal cord, brainstem, cerebellum, cerebrum)i. Spinal cord1. Ascending tracts – impulses from body receptors to brain2. Descending tracts – impulses from brain to bodyii. Brainstem1. From top down: midbrain, pons, respiratory centers, reticular formation, medulla oblongataa. Medulla = center for breathing/cardiovascular responsesiii. Cerebellum1. Second largest structure, controls motor systemiv. Cerebrum1. Right/left hemispheres, connected by corpus callosumv. Cerebral cortex 1. “bark” of the brain -- where cerebral neurons locatedvi. Gryus 1. bulging part of wrinkle on cortex2. allows local connections to use shorter axonsvii. Sulcus1. the valley of the fold (between the wrinkles)viii. Ventricles & CSF1. Spaces in brain and spinal cord filled with cerebral spinal fluid (CSF)ix. Spinal nerves1. Transmit motor, sensory, autonomic signals b/w spinal cord and body2. Ganglia – cluster of neurons3. Somatic nerves – motor neurons in CNS4. Impulses go from spinal cord to somatic motor neurons to musclesx. Cranial nerves1. Sensory/motor nerves straight to and from the brain2. 5 senses, balance, GI tract3. Nucleus – cluster of neurons12. Be able to point to the 4 different lobes of the cerebrum (Fox Figure 8.5a). a. Frontal lobe i. large lobe in front of brainii. motor control, personality, higher intellectual proccessesb. Parietal lobe i. second large lobe behind frontal lobeii. somatesthetic interpretation (cutaneous/muscular sensations); understanding speech, formulating words to express thoughts and emotions; interpretation of textures/shapesc. Temporal lobe i. on sides near the templesii. interpret audition, auditory/visual memoryd. Occipital lobe i. back of headii. focusing the eye, perception of vision23. Understand the homunculus of the motor and somatosensory cortex. a. Homunculusi. Map of sensory input and motor output; map looks like “little person”1. Parts of body w/ high density of sensory input get bigger share of somatosensory cortex (hands and face)2. Parts of body w/ finest motor control get bigger share of motor cortex (muscles)a. Motor cortexi. In front of central sulcusii. Neurons that initiate movement, sending axons to spinal moto neuronsb. Somatosensory cortex i. Behind central sulcusii. End of sensory information coming from skinii. Sensation crosses over: felt on right side of body, sent from right side of brain1. Touch crosses over late but temperature/pain cross immediatelya. Can be used to detect brain/spinal cord damage3Chapter 9 Autonomic Nervous SystemSympathetic and Parasympathetic Nervous Systems 1. Be able to compare & contrasting the sympathetic (SNS) and parasympathetic (PNS) nervous systems. a. Sympathetic Nervous System (SNS) i. activate the response of the body during stressful situations, mobilize energy, divert blood to muscle (fight or flight)ii. Pathway: nerves from spinal cord to chain ganglia then to glands and smooth muscleb. Parasympathetic Nervous System (PNS) i. controls activities when body is at rest: prepare for digestion, energy storage, divert blood flow to gut (rest and digest)ii. Pathway: nerves from brainstem/spinal cord to glands/ smooth muscleiii. (opposite effect of SNS)2. You do NOT need to memorize all the specific effects of the autonomic nervous system, but be familiar with the examples covered in lecture. a. SNSi. Dilate pupilii. Accelerate heartiii. Stimulate adrenal medullaiv. Inhibit salivationv. Inhibit activity of stomach/intestinesb. PNSi. Constrict pupilii. Stimulate salivary glandiii. Slows heartiv. Stimulate activity of stomach/intestinesv. Stimulate activity of pancreas43. Know the (general) location of the preganglionic cell bodies and the ganglionic cell bodies (Recognize the parts of Fox Figure 9.5; do NOT need to memorize any of the specific nerves or what nerve projects to which organ). a. Spinal cord preganglionic neuron autonomic ganglion postganglionic neuron organ54. Understand the sympathetic chain ganglia and adrenal medulla circuitry in particular.a. Sympathetic chain gangliai. White ramus – connects spinal roots to sympathetic chain ganglion (preganglionic going into ganglion)ii. Gray ramus – connects sympathetic chain ganglion to different organ pathways (postganglionic leaving out of ganglion)b. Adrenal Medulla Circuitryi. Modified sympathetic ganglionii. Preganglionic fibers stimulate medullary cells to secrete epinephrine/norepinephrine into blood5. Know the major neurotransmitters used by the SNS and PNS neurons. a. Acetylcholine – preganglionic nerves release ACh to stimulate nicotinic receptors on postganglionic cells (both PNS and SNS neurons)i. (nicotinic receptors blocked by curare)ii. PNS postganglionic neurons also release ACh onto muscarinic receptors1. (muscarinic receptors blocked by atropine)b. Norepinephrine – postganglionic cells release NE to stimulate/inhibit adrenergic receptors on target tissues (SNS neurons)i. (Adrenergic receptors blocked by alpha/beta blockers)c. Exception: sympathetic fibers to sweat glands use ACh6. Understand the regulation of pupil constriction and dilation (and the drugs used to test pupil size), the control of sweating.a. Pupil constriction – PNS contracts circular muscle by sending ACh to muscarinic receptorb. Pupil dilation – SNS contracts radial muscle by sending NE to adrenergic receptor (cocaine increases NE so pupil dilates)c. Sweating – affected only by SNS, use ACh to muscarinic receptors (sweating is the exception)Thermoregulation and Fever1. Understand the concept of set point regulation, and the effects of raising or lowering the set point for body temperature. a. Body responds to restore body temp. to set pointi. Temperature > set point = too hot, sweat and vasodilate skinii. Temperature < set point = too cold, shiver and conserve heatOR6b. Central set point changes (responds to bring body temp to new set point)i. Lower set point – body responds as if hotii. Raise set point – body responds as if cold2. Know the 2 centers in the hypothalamus (preoptic area and posterior area) that regulate
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