Brain Anatomy

Meninges - 3 layers Dura Mater Superficial Fuses brain to skull Arachnoid Reduces friction Filled with CSF; shock absorber Pia Mater Very Vascular; needs a lot of oxygen due to high metabolic rate of neurons

Gross Anatomy: 6 Regions Cerebrum Diencephalon Midbrain Pons Medulla Oblongata Cerebellum Gross Anatomy: 6 Regions

Precentral gyrus – Motor Strip Postcentral gyrus – Sensory Strip Central Sulcus – separates frontal from parietal lobe Gyri: elevated ridges Sulci: furrows

Corpus Callosum Bridge between Right and Left Hemispheres Enables Right and Left sides to communicate with each other Problems “Split Brain” Syndrome

Cerebrum: Frontal Lobe Functions: Cognition and Memory Prefrontal Area: involved with intellect, complex learning abilities and personality; plays a role in mood; feelings of frustration and anxiety are formed here “Gatekeeper” Judgment, critical thinking and reasoning skills Problems Relationships between events, memory loss, behavior disorders, Inappropriate social and/or sexual behavior Prefrontal lobotomy – 1950s Cerebrum: Frontal Lobe

Motor Areas Function: Motor Strip: Control voluntary motor function Premotor Cortex: skill area; controls learned motor skills Precentral gyrus Broca’s area Left hemisphere Directs the muscles of tongue, throat and lips when speaking Becomes active as we plan to speak Syntax and grammar rules are remembered

Try This!! Yes the bick. I would say tha the vick daysis nosis or chipickers. Represents problems with Broca’s area!! Only found in the left hemisphere of the frontal lobe Problems will affect our ability to pronounce words, form sentences, speaking becomes a problem

Sensory Areas Located in parietal, temporal and occipital lobes

Parietal Lobe Primary Somatosensory Cortex Spatial Discrimination – ability to identify the body region being stimulated Area is identified by receiving information from skin sensory receptors and proprioceptors in skeletal muscles. Try This!! Problems Inability to locate and recognize body parts; disorientation Can’t discriminate between different sensory stimuli

Somatosensory Area Located posterior to Primary Somatosensory Cortex Major function to analyze different sensory stimuli (temp, pressure Evaluate what the body is feeling Try this!! Different senses are distributed through all lobes Somatosensory Area

Temporal Lobe Auditory Areas – sound waves are interpreted Gustatory cortex – perception of taste Olfactory Cortex – interprets chemical odors Language Wernicke’s area – called the speech area Language comprehension Reading unfamiliar sounds Problems Hearing problems Aphasia – inability to speak Temporal Lobe

Occipital Lobe Visual Areas Receives stimuli from eyes Interprets information from past experiences Problems Loss of vision or “seeing stars” Can’t recognize the object you see

Posterior Association Area Large region including parietal, temporal and occipital lobes Plays a role in recognizing faces, patterns, and identifying surroundings Also includes Wernicke’s area

Stroke Left Hemisphere 90% is dominant for Language abilities, logic and math skills Right Hemisphere 90% is involved in visual- spatial skills, emotion, music,poetry, & creativity Stroke

Diencephalon Connects to cerebrum Includes: Thalamus, Hypothalamus, Limbic system Pineal gland (epithalamus) Pituitary gland

Thalamus Greek for “Inner room” Contains relay and processing centers Relay Station; involved in memory process Sorts out information, edits Gateway to cerebrum

Hypothalamus Controls Body Homeostasis Autonomic Nervous System Influences BP HR (force and rate) Digestive tract motility Emotions Pleasure, fear, rage Sex Drive Body temperature regulation Food intake; hunger Thirst (water balance) No blood-brain barrier Circadian rhythms Control of Endocrine (secrete ADH, oxytocin)

Hypothalamus and Pineal Gland Problems with hypothalamus Pineal Gland Problems Hormonal Imbalances Hypothermia Diabetes Obesity Sleep Disturbances Dehydration Part of epithalamus Secretes hormone melatonin Helps regulate Sleep-Wake Cycle

Limbic System Hypothalamus is heart of Limbic System: Emotional Brain Contains Amygdala Recognizes angry or fearful facial expressions Contains Hippocampus Involved with learning, long-term memory and storage Problems H.W. Case Study STM to LTM “Ring”

Pituitary Gland Link between NS and Endocrine system Produces GH and TSH Posterior part of gland is a hormone storage area   Pituitary Gland Pituitary Gland ->

Brain Stem: Midbrain, Pons, Medulla Oblongata Primitive Brain Pathway between lower brain and spinal cord and lower brain and higher brain functions

Contains 2 pairs of sensory nuclei (Colliculi); Auditory and Visual Reflex Centers I.e. rxns to flashlight or loud noises Motor nuclei for 2 cranial nerves (III, IV) involved in eye movements III Oculomotor – eye movement IV Trochlear – rotates eye up and down Cerebral Peduncles – descending bundles of motor nerve fibers – connect to cerebellum RAS center begins here; Filters out repetitive sensory stimuli. (99% of all stimuli is ignored) Midbrain

Colliculi of Midbrain Superior Colliculi Midbrain Inferior Colliculi Corpus Quadrigemini Superior Colliculi Visual Reflex Centers Follow movement with eye Associated with Cranial nerve III Inferior Colliculi Auditory Reflex Startle Reflex Midbrain

Pons Bridge: Connects cerebellum to brain stem; cerebrum and S. cord Relay Center Cranial Nerves (V-VIII) are attached here Respiratory Center – Involuntary Control of pace and depth of breathing Problems Hyperventilation Pons Bridge

Connects Brain to S. cord; relays info to Thalamus Contains major centers for Autonomic Regulation such as HR, Bp, respiration and digestive activities Cardiac Center – adjusts force and rate of heart beat Vasomotor Center – regulates BP Respiratory Center – controls rate and depth of breathing with N. Fdbk loop in pons. Controls other pleasant body Activities: vomit, hiccupps, cough, sneeze, swallow, and gag Again no blood-brain barrier! Medulla Oblongata

Coordination; fine tunes voluntary and involuntary movement (Sports) Receives stimuli from proprioceptors – evaluate body position Maintains balance and posture Imbalances Ataxia; Lack of coordination Tremors Alcohol – affects motor skills; reaction time Easily passes through blood-brain barrier Cerebellum

Cranial Nerves Olfactory – On One Optic – old Old Oculomotor – Olympus Octopus Trochlear – towering traveled Trigeminal – tops to Abducens – a a Facial – Finn familar Vestibulocochlear – valued village; Glossopharyngeal - good go Vagus – venison vanish Accessory – and and Hypoglossal – Hops. Hide.