Nervous System Part 2 Lecture Outline (PDF)

Because learning changes everything.® Nervous System Part 2 Lecture Outline Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. The Nervous System The nervous system can be divided into the central...

Because learning changes everything.® Nervous System Part 2 Lecture Outline Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. The Nervous System The nervous system can be divided into the central nervous system and the peripheral nervous system. The central nervous system (CNS), consists of the brain and spinal cord. The peripheral nervous system (PNS) consists of all the nerves and ganglia outside the brain and spinal cord. Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 2 Spinal Cord Extends from the foramen magnum to the 2nd lumbar vertebra Protected by vertebral column Spinal nerves allow movement If damaged paralysis can occur Figure 8.14 Access the text alternative for slide images. Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 3 Gray Matter and White Matter Gray Matter: center of spinal cord looks like letter H or a butterfly White Matter: Outer layer of spinal cord contains myelinated fibers Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 4 Spinal Cord Cross Section Figure 8.15 Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 5 Reflexes A reflex is an involuntary reaction in response to a stimulus applied to the periphery and transmitted to the CNS. Reflexes allow a person to react to stimuli more quickly than is possible if conscious thought is involved. Most reflexes occur in the spinal cord or brainstem rather than in the higher brain centers. A reflex arc is the neuronal pathway by which a reflex occurs and has five basic components. Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 6 Reflex Arc Components 1. A sensory receptor 2. A sensory neuron 3. Interneurons, which are neurons located between and communicating with two other neurons 4. A motor neuron 5. An effector organ (muscles or glands). Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 7 Reflex Arc Figure 8.16 Access the text alternative for slide images. Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 8 Reflexes 1 The simplest reflex is the stretch reflex. A stretch reflex occurs when muscles contract in response to a stretching force applied to them. The knee-jerk reflex, or patellar reflex is a classic example of a stretch reflex. Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 9 Reflexes 2 The withdrawal reflex, or flexor reflex, is to remove a limb or another body part from a painful stimulus. The sensory receptors are pain receptors, and stimulation of these receptors initiates the reflex. Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 10 Spinal Nerves Arise along spinal cord from union of dorsal roots and ventral roots. Contain axons of sensory and somatic motor neurons. Located between vertebra. Categorized by region of vertebral column from which it emerges (C for cervical). 31 pairs organized in 3 plexuses. Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 11 Cervical Plexus Spinal nerves C1-C4 Innervates muscles attached to hyoid bone and skin of neck and back of head. Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 12 Brachial Plexus Originates from spinal nerves C5-T1. Supply nerves to the upper limbs, shoulders, hand. Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 13 Lumbosacral Plexus Originates from spinal nerves L1 to S4. Supplies nerves lower limbs. Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 14 Plexuses Figure 8.19a Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 15 The Brain The four major regions of the brain are: the brainstem the cerebellum the diencephalon the cerebrum Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 16 Brainstem Dennis Strete/McGraw-Hill Education Components: Medulla oblongata Pons Midbrain Figure 8.20 Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 17 Brainstem Components 1 Medulla oblongata Location: continuous with spinal cord Function: regulates heart rate, blood vessel diameter, breathing, swallowing, vomiting, hiccupping, coughing, sneezing, balance Other: involved in conscious control of skeletal muscle Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 18 Brainstem Components 2 Pons Location: above medulla, bridge between cerebrum and cerebellum Function: breathing, chewing, salivation, swallowing, relay station between cerebrum and cerebellum Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 19 Brainstem Components 3 Midbrain Location: above pons Function: coordinated eye movement, pupil diameter, turning head toward noise Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 20 Brainstem Components 4 Reticular Formation Location: scattered throughout brainstem Function: regulates cyclical motor function, respiration, walking, chewing, arousing and maintaining consciousness, regulates sleep-wake cycle Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 21 Cerebellum Location: attached to the brainstem by the cerebellar peduncles Characteristics: means “little brain” cortex is composed of gyri, sulci, gray matter Functions: controls balance muscle tone coordination of fine motor function Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 22 Diencephalon 1 Dennis Strete/McGraw-Hill Education Located between the brainstem and cerebrum Components: Thalamus Hypothalamus Epithalamus Figure 8.20 Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 23 Diencephalon Components 1 Thalamus Characteristics: largest portion of diencephalon Function: influences moods and detects pain Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 24 Diencephalon Components 2 Epithalamus: Location: above thalamus Function: emotional and visceral response to odors contains the pineal gland which is an endocrine gland that plays a role in controlling some long-term cycles that are influenced by the light-dark cycle Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 25 Diencephalon Components 3 Hypothalamus Location: below thalamus Characteristics: controls pituitary gland and is connected to it by infundibulum Function: controls homeostasis, body temp, thirst, hunger, fear, rage, sexual emotions Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 26 Diencephalon 2 Figure 8.22 Access the text alternative for slide images. Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 27 Cerebrum Characteristics Largest portion of brain Divisions: Right hemisphere Left hemisphere separated by longitudinal fissure Lobes: frontal, parietal, occipital, and temporal, Rebecca Gray/McGraw-Hill Education Figure 8.23b Access the text alternative for slide images. Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 28 Cerebrum Components Cerebral Cortex Location: surface of cerebrum, composed of gray matter Function: controls thinking, communicating remembering, understanding, and initiates voluntary movements Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 29 Cerebrum Surface Features Longitudinal fissure: divides cerebrum into left and right hemispheres Gyri: folds on cerebral cortex that increase surface area Sulci: shallow indentations Fissure: deep indentations Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 30 Cerebral Hemispheres Left hemisphere: controls right side of body responsible for math, analytic, and speech Right hemisphere: controls left side of body responsible for music, art, abstract ideas Corpus callosum: connection between the two hemispheres Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 31 Lobes of the Brain 1 Frontal lobe Location: anterior Function: controls voluntary motor functions, aggression, moods, smell Parietal lobe Location: top Function: evaluates sensory input such as touch, pain, pressure, temperature, taste Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 32 Lobes of the Brain 2 Occipital lobe Location: posterior Function: vision Temporal lobe Location: lateral Function: hearing, smell, memory Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 33 Cerebrum 1 ©R. T. Hutchings Figure 8.23a Access the text alternative for slide images. Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 34 Cerebrum 2 Rebecca Gray/McGraw-Hill Education Figure 8.23b Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 35 Speech Mainly in left hemisphere Sensory speech (Wernicke’s area): parietal lobe where words are heard and comprehended Motor speech (Broca’s area): frontal lobe where words are formulated Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 36 Meninges 1 The meninges are three connective tissue layers that surround the brain and spinal cord. The outermost (most superficial) meningeal layer is the dura mater, which is the toughest of all the meninges. The second meningeal membrane is the very thin, arachnoid mater. Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 37 Meninges 2 The space between the dura mater and the arachnoid mater is the subdural space, The third meningeal membrane, the pia mater, is very tightly bound to the surface of the brain and spinal cord. Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 38 Meninges 3 Between the arachnoid mater and the pia mater is the subarachnoid space, which is filled with cerebrospinal fluid and contains blood vessels. Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 39 Meninges Figure 8.33 Access the text alternative for slide images. Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 40 Ventricles 1 The CNS contains fluid-filled cavities, called ventricles. Each cerebral hemisphere contains a relatively large cavity called the lateral ventricle. Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 41 Cerebrospinal Fluid 1 Cerebrospinal Fluid Cerebrospinal fluid (CSF) bathes the brain and spinal cord, providing a protective cushion around the CNS. The ependymal cells located in the choroid plexuses of the ventricles produce the CSF. CSF fills the brain ventricles, the central canal of the spinal cord, and the subarachnoid space. Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 42 Flow of Cerebrospinal Fluid Figure 8.35 Access the text alternative for slide images. Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 43 Cranial Nerves 1 12 pair of cranial nerves Named by roman numerals 2 categories of functions: sensory and motor Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 44 Cranial Nerves 2 Cranial Nerve I (Olfactory) is a pure sensory nerve for smell Cranial Nerve II (Optic) is a pure sensory nerve for vision Cranial Nerve III (Occulomotor) is a pure motor nerve for eye movement Cranial Nerve IV (Trochlear) is a pure motor nerve for eye movement Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 45 Cranial Nerves 3 Cranial Nerve V (Trigeminal) is both a motor and sensory nerve. It is sensory for pain, touch, and temperature for the eye and lower and upper jaws. It is motor for muscles of chewing. Cranial Nerve VI (Abducens) is a pure motor nerve for eye movement Cranial Nerve VII (Facial) is both a sensory and motor nerve. It is sensory for taste and motor for facial expression. Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 46 Cranial Nerves 4 Cranial Nerve VIII (Vestibulocochlear) is a pure sensory nerve for hearing and equilibrium Cranial Nerve IX (Glossopharyngeal) is both a motor and sensory nerve. It is sensory for taste and motor for swallowing. Cranial Nerve X (Vagus) is both a motor and sensory nerve. It is sensory and motor for organs in the thoracic and abdominal cavities. Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 47 Cranial Nerves 5 Cranial Nerve XI (Accessory) is a pure motor nerve for the trapezius, sternocleidomastoid, and muscles of the larynx. Cranial Nerve XII (Hypoglossal) is a pure motor nerve for the tongue Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 48 Cranial Nerves 6 Figure 8.36 Access the text alternative for slide images. Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 49 Autonomic Nervous System 1 The autonomic neurons innervate smooth muscle, cardiac muscle, and glands. Autonomic functions are largely controlled unconsciously. The autonomic nervous system is composed of the sympathetic division and the parasympathetic division. Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 50 Autonomic Nervous System 2 Increased activity in sympathetic neurons generally prepares the individual for physical activity, whereas parasympathetic stimulation generally activates involuntary functions, such as digestion, that are normally associated with the body at rest. Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 51 Autonomic Nervous System 3 In the autonomic nervous system, two neurons in series extend from the CNS to the effector organs. The first neuron is called the preganglionic neuron; the second neuron is the postganglionic neuron. Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 52 Enteric Nervous System 2 Enteric neurons are capable of monitoring and controlling the digestive tract independently of the CNS through local reflexes. For example, stretching of the digestive tract is detected by enteric sensory neurons, which stimulate enteric interneurons. The enteric interneurons stimulate enteric motor neurons, which stimulate glands to secrete. Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 53  Because learning changes everything. ® www.mheducation.com Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC.