1 / 19
Télécharger la présentation

Brain's Protective Coverings and Blood Flow

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

Playing audio...

  1. Encephalon – Brain

  2. Brain ComponentsFig 14.1 • Brain Stem • Midbrain, Pons, Medulla Oblongata • Cerebellum • “Little Brain” • Diencephalon • Thalamus, Hypothalamus, Epithalamus • Cerebrum

  3. Protective Coverings of the Brain Cranial bones Meninges Dura mater Arachnoid mater Pia mater

  4. Cranial Bones • Cranial vault formed by 8 cranial bones • Encloses and protects brain • Floor divided into 3 fossa: • Anterior – front lobes • Middle – temporal lobes and base of diencephalon • Posterior - cerebellum

  5. Meninges Surround and protect the brain and spinal cord Three membranes: 1. Dura mater 2. Arachnoid mater 3. Pia mater

  6. Dura Mater • Tough outermost meninx. • Composed of two layers: • Periosteal • Meningeal • Venous sinuses between the layers.

  7. Dura Mater • Falx cerebri • Falx cerebelli • Tentorium cerebelli Separates cerebrum from cerebellum Separates 2 hemispheres of cerebrum Separates 2 hemispheres of cerebellum

  8. Arachnoid Mater • Middlemost meninx • Characterized by its filmy, weblike structure • Loosely follows contours of cerebral structures but lies over sulci

  9. Pia Mater • Thin, delicate innermost meninx • Closely adheres to surface of brain and follows sulci and fissures • Provides support for blood vessels serving brain tissue • Sheath of pia mater

  10. Meningeal Spaces • Real or potential spaces between meningeal layers: • Epidural Space = potential space • Between Skull and Dura • Subdural Space = Real space • Between dura and arachnoid • Small bridging veins (little support) cross the space • Subdural hematoma • Subarachnoid space is a real space • Lies between the arachnoid and pia mater • Contains cerebrospinal fluid • Subarachnoid hemorrhage

  11. Brain Injuries • Hemorrhage – active or ongoing bleeding. • Hematoma – accumulation of blood within one of the meningeal spaces or surrounding tissues. • Contusion – Type of hematoma. Blood escapes ruptured capillaries and enters surrounding tissue.

  12. Brain Blood Flow Internal carotid arteries Vertebral arteries Internal jugular veins

  13. Arterial Brain Blood Flow • ANTERIOR: • Common Carotid Arteries  Internal Carotid Arteries  • Base of skull  Cranium  • Branch to anterior and middle cerebral arteries

  14. Arterial Brain Blood Flow • POSTERIOR: • Subclavian arteries  Vertebral arteries • Transverse foramina of cervical vertebrae  foramen magnum • Join at junction of pons and medulla  Basilar artery  Pontine branches • Posterior inferior cerebellar arteries (off the vertebral artery) • Basilar divides at midbrain anterior inferior cerebellar and superior cerebellar arteries

  15. Arterial Brain Blood Flow • Vertebral arteries • Subclavian • Cervical vertebrae transverse foramina • Basilar artery • Cerebellum, brainstem and occipital lobes. • Pontine arteries • Cerebellar arteries: • Cerebellum • Cerebral arteries • Internal Carotid Artery • Posterior communicating artery • Anterior communicating artery

  16. Arterial Brain Blood Flow • Terminal branches of Carotid and Vertebral arteries = circle of Willis • Circulatory anastomosis (connection between 2 blood vessels) • Backup route in case of blockage • Branch into various cerebral arteries to supply brain with blood

  17. Brain Blood Flow Animation https://www.youtube.com/watch?v=MPcO2ibO75o

More Related