Lecture 10

Question 1

Name the major veins on this specimen:

Answer 1

1. Maxillary
2. Linguofacial
3. External Jugula Vein

Question 2

Define the term rete mirabile:

Answer 2

A complex of arteries and veins that lie very close together found in some vertebrates mainly the warm blooded one’s. Occurs at anastomosis of internal carotid and internal maxillary. Thought to act as a counter current mutiplier

Question 3

Name and describe the shape of the venous strucrture that is present within the spinal cord:

Answer 3

• Internal Vertebral Venous plexus
• Pair of longitudinal veins that running parallel and anastomising at each major segment (like train tracks)

Question 4

What does the internal vertebral venous plexus run into?

Answer 4

Azygous (thorax) and caudal vena cava (abdomen)

Question 5

How is the brain drained dorsally?

Answer 5

The brain is drained dorsally via the dorsal sagittal sinus and by the deeper great cerebral vein (within the dural faux cerebri). At the tentorium cerebelli this bilaterally splits at the tranverse sinus and then descends. The dorsal sinus system drains through the maxillary vein or via the ventral system.

Question 6

Explain how the brain is drained ventrally:

Answer 6

Ventrally the brain is drained via the cavernous sinus and the dorsal petrosal sinuses which communicate with the internal vertebral venous plexus. The cavernous sinus drains the deep face, upper tooth roots, nasal cavity and the orbit

Question 7

What is the name of this structure and describe some of the characteristic feautures of it:

Answer 7

Internal vertebral venous plexus. Anastomises at each segment.

Question 8

Name the following sinuses:

Answer 8

1. Dorsal sagittal sinus
2. Transverse Venous sinus
3. Internal Vertebral Venous Plexus
4. Cavernous venous sinus

Question 9

Name each of the following parts of the brain:

Answer 9

* = lateral ventricle

** = 3rd ventricle

*** = 4th ventricle

Question 10

Describe the appearanceo of cerebral spinal fluid:

Answer 10

thin colourless fluid

Question 11

Name the three main sites where cerebrospinal fluid is produced:

Answer 11

1. Leakage of vessels in pia mater
2. Secretion of the ependymal cells lining the central canal and ventricles
3. Choroid plexus - leaky tufts of arterioles, pia and ependymal epithlium within 4 brain ventricles

Question 12

How is CSF drained?

Answer 12

Drainage is via the arachnoid villi (tuft like invaginations of arachnoid into the dorsal sagittal sinus)

Question 13

Describe the overall pathway of cerebrospinal fluid:

Answer 13

1. Produced in the ventricles
2. Out through the lateral apertures of the fourth ventricle
3. Travels to the subarachnoid space
4. Reabsorption by the archanoid villi occurs

Question 14

Name the features circled in red and breifly explain the clinical significance of this structure:

Answer 14

Cisterna Magna- clinically signifcant as it is a good spot to tap cerebrospinal fluid from