Chapter 11- Nervous System II PowerPoint Presentation to accompany Hole’s Human Anatomy and Physiology, 10 th edition , edited by S.C. Wache for Biol2064.01
You are responsible for the following figures and tables : Review Fig. 10.7. Differentiate CNS and PNS general tasks. Compare Fig. 11.5 - Structure of the CNS - the brain and spinal cord. Compare Tab. 11.9 and Fig. 11.29 - Components of the PNS Fig. 11.1 , 11.2 - meninges. Fig. 11.3, 11.4 - CSF. TB, blue box, p. 368 Clinical Applications 11.1 - Spinal tap. Fig. 11.6 - Structure of the spinal cord. Fig. 11.7 - Define 'reflex arc‘. Fig. 11.8, 11.9 - Examples: Knee-jerk reflex, withdrawal reflex. Tab. 11.2 - Study the parts of a reflex arc. Fig. 11.15, Tab. 11.7 - CNS/ Brain structure - Read p.388-391, endocrine functions. Fig. 11.16 - Note fissures, sulci, gyri. Fig. 11.17, 11.18 - Areas of the cerebrum. Tab. 11.5 - Functions of the cerebral lobes. Fig. 11.25. PNS / Cranial nerves . Fig. 11.26. The vagus nerve # X, is important. Fig. 11.6.- CNS/ Spinal cord structure. Fig. 11.29 - PNS/ Spinal nerves - (see table in the attached lecture handout). Fig. 11.35 - ANS innervates smooth muscle and glands. Fig. 11.40 - sympathetic / parasympathetic nerves (see diagram in the attached lecture).
The meninges are membranes that protect the brain and the spinal cord
Insula: the lobe in the center of the cerebral hemisphere that is situated deeply between the lips of the sylvian fissure -- called also central lobe, island of Reil
Note the lobes, fissures and sulci.
Brain Areas and Their Functions (Tab. 11.5) visual association area / perceptions occipital lobes Wernicke’s speech comprehension area; primary auditory / hearing association area temporal lobe gustatory area parietal lobe / along lateral sulcus primary olfactory area, Broca’s speech motor area frontal lobe concerned autonomic functions , limbic system hypothalamus integrates neurons for short-term memory thalamus is part of the diencephalon short-term memory processing, limbic system (emotions and motivation) lateral ventricle hippocampus / internal frontal lobe areas Function Region of Brain
Cerebral Functions (Fig. 11.16)
Broca’s area : motor speech area
Frontal eye field : voluntary eye movements
Motor areas: primary motor areas contain pyramidal cells and contain synapses with descending spinal tracts.
Sensory Areas : contain synapses from ascending tracts
Association Areas : regions rich in interneurons that are neither motor or sensory, but interconnect with each other and other centers.
General interpretative area (Wernicke’s area): complex thought processing
Cerebral Lobes (Figure 11.18)
Frontal lobes : motor areas for voluntary skeletal muscles, association areas
Parietal lobes : sensory areas of temperature, touch, pressure, pain, speech association
Temporal lobes: sensory area for hearing, sensory association areas
Occipital lobes : sensory area for vision, visual association area
Cerebral Lobe Functions
Both hemispheres participate in basic functions.
One side is usually the dominant hemisphere for some functions.
For 90% of the population the left side is dominant for language-related activities of speech, writing, reading.
Coronal Cut - Left Cerebral Hemisphere (Fig.11.19)
Short-term memory : patterns of synapses that change;
Limbic system (emotions and motivation): thalamus integrates neurons for short-term memory
Long-term memory :
patterns of synapses that remain unchanged.
Basal Nuclei: masses of gray matter which consists of unmyelinated interneurons within the cerebral hemispheres
Hippocampus: a curved elongated ridge that is an important part of the limbic system , extends over the floor of the descending horn of each lateral ventricle of the brain, and consists of gray matter covered on the ventricular surface with white matter;
a region of the cerebral cortex that performs repeated stimulations to strengthen synapses.
Caudate nucleus, putamen, globus pallidus:
Relay motor impulses and produce the inhibitory neurotransmitter, dopamine
Posterior and anterior pituitary gland (controls a variety of effector endocrine glands) attached to the hypothalamus via the infundibulum
Optic tract and optic chiasma ( cranial sensory nerve II )
Pineal gland releases melatonin which controls the biorhythm / circadian rhythm
Composed of portions of the cerebral cortex, thalamus, hypothalamus, basal nuclei, and other deep nuclei
Controls emotional experiences
Produces feelings of fear, anger, pleasure
Interprets sensory impulses of smell / olfactory sense
Connects brain stem and spinal cord with the CNS
Cerebral peduncles : motor and sensory pathways
Red nucleus : posture reflexes
Superior colliculi: visual reflexes
Inferior colliculi: auditory reflexes
Fig. 11.20 midbrain Medulla oblongata
Brain Stem-dorsal view (Fig. 11.20)
Midbrain: the middle division of the three primary divisions of the adult brain that includes a ventral part with the cerebral peduncles and a dorsal part with the corpora quadrigemina and that surrounds the aqueduct of Sylvius connecting the third and fourth ventricles
Pons: sensory impulses relayed to brain, works with the medulla oblongata
Medulla Oblongata: ascending and descending tracts pass through; contains the cardiac center which controls heart rate; contains the vasomotor center which controls blood pressure; contains the respiratory center which controls rate, rhythm, depth of breathing;
corticospinal tract: any of four columns of motor fibers of which two run on each side of the spinal cord and which are continuations of the pyramids of the medulla oblongata : PYRAMIDAL TRACT : a : LATERAL CORTICOSPINAL TRACT
b : VENTRAL CORTICOSPINAL TRACT
Reticular Formation (shown in green) :
Extends from the superior portion of the spinal cord into the diencephalon
Activates the cerebral cortex into a state of wakefulness
Filters incoming sensory impulses and regulates motor activities
Integrates sensory information concerning positions of body parts, coordination of skeletal muscle activity, maintain posture
Two lateral hemispheres separated by the falx cerebelli , a layer of dura mater; the Vermis connects the hemispheres
Cerebellar cortex : gray matter on outside
Arbor vitae : treelike pattern of white matter
Cerebellar peduncles: - inferior
Fig. 11.22 Arbor vitae- ‘ tree of life’
Peripheral Nervous System
Cranial nerves and spinal nerves:
Somatic Nervous System : nerves that connect CNS to skin and skeletal muscles
Autonomic Nervous System : nerves that connect CNS to viscera, smooth muscle nad glands.
Fig. 11.24 Epineurium : outer layer of connective tissue Perineurium : sleeve of looser connective tissue surrounding a fascicle Endoneurium : loose connective tissue surrounding each nerve fibers
Twelve pairs of nerves which originate from brain stem and cerebrum
Pass through foramen magnum in the skull
Mixed nerves and special senses; some motor nerves