Coverings of the Brain (Meninges)

1
Coverings of the Brain (Meninges)

• Dura Mater- outer brain covering, lines the
  inside of the skull, tough dense fibrous
  connective tissue.
• Arachnoid-middle layer, resembles fine cobweb,
• Pia Mater- covers the brains surface, comprised
  of blood vessels held together by connective
  tissue.

2
Subarachnoid Space

• Between arachnoid and pia mater. Filled with
  cerebrospinal fluid- acts as a liquid shock
  absorber and source of nutrients for the brain.

3
Ventricles of the Brain

• The brain contains four cavities filled with
  cerebrospinal fluid called cerebral ventricles
• Right and left lateral ventricles
• Third ventricle-behind and below the lateral
  ventricles
• Fourth ventricle is below the 3rd in front of the
  cerebellum and behind the pons and medulla
  oblongota

4
Choroid Plexus

• Network of blood vessels lining the ventricles
  which helps in the formation of cerebrospinal
  fluid.

5
Cerebrospinal Fluid

• Forms inside ventricles of the brain
• Serves as a liquid shock absorber protecting the
  brain and spinal cord.
• Blood brain barrier- choroid plexus capillaries
  prevent substances (like drugs) from penetrating
  brain tissue this makes infections, like
  meningitis difficult to cure.

6
Lumbar Puncture

• Removal of CSF from spinal canal, needle puncture
  between 3rd and 4th lumbar vertebrae.

7
Cerebrum
Cerebral Function- conscious thought, judgment,
memory, reasoning, and will power

• Largest part of the brain
• Divided into R and L hemispheres by deep groove
  (longitudinal fissure)
• Convolutions- elevated folds on the surface of
  the cerebrum, they increase the surface area of
  the brain
• Sulci- fissure or grooves separating cerebral
  convolutions.

Divided into four lobes- Frontal, Parietal,
Occipital, and Temporal
8
Diencephalon

• Located between cerebrum and midbrain
• Composed of Thalamus and Hypothalamus
• Vital functions of the hypothalamus
• Autonomic nervous control
• Temperature control
• Appetite control
• Emotional state
• Sleep control

9
Cerebellum

• Located behind the pons and below the cerebrum
• Composed of two hemispheres
• Controls all body functions related to skeletal
  muscles, including
• Balance
• Muscle tone
• Coordination of muscle movements

10
Brain Stem

• Made up of Pons, medulla and midbrain
• Pathway for ascending and descending tracts
• Pons in front of cerebellum, between midbrain
  and medulla- contains center that controls
  respiration
• Midbrain- vision and hearing
• Medulla oblongota- bulb shaped structure between
  pons and spinal cord, inside the cranium above
  foramen magnum. Responsible for
• Heart rate
• Blood pressure

11
Spinal Cord

• Begins at foramen magnum and continues down to
  2nd lumbar vertebrae
• White and soft, in spinal canal
• Surrounded by cerebrospinal fluid
• Functions as
• Reflex center
• Conduction pathway to and from the brain

12
Limbic System

• Part of the brain associated with emotional
  control, mood and memory
• Includes the hypothalamus which is considered the
  brain of the brain.

13
(No Transcript)
14
Questions for 3.01 ppt BM two

• Draw a picture of the brain and label all of the
  structures on the bubble map.
• Color the bubble map and write the words in
  color.
• Make sure your brain covers the entire page and
  each structure needs to be in color.