Brain Structures (unit 3)

Question 1

The brain consists of roughly?

Answer 1

-20 billion neurons

Question 2

Major regions and landmarks of the brain

Answer 2

• Medulla Oblongata (Brain stem)
• Pons (Brain stem)
• Diencephalon (Brain stem)
• Mesencephalon (midbrain)
• Cerebellum
• Cerebrum (telencephalon)

Question 3

Cerebrum

Answer 3

• Conscious thought processes, intellectual functions
• Memory storage and processing
• Conscious and subconscious regulation of skeletal muscle contractions

Question 4

Cerebellum

Answer 4

• Coordinates complex Somatic motor patterns

- Adjusts output of other Somatic motor centers in brain and spinal cord

Question 5

Diencephalon

Answer 5

-Thalamus
•Relay and processing centers fir sensory information

-Hypothalamus
•Centers controlling emotions, autonomic functions, and hormone production

Question 6

Mesencephalon

Answer 6

• Processing of visual and auditory data
• Generation of reflexive Somatic motor responses
• Maintenance of consciousness

Question 7

Pons

Answer 7

• Relays sensory information to cerebellum and thalamus

- Subconscious Somatic and visceral motor centers

Question 8

Medulla Oblongata

Answer 8

• Relays sensory information to thalamus and to other portions of the brain stem
• Autonomic centers for regulation of visceral function (cardiovascular, respiratory, and digestive system activities)

Question 9

Four sources of protection and support

Answer 9

-Plate bones of the skull
•Parietal, frontal, occipital, and temporal bones

-Cranial meninges
•Dura Mater, Arachnoid Mater, and Pia mater

• Blood-Brain barrier
• Cerebrospinal fluid

Question 10

Dura Mater consists of two layers

Answer 10

-Periosteal layer: the outer layer of connective tissue that connects to the periosteum of cranial bones.

-Meningeal layer: a deeper supporting layer,
These two layers are separated by a gap containing fluid and blood vessels
•some gaps enlarged into dural sinuses

Question 11

Dural venous sinuses

Answer 11

• Situated between the layers of Dura Mater

- They are lined by ENDOTHELIUM, and their walls are thick but devoid of muscular tissue. They have no valves.

Question 12

Dural venous sinuses Function

Answer 12

-To receive blood from the brain through the cerebral veins and the cerebrospinal fluid from The subarachnoid space through the Arachnoid villi

Question 13

Dural folds

Answer 13

• Extensions of the inner layer of dura mater into the cranial cavity
• Stabilize and support the brain

Question 14

3 large dural folds

Answer 14

• Falx cerebri: separates cerebral hemispheres
• Tentorium cerebelli: separates cerebrum from cerebellum
• Falx cerebelli: separates two cerebellar hemispheres

Question 15

Arachnoid Mater consists of?

Answer 15

-Arachnoid membrane
•Connects loosely to Dura Mater

-Arachnoid trabeculae
•Connect to the Pia mater

-Subarachnoid space
•Between the Arachnoid membrane and Pia mater, spanned by trabeculae

Question 16

Pia mater

Answer 16

• Bound to the surface of the brain by astrocyte processes
• Extends into every fold
• Accompanies branches of cerebral blood vessels as they penetrate the surface of the brain to reach internal structures

Question 17

Blood brain Barrier

Answer 17

-The Lining of cerebral blood vessels consists of simple squamous endothelial cells that are highly interconnected by tight junctions
•This tight junction barrier restricts what materials can pass from capillary to fluid surrounding cells of the CNS.

Question 18

Cerebrospinal fluid (CSF)

Answer 18

-Completely surrounds and bathed exposed surfaces of the CNS
-Total volume of CSF at any moment is about 150 ml
-Entire volume replaced about every 8 hours
-Brain has four reservoirs of CSF called ventricles
-CSF is produced and maintained by choroid plexus
•Located in each of the ventricles of the brain
•Consists of combination of Specialized Ependymal Cells and capillaries