Central Nervous System Chapter 13

Meninges Protective coverings of the brain & spinal cord

Meninges Dura mater Arachnoid membrane Pia mater Strong, white, fibrous Arachnoid membrane Web-like Pia mater Transparent On brain & spinal cord Contains blood vessels

Spaces around Meninges Epidural Under bone, above dura Fat & other connective tissue Subdural Between dura & arachnoid Has fluid to lubricate Subarachnoid Between arachnoid & pia mater Contains lots of cerebrospinal fluid (CSF)

Coverings of CNS Skin Periosteum (of bone) Bone Dura mater Subdural space Arachnoid Subarachnoid space Pia mater Brain

Cerebrospinal Fluid Provides cushion Found in subarachnoid space and within spaces of brain and spinal cord Formed by separation of fluid from blood Fluid-filled spaces in brain called ventricles

Fluid-filled Ventricles

Spinal Cord About 18 in. long Extends to 1st lumbar vertebrae Cylindrical; narrows at end 2 bulges: cervical & lumbar Divides into “tracts” which are all from same areas and have same functions

Spinal Cord Provides conduction routes to & from brain Serves as reflex center for spinal reflexes

Spinal Cord

Overview of Brain 100 bln neurons 900 bln glia Weighs ~ 3 lb Only mitosis at fetal stage…after that only growth in size Full size at ~18 yrs

Brain Anatomy

Brainstem Basic life functions: breathing, heart beat, vessel dilation Basic reflexes: vomit, cough, sneeze, hiccup, swallow

Cerebellum Separated from cerebrum by “transverse fissure” Has many grooves (sulci, sulcus) and raised areas (gyri, gyrus) Motor Functions Coordinates muscle groups (skilled mvmts) Controls posture Controls skeletal muscles to keep balance

What is it? cerebellum midbrain pons medulla oblongata

thalamus, hypothalamus, and pineal gland Diencephalon In middle of brain Made up of 3 main areas: thalamus, hypothalamus, and pineal gland

Thalamus Relay station for sensory info going to cerebral cortex Associates sensory input with feelings Arousal/alerting mechanisms

Hypothalamus Beneath thalamus; pituitary gland attached below Links NS to endocrine system Pleasure-reward center Integrates autonomic functions Mind-body link Appetite center Body temp. regulation Maintaining waking state

Regulates “body clock” Pineal Gland (Body) Posterior to thalamus Regulates “body clock” Makes melatonin

Surface (top 2-4mm) is called the cerebral cortex Cerebrum Has 2 hemispheres Surface (top 2-4mm) is called the cerebral cortex

Lobes of the Cerebrum Parietal Frontal Occipital Temporal

Self-Quiz! Answer on a “left-side” page

1. Name It! A D B C

2. Name It! What does it do? C A* B*

3. Name It! What does it do? C A D B

Landmarks of the Cerebrum Central Sulcus between frontal & parietal lobes Longitudinal fissure Divides into L/R sides (not shown) Transverse fissure Between occipital & cerebellum Lateral fissure between temporal & upper section

Connects left and right hemispheres Corpus Callosum Connects left and right hemispheres

Integrative Cerebral Functions Consciousness State of awareness of self & surroundings Language Usually on left side Broca’s area: movements of speech Wernicke’s: sensory speech (see/hear)

Integrative Cerebral Functions Emotions Involves the limbic system Memory Much still unknown Related to limbic system but also several cerebral areas

Areas of the Cerebral Cortex Look for landmarks Need to know location & general function Remember: these are generalities…most functions are integrated through many areas of brain “Primary cortex” areas receive info, while “association areas” evaluate that info

Functional Areas of the Cortex Locate on your handout: Postcentral gyrus – primary somatic sensory area

Functional Areas of the Cortex Locate on your handout: Somatic sensory association area

Functional Areas of the Cortex Locate on your handout: Gustatory area - taste

Functional Areas of the Cortex Locate on your handout: Visual cortex – (primary + association)

Functional Areas of the Cortex Locate on your handout: Wernicke’s area – sensory speech

Functional Areas of the Cortex Locate on your handout: Auditory cortex – primary + association

Functional Areas of the Cortex Locate on your handout: Precentral gyrus – primary somatic motor area

Functional Areas of the Cortex Locate on your handout: Premotor area

Functional Areas of the Cortex Locate on your handout: Broca’s area – motor speech

Functional Areas of the Cortex Locate on your handout: Prefrontal area – higher reasoning; judgment

Specialization of Hemispheres Right Side: Perception of some auditory msgs (melody, coughs, crying, laughing); tactile perception; spatial relationships Left Side: Language functions; skilled & gesturing movements

The End

Fake Quiz - Brain Answer on a “left-side” page that does not already have a picture of a brain on it. You are welcome to sketch the picture and label instead of just writing the answers. Take note of the ones you DO NOT know off the top of your head…those need special emphasis when you study tonight!

Fake Quiz – Brain 1. What is the structure marked with the RED LINE? 2. What is the name of the YELLOW part? 3. What is CONTROLLED on the YELLOW part?

Fake Quiz – Brain 4. What is the name of the PURPLE part? 5. What is CONTROLLED on the PURPLE part? 6. Which LOBE is the PURPLE part in?

Fake Quiz – Brain 7. On which color gyrus is the GUSTATORY cortex? 8. What division separates the purple & yellow from the lobe below? Which LOBE is below them?

Fake Quiz – Brain A B C D E F G 9. Name each functional part. 10. Describe the function of each part.