13.3 Flashcards
What is the primary function of the blood-brain barrier?
A) To protect the brain from toxins and pathogens in the bloodstream
B) To allow all blood contents to pass into the central nervous tissue
C) To regulate body temperature
D) To control hormone levels
A) To protect the brain from toxins and pathogens in the bloodstream
Explanation: The blood-brain barrier ensures that only specific substances can pass into the brain, protecting it from harmful toxins and pathogens.
The CNS needs specialized structures for the maintenance of circulation, beginning with a unique arrangement of blood vessels carrying fresh blood into the _____.
A) Heart
B) CNS
C) Lungs
D) Liver
B) CNS
Explanation: Specialized structures and a unique arrangement of blood vessels are essential for maintaining circulation within the CNS.
The orthostatic reflex helps maintain blood pressure when changing body position.
A) True
B) False
A) True
Explanation: The orthostatic reflex responds to changes in body position to help maintain blood pressure, preventing dizziness or fainting upon standing.
Which artery supplies blood to the anterior aspect of the spinal cord?
A) Internal carotid artery
B) Anterior spinal artery
C) Vertebral artery
D) Basilar artery
B) Anterior spinal artery
Explanation: The anterior spinal artery supplies blood to the anterior aspect of the spinal cord, crucial for its function.
The circle of Willis is a specialized arrangement of arteries that ensure constant perfusion of the _____ even in the event of a blockage of one of the arteries in the circle.
A) Liver
B) Brain
C) Heart
D) Lungs
B) Brain
Explanation: The circle of Willis helps maintain a constant blood supply to the brain, even if one part is blocked.
After passing through the CNS, blood returns to the circulation through a series of dural sinuses and veins, including the _____ sinus and the transverse sinuses.
A) Superior sagittal
B) Inferior mesenteric
C) Coronary
D) Hepatic portal
A) Superior sagittal
Explanation: The superior sagittal sinus and the transverse sinuses play key roles in returning blood from the CNS to the heart.
The dura mater is a thin, delicate membrane that forms a loose sac around the CNS.
A) True
B) False
B) False
Explanation: The dura mater is a thick fibrous layer that forms a strong protective sheath over the brain and spinal cord.
What structure directly follows the convolutions of gyri and sulci in the cerebral cortex?
A) Dura mater
B) Arachnoid mater
C) Pia mater
D) Superior sagittal sinus
C) Pia mater
Explanation: The pia mater is a thin fibrous membrane that closely follows the contours of the brain’s gyri and sulci, providing an additional layer of protection and support.
Which meningeal layer is described as a tough outer covering that encloses the entire CNS?
A) Arachnoid mater
B) Dura mater
C) Pia mater
D) Subarachnoid space
B) Dura mater
Explanation: The dura mater is a thick, tough outer layer that physically protects the CNS and encloses major blood vessels.
The arachnoid mater is named for its resemblance to a spider web.
A) True
B) False
A) True
Explanation: The arachnoid mater is named for its web-like appearance due to the arachnoid trabeculae that span the subarachnoid space.
The subarachnoid space is filled with _____.
A) Blood
B) Cerebrospinal fluid (CSF)
C) Interstitial fluid
D) Air
B) Cerebrospinal fluid (CSF)
Explanation: The subarachnoid space is filled with CSF, which provides a cushion for the brain and spinal cord.
What is the purpose of a lumbar puncture?
A) To inject medication into the spinal cord
B) To withdraw cerebrospinal fluid (CSF) for testing
C) To relieve pressure in the brain
D) To measure blood pressure in the CNS
B) To withdraw cerebrospinal fluid (CSF) for testing
Explanation: A lumbar puncture is used to collect CSF for chemical testing to diagnose conditions like meningitis.
Bacterial meningitis can be treated with antibiotics, but viral meningitis cannot.
A) True
B) False
A) True
Explanation: Antibiotics are effective against bacterial infections, but viral infections do not respond to antibiotics.
What are the open spaces within the brain where cerebrospinal fluid (CSF) circulates called?
A) Sinuses
B) Ventricles
C) Arteries
D) Veins
B) Ventricles
Explanation: The ventricles are the open spaces within the brain where CSF circulates, providing cushioning and nutrient transport.
The CSF circulates through all of the ventricles to eventually emerge into the _____ where it will be reabsorbed into the blood.
A) Dural sinuses
B) Subarachnoid space
C) Interstitial space
D) Capillaries
B) Subarachnoid space
Explanation: CSF is eventually reabsorbed into the blood after circulating through the subarachnoid space.