1. Warm-Up List and describe the 5 elements of a reflex arc.
List an example of a reflex.
What is the difference between a reflex and a voluntary reaction?

2. Human Brain

3. 4 Major Regions Cerebral Hemispheres Diencephalon Brain stem
Cerebellum

4. 1. Cerebral Hemispheres (Cerebrum)
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

8. Cerebral Cortex
Grey matter
“Executive suite”  conscious mind

10. Functions of the Major Lobes

11. 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

12. Parieto-occipital sulcus (on medial surface of hemisphere)
Precentral
gyrus
Central
sulcus
Postcentral
gyrus
Frontal
lobe
Parietal lobe
Parieto-occipital sulcus
(on medial surface
of hemisphere)
Lateral sulcus
Occipital lobe
Temporal lobe
Transverse cerebral fissure
Cerebellum
Pons
Medulla oblongata
Fissure
Spinal cord
(a deep
sulcus)
Gyrus
Cortex (gray matter)
Sulcus
White matter
(a)
Figure 12.6a

13. Thin (2–4 mm) superficial layer of gray matter
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

14. 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

15. Motor Areas
Primary (somatic) motor cortex
Premotor cortex
Broca’s area
Frontal eye field

16. Sensory areas and related association areas Primary motor cortex
Motor areas
Central sulcus
Sensory areas and related
association areas
Primary motor cortex
Primary somatosensory
cortex
Premotor cortex
Somatic
sensation
Frontal eye field
Somatosensory
association cortex
Broca’s area
(outlined by dashes)
Gustatory cortex
(in insula)
Taste
Prefrontal cortex
Working memory
for spatial tasks
Wernicke’s area
(outlined by dashes)
Executive area for
task management
Working memory for
object-recall tasks
Primary visual
cortex
Visual
association
area
Vision
Solving complex,
multitask problems
Auditory
association area
Hearing
Primary
auditory cortex
(a) Lateral view, left cerebral hemisphere
Primary motor cortex
Motor association cortex
Primary sensory cortex
Sensory association cortex
Multimodal association cortex
Figure 12.8a

17. Posterior
Motor
Motor map in
precentral gyrus
Anterior
Toes
Jaw
Tongue
Primary motor
cortex
(precentral gyrus)
Swallowing
Figure 12.9

18. Sensory Areas Primary somatosensory cortex
Somatosensory association cortex
Visual areas
Auditory areas
Olfactory cortex
Gustatory cortex
Visceral sensory area
Vestibular cortex

19. Sensory areas and related association areas Primary motor cortex
Motor areas
Central sulcus
Sensory areas and related
association areas
Primary motor cortex
Primary somatosensory
cortex
Premotor cortex
Somatic
sensation
Frontal eye field
Somatosensory
association cortex
Broca’s area
(outlined by dashes)
Gustatory cortex
(in insula)
Taste
Prefrontal cortex
Working memory
for spatial tasks
Wernicke’s area
(outlined by dashes)
Executive area for
task management
Working memory for
object-recall tasks
Primary visual
cortex
Visual
association
area
Vision
Solving complex,
multitask problems
Auditory
association area
Hearing
Primary
auditory cortex
(a) Lateral view, left cerebral hemisphere
Primary motor cortex
Motor association cortex
Primary sensory cortex
Sensory association cortex
Multimodal association cortex
Figure 12.8a

20. Posterior
Sensory
Anterior
Sensory map in
postcentral gyrus
Genitals
Primary somato-
sensory cortex
(postcentral gyrus)
Intra-
abdominal
Figure 12.9

21. 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

22. Multimodal Association Areas
Three parts
Anterior association area (prefrontal cortex)
Posterior association area
Limbic association area

23. 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

24. 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)

25. Limbic Association Area
Part of the limbic system
Provides emotional impact that helps establish memories

27. 2. Diencephalon (interbrain)
3 main structures:
Thalamus: relay station for incoming info
Hypothalamus:
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)

28. Diencephalon

29. Thalamic Function 80% of diencephalon Gateway to the cerebral cortex
Sorts, edits, and relays information
Mediates sensation, motor activities, cortical arousal, learning, and memory

30. (b) The main hypothalamic nuclei.
Paraventricular
nucleus
Anterior
commissure
Dorsomedial
nucleus
Fornix
Preoptic
nucleus
Posterior
hypothalamic
nucleus
Anterior
hypothalamic
nucleus
Lateral
hypothalamic
area
Supraoptic
nucleus
Ventromedial
nucleus
Supra-
chiasmatic
nucleus
Mammillary
body
Arcuate
nucleus
Optic
chiasma
Pituitary
gland
Infundibulum
(stalk of the
pituitary gland)
(b) The main hypothalamic nuclei.
Figure 12.13b

31. Hypothalamic Function
Autonomic control center for many visceral functions (e.g., blood pressure, rate and force of heartbeat, digestive tract motility)
Center for emotional response: Involved in perception of pleasure, fear, and rage and in biological rhythms and drives

32. Hypothalamic Function
Regulates body temperature, food intake, water balance, and thirst
Regulates sleep and the sleep cycle
Controls release of hormones by the anterior pituitary
Produces posterior pituitary hormones
Infundibulum—stalk that connects to the pituitary gland

33. Pineal gland—extends from the posterior border and secretes melatonin
Epithalamus
Pineal gland—extends from the posterior border and secretes melatonin
Melatonin—helps regulate sleep-wake cycles

34. 3. Brain Stem Programmed, automatic behaviors for survival 3 regions:
Midbrain: vision, hearing, reflex
Pons: breathing
Medulla oblongata: heart rate, BP, breathing, swallowing, vomiting, coughing, sneezing
Associated with 10 of the 12 pairs of cranial nerves

35. Brain Stem

37. Frontal lobe Olfactory bulb (synapse point of cranial nerve I)
Optic chiasma
Optic nerve (II)
Optic tract
Mammillary body
Midbrain
Pons
Temporal lobe
Medulla
oblongata
Cerebellum
Spinal cord
Figure 12.14

38. Oculomotor nerve (III) Trochlear nerve (IV)
View (a)
Optic chiasma
Optic nerve (II)
Diencephalon
Crus cerebri of
cerebral peduncles
(midbrain)
• Thalamus
• Hypothalamus
Thalamus
Mammillary body
Diencephalon
Hypothalamus
Oculomotor nerve (III)
Midbrain
Pons
Brainstem
Trochlear nerve (IV)
Medulla
oblongata
Trigeminal nerve (V)
Middle cerebellar
peduncle
Pons
Facial nerve (VII)
Abducens nerve (VI)
Vestibulocochlear
nerve (VIII)
Glossopharyngeal nerve (IX)
Hypoglossal nerve (XII)
Pyramid
Vagus nerve (X)
Ventral root of first
cervical nerve
Accessory nerve (XI)
Decussation of pyramids
Spinal cord
(a) Ventral view
Figure 12.15a

39. Superior cerebellar peduncle Pons Middle cerebellar peduncle
Crus cerebri of
cerebral peduncles
(midbrain)
Thalamus
View (b)
Infundibulum
Superior colliculus
Pituitary gland
Inferior colliculus
Trochlear nerve (IV)
Trigeminal nerve (V)
Superior cerebellar peduncle
Pons
Middle cerebellar peduncle
Facial nerve (VII)
Inferior cerebellar peduncle
Abducens nerve (VI)
Vestibulocochlear nerve (VIII)
Glossopharyngeal nerve (IX)
Olive
Hypoglossal nerve (XII)
Thalamus
Vagus nerve (X)
Diencephalon
Hypothalamus
Accessory nerve (XI)
Midbrain
Pons
Brainstem
Medulla
oblongata
(b) Left lateral view
Figure 12.15b

40. Midbrain Nuclei
Nuclei (small areas of gray matter) that control cranial nerves III (oculomotor) and IV (trochlear)
Visual reflex centers
Auditory relay centers

41. Pons Connect higher brain centers and the spinal cord
Relay impulses between the motor cortex and the cerebellum
Origin of cranial nerves V (trigeminal), VI (abducens), and VII (facial)
Nuclei that help maintain normal rhythm of breathing

42. Medulla Oblongata
Joins spinal cord at foramen magnum
Relay sensory information from muscles and joints to cerebellum
Cranial nerves VIII, X, and XII are associated with the medulla
Mediates responses that maintain equilibrium

43. Autonomic reflex centers Cardiovascular center
Medulla Oblongata
Autonomic reflex centers
Cardiovascular center
Cardiac center adjusts force and rate of heart contraction
Vasomotor center adjusts blood vessel diameter for blood pressure regulation
Respiratory centers
Generate respiratory rhythm
Control rate and depth of breathing

44. Additional centers regulate
Medulla Oblongata
Additional centers regulate
Vomiting
Hiccuping
Swallowing
Coughing
Sneezing

45. 4. Cerebellum
Balance, equilibrium, timing of skeletal muscle activity

46. The Cerebellum
11% of brain mass
Dorsal to the pons and medulla
precise timing and appropriate patterns of skeletal muscle contraction
Sports

47. Cognitive Function of the Cerebellum
sequences of events during complex movements
nonmotor functions such as word association and puzzle solving

48. 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 nerve (CN XII)

49. Protection of CNS 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 and provides oxygen, nutrients and vital chemicals to the brain and spinal cord
Lumbar (spinal) tap – test for infection, tumors, multiple sclerosis

51. Meningitis

52. Symptoms of Meningitis

53. Treatment for Meningitis
Bacterial  antibiotics
Herpes meningitis  antiviral meds
IV fluids
Prevention: vaccines for bacterial infections (HiB)

54. Blood-Brain Barrier: endothelial cells in capillaries prevent substances from crossing into brain
NO:
YES:
Urea
Toxins
Proteins
White blood cells
Bacteria
Most drugs
Water
Glucose
Amino acids
Gases
Fat-soluble substances
Some drugs: anesthetics, alcohol, nicotine