Brain Anatomy

Dura Mater•Superficial•Fuses brain to skullArachnoid•Reduces friction•Filled with CSF; shock absorberPia MaterVery Vascular; needs a lot of oxygen due to high metabolic rate of neurons

1. Cerebrum

2. Diencephalon

3. Midbrain

4. Pons

5. Medulla Oblongata

6. Cerebellum

Gyri: elevated ridgesSulci: furrows

Precentral gyrus – Motor StripPostcentral gyrus – Sensory StripCentral Sulcus – separates frontal from parietal lobe

Bridge between Right and Left Hemispheres•Enables Right and Left sides to communicate with each otherProblems“Split Brain” Syndrome

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

Function:•Motor Strip: Control voluntary motor function•Premotor Cortex: skill area; controls learned motor skills

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

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

Try This!!

Located in parietal, temporal and occipital lobes

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

•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

•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•Understanding jokes•Reading unfamiliar sounds

Problems•Hearing problems•Aphasia – inability to speak

Visual Areas•Receives stimuli from eyes•Interprets information from past experiencesProblemsLoss 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

Connects to cerebrumIncludes:•Thalamus, •Hypothalamus, •Limbic system •Pineal gland (epithalamus)•Pituitary gland

•Contains relay and processing centers•Relay Station; involved in memory process•Sorts out information, edits•Gateway to cerebrum

Greek for “Inner room”

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• Problems

– Hormonal Imbalances

– Hypothermia

– Diabetes

– Obesity

– Sleep Disturbances

– Dehydration

Pineal Gland• Part of epithalamus

• Secretes hormone melatonin– Helps regulate Sleep-Wake

Cycle

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.M. Case Study STM to LTM

•Had difficulty remembering anything after his surgery

•Was able to learn new motor skills, despite not being able to remember learning them

“Ring”

Pituitary Gland ->

 •Link between NS and Endocrine system•Produces GH and TSH •Posterior part of gland is a hormone storage area

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)

Corpus Quadrigemini

Superior Colliculi•Visual Reflex Centers

•Follow movement with eye•Associated with Cranial nerve III

Inferior Colliculi•Auditory Reflex

•Startle Reflex

Midbrain

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

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!

•Coordination; fine tunes voluntary and involuntary movement (Sports)•Receives stimuli from proprioceptors – evaluate body position•Maintains balance and postureImbalances•Ataxia; Lack of coordination•Tremors•Alcohol – affects motor skills; reaction time

•Easily passes through blood-brain barrier