Pdf human brain


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Pdf human brain

  1. 1. The HUMAN BRAIN
  2. 2. Protective Structures
  3. 3. Meninges Three layers of connective tissue that enclose the brain Dura Mater Arachnoid Pia Mater
  4. 4. Dura Mater  Outermost layer  Thickest and toughest part of the meninges  There are two layers, the outer layer is fused to the cranial bones.
  5. 5. Dura Mater  In various places, the two layers separate to allow venous channels called dural sinuses to drain blood from the brain.  Function containment of the cerebrospinal fluid in the brain.
  6. 6. Arachnoid  Middle layer of the meninges  Loosley attached to the pia mater by weblike fibers.  Function Allows for movement of cerebrospinal fluid.
  7. 7. Cerebrospinal Fluid Fluid that circulates in and around the brain. Protects the brain from shock and injury. Function-Transports nutrients and waste to and from cells. .
  8. 8. Cerebrospinal Fluid  Formed in four spaces called ventricals.  The ventricals hold a vascular portion called the choroid plexus, which produces the cerebrospinal fluid by filtering the blood and cellular excretion.
  9. 9. Pia Mater  Innermost layer of the meninges  A delicate connective tissue that covers the brain and spinal chord  Function-Holds the blood vessels that supply nutrients and oxygen to the brain and spinal cord.
  10. 10. Meninges
  11. 11. Cerebral Hemispheres
  12. 12. Structure of the Hemispheres  Two layers  An outer layer of gray matter called the cerebral cortex.  Supported by an inner layer of white matter
  13. 13. Structure of the hemispheres Each hemisphere has four lobes Frontal Parietal Temporal Occipital
  14. 14. Structure of the hemispheres Gray Matter – The Cerebral Cortex  The most highly evolved portion of the brain.  Arranged in folds of elevations called gyri, and grooves called sulci
  15. 15. Gyri and Sulci The surfaces on which brain cells reside. More surface = more complex calculations
  16. 16. Structure of the hemispheres White Matter  Connects the gray matter areas with one another and with other parts of the brain.  Dispersed in a tree like pattern  Made of myelinated fibers
  17. 17. White and Gray Matter White matter Gray Matter
  18. 18. Structure of the hemispheres Corpus Callosum  Largest white matter structure in the brain  Facilitates communication between the right and left hemispheres by electrical impulses
  19. 19. Structure of the hemispheres Basal Ganglia  Base of forbrain, deep in each hemisphere. Functions: helps to re- gulate body movement and facial expressions.
  20. 20. Structure of the hemispheres Internal Capsule  In between the hemi- spheres and the brain stem Function – Carries im- pulses between the cerebral hemispheres and the brainstem.
  21. 21. Functions of the Cerebral Cortex The functions of the Cerebral Cortex are localized according to the four lobes. They are named for the overlying cranial bones.
  22. 22. CEREBRAL CORTEX FUNCTIONS CEREBRAL CORTEX- Functions  Conscious deliberation  Voluntary actions  Memory  Association  Discrimination  Judgement
  23. 23. Functions of the Cerebral Cortex The Frontal Lobe lies anterior to the central sulcus.
  24. 24. Functions of the Cerebral Cortex Some Frontal Lobe Functions  Contains an area that provides the conscious control of skeletal muscles.  Contains two areas that are important in speech
  25. 25. Functions of the Cerebral Cortex The Parietal Lobe occupies the superior part of each hemisphere and lies posterior to the central nucleus
  26. 26. Functions of the Cerebral Cortex Some Parietal Lobe Functions  Contains a primary sensory area where impulses from the skin are interpreted  Estimates distance and size.
  27. 27. Functions of the Cerebral Cortex The Temporal Lobe lies inferior the lateral sulcus snd folds under the hemi- sphere on each side.
  28. 28. Functions of the Cerebral Cortex Some Temporal Lobe Functions  Responsible for receiving and interpreting auditory impulses from the ear.  An olfactory area that concerns the sense of smell.
  29. 29. Functions of the Cerebral Cortex The Occipital Lobe lies posterior to the parietal lobe and extends over the cerebellum.
  30. 30. Functions of the Cerebral Cortex Some Occipital Lobe Functions  Visual receiving area and visual ass- ociation for interpreting impulses from the retina of the eye.
  31. 31. Functions of the Cerebral Cortex The Insula lies deep within each hemisphere and cannot be seen from the surface.
  32. 32. Functions of the Cerebral Cortex The Insula Functions  Visceral reactions and judgments  Receives, integrates and responds to autonomic influx.
  33. 33. Communication areas of the lobes TEMPORAL LOBE Auditory Cortex  Lies at the posterior area of the temporal lobe  Contains the auditory receiving and association areas.
  34. 34. Communication areas of the lobes Auditory Receiving Area  Detects sound impulses from the surrounding environment Auditory association area  Interprets and translates the sound impulses. 1 1 2
  35. 35. Communication areas of the lobes FRONTAL LOBE- Motor cortex  Lies anterior to the most inferior part of the frontal lobe  Contains the Broca area
  36. 36. Communication areas of the lobes Broca Area – Responsible for spoken and written communication. Functions- Controls:  Muscles in the tongue  Soft Palate  The larynyx  Lies anterior to the area that controls the arm and hand muscles that produce written speech
  37. 37. Diencephalon  The area between the cerebral hemispheres and the brain stem.  Contains the thalamus and the hypothalamus.
  38. 38. The Thalamus  Sorts and directs sensory impulses to areas of the cerebral cortex.  Nearly all sensory impulses travel through the thalamus.  Important role in sleep and wakefullness.
  39. 39. Hypothalamus  Locatedinferior to the thalamus  The Boss of you.
  40. 40. Hypothalamus  Helps maintain homeostasis  Controls autonomic function such as: heartbeat, blood flow, and hormone secretion.  Controls the pituitary gland.
  41. 41. Pituitary Gland  A „master gland‟ lo- cated at the bottom of the hypothalamus.  Pea sized  Assists in the regulation of homeostasis.
  42. 42. Pituitary Gland Functions Helps to regulate:  Growth  Blood pressure  Child birth  Sex organ function  Thyroid gland  Metabolism  Temperature regulation
  43. 43. Hypothalamus/ Pituitary Homeostasis  Balance  Maintenance of body con- ditions within set limits.
  44. 44. The Limbic System  Located between the cerebrum and diencephalon  Includes the Hip- pocampus  Links conscious functions of the cerebral cortex and autonomic functions of the brainstem.
  45. 45. The Limbic System  Located between the cerebrum and diencephalon  Includes the Hip- pocampus  Links conscious functions of the cerebral cortex and autonomic functions of the brainstem.
  46. 46. The Limbic System  Emotional states and behavior  Formation of long term memory
  47. 47. The Hippocampus Long term memory Spacial navigation
  48. 48. The Hippocampus
  49. 49. The Brain Stem The brainstem is located in the anterior region below the cerebrum
  50. 50. The Brain Stem Connects the cerebrum and the diencephalon with the spinal cord. The brainstem includes:  The Midbrain  The Pons  The Medulla Oblongata
  51. 51. The Midbrain  The midbrain is located below the center of the cerebrum.  The midbrain forms the superior part of the brain stem.
  52. 52. The Midbrain The midbrain consists of centers that are concerned with aspects of vision and hearing.
  53. 53. The Pons  Located anterior to the cerebellum.  Lies between the midbrain and the medulla  Connects the two halves of the cerebellum with the brainstem.
  54. 54. Medulla Oblongata  Located between the pons and spinal cord.  Contains gray matter which has centers that play an important role in many involuntary actions such as respiration.  The centers are called vital centers.
  55. 55. The Medulla Vital Centers  The respiratory center  The cardiac center  The vasomotor center
  56. 56. The Cerebellum “Little Brain”  Divided into two hemispheres, and one middle part(vermis).  Outer layer gray matter, inner layer white matter.  Located above the brainstem, and beneath the occipital lobes.
  57. 57. The Cerebellum Functions:  Coordination in voluntary movement.  Helps maintain balance and equilibrium.  Helps maintain muscle tone.
  58. 58. Brain Studies Imaging used to study the brain without physically entering it
  59. 59. Brain Studies CT Scan Provides photographs of the bone, soft tissue, and cavities of the brain. Used to de- tect:  Scar tissue accumulations  Anatomic lesions such as tumors
  60. 60. Brain Studies MRI Magnetic Resonance Imaging  Shows more views than CT scans  Often reveals issues that the CT scan can miss such as tumors, scar tissue, and hemorrhaging.
  61. 61. Brain Studies EEG The Electroencephalograph records Electrical currents produced by the brain‟s Nerve cells.
  62. 62. Cranial Nerves
  63. 63. Cranial Nerves  12 pairs of cranial nerves  Numbered 1- 12 based on connection with the brain.  Originate in the brain stem  Divided into 4 categories based on the impulses they send.
  64. 64. Cranial Nerves Types Special sensory impulses Located in special sense organs in the head, responsible for:  Smell  Taste  Vision  Hearing
  65. 65. Cranial Nerves Types General sensory impulses Originate from receptors through the body.  Pain  Touch  Temp  Pressure  Vibration  Deep muscle sense
  66. 66. Cranial Nerves Types Somatic Motor Impulses  Voluntary control of skeletal muscles
  67. 67. Cranial Nerves Types VISCERAL MOTOR IMPULSES  Part of autonomic nervous system  Involuntary control of glands and involuntary muscle
  68. 68. Aging and the Nervous System
  69. 69. Aging of the brain The brain loses 5-10 % of it’s volume between the ages of 20-90. The grooves widen and the surface shrinks.
  70. 70. Agingof the brain Aging in the Brain Senile plaque forms Synapses and neurons decrease, esp in the cere- bral cortex.
  71. 71. Aging in the brain  Movement is slowed  Information processing slows  Chance of stroke, and alzheimers increases
  72. 72. Dementia Loss of cognitive ability in a previously-unimpaired person, beyond what might be expected from normal aging. Massage - Yes
  73. 73. Alzheimers Alzheimer’s disease leads to nerve cell death and tissue loss throughout the brain. Over time, the brain shrinks dramatically, affecting nearly all Massage –Yes, best to its functions. start in early stages
  74. 74. Multiple Sclerosis Eats away at the protective sheath that covers your nerves. This interferes with the communication between your brain and the rest of your body. Massage- During remissions