Biology 201 Study Guide
BIO 201 – HUMAN ANATOMY AND PHYSIOLOGY I
CHAPTER 13: THE BRAIN AND CRANIAL NERVES- CLASS LECTURE NOTES
VISUAL A & P,MARTINI
SECTION 1: FUNCTIONAL ANATOMY OF BRAIN AND CRANIAL NERVES
INTRODUCTION: Brain characteristics A. Equals ~97% of body’s neural tissue in adults B. “Typical” brain 1. Weighs 1.4 kg (3 lb) 2. Volume of 1200 mL (71 in.3) C. Size varies among individuals 1. Male brains are ~10% larger than female (related to body size) 2. No correlation between size and intelligence 3. Normal function occurs from smallest (750 mL) to largest (2100 mL) brains
EMBRYONIC BRAIN DEVELOPMENT AT 4 WEEKS A. Neural tube is present: A hollow cylinder that is the beginning of CNS B. Has internal passageway (neurocoel) C. Cephalic portion enlarges into three portions (primary brain vesicles) 1. Prosencephalon (proso, forward + encephalos, brain)
“FOREBRAIN” is at tip of neural tube 2. Mesencephalon
“MIDBRAIN” is an expansion caudal to prosencephalon 3. Rhombencephalon
“HINDBRAIN” caudal portion, continuous with spinal cord
EMBRYONIC BRAIN DEVELOPMENT AT 5 WEEKS
(secondary brain vesicles develop) 1. Prosencephalon a. Diencephalon (dia, through + encephalos, brain) * Becomes THALAMUS, a major relay center b. Telencephalon (telos, end) * Becomes CEREBRUM in adult brain 2. Rhombencephalon a. Metencephalon (meta, after) * Adjacent to mesencephalon * Forms CEREBELLUM and PONS in adult brain b. Myelencephalon (myelon, spinal cord) * Becomes medulla oblongata in adult brain
MODULE 13.1 MAJOR BRAIN REGIONS 1. CEREBRUM a. Divided into a pair of large cerebral hemispheres b. Outer surface is a layer of gray matter = Cerebral cortex (cortex, rind or bark) c. Superficial cerebral structures 1) Fissures - Deep grooves that subdivide hemispheres 2) Gyri (singular, gyrus) - Folds in cerebral cortex that increase surface area
CHAPTER 13: THE BRAIN AND CRANIAL NERVES- CLASS LECTURE NOTES
VISUAL A & P,MARTINI
SECTION 1: FUNCTIONAL ANATOMY OF BRAIN AND CRANIAL NERVES
INTRODUCTION: Brain characteristics A. Equals ~97% of body’s neural tissue in adults B. “Typical” brain 1. Weighs 1.4 kg (3 lb) 2. Volume of 1200 mL (71 in.3) C. Size varies among individuals 1. Male brains are ~10% larger than female (related to body size) 2. No correlation between size and intelligence 3. Normal function occurs from smallest (750 mL) to largest (2100 mL) brains
EMBRYONIC BRAIN DEVELOPMENT AT 4 WEEKS A. Neural tube is present: A hollow cylinder that is the beginning of CNS B. Has internal passageway (neurocoel) C. Cephalic portion enlarges into three portions (primary brain vesicles) 1. Prosencephalon (proso, forward + encephalos, brain)
“FOREBRAIN” is at tip of neural tube 2. Mesencephalon
“MIDBRAIN” is an expansion caudal to prosencephalon 3. Rhombencephalon
“HINDBRAIN” caudal portion, continuous with spinal cord
EMBRYONIC BRAIN DEVELOPMENT AT 5 WEEKS
(secondary brain vesicles develop) 1. Prosencephalon a. Diencephalon (dia, through + encephalos, brain) * Becomes THALAMUS, a major relay center b. Telencephalon (telos, end) * Becomes CEREBRUM in adult brain 2. Rhombencephalon a. Metencephalon (meta, after) * Adjacent to mesencephalon * Forms CEREBELLUM and PONS in adult brain b. Myelencephalon (myelon, spinal cord) * Becomes medulla oblongata in adult brain
MODULE 13.1 MAJOR BRAIN REGIONS 1. CEREBRUM a. Divided into a pair of large cerebral hemispheres b. Outer surface is a layer of gray matter = Cerebral cortex (cortex, rind or bark) c. Superficial cerebral structures 1) Fissures - Deep grooves that subdivide hemispheres 2) Gyri (singular, gyrus) - Folds in cerebral cortex that increase surface area