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1.
List and describe the 5 elements of a reflex
arc.
2.
List an example of a reflex.
3.
What is the difference between a reflex and
a voluntary reaction?
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4.
Cerebral
Hemispheres
Diencephalon
Brain stem
Cerebellum
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L & R hemispheres
Corpus callosum: large fiber tract; connects 2
hemispheres
Lobes: major regions (named for cranial bones)
 Parietal, frontal, occipital, temporal
Gyri (gyrus) = elevated ridges of tissue
Sulci (sulcus) = shallow grooves
Fissures = deeper grooves, separate large
regions of brain
Motor & sensory function: opposite hemispheres
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Grey matter
“Executive suite”  conscious mind
Cerebral Hemispheres
• Surface markings
• Central sulcus
• Separates the precentral gyrus of the frontal lobe
and the postcentral gyrus of the parietal lobe
• Longitudinal fissure
• Separates the two hemispheres
• Transverse cerebral fissure
• Separates the cerebrum and the cerebellum
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Precentral
gyrus
Frontal
lobe
Central
sulcus
Postcentral
gyrus
Parietal lobe
Parieto-occipital sulcus
(on medial surface
of hemisphere)
Lateral sulcus
Occipital lobe
Temporal lobe
Transverse cerebral fissure
Cerebellum
Pons
Medulla oblongata
Spinal cord
Fissure
(a deep
sulcus)
Gyrus
Cortex (gray matter)
Sulcus
White matter
(a)
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Figure 12.6a
Cerebral Cortex
• Thin (2–4 mm) superficial layer of gray
matter
• 40% of the mass of the brain
• Site of conscious mind: awareness,
sensory perception, voluntary motor
initiation, communication, memory storage,
understanding
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Functional Areas of the Cerebral Cortex
• The three types of functional areas are:
• Motor areas—control voluntary movement
• Sensory areas—conscious awareness of
sensation
• Association areas—integrate diverse
information
• Conscious behavior involves the entire cortex
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Motor Areas
• Primary (somatic) motor cortex
• Premotor cortex
• Broca’s area
• Frontal eye field
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Motor areas
Central sulcus
Primary motor cortex
Premotor cortex
Frontal eye field
Broca’s area
(outlined by dashes)
Prefrontal cortex
Working memory
for spatial tasks
Executive area for
task management
Working memory for
object-recall tasks
Solving complex,
multitask problems
(a) Lateral view, left cerebral hemisphere
Sensory areas and related
association areas
Primary somatosensory
cortex
Somatic
Somatosensory
sensation
association cortex
Gustatory cortex
(in insula)
Taste
Wernicke’s area
(outlined by dashes)
Primary visual
cortex
Visual
association
area
Auditory
association area
Primary
auditory cortex
Vision
Hearing
Motor association cortex
Primary sensory cortex
Primary motor cortex
Sensory association cortex
Multimodal association cortex
Copyright © 2010 Pearson Education, Inc.
Figure 12.8a
Posterior
Motor
Motor map in
precentral gyrus
Anterior
Toes
Jaw
Tongue
Swallowing
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Primary motor
cortex
(precentral gyrus)
Figure 12.9
Sensory Areas
• Primary somatosensory
cortex
• Somatosensory
association cortex
• Visual areas
• Auditory areas
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• Olfactory cortex
• Gustatory cortex
• Visceral sensory area
• Vestibular cortex
Motor areas
Central sulcus
Primary motor cortex
Premotor cortex
Frontal eye field
Broca’s area
(outlined by dashes)
Prefrontal cortex
Working memory
for spatial tasks
Executive area for
task management
Working memory for
object-recall tasks
Solving complex,
multitask problems
(a) Lateral view, left cerebral hemisphere
Sensory areas and related
association areas
Primary somatosensory
cortex
Somatic
Somatosensory
sensation
association cortex
Gustatory cortex
(in insula)
Taste
Wernicke’s area
(outlined by dashes)
Primary visual
cortex
Visual
association
area
Auditory
association area
Primary
auditory cortex
Vision
Hearing
Motor association cortex
Primary sensory cortex
Primary motor cortex
Sensory association cortex
Multimodal association cortex
Copyright © 2010 Pearson Education, Inc.
Figure 12.8a
Posterior
Sensory
Anterior
Sensory map in
postcentral gyrus
Genitals
Primary somatosensory cortex
(postcentral gyrus)
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Intraabdominal
Figure 12.9
Visual Areas
• Primary visual (striate) cortex
• Extreme posterior tip of the occipital lobe
• Receives visual information from the retinas
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Multimodal Association Areas
• Receive inputs from multiple sensory areas
• Send outputs to multiple areas
• Allow us to give meaning to information
received, store it as memory, compare it to
previous experience, and decide on action to
take
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Multimodal Association Areas
• Three parts
• Anterior association area (prefrontal cortex)
• Posterior association area
• Limbic association area
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Anterior Association Area (Prefrontal
Cortex)
• Most complicated cortical region
• Involved with intellect, cognition, recall, and
personality
• Contains working memory needed for
judgment, reasoning, persistence, and
conscience
• Development depends on feedback from
social environment
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Posterior Association Area
• Large region in temporal, parietal, and
occipital lobes
• Plays a role in recognizing patterns and faces
and localizing us in space
• Involved in understanding written and spoken
language (Wernicke’s area)
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12 Cranial Nerve Mnemonic:
On old Olympus' towering top a Fin and German viewed some hops
• O: olfactory nerve (CN I)
• O: optic nerve (CN II)
• O: oculomotor nerve (CN III)
• T: trochlear nerve (CN IV)
• T: trigeminal nerve(CN V)
• A: abducens nerve (CN VI)
• F: facial nerve (CN VII)
• A: auditory (or vestibulocochlear) nerve (CN VIII)
• G: glossopharyngeal nerve (CN IX)
• V: vagus nerve (CN X)
• S: spinal accessory nerve (CN XI)
• H: hypoglossal (CN XII)
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3 main structures:
1. Thalamus: relay station for incoming info
2. Hypothalamus:
A.
B.
C.
D.
E.
F.
3.
Autonomic control center (heart rate, BP, digestion)
Emotional response (limbic system)
Body temperature regulation
Regulate food intake
Sleep-wake cycles
Control endocrine system  pituitary gland at base
Epithalamus: pineal gland (sleep-wake cycle)
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Programmed, automatic behaviors for survival
3 regions:
1. Midbrain: vision, hearing, reflex
2. Pons: breathing
3. Medulla oblongata: heart rate, BP, breathing,
swallowing, vomiting, coughing, sneezing
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Balance, equilibrium, timing of skeletal
muscle activity
Meninges: connective tissue covering CNS structures
 Dura mater (leathery outer), arachnoid mater
(web-like middle), pia mater (surface of brain)
 Meningitis: inflammation of meninges; bacterial or
viral infection
 Cerebrospinal fluid (CSF): watery cushion to protect
NS from trauma
 Lumbar (spinal) tap – test for infection, tumors,
multiple sclerosis
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Bacterial  antibiotics
Herpes meningitis  antiviral meds
IV fluids
Prevention: vaccines for bacterial infections (HiB)
NO:
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Urea
Toxins
Proteins
White blood cells
Bacteria
Most drugs
YES:
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Water
Glucose
Amino acids
Gases
Fat-soluble substances
Some drugs:
anesthetics, alcohol,
nicotine