1. Human Brain
Brain: about 1400 g (2% of body weight) but receives 20% of body blood supply.
1. Cerebral hemispheres
2. Basal Ganglia
3.Diencephalon: thalamus & hypothalamus.
Brain Stem:
1. Midbrain
2. Pons
3. Medulla

3. The Brain Largest organ in the body at almost 3 lb (1400 g).
Brain functions in sensations, memory, emotions, decision making, behavior

4. Embryonic and Fetal Development of the Human Brain
Actual Size
Actual Size

5. Developmental Anatomy of the NS
Begins in 3rd week
ectoderm forms thickening (neural plate)
plate folds inward to form neural groove
edges of folds join to form neural tube
Neural crest tissue forms:
spinal & cranial nerves
dorsal root & cranial nerve ganglia
adrenal gland medulla
Layers of neural tube form:
marginal layer which forms white matter
mantle layer forms gray matter
ependymal layer forms linings of cavities within NS

6. Brain growth
Changes in brain growth clearly show the emphasis on “head” development early on.
The brain is 25% of it’s adult weight at birth, but body weight is only 5% of adult weight.
These physical indicators illustrate the cephalocaudal directionality of development, but this directionality is more general.
Motor skills tend to develop in this order (children can sit before they can stand).

8. Principal Parts of the Brain
Cerebrum
Diencephalon
thalamus & hypothalamus
Cerebellum
Brainstem
medulla, pons & midbrain

9. Protective Coverings of the Brain
Bone, meninges & fluid
Meninges same as around the spinal cord
dura mater
arachnoid mater
pia mater
Dura mater extensions
falx cerebri
tentorium cerebelli
falx cerebelli

10. Cerebrum (Cerebral Hemispheres)
Cerebral cortex is gray matter overlying white matter
2-4 mm thick containing billions of cells
grew so quickly formed folds (gyri) and grooves (sulci or fissures)
Longitudinal fissure separates left & right cerebral hemispheres
Corpus callosum is band of white matter connecting left and right cerebral hemispheres
Each hemisphere is subdivided into 4 lobes

11. Cerebral White Matter
Association fibers between gyri in same hemisphere
Commissural fibers from one hemisphere to other
Projection fibers form descending & ascending tracts

12. CEREBRAL HEMISPHERES

13. Poles, Borders, Surfaces and Lobes

14. Each cerebral hemisphere has 3 poles, 3borders, 3 surfaces, 4 major sulci and 4 lobes
The 3 poles are:
1- Frontal pole: is the anterior end
2- Occipital pole: Posterior end
3- Temporal pole: the anterior end of the temporal lobe
the 3 borders:
1- Superior border that related to a venous sinus named superior sagittal sinus.
2- Inferomedial border that divided into:
Medial orbital border: from the frontal pole to optic chiasma
Hippocampal border: around midbrain
Medial Occipital border: from splenium of corpus callosum to the occipital pole
3- inferolateral boder
The 3 surfaces:
1- Lateral surface: convex and related to the vault of the skull
2- Medial surface: is flat and separated from the opposite one by falx cerebri
3- Inferior surface: is divided by the lateral sulcus into:
Orbital part: lies on the roof of the orbit
Tentorial part: lies on the tentorium cerebelli
The 4 major sulci:
1- Central sulcus
2- Lateral sulcus: begins on the inferior surface and consists of stem and 3 rami: anterior ramus, ascending ramus and posterior ramus.

15. 3- Calcarine sulcus: begins below splenium of corpus callosum and arches upwards and backwards to reach the occipital pole
4- Parieto-occipital sulcus: it extends from the middle of calcarine sukcus to the superior border and continues on the lateral surface

16. Lobes and Fissures Calcarine sulcus: Longitudinal fissure (green):
Between the 2 cerebral hemispheres
Central sulcus (yellow)
Between precentral & postcentral gyrus
Parieto-occipital sulcus
Lateral sulcus (blue)
Calcarine sulcus:
Frontal lobe
Parietal lobe
Occipital lobe
Temporal lobe

17. Central sulcus
Parieto-occipital
Ascending ramus of lateral sulcus
calcarine
Anterior ramus of lateral sulcus
Posterior ramus of lateral sulcus

19. Medial orbital Superior border Medial occipital Hippocampal border
Occipital pole
Frontal pole
Temporal pole

21. Sulci, Gyri and Cortical Areas of Superolateral Cerebral Surface

23. Main cortical areas of the lateral surface:
primary motor area ( area 4):
site: precentral gyrus, anterior wall of central sulcus
function: give origin of 40% of corticospinal tract ( pyramidal tract) that intiate the highly skilled movement such as playing piano
it controls the opposite side of the body and the body represented in this area upside down
premotor area (area 6):
site: anterior to the motor area
Function: Gross movement, execution of learned motor activity by storing programs of motor activity learned by experience such as walking, dancing,…..
Motor speech area ( Broca’s area, area 44&45)
site: posterior part of the inferior frontal gyrus of the dominant hemisphere (opercular and trianglar gyri)
function: coordinates actions of the muscles used in speech ( lips, tongue and larynx)
Prefrontal cortex ( personlaity center) ( areas 9.10,11&12)
site: frontal pole ( anterior to the premotor area)
function: make up personality, intellectual functions and his reactions to situations

24. General somatosensory area (area 3,2,1):
Site: postcentral gyrus and posterior wall of the central sulcus
function: it recieves all sensations from the opposite side of body and face
Somatosensory association areas ( area 5,7 & 40):
site: 1- area 5, 7 : in the superior parietal lobule
2- area 40: in supramarginal gyrus
function: Stereognosis. Interpretation of senses percieved in the general sensory area
Primary auditory area ( area41&42):
site: in the middle of the upper surface of the superior temporal gyrus ( floor of the lateral sulcus)
function: receives the sounds from both ears especially the opposite one
Auditory association area ( area22):
site: in the dominant hemisphere in the posterior part of the superior temporal gyrus
function: recognition of sounds. It is a sensory speech area ( we learn by hearing)
Primary visual area ( area17):
site: lips of calcarine sulcus ( above and below it)
Function: perception of the light
Visual association area areas 18, 19 & 39)
site: 1- Areas (18,19) : Around ( above and below) the primary visual area
2- Area (39): Angular gyrus
function: recognize of what we see, color vision
Angular gyrus: comprehension of written language

26. Sensory Areas of Cerebral Cortex
Receive sensory information from the thalamus
Primary somatosensory area = postcentral gyrus = 1,2,3
Primary visual area = 17 (vision)
Primary auditory area = 41 & 42 (sound)
Primary gustatory area = 43 (taste)

27. Motor Areas of Cerebral Cortex
Voluntary motor initiation
Primary motor area = 4 = precentral gyrus
controls voluntary contractions of skeletal muscles on other side
Motor speech area = 44,45 = Broca’s area
production of speech -- control of tongue & airway

28. Association Areas of Cerebral Cortex
Somatosensory area = 5 & 7 (integrate & interpret)
Visual association area = 18 & 19 (recognize & evaluate)
Auditory association area = 22 (Music & speech and nois)
Gnostic area = 5,7= integrates sensory interpretation from the association areas to form common thought
Wernike’s area 39 & 40 (integrate all senses & speech to words)
Premotor area = 6 (learned skilled movements such as typing, piano player, gymnastic)
Frontal eye field =8 (scanning eye movements such as phone book)

29. Insula within Lateral Fissure

30. Sulci, Gyri and Cortical Areas of Medial Cerebral Surface

31. Central sulcus
Paracentral lobule

32. Main cortical areas of the medial surface:
primary motor area ( area 4):
site: anterior part of the paracentral area ( leg and foot area)
General somatosensory area (area 3,2,1):
Site: posterior part of the paracentral lobule (leg and foot area)
Main cortical areas of the inferir surface:
primary olfactory area
site: uncus
Olfactory association area (area 28):
Site: anterior part of parahippocampal gyrus
function: discrimination of different odors

33. Sulci, Gyri and Cortical Areas of Inferior Cerebral Surface

34. 28

35. Reticular Formation Scattered nuclei in medulla, pons & midbrain
Reticular activating system (RAS)
alerts cerebral cortex to sensory signals (sound of alarm, flash light, smoke or intruder) to awaken from sleep
maintains consciousness & helps keep you awake with stimuli from ears, eyes, skin and muscles
Motor function is involvement with maintaining muscle tone (postural muscles)

36. Cerebellum Is the largest part of hindbrain
2 cerebellar hemispheres and vermis (central area) An organ concerned with the coordination of the voluntary movements
Situation
Below the posterior portion of cerebrum ( separated from it by tentorium cerebelli)
In the posterior cranial fossa
Function
correct voluntary muscle contraction and posture based on sensory data from body about actual movements
sense of equilibrium

38. Cerebellum Structure and Function

39. Structure Ovoid in shape Two hemispheres
Seaparated by vermis a median strip of tissue
Grey matter forms the cerebellar cortex
White matter in depth
4 deep cerebellar nuclei (from medial to lateral)
1. Fastigial N 2. Globose N Emboliform N.
4. Dentate N.
Cerebellum communicates with other regions of the CNS through three large nerve tracts called the cerebellar peduncles

40. Cerebellum Cerebellar cortex (folia) & central nuclei are grey matter
Arbor vitae = tree of life = white matter

41. Intracerebellar Nuclei
All are present beneath the roof of the 4th ventricle:
These are:
1- Fastigial N.
2- Globose N.
3- Emboliform N.
4- Dentate N.

42. Important fissures of cerebellum:
1. Horizontal fissure: divides the cerbellum into superior and inferior sufaces
2. Primary fissure: at the junction of its anterior1/3 and posterior 2/3
3- posterolateralfissure: extending on the inferior surface separating the flocculonodular lobe from the rest of the of cerebellar hemisphere
Subdivisions of cerebellum
Anatomically divided into:
Anterior lobe: anterior to primary fissure
Posterior lobe: between primary and horizontal fissures
Flocculonodular lobe: lies caudal to the posterolateral fissure
Functionally the cerbellum divided into 3 functional zones
Archicerebellum (Vestibloceremellum): consists of flocculonodular lobe
Paleoceremellum (Spinocerebellum): consists of vermal and paravermal zones of the anterior and posterior lobes
Neocerebellum ( Cerebrocerebellum): consists of lateral zone of the cerebellar hemisphere

44. PARTS CONTROL flocculonodular Balance and maintenance of muscle tone
Paleocerebellum
Motor coordination and muscle tone
Neocerebellum
Planning and automatic control of movement

45. Sensory input for cerebellum
Derived from
Muscles and joints
Eyes
Ears (from semicircular canals)

46. Its function is entirely motor.
FUNCTIONS:
Each cerebellar hemisphere controls the same side of the body.
Cerebellar activities are carried out below the level of consciousness i.e. not under voluntary control.
Its function is entirely motor.
1-Motor learning & retention
2-Planning and fine tuning of skeletal muscle contraction
3-Co-ordination of voluntary motor activity (force,
extent, speed and duration) so that movements are smooth, even and precise
4-Control of muscle tone
5-Control of equilibrium and maintenance of posture

47. Applied anatomy Cerebellar dysfunction cause:
1- Intension tremors: tremors absent at rest and appears when the patient start to move
2- Disturbance in muscle coordination:
Ataxia: the patient walks with wide legs far apart to avoid falling
Nystagmus: due to incoordination of the extraoccular
Scanning speech: slurred and hesitating with pauses in the wrong place
3- Disturbance in the range of movement (dysmetria with overshooting)
4- Disturbance in proper initiation and termination of movement (dysdiadochokinesia)
CHARCOT’S TRIAD: A combination of nystagmus, dysarthria and intention tremor, is highly diagnostic of the Cerebellar disease

48. CEREBELLAR DYSFUNCTIONS
Note:
The Cerebellar disease affects the muscular activity on the same side of the body
No sensory deficits
No paralysis or atrophy of muscles

49. A midline lesion ( archicerebellum ) as tumor leads to loss of postural control.
A unilateral hemisphere lesion (neocerebellum) causes ipsilateral in-coordination of the arm (intention tremors), and of the leg leads to unsteady gait.
Bilateral dysfunction caused by alcoholic intoxication, hypothyroidism, or inherited cerebellar degeneration causing slowness, & slurring of speech (dysarthia), in-coordination of both arms, and staggering, wide-based & unsteady gait (cerebellar ataxia).

51. Floculonodular lobe syndrom: truncal ataxia standing on wide base & reeling from side to side.
Lesion of anterior lobe, Ataxia, Clumsy movement of the lower limb.

52. Posterior Lobe Syndrome
Intention tremors

53. Cerebellar Peduncles Inferior Cerebellar peduncle: (Restiform body)
It connects the cerebellum with the medulla.
It arises from superior half of medulla.
It contains many afferent fibers & few efferent fibers.
Example of:
Afferent: Efferent
Vestibulocerebellar tract Cerebello-vestibular from fastigial
Olivocerebellar tract.
Reticulocerebellar tract Cerebello-reticular from fastigial.
Dorsal spinocerebellar tract.

54. Middle Cerebellar Peduncle: Brachium Pontis
It connects the cerebellum with the pons.
It is the thickest of the 3 peduncles.
It contains mainly afferent fibers which form a part of the Cortico- Ponto-Cerebellar pathway.
Afferent:
1- Ponto-Cerebellar fibers: arise from pontine nuclei and cross the middle line to the opposite side and terminate in the cerebellar hemisphere of the opposite side.

55. Superior cerebellar peduncle: Brachium conjunctivum.
It connects the cerebellum with the midbrain.
It contains mainly efferent fibers, but it contain some afferent fibers.
Afferent:
1- Ventral Spinocerebellar tract.
2- Tectocerebellar tract.
3- Trigeminocerebellar
Efferent:
1- Dentatorubral tract.
2- Dentatothalamic tract. It reaches the ventrolateral nucleus of thalamus either directly or after relay in red nucleus. Through this the cerebellum can coordinate activity of cerebral cortex.

56. Cerebellar Peduncles
Superior, middle & inferior peduncles attach to brainstem
inferior carries sensory information from spinal cord
middle carries sensory fibers from cerebral cortex & basal ganglia
superior carries motor fibers that extend to motor control areas

57. Blood Supply
3 arteries: one to superior surface & 2 to inferior surface.
(PICA) posterior Inferior Cerebellar artery: from vertebral
(AICA) anterior Inferior Cerebellar artery: from basilar.
Superior Cerebellar artery, from basilar.

58. Diencephalon Surrounds 3rd Ventricle
Superior part of walls is thalamus
Inferior part of walls & floor is hypothalamus
Diencephalon is formed of 4 parts:
1- Thalamus Hypothalamus Epithalamus Subthalamus

59. Thalamus
1 inch long mass of gray mater in each half of brain (connected across the 3rd ventricle by intermediate mass)
Relay station for sensory information on way to cortex
Crude perception of some sensations

60. Boundries and relations of the thalamus:
Thalamus has 2 ends and 4 surfaces
Anterior end : related to interventricular foramen
Posterior end (Pulvinar): lies between splenium of corpus callosum above and tectum of midbrain below
Superior sufrace: related to lateral ventricle and fornix
inferior surface : related to A- hypothalamus & subthalamus
B- metathalamus that is formed of:
1- Lateral geniculate body (LGB): lower visual center
2- Medial geniculate body (MGB): lower auditory center
medial surface: related to the 3rd, ventricle and in 70% of humans connected to the opposite one by interthalamic adhesion
lateral surface: related to internal capsulle

65. Thalamic Nuclei
Thalamus is divided into three nuclear groups by a Y- shaped band of fibers called internal medullary lamina into:
1- Anterior nucleus
2- Medial nucleus
3- Lateral nucleus; is divided into two groups, ventral and dorsal:
A- Dorsal group: is divided into lateral dorsal , lateral posterior and pulvinar
B- Ventral group: divided into ventral nucleus and metathalamus
a- ventral nucleus: is divided into ventral anterior, ventral lateral, ventral posterior ( ventral posterior medial and ventral posterior lateral)
b- metathalamus: is formed of LGB and MGB

67. Thalamic Nuclei
Functional classification of the thalamic nuclei into: according to the main function of thalamic nuclei, the are divided into following groups:
1- 2 Specific Motor nuclei: VA and VL
2- 2 Specific sensory nuclei: VP and metathalamus
3- 2 limbic system nuclei: Anterior and medial nuclei
4- 3 Association Nuclei: the 3 dorsal nuclei ( LD, LP and pulvinar)
Anterior and medial nuclei: are concerned with memory, mood, depth of feeling and emotional behavior as the rest of limbic system
Ventral anterior and ventral lateral nuclei: link the cerebellum and the basal ganglia with the motor cortex for control of motor activity
Dorsal group nuclei: form an indirect connection between specific thalamic nuclei and their respective association cortical areas
Ventral posterior lateral nucleus (VPLNT): receive all sensations from opposite side of body
Ventral posterior medial nucleus (VPMNT): receive all sensations from the opposite side of the face
Medial geniculate body: is an auditory relay nucleus
Lateral geniculate body: is a visual relay nucleus

68. Thalamic syndrome:
It occurs in patients during their recovery from thalamic infarction
It is usually due to occlusion of the thalamogeniculate branch of the posterior cerebral artery supplying the ventral posterior nucleus and the geniculate bodies
There is thalamic overreaction to pain and touch on the opposite side of the body. A mild pain or touch is often excessive and agonizing and fails to respond to powerful analgesics

69. Hypothalamus
The fornix divides the hypothalamus into medial and lateral regions:
A- Medial Region: contains 4 nuclear groups:
Pre optic area
Supraoptic nuclear group: contains 3 nuclei
a- anterior nucleus b- supraoptic nucleus c- paraventricular nucleus
3. Tuberal nuclear group: contains 3 nuclei
a- Arcuate nucleus b- Ventromedial nucleus c- Dorsomedial nucleus
4- Mamillary group: posterior and contains the mamillary body and posterior nucleus
B- Lateral Region: contains the lateral hypothalamic nucleus

72. Functions of Hypothalamus
1- Endocrine function: control the pituitary secretions:
Neurohypophysis ( post. Lobe of pituitary): Contains cell bodies of axons that end in posterior pituitary where they secrete hormones
Supraoptic nucleus: secretes (antidiuretic hormone) (ADH)
Paraventricular nucleus: secretes oxytocin
B. Adenohypophysis ( anterior lobe of pituitary)
Hypothalamus secretes releasing and inhibiting hormones which control the production of the anterior pituitary hormones.
2- Autonomic function: controls the brainstem and spinal cord autonomic centers:
Parasympathetic centers: the anterior hypothalamic and preoptic nuclei ( vasodilatation, ↓ HR, ↓ BP,……)
Sympathetic centers: the posterior hypothalamic and lateral hypothalamic nuclei ( vasoconstriction, ↑ HR, ↑BP,…….)

73. 3- Temperature regulation:
Heat dissipation centers: sensitive to heat. In the anterior nucleus
Heat production: sensitive to cold. In the posterior nucleus
4- Regulation of food intake:
Satiety center: inhibits food intake. In ventromedial nucleus
Hunger center: stimulates food intake. In lateral hypothalamic nucleus
5- Regulation of water intake and excretion:
The lateral nucleus is the thirst center
ADH increases reabsorption of water from kidneys
6- Relation to emotions: it plays an important role in emotions since mamillary body is part of the limbic system
7- Relation to sleep:
It has no direct role in regulation of sleep. But because fibers of reticular activating system pass through it , it has a role in the arousal

74. Epithalamus Pineal gland Habenular nuclei
endocrine gland the size of small pea
secretes melatonin during darkness
promotes sleepiness & sets biological clock
Habenular nuclei
emotional responses to odors
Pineal gland

75. Subthalamus & CVO Subthalamus Circumventricular organs
small area just inferior to thalamus
work with basal ganglia, cerebrum & cerebellum to control body movements
Circumventricular organs
in walls of 3rd & 4th ventricles
monitor changes in blood chemistry because lack blood brain barrier (parts of hypothalamus, pineal & pituitary gland)
sites of entry of HIV virus (Human Immunodeficiency Virus) into brain

76. Basal Ganglia
Connections to red nucleus, substantia nigra & subthalamus
Input & output with cerebral cortex, thalamus & hypothalamus
Control large automatic movements of skeletal muscles

78. Basal ganglia: components:
1- Corpus striatum: formed of caudate nucleus and lentiform nucleus
2- Subthalamic nucleus
3- Substantia nigra of midbrain
4- Thalamus: ventral anterior and ventral lateral
Function: the basal ganglia regulate the stereotyped motor activity (as walking & swimming) and postural mechanism by influencing the brainstem and spinal cord motor neurons
A: Caudate nucleus:
Formed of head, body and tail that related to lateral ventricle
it forms with the substantia nigra a circuit through which the dopamine inhibits the activity of the caudate nucleus
Parkinson’s disease: is associated with degeneration of substantia nigra with depletion of dopamine resulting in over activity of caudate
This disease characterized by triad of symptoms ( tremor, rigidity, bradykinesia)
Chorea : due to inhibition of caudate with over activity of dopamine secreting neurons of subtantia nigra and manifisted by abnormal irregular and jerky movements of limbs
B: Lentiform nucleus is formed of 2 parts
1- globus pallidus is the medial part
2- Putamen is the lateral part: that forms together with caudate neostriatum

79. Note: the amygdaloid nucleus is anatomically included with the basal ganglia
it lies at the tail of the caudate nucleus at the temporal lobe deep to the uncus
Functionally it belongs to the limbic and olfactory systems

81. Inputs To the Basal Ganglia System
Nearly all inputs arrive at the caudate and putamen.
All outputs go out from globus pallidus or from substantia nigra.
Parallel pathways in BG function in general motor
control, eye movements, cognitive functions,
and emotional functions.
Inputs:
Cerebral cortex: all lobes (sensory, motor and premotor) have projections
to striatum; most are (+) and use glutamate as neurotransmitter.
Substantia nigra (pars compacta): to striatum: (–) connections, uses dopamine.
Thalamus (intralaminar nuclei): to striatum: (+) and use glutamate.
Outputs of the Basal Ganglia System
1- Striatum (caudate and putamen): to globus pallidus (-) using (GABA)
2- Substantia nigra pars reticulata: to VL and VA thalamus; (-) using GABA.
3- Globus pallidus internal segment: to VL and VA thalamus; (-) using GABA.
VL/VA thalamus carries basal ganglia output to frontal lobe premotor cortex, supplementary motor cortex, and primary motor cortex.

82. - GABA Substantia nigra (pars compacta + GLU Striatum
Intrinsic Basal Ganglia Connections
Direct pathway from the striatum to the globus pallidus internal segment and
substantia nigra pars reticulata.
Pars reticularis projects inhibitory to thalamus
Indirect pathway from striatum to GP external segment to subthalamus, to GP
internal segment to VA/VL thalamus.
Net effect of direct path is excitation of thalamus = facilitation of movement
Net effect of indirect path is inhibition of thalamus = inhibition of movement
Note : subthalmus can inhibit or excitate the globus pallidus
- GABA
Substantia nigra
(pars compacta
+ GLU
Striatum
(caudate, putamen)
Cerebral cortex
+ GLU
+ GLU
- GABA
- GABA
- GABA
Globus pallidus
subthalamus
thalamus

83. Limbic System

84. History Paul Broca (1824-1880): 1878: “le grand lobe limbique”
Refers to a ring of gray matter on the medial aspect of the cerebral hemispheres.
James Papez ( ):
1930’s: defined a limbic system that might underlie the relationship between emotion and memory (Papez’ circuit).

85. Components of the limbic system
Nuclei of limbic system
Limbic lobe: formed of cingulate gyrus, parahippocampal gyrus and the uncus
Hippocampus with is continuous externally with parahippocampal gyrus
Hypothalamus: mainly mamillary body
Thalamic nuclei: Anterior nucleus and medial nucleus
Prefrontal cortex (personality center)
Amygdaloid nucleus
Habenular nucleus
B. Fibers connecting the nuclei:
1- Fornix originates in hippocampus and terminates in mamillary body 2-
Function of limbic system:
Emotional behavior: play major role in feeling, feeding, aggression, anger. These emotional expressions are carried out through the hypothalamus via autonomic and endocrine systems
Recent memory: the hippocamus plays a role in short term memory
olfaction
Note: 1- Emotional brain--intense pleasure & intense pain
2- Strong emotions increase efficiency of memory
3- Alzheimer’s disease is due to due to degeneration of hippocampus

86. Hippocampal Formation

87. Midbrain One inch in length Extends from pons to diencephalon
Cerebral aqueduct connects 3rd ventricle above to 4th ventricle below and divides the midbrain into anterior part (cerebral peduncle) posterior part (tectum)
The cerebral peduncle formed of 3 parts:
1- crus cerebri
2- Substantia nigra
3- Tegmentum

88. Midbrain in Section
The Crus cerebri---clusters of motor & sensory fibers
Substantia nigra---helps controls subconscious muscle activity
Red nucleus-- rich blood supply & iron-containing pigment
cortex & cerebellum coordinate muscular movements by sending information here from the cortex and cerebellum

89. Dorsal Surface of Midbrain
Corpora quadrigemina = superior & inferior colliculi
coordinate eye movements with visual stimuli
coordinate head movements with auditory stimuli

90. Medulla Oblongata Continuation of spinal cord Ascending sensory tracts
Descending motor tracts
Nuclei of 5 cranial nerves
Cardiovascular center
force & rate of heart beat
diameter of blood vessels
Respiratory center
medullary rhythmicity area sets basic rhythm of breathing
Information in & out of cerebellum
Reflex centers for coughing, sneezing, swallowing etc

91. Ventral Surface of Medulla Oblongata
Ventral surface bulge
pyramids
large motor tract
decussation of most fibers
left cortex controls right muscles
Olive = olivary nucleus
neurons send input to cerebellum
proprioceptive signals
gives precision to movements

92. Dorsal Surface of Medulla Oblongata
Nucleus gracilis & nucleus cuneatus = sensory neurons
relay information to thalamus on opposite side of brain
5 cranial nerves arise from medulla -- 8 thru 12

93. Hemispheric Lateralization
Functional specialization of each hemisphere more pronounced in men
Females have larger connections between 2 sides
Damage to left side produces aphasia
Damage to same area on right side produces speech with little emotional inflection