It will guide MSc. Nursing students to develop programme instruction.

1. PROGRAMME INSTRUCTION
ON
ANATOMY & PHYSIOLOGY OF BRAIN
By-
Sampurna Das
Msc. nursing 1st year
College of Nursing
Medical College & Hospital

2. 2014-2015
FRAME: 1:
The brain constitutes about one- fifth of the body weight and it lies within the cranial cavity.
The brain is made of three main parts: the forebrain, midbrain, and hindbrain. The forebrain
consists of the cerebrum, thalamus, and hypothalamus (part of the limbic system). The
midbrain consists of the tectum and tegmentum. The hindbrain is made of the cerebellum,
pons and medulla. Often the midbrain, pons, and medulla are referred to together as the
brainstem.
QUESTIONS AS PER FRAME 1:--
Q. 1. Brain is made up of how many parts?
ANS. ----------------------------------------------------------------
Q. 2. Midbrain consists of which parts?
Q. 3. Hindbrain is composed of ________, _________ & ____________.
ANSWERS:

3. 1.nerve fibers, cerebrum; 2. motor, sensory, cognitive; 3. ~10, C, supratentorial;
4. four parts:- genu, rostrum, trunk, splenium ; 5. frontal; 6.occipital
FRAME 2:
Cerebrum:
This is the largest area of the brain and it occupies the anterior and middle cranial fossae. It
controls all higher mental functions, such as thinking and memory. It is divided by a deep
cleft, the longitudinal cerebral fissure into right and left cerebral hemispheres. The right
cerebral hemisphere controls the left side of the body, and the left cerebral hemisphere
controls the right side of the body. For descriptive purpose each hemisphere of the cerebrum
is divided into lobes which takes the name of the bones of the cranium under which they lie:
frontal, parietal, temporal, occipital
QUESTIONS AS PER FRAME 2:--
1. Brain occupies __________________ & ____________________ cranial fossae.
2. The right cerebral hemisphere controls the ________ side of the body.
ANSWERS:
1. anterior , middle . 2. left

4. FRAME: 3:
Frontal lobe
The Frontal Lobe is the most recently-evolved part of the brain and the last to develop in
young adulthood. It’s dorso-lateral prefrontal circuit is the brain’s top executive. It organizes
responses to complex problems, plans steps to an objective, searches memory for relevant
experience, adapts strategies to accommodate new data, guides behavior with verbal skills
and houses working memory. Its orbitofrontal circuit manages emotional impulses in socially
appropriate ways for productive behaviors including empathy, altruism, interpretation of
facial expressions. Stroke in this area typically releases foul language and fatuous behavior
patterns.
QUESTIONS AS PER FRAME 3:--
1. The frontal lobe is the most _________ evolved part of the brain & _____ to develop
in young adulthood.
2. Frontal lobe’s __________ circuit is the brain’s top executive.
3. Frontal lobe’s ________circuit manages emotional impulses in socially appropriate
ways for productive behaviors including empathy, altruism, interpretation of facial
expressions.
4. Stroke in this area typically releases__________________________.
ANSWERS:

5. 1.recently, last ; 2. dorso-lateral prefrontal ; 3. orbitofrontal; 4. foul language and fatuous
behavior patterns
FRAME: 4:
Parietal Lobe: Located in the cerebral hemisphere, this lobe focuses on comprehension.
Visual functions, language, reading, internal stimuli, tactile sensation and sensory
comprehension will be monitored here.
Sensory Cortex- The sensory cortex, located in the front portion of the parietal lobe, receives
information relayed from the spinal cord regarding the position of various body parts and
how they are moving. This middle area of the brain can also be used to relay information
from the sense of touch, including pain or pressure which is affecting different portions of the
body.
Motor Cortex- This helps the brain monitor and control movement throughout the body. It is
located in the top, middle portion of the brain.
QUESTIONS AS PER FRAME 4:--
1. Parietal lobe focuses on____________.
2. The sensory cortex, located in the ______________________portion of the parietal
lobe, receives information relayed from the
____________________________________________________.
3. Motor cortex helps the brain ________________________
________________________________________________.
4. Motor cortex is located in the_____________________________.

6. ANSWERS:
1. comprehension; 2. front, spinal cord regarding the position of various body parts and how
they are moving; 3. monitor and control movement throughout the body;4. top, middle
portion of the brain.
FRAME:5:
Temporal Lobe: The temporal lobe controls visual and auditory memories. It includes areas
that help manage some speech and hearing capabilities, behavioral elements, and language. It
is located in the cerebral hemisphere.
Wernicke's Area- This portion of the temporal lobe is formed around the auditory cortex.
While scientists have a limited understanding of the function of this area, it is known that it
helps the body formulate or understand speech.
Occipital Lobe: The occipital lobe is located in the cerebral hemisphere in the back of the
head. It helps to control vision.
Broca's Area- This area of the brain controls the facial neurons as well as the understanding
of speech and language. It is located in the triangular and opercular section of the inferior
frontal gyrus.
QUESTIONS AS PER FRAME 5:--
1. The temporal lobe controls_________________________________.
2. ______________________________, portion of the temporal lobe is formed around
the auditory cortex.
3. The optical lobe is located in the _____________________________
__________________________________________________________________.
4. Broka’s area is located in the________________________________
___________________________________________________________________________
.

7. ANSWERS:
1 visual and auditory memories; 2 Wernicke's Area; 3. cerebral hemisphere in the back of the
head; 4. triangular and opercular section of the inferior frontal gyrus.
FRAME .6.
Cerebral cortex
The cerebral cortex is the cerebrum's (brain) outer layer of neural tissue in humans and
other mammals. It is divided into two cortices, along the sagittal plane: the left and
right cerebral hemispheres divided by the medial longitudinal fissure. The human cerebral
cortex is 2 to 4 millimetres (0.079 to 0.157 in) thick. The cerebral cortex is folded, giving a
much greater surface area in the confined volume of the skull. A fold or ridge in the cortex is
termed a gyrus and a groove or fissure is termed a sulcus (plural sulci). In the human
brain more than two-thirds of the cerebral cortex is buried in the sulci. The cerebral cortex
is gray matter, consisting mainly of cell bodies and capillaries. It contrasts with the
underlying white matter. There are three main types of activity associated with the cerebral
cortex: 1.Mental activities involved in memory, intelligence, sense of responsibility, thinking,
reasoning, moral sense and learning, 2. Sensory perception, including the perception of pain,
temperature, touch, sight hearing, taste, and smell, 3. Initiation and control of skeletal muscle
contraction and therefore voluntary movement.
QUESTIONS AS PER FRAME 6:--
1. The cerebral cortex is the_________________________________ in humans and
other mammals.
2. It is divided into two cortices, along the _________________ : the left and
right cerebral hemispheres divided by the ________________________.
3. A fold or ridge in the cortex is termed a_______________ and a groove or fissure is
termed a _______________.
ANSWERS:

8. 1. cerebrum's (brain) outer layer of neural tissue ;2. sagittal plane, medial longitudinal
fissure; 3. gyrus, sulcus
.
FRAME. 7.
CORTICAL AREAS
There are different types of functional area: sensory areas of cerebral cortex, motor areas of
cerebral cortex and association areas of cerebral cortex: 1. Sensory area(somatosensory area,
auditory area, olfactory area, taste area, visual area), 2.motor area(primary motor cortex ), 3.
Association area (premotor, prefrontal, wernicke’s, parieto-occipitotemporal)
QUESTIONS AS PER FRAME 7:--
1. Sensory area include: _________________________________________
_________________________________________________.
2. Motor area include:________________________________________.
3. Association area : ______________________________________________
_____________________________________________________________________
______.
ANSWERS:
1. somatosensory area, auditory area, olfactory area, taste area, visual area; 2. primary motor
cortex; 3. premotor, prefrontal, wernicke’s, parieto-occipitotemporal

9. FRAME: 8:
1)Sensory areas:
The somatosensory area: This is the area immediately behimd the central sulcus. Here the
sensations of pain, temperature, pressure and touch, and awareness of muscular movements
and the positions of joints are perceived. The somatosensory area of right hemisphere
receives impulses from the left side of the body and vice versa. The size of the cortical areas
representing different parts of the body is proportional to the extent of sensory innervations,
e.g. the large area of face is consistent with the extensive sensory nerve supply by the three
branches of the trigeminal nerves.
The auditory area: This lies immediately below the lateral sulcus within the temporal lobe.
The nerve cells receive and interpret impulses and transmitted from the inner ear by the
cochlear part of the vestibulocochlear nerves.
The olfactory area: This lies deep within the temporal lobe whwew impulses from the nose,
transmitted via the alfactory nerves, are received and interpreted.
The taste area: This lies just above the lateral sulcus in the deep layer of the somatosensory
area. Here the impulses from the sensory receptors in the taste buds are received and
perceived as taste.
The visual area: This lies behind the parieto-occipital sulcus and includes the greater part of
the occipital lobe. The optic nerves pass from the eye to this area, which receives and
interprets impulses as visual impression.
QUESTIONS AS PER FRAME 8:--
1. The somatosensory area immediately behimd the ________________.
2. The auditory area lies_____________________________________.
3. The taste area lies________________________________________

10. _____________________________________________________.
ANSWERS:
1. central sulcus; 2. immediately below the lateral sulcus within the temporal lobe; 3. just
above the lateral sulcus in the deep layer of the somatosensory area
FRAME:9:
2)Motor areas
The motor areas are located in both hemispheres of the cortex .They are shaped like a pair
of headphones stretching from ear to ear. The motor areas are very closely related to the
control of voluntary movements, especially fine fragmented movements performed by the
hand. The right half of the motor area controls the left side of the body, and vice versa. Two
areas of the cortex are commonly referred to as motor:Primary motor cortex: This lies in the
frontal lobe immediately anterior to the central sulcus. The cell bodies are pyramid shapes
and control skeletal muscle activity. There are two neurons involved in the pathway of
skeletal muscle. The first, the upper motor neurone, descend from the motor cortex through
the internal capsule to the medulla oblongata. Here it crosses to the opposite side and descend
in the spinal cord. At the appropriate level in the spinal cord it synapses with a second
neurone (the lower motor neurone), which leaves the spinal cord and travels to the target
muscle. It terminates at the motor end plate of a muscle fibre. This means that the motor area
of the right hemisphere of the cerebrum controls voluntary muscle movement on the left side
of the body and vice versa. Damage to either of these neurons may result in paralysis. In the
motor area of the cerebrum the body is represented upside down, i.e. the upper most cells
control the feet and those in lowest part control the head, neck, face and fingers.
QUESTIONS AS PER FRAME 9:--
1. They are shaped like _____________________________________ stretching from
ear to ear.
2. Primary motor cortex lies in the ___________________________________
_____________________________________________________________________
___.

11. 3. The upper motor neurone, descend from _____________________________ to
the________________________________________.
ANSWERS:
1. a pair of headphones ; 2. frontal lobe immediately anterior to the central sulcus; 3 the
motor cortex through the internal capsule , medulla oblongata
FRAME: 10:
3)Association areas
These are connected to each other and the other areas of cerebral cortex by association tracts
and some are outlined below. They receive, coordinate and interpret from the sensory and
motor cortices permitting higher cognitive abilities and, although depicts some of the areas
involved, their functions are much more complex.
The premotor area: This lies in the frontal lobe immediately anterior to the motor area. The
neurons here coordinate movement initiated by the primary motor cortex, ensuring that
learning pattern of movement can be repeated.
The prefrontal area: This extends anteriorly from the premotor area to include the reminder
of the frontal lobe.It is a large area and more develop in humans than in other animals.
Intelectual functions controlled here include perception and comprehension of passage of
time, the ability anticipate consequences of events and normal management of emotions.
Wernicke's Area: This portion of the temporal lobe is formed around the auditory cortex.
While scientists have a limited understanding of the function of this area, it is known that it
helps the body formulate or understand speech.
The parieto-occipitotemporal area: This lies behind the somatosensory area and includes most
of the parietal lobe. Its functions are thought to include spatial awareness, interpreting written
language and the ability to name objects. It has been suggested that objects can be recognised
by touch alone because of knowledge from past experience(memory)retained in this area.
QUESTIONS AS PER FRAME 10:--
1. The parieto-occipitotemporal area lies behind the
_____________________________________________________.
2. The prefrontal area extends ________________________________

12. _____________________________________________________________________
.
ANSWERS:
1. somatosensory area and includes most of the parietal lobe; 2. anteriorly from the premotor
area to include the reminder of the frontal lobe.
FRAME: 11:
Basal ganglia
Deep within the cerebral hemispheres are group of cell bodies called nuclei, the exception
begin those that form the basal ganglia, which form the parts of the extrapyramidal tracts.
They act as a relay stations with connections to many parts of the brain including motor
areas of cerebral cortex and thalamus. Their functions include initiation and fine control of
complex movement and learned coordinated activities, such as posture and walking. If
control is inadequate and absent, movements are jerky, clumsy, and uncoordinated.
QUESTIONS AS PER FRAME 11:
1. Basal ganglia act as a relay stations with connections to many parts of the brain
including _______________________________________.
2. Their functions include ____________________________________
________________________________________________.
3. In case of Basl ganglia’s inadequate and absent control, movements are
__________________________________________________.

13. ANSWERS:
1. motor areas of cerebral cortex and thalamus; 2. initiation and fine control of complex
movement and learned coordinated activities, such as posture and walking; 3. jerky, clumsy,
and uncoordinated.
FRAME: 12:
Corpus Callosum:
The corpus callosum is a thick band of nerve fibers that divides the cerebrum into left and
right hemispheres. It connects the left and right sides of the brain allowing for
communication between both hemispheres. The corpus callosum transfers motor, sensory,
and cognitive information between the brain hemispheres. The corpus callosum is ~10cm in
length and is C-shaped, like most of the supratentorial structures, in a gentle upwardly convex
arch. It is divided into four parts (anterior to posterior):- 1.genu: connect medial and lateral
surfaces of the frontal lobes, 2. rostrum: connecting the orbital surfaces of the frontal lobes,
3. trunk (body): pass through the corona radiata to the surfaces of the hemispheres,
splenium: connect the occipital lobes. Function:1. The corpus callosum is involved in
several functions of the body including, 2. Communication Between Brain Hemispheres,
3.Eye Movement, 4. Maintaining the Balance of Arousal and Attention, 5.Tactile
Localization.
QUESTIONS AS PER FRAME 12:
1. The corpus callosum is a thick band of ________ that divides the _________ into left
and right hemispheres.
2. The corpus callosum transfers _______, ________ and _______ information between
the brain hemispheres
3. The corpus callosum is _____in length and is __-shaped, like most of the
___________ structures, in a gentle upwardly convex arch.
4. Corpus callosum divided in how many parts & what are those parts?
Ans:_________

14. 5. Genu connects medial & lateral surfacecs of which lobe?
Ans:_________
6. Splenium connects which lobe?
Ans: _________
ANSWERS:
1.nerve fibers, cerebrum; 2. motor, sensory, cognitive; 3. ~10, C, supratentorial;
4. four parts:- genu, rostrum, trunk, splenium ; 5. frontal; 6.occipital.
FRAME: 13:
Thalamus:
The thalamus is a large, dual lobed mass of grey matter buried under the cerebral cortex. It is
involved in sensory perception and regulation of motor functions. The thalamus is a limbic
system structure and it connects areas of the cerebral cortex that are involved in sensory
perception and movement with other parts of the brain and spinal cord that also have a role in
sensation and movement. As a regulator of sensory information, the thalamus also controls
sleep and awake states of consciousness. The thalamus is situated at the top of the brainstem,
between the cerebral cortex and midbrain. It is superior to the hypothalamus.
Function: The thalamus is involved in several functions of the body including:
1.Motor Control, 2. Receives Auditory, Somatosensory and Visual Sensory Signals, 3.Relays
Sensory Signals to the Cerebral Cortex, 4. Controls Sleep and Awake States.
QUESTIONS AS PER FRAME 13:
1. The thalamus is a _____________________________________
buried under the cerebral cortex.
1. Thalamus involved in _____________________________________
____________________________________________.
2. The thalamus is
a _______________________________________________________.
3. The thalamus is involved in several functions of the body including:
_____________________________________________________________________
_____________________________________.

15. ANSWERS:
1. large, dual lobed mass of grey matter; 2. sensory perception and regulation of motor
functions; 3.limbic system structure; 4. Motor Control, Receives Auditory, Somatosensory
and Visual Sensory Signals, Relays Sensory Signals to the Cerebral Cortex, Controls Sleep
and Awake States.
FRAME : 14:
Hypothalamus:
About the size of a pearl, the hypothalamus directs a multitude of important functions in the
body. The hypothalamus is inferior to the thalamus. It is posterior to the optic chiasm and
bordered on the sides by the temporal lobes and optic tracts. It is the control centre for many
autonomic functions of the peripheral nervous system. Connections with structures of the
endocrine and nervous systems enable the hypothalamus to play a vital role in maintaining
homeostasis. For example, blood vessel connections between the hypothalamus and pituitary
gland allow hypothalamic hormones to control pituitary hormone secretion. As a limbic
system structure, the hypothalamus also influences various emotional responses. The
hypothalamus is involved in several functions of the body including: 1. Autonomic Function
Control, 2. Endocrine Function Control, 3. Homeostasis, 4. Motor Function Control, 5. Food
and Water Intake Regulation, 5. Sleep-Wake Cycle Regulation.
QUESTIONS AS PER FRAME 14:
1. Hypothalamus is posterior to the _________and bordered on the sides by
the____________.
2. The hypothalamus is involved in several functions of the body including:
___________________________________________________________________
___________________________________________________________________.
3. Blood vessel connections between the_____________________________________
___________________________allow hypothalamic hormones to control pituitary
hormone secretion.

16. ANSWERS:
1. optic chiasm, temporal lobes and optic tracts; 2. Autonomic Function Control, Endocrine
Function Control, Homeostasis, Motor Function Control,Food and Water Intake Regulation,
Sleep-Wake Cycle Regulation; 3. hypothalamus and pituitary gland
FRAME : 15:
BRAIN STEM:
The brain stem houses the midbrain (mesencephalon), pons (part of the metencephalon), and
medulla oblongata (myelencephalon). This is the posterior area of the brain that attaches to the
spinal cord. It's here, at the brain stem, where information is sent back and forth between the
cerebrum or cerebellum and the body. Cranial nerves 3-12 are located here as well as
significant processing centers.
QUESTIONS AS PER FRAME 15:
1. The brain stem houses the ____________________________________________
________________________________________________________________.
2. Brainstem is the _______________________________________________ area of
brain which attaches spinal cord.
3. Cranial nerves _________________________________________ are located here.

17. ANSWERS:
1. midbrain, pons and medulla oblongata, 2. posterior, 3. 3-12
FRAME: 16
Midbrain:
The midbrain is the area of the brain situated around the cerebral aqueduct between the
cerebrum above and pons below. It consists of nuclei and nerve fibers(tracts), which connect
the cerebrum with lower part of the brain and with the spinal cord. The nuclei act as a relay
stations for the ascending and descending nerve fibres.
QUESTIONS AS PER FRAME 16:
1. Midbrain is situated around the ___________________ between the
_________________________________.
2. Midbrain consists of _________________________________________, which
connect the ______________________________________________with lower
part of the brain and with the spinal cord.
3. Brainstem act as a relay stations for the __________________________________
__________________________________________.

18. ANSWERS:
1. cerebral aqueduct, cerebrum above & pons below; 2. nuclei and nerve fibers(tracts),
cerebrum; 3. ascending and descending nerve fibres.
FRAME:17:
Pons:
In Latin, the word Pons literally means bridge. The pons is a portion of the hindbrain that
connects the cerebral cortex with the medulla oblongata. It also serves as a communications
and coordination centre between the two hemispheres of the brain. As a part of the brainstem,
the Pons helps in the transferring of messages between various parts of the brain and the
spinal cord. the Pons is superior to the medulla oblongata and inferior to the midbrain.
Sagittally, it is anterior to the cerebellum and posterior to the pituitary gland.The pons is
involved in several functions of the body including:1. Arousal, 2. Controlling Autonomic
Functions, 3. Relaying Sensory Information Between the Cerebrum and Cerebellum, 4. Sleep
QUESTIONS AS PER FRAME 17:
1. In Latin, the word Pons literally means ________.
2. The pons is a portion of the ___________.
3. Pons connects the cerebral cortex with the ___________________.
4. Pons also serves as a communications and coordination centre between
the______________________________________________________.
5. The pons is involved in several functions of the body including:
___________________________________________________________________
____________________________________________________________________.

19. ANSWERS:
1.bridge; 2. hindbrain; 3. medulla oblongata; 4. two hemispheres of the brain; 5. Arousal,
Controlling Autonomic Functions, Relaying Sensory Information Between
the Cerebrum and Cerebellum, Sleep.
FRAME: 18:
Medulla oblongata
Medulla oblongata, also called medulla, the lowest part of the brain and the lowest portion of
the brainstem. The medulla oblongata is connected by the pons to the midbrain and is
continuous posteriorly with the spinal cord, with which it merges at the opening (foramen
magnum) at the base of the skull. Like the cerebrum and cerebellum, the medulla consists of
both myelinated (white matter) and unmyelinated (gray matter) nerve fibres. In the medulla,
however, the normal anatomic relationship of the two is reversed, with the white matter on
the outside and the gray matter on the inside, around the fourth ventricle (a fluid-filled cavity
formed by the expansion of the central canal of the spinal cord upon entering the brain). A
complex network of medullary nerve cells and processes from elsewhere in the
centralnervous system enables the medulla to carry on complex integrative functions. The
medulla also contains several functional centres that control autonomic nervous activity,
regulating respiration, heart rate, and digestive processes. The last seven cranial
nerves emerge from the medulla, which influences their functional activities. Injuries or
disease affecting the middle portion of the medulla may produce paralysis of the opposite
side of the body, loss of the senses of touch and position, or partial paralysis of the tongue.
Injuries or disease of the lateral medulla may cause loss of pain and temperature sensations,
loss of the gag reflex, difficulty in swallowing, vertigo, vomiting, or loss of
coordination.Function:1. Control of Autonomic Functions,2. Relay of Nerve Signals Between
the Brain and Spinal Cord, 3. Coordination of Body Movements
QUESTIONS AS PER FRAME 18:
1. The medulla oblongata is connected by the ____________________.
2. ___________________ cranial nerves emerge from medulla.

20. 3. Functions of medulla includes:______________________________________
____________________________________________________________________.
ANSWERS:
1. pons & midbrain; 2. last 7; 3. Control of Autonomic Functions,Relay of Nerve Signals
Between the Brain and Spinal Cord, Coordination of Body Movements.
FRAME: 19:
Cerebellum:
The cerebellum is situated behind the pons and immediately below the posterior portion of the
cerebrum occupying the posterior cranial fossa. It is ovoid in shape and two hemisphares,
separated by a narrow median strip called the vermis. Gray matter forms the surface of
cerebrum and the white matter lies deeply. Functions of cerebellum: 1. Maintenance of balance
and posture. 2. Coordination of voluntary movements.3. Motor learning. Cognitive functions.
QUESTIONS AS PER FRAME 19:
1. cerebellum is ___________________________________________________in
shape.
2. Functions of cerebellum includes:
_____________________________________________________________________
____________________________________________________________________.
3. Gray matter forms the __________and the white matter lies ______________.
4. What is vermis?
Ans:___________________________________________________________
____________________________________________________________.
ANSWERS:

21. 1.ovoid ; 2. Maintenance of balance and posture, Coordination of voluntary movements,
Motor learning, Cognitive functions; 3. surface of cerebrum, deeply; 4. a narrow median strip
that separates two cerebellar hemispheres.
FRAME : 20:
BLOOD SUPPLY OF THE BRAIN
Cerebral circulation is the movement of blood through the network of blood
vessels supplying the brain. The arteries deliver oxygenated blood, glucose and other nutrients
to the brain and the veins carry deoxygenated blood back to the heart, removing carbon
dioxide, lactic acid, and other metabolic products. The blood supply of the brain arises from
the internal carotid arteries(anterior circulation) and the vertebral arteries(posterior
circulation). Each internal carotid artery supplies the ipsilateral hemisphere, whereas the
basilar artery form by the junction of the two vertebral arteries, supplies structures within the
posterior fossa(cerebellum and brain stem). The circle of Wills arise from the basilar artery
and the two internal carotid arteries. This vascular circle may act as a safety valve when
differential pressures are present in these arteries. It also may function as an anastomotic
pathway when occlusion of a major artery on one side of the brain occurs. In general, the two
anterior cerebral arteries supply the medial and anterior portion of the frontal lobes. The two
middle cerebral arteries supply the outer portions of the frontal, partial, and superior temporal
lobes. The two posterior cerebral arteries supply the medial portions of the occipital and
inferior temporal lobes. Venous blood drain from the brain through the dural sinuses, which
form channels that drain into the two jugular veins.
QUESTIONS AS PER FRAME20 :
1. The blood supply of the brain arises from the__________________________
________ ___and the__________________________________________.
2. The circle of Wills arise from the________________________________
_____and the______________________________________________________.
3. ________________________________________, the vascular circle may act as
a safety valve when differential pressures are present in these arteries.

22. 4. The two posterior cerebral arteries supply the ____________________________
_________________________________________________________________.
ANSWERS:
1. internal carotid arteries , vertebral arteries; 2. basilar artery, two internal carotid arteries;
3. circle of Wills; 4. medial portions of the occipital and inferior temporal lobes;