Hindbrain

1. AAU UNIVERSTIY BY BIRUK MEDHANITE DATE MAY 20 4/17/2007 HINDBRAIN 1

2. HINDBRAIN 4/17/2007 HINDBRAIN 2

3. INTRODUCTION 4/17/2007 HINDBRAIN 3

4. Cont……… BRAIN is the most specialized tissue in the body and it is almost entirely composed of nervous tissue . It is enclosed in the protective covering called meninges. It has main three division _hindbrain _midbrain _forebrains. 4/17/2007 HINDBRAIN 4

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7. Hindbrain It is also called rhombencephelon that occupies the posterior fossa of cranial cavity. It consists of A) myelenocephalon include medulla oblongata & fourth ventricle B) metacephalon include pons &cerebellum. 4/17/2007 HINDBRAIN 7

8. Medulla oblongata It is the caudal portion of brain extend from foramen magnum to the pons & pyramidal in shape. Has two extremity :.A)the rostral that is toward the pons B) the caudal that continues with medulla spinals. Parts of medulla oblongata divided by anterior lateral sulcus &posterior lateral sulcus in to three distinct such as anterior ,meddle &posteriors. 4/17/2007 HINDBRAIN 8

9. Cont………. It has three surface such as A) venteral surface of medulla is marked by median fissure continues with that of cord &flanked by longitudinally ridges& pyramids. The caudal portion of the fissures(groove) is partially filled by the decussately of the pyramids. Pyramid is the longitudinally band fiber on either side of the midline between the median fissures &the lateral one . B)dorsal surface resemble the half spinal cord &its rostra hay. It form s the rhomboid fossa which is the floor of fourth ventricle. 4/17/2007 HINDBRAIN 9

10. Cont…. The dorsal medial sulcus is the contination of the median sulcus of spinal cord&end at apex. C)lateral surface it is marked by different origin of cranial nerves. for example glosso pharyngeal vagus & accessory nerves. The medulla oblongata is the most vital part of the brain because it is the control center for breathing, blood pressure and heart beat among other involuntary body functions 4/17/2007 HINDBRAIN 10

11. pons Is a thick transverse fiber tract divided in to bie laterally symmetrically halves by a slight midline depression. It has three surface such as A)ventral appear as large ,wide convex protuberance decreasing in size laterally . Marked by a slight depression in midline refered to as basilar sulcus. B)lateral consider by decrease in width that continuous with the middle cerebella pedicle which run caudodorsal direction & disappearing in the cerebllum. 4/17/2007 HINDBRAIN 11

12. Cont….. C) dorsal corresponding to rostra part of rhomboid fossa. The pons contains nuclei that relay signals from the cerebrum to the cerebellum, along with nuclei that deal primarily with sleep, respiration, swallowing, bladder control, hearing, equilibrium, taste, eye movement, facial expressions, facial sensation, and posture. 4/17/2007 HINDBRAIN 12

13. Internal anatomy of medulla oblongata &pons The principal feature on the internal anatomy of medulla oblongata& pons are the nuclie of cranial nerve ,olivary & potinc nuclie ,the formation of certain reticular formation & certain ascending & desending fibers tract that connect the spinal cord with high level of the brain. 4/17/2007 HINDBRAIN 13

14. cerebellum The cerebellum ((Latin for little brain ) is the second largest part of your brain, and is located near the base of the brain. Constituent the larg part of hindbrain. Is roughly globular having much fissure & located above the pons medulla. Separet from cerebral hemispher by transvers fissure &tentorium cereblli which contain it. It consists of two larger part such as cerebral hemispher narrow ridge named as vermis. The body of cerebellum subdivided to rostral& caudal lobs by primary fissures. The rostral lobe sub divided in to small lingual. which is the rostral part of the central nerve system by numerous fibers which make up the cerebral pendicels such as caudal cerebral pendicel that connect medulla &spinal cord with cerebellum. 4/17/2007 HINDBRAIN 14

15. Cont……. Middle cerebrall pendicl And rostral cerebral pendicle. In the cerebellum the bulk of the gray substance is arranged as external cortex that in colour the white substance of medulla. The cerebellum is involved in balance, equilibrium, muscle tone, and the coordination of voluntary motor movement. 4/17/2007 HINDBRAIN 15

16. 4/17/2007 HINDBRAIN 16 Thanks for yours attention