Regions of the brain | 1. Cerebral hemispheres (cerebrum)
2. Diencephalon
3. Brain stem
4. Cerebellum |
Ventricles of the brain | -Spaces containing cerebrospinal fluid
Lateral ventricles (ventricle 1 & 2)
-Paired in cerebral hemispheres
Third ventricle
-In diencephalon
Fourth ventricle
-In hindbrain
They are connected to one another and to central canal of spinal cord
-Lined by Ependymal cells |
Five lobes of the brain | 1. Frontal
2. Parietal
3. Occipital
4. Temporal
5. Insula (insulated insula) |
Surface marking terms | Gyri- ridges
Sulci- Shallow grooves
Fissure- Deep groove |
Cerebral cortex | -Thin (2-4mm) superficial layer of gray matter
-40% of the mass of brain
-Side of conscious mind: awareness, sensory perception, Voluntary motor Initiation, Communication, Memory stage, and understanding
-Each hemisphere connects to contralateral side of body |
Three types of functional areas of the cerebral cortex | Motor areas
Sensory areas
Association areas |
Motor areas | Control voluntary movement
-Primary motor cortex
-Premotor cortex
-Brocas area
-Frontal eye field |
Sensory areas | Conscious sensation
-Primary somatosensory cortex
-somatosensory association cortex
-Visual areas
-Auditory areas
-Olfactory cortex
-Gustatory cortex
-Visceral sensory area
-Vestibular cortex |
Association areas | Integrate diverse information |
Primary motor cortex | -Precentral gyri
Conscious control of precise, skilled and involuntary movements |
Primary somatosensory cortex | Postcentral gyri
-information from skin, Skeletal muscles and joints
-Capable of spatial discrimination |
Lateralization | Division of labor between hemispheres |
Left hemisphere | Controls language, math and logic |
Right hemisphere | Insight, Visual spatial skills, Intuition and artistic skills |
Cerebral dominance | Designates hemisphere dominant for language (Left hemisphere and 90% of people) |
Cerebral white matter | -Myelinated fibers and their tracts
-Responsible for communication
-Commissures
-Association Fibers
-Projection fibers
-Left and right hemispheres communicate via fiber tracts in cerebral white matter |
Gray matter: Basal nuclei | -Subcortical Nuclei- influences posture and voluntary movement
input from:
-Sensory cortex, thalamus, brain stem
output from
-Motor cortex, brain stem |
Thalamus | -Largest part of diencephalon
-Most sensory input projects to here
-sorts, edits, relays information |
Epithalamus | Pineal glad may influence sleep wake cycles |
Hypothalamus | -ANS control
-Emotions
-Endocrine control
-Muscle control
-Temperature regulation
-Regulation of food and water intake
-Regulation of sleep wake cycle |
Brainstem | -Controls Automatic behaviors necessary for survival
-contains embedded nuclei
-contains fiber tracks connecting higher and lower neural centers
-Associated with 10 pairs of cranial nerves |
Medulla oblongata | Regulates:
-Heart rate
-Blood vessel diameter
-Respiration
-Swallowing
-Vomiting
-Hiccuping
-Coughing
-Sneezing |
Pons | -Connect higher brain centers and spinal cord
-relay impulses between motor cortex and cerebellum
-Sleep and respiratory center |
Midbrain | -Visual reflex center
-Auditory relay center |
Cerebellum | -11% of brain mass
-Precise timing and patterns or skeletal muscle contraction
Control of:
-Balance
-Posture
-Coordination
-Puzzle solving
-Word association |
Anatomy Of the cerebellum | - 2 hemispheres connected by vermis
- Each hemisphere has three lobes
1. Anterior
2. Posterior
3. Flocculonodular
Folia: Transversely oriented gyri
Arbor vitae: tree like pattern of cerebral white matter |
Protection of brain | 1. Bone (skull)
2. Membranes (Meninges)
3. Watery cushion (cerebral spinal fluid)
4. Blood brain barrier |
Meninges (Brain and spinal cord) | Connective tissue membrane:
-Dura mater
-Arachnoid mater
-Pia mater
Spaces
-Subarachnoid: Cerebrospinal fluid (csf) |
Cerebral spinal fluid | -Provides a protective cushion around CNS
-Provide some nutrients to CNS tissues
-baths brain and spinal cord |
Brain blood supply | -15 to 20% of blood from heart
-High metabolic rate independence on constant supply of oxygen and glucose
-receives blood from internal carotid arteries and vertebral arteries
Interruption can cause unconscious and Irreversible brain damage |
Spinal cord | -Begins at foramen magnum
-ends at conus medullaris at L1 vertebra (in adults) |
Functions of the spinal cord | -Two way communication to and from brain
-Contains spinal reflex center |
White matter | -Consists of ascending (sensory) and descending (motor) tracts |
White matter | -Consists of ascending (sensory) and descending (motor) tracts |