BOARDS review part 1 week #2 slides

The vertebral artery is part of what system?

Vertebrobasilar system

Is the vertebral artery a bilateral structure?

Yes

The vertebral artery is serviced from the _________ artery?

Subclavian

What courses upward through the transverse foramen and then ultimately through the foramen magnum?

Vertebral artery

The vertebral artery converge to form the?

Basilar artery

What does the vertebral artery supply?

-upper spinal cord

-brainstem (midbrain, pons, medulla oblongata)

-cerebellum

-posterior cerebral hemisphere

-indirectly contribute to the circle of Willis

Why are the cervical vertebrae unique?

Vertebral artery runs through there transverse processes (enter C6 transverse foramen)

Where do the vertebral veins enter?

C7

V1 =

comes off the subclavian artery and enters the C6 transverse

foramen (foramina transversarium)

v2 = 23 m/s (use the equation A1V1=A2V2

Runs between the C6 transverse foramen and the C2 transverse foramen

V3 =

leaves the C2 transverse foramen, superiorly, and goes through the C1 transverse foramen, after which it goes through the groove for the vertebral artery on atlas, and then pierces the dura mater to enter the dural sac

V4 =

once it has enters the dural sac it becomes V4, which combines with the opposite side vertebral artery to form the basilar artery

Once part 3 of the vertebral artery punches through the dura mater of the cervical thecal sac, as it does so, the name changes to?

Part 4 of the vertebral artery

Which part of the vertebral artery is more delicate than the others?

Part 4

V3 penetrates the ligamentum flavum-like posterior atlantooccipital membrane then runs in the groove for the vertebral artery for a short distance and finally penetrates the dura to become?

V4

What branch of the vertebral artery supplies the occiput and the falx cerebelli?

Meninges artery

What is the falx cerebelli?

A fold of the dura mater which is used to partition the cerebellum into right and left hemispheres

What branch of the vertebral artery arises near the terminal ends of the vertebral arteries?

Anterior spinal artery

The anterior spinal artery supplies the anterior part of what structure?

Spinal cord

Is there two posterior inferior cerebellar arteries?

Yes

What is the large branch of the vertebral artery?

Posterior inferior cerebellar artery

The posterior inferior cerebellar artery supplies what?

Cerebellum and medulla

The posterior inferior cerebellar artery has a large branch coming off it called the?

Posterior spinal artery

What is the aka for the circle of Willis?

Cerebral arterial circle or circulus arteriosus cerebri

The circle of Willie is formed at what by the union of the vertebrobasilar system and internal carotid system?

Base of the brain

The circle of Willis lies in the middle cranial fossa within the?

Subarachnoid space

What is the circle of Willis bathed in?

CSF

The circle of Willis surrounds what three things?

-Clivus

-Sella Turica

-Optic Chiasm

66% of what aneurysms occur within the circle of Willis?

Berry aneurysms

A berry aneurysm in the posterior communicating artery can enter the?

Oculomotor nerve

When a berry aneurysm enters the Oculomotor nerve the injury results in?

-ptosis

-down and out CNIII palsy

The Oculomotor nerve supplies what 5 muscles of the eye?

-superior rectus

-inferior rectus

-medial rectus

-inferior oblique

-levator palpebrae superioris

Trochlear nerve supplies what muscle of the eye?

Superior oblique

The abducens nerve supplies what muscle of the eye?

Lateral rectus

Sympathetic postganglionic efferent fiber supplies what muscle of the eye?

Mullers muscle

The medial rectus does what?

Turns eye in and does adduction

The lateral rectus does what?

Turns eyeballs out and does abduction

The superior rectus does what?

Turns eyeballs up and in (adduction)

The inferior rectus does what?

Turns eyeballs down and in

Superior oblique does what action?

Turns eyeballs out and down

The inferior oblique does what action?

Turns eyeballs out and up

The superior oblique does what action?

Intorsion, rotates superior eye in

The inferior oblique does what action?

Extorsion, rotators superior eye out

What does the mullers muscle and levator palpebrae superioris do?

Holds the eyelid up so it does not sad or droop

Injury to cranial nerve III will cause the eyelid to partially droop, what is this called?

Ptosis

When someone has ptosis of the eye it narrows the?

Palpebrae fissure

An injury to the Oculomotor nerve will cause _______ ptosis?

Partial or incomplete

When there is partial or incomplete ptosis of the eye it is because?

The sympathetically-controlled superior tarsal muscle (mullers muscle) is still working to hold the eyelid up

Is there is an injury to the sympathetic fibers usually at the cervical sympathetic chain will also cause what?

Partial or incomplete ptosis

The frontalis muscle is innervated by what nerve?

Facial nerve

The frontalis muscle does what action?

Elevates the eyebrows and the tissue beneath

An injury to the cranial nerve VII can also present with?

Pseudo-ptosis (brow ptosis)

Orbicularis oculi will also be out of action if there is an injury to CN VII so the patient loses the ability to completely close the eye which is called?

Lagophthalmos

What are the two key intraocular muscles of the eye?

-sphincter pupillae muscle

-ciliary muscle

The sphincter pupillae and ciliary muscle are controlled by what nucleus?

Edinger westphal nucleus

The edinger Westphal nucleus sends preganglionic parasympathetic fibers to the?

Ciliary ganglion

The preganglionic fibers synapse within the ciliary ganglia and sen forth postganglionic parasympathetic fibers which travel through what which plug into these muscles?

Short ciliary nerves

By the end of the 4th week the fetus has developed a complete?

Circulatory system

Since the baby cannot use the fetal lungs and kidneys to get oxygen or remove waste what happens?

Mom must provide the functions and substances for the fetus

The placenta is made of two parts, what are they?

-decidua basalis (maternal part)

-chorion frondosum (fetal part)

The decidua basalis is from the?

Stratum functionale

The umbilical cord connects to what part of the chorion frondosum of the fetal placenta?

Chorionic plate

After week 7 the umbilical cord contains a single _________ ____ which carries oxygenated blood from the placenta to the fetus?

Left umbilical vein

The two umbilical arteries carry deoxygenated blood back to the?

Placenta for CO2 removal and other wastes

The placental exchange unit is made up of what two parts?

-intervillous space (maternal)

-tertiary chorionic villus (fetal)

The PEU is also the place where the placental barrier or placental membrane lives and the placental membrane is the tissue where what occurs?

Gas, nutrients, and waste exchange occur

The placental membrane is made up of what two things?

Trophoblast and capillary endothelium

The PEU allows the deoxygenated fetal blood to get rid of what?

CO2, bilirubin, urea, lactic acid, and other waste...... also picks up nutrients

The maternal blood and fetal blood do NOT _______?

Touch

The fetal circulatory system is unique because it diverts blood away from?

Nonfunctional lungs and immature liver

Oxygenated blood comes out of the placenta via?

Left umbilical vein

The umbilical veins enters the fetus though the?

Umbilicus

Once the umbilical vein passes through the umbilicus it travels up to the developing liver which is wrapped in?

Ventral mesentery

The ventral mesentery which later form what ligament?

Falciform

The left umbilical vein terminates into what two structures?

-ductus venosus

-left hepatic portal vein

The ductus venosus bypasses the hepatic sinusoids and dumps directly into what?

Inferior vena cava

Is any oxygen content lost through the ductus venosus?

No

The left hepatic portal vein dumps into the?

Left hepatic sinusoids which dumps into the inferior vena cava

Is some oxygen lost from the left hepatic portal vein and receives some deoxygenated blood as well?

Yes

The formane ovale is an open passageway where moms fresh arterial blood was injected into the?

Left atria

The fossa oval is has two parts, what are they?

-limbus of septum secundum

-valve of septum primum

Mom's oxygenated blood comes into the heart through the inferior vena cava and blood is guided by what valve into the open Forman ovale?

Eustachian valve

The foramen ovale is a hole between the?

Right and left atrium

The foramen ovale moves semi-oxygenated blood directly into the?

Left atrium

From the left atrium, semi-oxygenated blood goes into the left ventricle and then up the?

Pulmonary trunk and services the systemic loop

Oxygenated blood is mixed with deoxygenated blood from the?

Superior vena cava

The mixed blood flows into the right ventricle and is ejected into the pulmonary trunk and it tries to go down the left and right pulmonary arteries but the lungs are not working yet? T/F

True

When the blood tries to go down the left and right pulmonary arteries and it does not work, blood is pressure forced through a passageway called the?

Ductus arteriosus

The ductus arteriosus takes shouted blood and mixes it into the blood into the beginning of the?

Descending aorta (isthmus of the thoracic aorta)

My the time moms blood reaches the internal iliac arteries how much of the oxygen is gone?

50%

The right and left umbilical arteries arise off of the?

Internal iliac arteries

The left and right umbilical arteries travel down the lateral aspect of the internal anterior abdominal pass through the umbilicus into the?

Umbilical cord

The adult remnant of these right and left umbilical arteries are the?

Right and left medial umbilical ligaments

What is the fossa ovalis and where is it located?

A very thin membrane which is found in between the right and left atrium within the interatrial septum

When does the fossa ovalis permanently close?

One year

After birth pressure in the left atrium quickly becomes higher than the?

Right atrium

Therefore the one way valve of the fossa ovalis is pressure pushed into the limbus and held there by the high pressured blood of the?

Left atrium

What happens if the welding of the valve to the limbus does not happen?

It turns into the patent foramen ovale

In people with normal lung and heart pressure they will not know they have a PFO because?

As long as the left arterial pressure is higher than the right the valve and limbus have a pressure seal so not blood will shunt from left to right atria

PFO can become dangerous in people who develop?

Pulmonary hypertension