Presentation is loading. Please wait.

Presentation is loading. Please wait.

Chapter 9a The Central Nervous System. About this Chapter Anatomy of the central nervous system The spinal cord The brain Brain function.

Similar presentations


Presentation on theme: "Chapter 9a The Central Nervous System. About this Chapter Anatomy of the central nervous system The spinal cord The brain Brain function."— Presentation transcript:

1 Chapter 9a The Central Nervous System

2 About this Chapter Anatomy of the central nervous system The spinal cord The brain Brain function

3 Figure 9-3a ForebrainMidbrain Hindbrain Lumen of neural tube Spinal cord The Embryonic Nervous System The neural tube specializes into the seven major regions of the central nervous system A 4-week human embryo showing the anterior end of the neural tube, which has specialized into three brain regions (a)

4 The Embryonic Nervous System At 6 weeks, the neural tube has differentiated into the brain regions present at birth. The central cavity (lumen) shown in the cross section will become the ventricles of the brain. (see Fig. 9.5) Figure 9-3b Cerebrum Diencephalon MidbrainEyeMedulla oblongata Spinal cord (b) Cerebrum Diencephalon Midbrain Medulla oblongata Cerebellum and Pons Forebrain Hindbrain

5 The Embryonic Nervous System By 11 weeks of embryonic development, the growth of the cerebrum is noticeably more rapid than that of the other divisions of the brain. Figure 9-3c Cerebrum Diencephalon Midbrain Medulla oblongata Cerebellum Spinal cord Pons (c)

6

7 Early Developmental Regions Late Developmental Regions Structure Derived from Regions Thalamus

8 Encephalons Development

9

10 CNS: Bone and Connective Tissue Brain is encased in bony skull or cranium Spinal cord runs through vertebral column Meninges lies between bone and tissues Dura mater Arachnoid membrane Pia mater Meningeal layers of the brain cushion and protect delicate neural tissue

11 Anatomy of the Central Nervous System Figure 9-4 Cerebral hemispheres Cerebellum Cranium Cervical spinal nerves Cranium Dura mater Subdural space Subarachnoid space Pia mater Arachnoid membrane Brain Thoracic spinal nerves Lumbar spinal nerves Sacral spinal nerves Coccygeal nerve Spinal nerve Central canal Spinal nerve (b) Meningeal layers of the brain cushion and protect delicate neural tissue. (c) Posterior view of spinal cord and vertebra (a) Posterior view Body of vertebra Spinal cord Autonomic ganglion Arachnoid membrane Pia mater Dura mater White matter Gray matter Meninges Sectioned vertebrae CENTRAL NERVOUS SYSTEMSECTIONAL VIEWS OF THE CNS ANATOMY SUMMARY Venous sinus

12 CNS: Gray and White Matter Gray matter Unmyelinated nerve cell bodies Dendrites Axon terminals White matter Myelinated axons Contains very few cell bodies

13 Thoracic spinal nerves Lumbar spinal nerves Sacral spinal nerves Coccygeal nerve Central canal Spinal nerve (c) Posterior view of spinal cord and vertebra (a) Posterior view Body of vertebra Spinal cord Autonomic ganglion Arachnoid membrane Pia mater Dura mater White matter Gray matter Meninges Sectioned vertebrae CENTRAL NERVOUS SYSTEM ANATOMY SUMMARY Spinal nerve CNS: Gray and White Matter Figure 9-4 (2 of 2)

14 CNS: Gray and White Matter Figure 9-4c Spinal nerve Central canal Spinal nerve (c) Posterior view of spinal cord and vertebra Body of vertebra Spinal cord Autonomic ganglion Arachnoid membrane Pia mater Dura mater White matter Gray matter Meninges CENTRAL NERVOUS SYSTEM ANATOMY SUMMARY

15 CNS: Bone and Connective Tissue Figure 9-4 (1 of 2) Cerebral hemispheres Cerebellum Cranium Cervical spinal nerves Cranium Dura mater Subdural space Subarachnoid space Pia mater Arachnoid membrane Brain (b) Meningeal layers of the brain cushion and protect delicate neural tissue. CENTRAL NERVOUS SYSTEMSECTIONAL VIEWS OF THE CNS ANATOMY SUMMARY Venous sinus Dural Sinses drain CSF only between dura

16 CNS: Bone and Connective Tissue Figure 9-4b Cranium Dura mater Subdural space Subarachnoid space Pia mater Arachnoid membrane Brain (b) Meningeal layers of the brain cushion and protect delicate neural tissue. CENTRAL NERVOUS SYSTEM SECTIONAL VIEWS OF THE CNS ANATOMY SUMMARY Venous sinus

17 CNS: Ventricles of the Brain Figure 9-5a ANATOMY SUMMARY VENTRICLES OF THE BRAIN Cerebrum Lateral ventricles Third ventricle Fourth ventricle Cerebellum Central canal Spinal cord Lateral view Frontal view (a)

18 CNS: Cerebrospinal Fluid Figure 9-5b-d ANATOMY SUMMARY CEREBROSPINAL FLUID CIRCULATION Choroid plexus of third ventricle Arachnoid villi Pia mater (b) Sinus Arachnoid membrane Dura mater Subarachnoid space Central canal Choroid plexus of fourth ventricle Spinal cord Cerebral cortex Endothelial lining Blood in venous sinus Fluid movement Arachnoid villus Dura mater (inner layer) Subdural space Arachnoid membrane Subarachnoid space Pia mater Cerebrospinal fluid Bone of skull Dura mater (d)

19 CNS: Cerebrospinal Fluid Figure 9-5d ANATOMY SUMMARY CEREBROSPINAL FLUID CIRCULATION Cerebral cortex Endothelial lining Blood in venous sinus Fluid movement Arachnoid villus Dura mater (inner layer) Subdural space Arachnoid membrane Subarachnoid space Pia mater Cerebrospinal fluid Bone of skull Dura mater (d)

20 CSF Flow

21

22 CNS: Blood-Brain Barrier Figure 9-6a (a) Astrocyte ★★ Astrocyte foot processes secrete paracrines that promote tight junction formation. Tight junction prevents solute movement between endothelial cells.

23 CNS: Blood-Brain Barrier Figure 9-6b

24 CNS: Neural Tissue – Metabolic Needs Oxygen Passes freely across blood-brain barrier Brain receives 15% of blood pumped by heart Glucose Brain responsible for about half of body’s glucose consumption Membrane transporters move glucose from plasma into the brain interstitial fluid Progressive hypoglycemia leads to confusion, unconsciousness, and death

25 Spinal Cord: Overview Figure 9-4a Cerebral hemispheres Cerebellum Cranium Cervical spinal nerves Thoracic spinal nerves Lumbar spinal nerves Sacral spinal nerves Coccygeal nerve (a)Posterior view Sectioned vertebrae CENTRAL NERVOUS SYSTEM ANATOMY SUMMARY Central nervous system, posterior view

26 Spinal Cord: Anatomy Specialization in the spinal cord Figure 9-7a Gray matter White matter (a) One segment of spinal cord, ventral view, showing its pair of nerves. Dorsal root: carries sensory (afferent) information to CNS. Ventral root: carries motor (efferent) information to muscles and glands.

27 Spinal Cord: Anatomy Figure 9-7b (b) Gray matter consists of sensory and motor nuclei. Dorsal root ganglion Ventral root Ventral horn Lateral horn Dorsal horn Visceral sensory nuclei Somatic sensory nuclei Autonomic efferent nuclei Somatic motor nuclei

28 Spinal Cord: Anatomy Propriospinal tracts remain within the cord Figure 9-7c (1 of 2)

29 Spinal Cord: Anatomy Figure 9-7c (2 of 2)

30 Spinal Cord: Integrating Center Figure 9-8 Stimulus Response Command to muscles or glands Sensory information Sensory information goes to the brain A spinal reflex initiates a response without input from the brain. ★ Spinal cord Integrating center Interneuron

31 Anatomy of the Brain Figure 9-9 Temporal lobe Occipital lobe Parietal lobe Temporal lobe Parietal lobe Occipital lobe Frontal lobe (a) (b) Lateral view of brain (e) The skull (c) Mid-sagittal view of brain (d) Lateral view of brain stem Cerebellum Medulla oblongata Pons Medulla oblongata Pons Corpus callosum Thalamus Cingulate gyrus Thalamus Spinal cord Cut edges of tracts leading to cerebellum Midbrain Cerebrum Spinal cord Vertebrae Parietal bone Occipital bone Frontal bone Cranial nerves Optic tract Cut edge of ascending tracts to cerebrum PonsTemporal bone LATERAL VIEW OF THE CNS ANATOMY OF THE BRAIN ANATOMY SUMMARY

32 The Brain: The Brain Stem Most cranial nerves originate along brain stem Cranial nerves can include sensory fibers, efferent fibers, or both (mixed nerves) Many nuclei are associated with reticular formation Medulla Somatosensory and corticospinal tracts in white matter - Pyramids

33 The Brain: The Brain Stem Figure 9-9d (d) Lateral view of brain stem Medulla oblongata Thalamus Spinal cord Cut edges of tracts leading to cerebellum Midbrain Cranial nerves Optic tract Cut edge of ascending tracts to cerebrum Pons ANATOMY OF THE BRAIN ANATOMY SUMMARY

34 The Brain: Cerebellum Figure 9-9b Temporal lobe Occipital lobe Parietal lobe Frontal lobe (b) Lateral view of brain Cerebellum Medulla oblongata Pons ANATOMY OF THE BRAIN ANATOMY SUMMARY

35 The Brain: Diencephalon Figure 9-10 Thalamus Hypothalamus Posterior pituitary Anterior pituitary Pineal gland Thalamus Epithalamus Hypothalamus

36 The Brain: Hypothalamus Activates sympathetic nervous system Maintains body temperature Controls body osmolarity Controls reproductive functions Controls food intake Interacts with limbic system to influence behavior and emotions Influences cardiovascular control center in medulla oblongata Secretes trophic hormones that control release of hormones from anterior pituitary gland

37 The Brain: Mid-Sagittal View Figure 9-9c Temporal lobe Parietal lobe Occipital lobe Frontal lobe (c) Mid-sagittal view of brain Cerebellum Medulla oblongata Pons Corpus callosum Thalamus Cingulate gyrus ANATOMY SUMMARY ANATOMY OF THE BRAIN

38 The Brain: Gray Matter of the Cerebrum Figure 9-11 Basal ganglia Lateral ventricle Corpus callosum Gray matter of cerebral cortex Tip of lateral ventricle Tracts of white matter

39 The Brain: Cell Bodies in the Cerebral Cortex Form Distinct Layers Figure 9-12

40 The Brain: The Limbic System Emotion, memory, and learning Figure 9-13 Thalamus Hippocampus is involved in learning and memory. Amygdala is involved in emotion and memory. Cingulate gyrus plays a role in emotion.


Download ppt "Chapter 9a The Central Nervous System. About this Chapter Anatomy of the central nervous system The spinal cord The brain Brain function."

Similar presentations


Ads by Google