Vasculature

Question 1

In what direction to arteries travel? veins?

Answer 1

arteries go from the heart

veins go to the heart

Question 2

What are the exceptions to the rule of arteries (largest->smallest) and veins (smallest->largest)?

Answer 2

hepatic portal vein: brings blood from intestine capilary bed to liver capilary bed
Renal efferent arteriole: between glomerulus capilary and vasa recta capilary

Question 3

What are the three common layers of arteries and veins?

Answer 3

tunica interna, tunica media and tunica externa.

Question 4

Tunica intima is made up of?

Answer 4

endothelial cells (simple squamous), subendothelial layer and interal elastic lamina (IEL)

Question 5

Tunica media is made up of?

Answer 5

circular smooth muscle, external elastic lamina (EEL)

Question 6

Tunica externa is made up of?

Answer 6

connective tissue and fibroblasts.

Question 7

What differs between arteries and veins in terms of the three common layers?

Answer 7

the width of the middle layer tunica media is much thinner in veins.

Question 8

which of the three layers in arteries and veins changes with the size of the artery or vein?

Answer 8

tunica media (larger artery, larger tunica media)

Question 9

What type of artery is the largest?

Answer 9

Elastic

Question 10

What is present in tunica media of elastic arteries? What is present in tunica externa?

Answer 10

collagen, elastic fibres and some smooth muscle (not very visible), thickest layer.
Blood vessels and nerves, some fibroblasts and it is loose connective tissue, this layer is thin compared to tunica media.

Question 11

Muscular arteries are what sized arteries? what is unique about their tunica interna? tunica media is made up of? tunica externa?

Answer 11

medium/small.
dense wavy IEL (internal elastic lumina)
smooth muscle and collagen
collagen, elastin, fibroblasts, adipose, clear EEL (external ealstic lumina), thick layer.

Question 12

EEL separates what two layers?

Answer 12

tunica media and tunica externa.

Question 13

What are metamerioles?

Answer 13

bypass channels that allow for thermoregulation of blood.

Question 14

Precapillary sphincters response to what?

Answer 14

temperature changes and internal signals i.e. vasomotor control allows for constriction if needed (for heat loss/retain)

Question 15

The microvascular bed is made up of?

Answer 15

1. arterioles
2. capillaries (smallest and is the ONLY palce gas exchange can occur).
3. postcapillary venules

Question 16

Which are bigger generally arteries or veins?

Answer 16

arteries. due to reduced tunica media in veins

Question 17

Small arteries normally only have how many layers of endothelium (tunica interna)? smooth muscle (tunica media)?

Answer 17

very few cells, usually not a full layer, can usually count.
usually only one layer of smooth muscle.

Question 18

What are the three types of capillaries and where are they located?

Answer 18

1. continuous capillary (most common, least leaky, has pericytes, has a BM, has tight junctions, 6-7 endothelial cells in tunica interna): located in retina and iris.
2. fenestrated: has pores bridged by diaphragm, has few pericytes and sometimes has a BM, located in choroid
3. discontinous: large pores, most leaky, no pericytes, no BM, found in liver, spleen and marrow (only three places in body)

Question 19

opthalamic artery enters orbit where?

Answer 19

within dura (dense CT that covers optic nerve) of optic nerve thru optic canal.

Question 20

What is usually the first branch off the opthalamic artery?

Answer 20

central retinal artery.

Question 21

Central retinal artery enters the dura aprx how far behind the globe?

Answer 21

10 mm

Question 22

Once the central retinal artery enters dura where does it go?

Answer 22

passes thru lamina cribosa (in sclera), enters disk nasal to center.

Question 23

Macula is positioned how to the optic disk?

Answer 23

temporally.

Question 24

The inner retina is supplied by?

Answer 24

central retinal artery

Question 25

collateral branches supply what?

Answer 25

CT surrounding optic nerve

Question 26

What is unique about the eye artery system?

Answer 26

it is an end artery system, no connections to other arteries therefore if there is a block it could be really bad because there is no where else to go.

Question 27

Photoreceptor layer gets its blood supply from?

Answer 27

choroid

Question 28

central retinal artery gives rise to what two capillary sets?

Answer 28

1. superficial: ganglion cell layer | 2. deep: at junction between INL (inner nuclear layer) and OPL (outer plexiform layer)

Question 29

Retinal arterioles and venules are unique in that they share a common what?

Answer 29

tunica externa, very unique only found in eye.

Question 30

What is A-V nicking?

Answer 30

in the eye where the artery compresses vein.

Question 31

Lacrimal artery is what branch of the opthalamic? What does it supply?

Answer 31

second or third | lacrimal gland and lateral part of eyelid.

Question 32

SPCA, some branches supply what? others supply?

Answer 32

posterior choroid | others form circle of zinn (made up of CT and optic nerve head) around optic nerve and disc and supply blood to those.

Question 33

LPCA run along what to the anterior portion of the globe? what do they supply?

Answer 33

between sclera and choroid. ciliary body, some of conjunctiva and anterior choroid. supplies both stroma of iris and ciliary body (because connected). also forms part of major circle of iris (with anterior ciliary arteries).

Question 34

Arteriole blood enters the eye through what 4 sets of arterioles?

Answer 34

1. central retinal artery (first branch of opthalamic) 2. long psoterior ciliary arteries 3. short posterior ciliary arteries 4. anterior ciliary arteries

Question 35

Central retinal artery branches in which directions?

Answer 35

inferiorly and superiorly | nasally and temporally

Question 36

macula is located in what direction compared to the disk?

Answer 36

temporally

Question 37

central retinal artery gives rise to what two sets of capillaries?

Answer 37

1. superficial (ganglion cell layer) | 2. deep (at junction between inner nuclear layer and outer plexiform layer)

Question 38

Which to things are supplied by the lacrimal artery?

Answer 38

lacrimal gland and lateral palpebral artery

Question 39

How many short posterior arteries? long?

Answer 39

10-20 | 2

Question 40

What is the function of circle of zinn?

Answer 40

throws back arteries and arterioles to supply ON/optic disc connective tissue and optice nerve head.

Question 41

Which arteries do the long posterior arteries anastomose with? together these form what?

Answer 41

anterior ciliary artery major arterial circle of iris.

Question 42

How many anterior ciliary arteries are there? where do they branch from? how many arise from each muscle? what do the anterior ciliary arteries supply?

Answer 42

7 vessels supplying the 4 rectus muscles. 2 from each muscle except for the lateral rectus which only gives rise to one. conjunctiva (bulbar and palpebral) and episcleral plexus.

Question 43

where is the major circle of iris located? where do the anterior ciliary arteries and the posterior ciliary arteries meet?

Answer 43

in ciliary body NOT in iris. | anterior to iris NOT IN IT.

Question 44

major circle of iris gives off what 4 sets of blood vessels? which two supply the ciliary body?

Answer 44

1. radial vessels (or arterioles) of iris 2. anterior ciliary arterioles 3. posterior ciliary arterioles 4. recurrent arterioles anterior and posterior.

Question 45

What is the sole blood supply of the iris? what type of capillaries are here?

Answer 45

radial vessel | continuous, cells joined by tight junctions preventing leakage.

Question 46

retinal capillaries are what? choroidal?

Answer 46

continous | fenestrated

Question 47

anterior ciliary arteries are located where? what type of capillaries? blood supply for what?

Answer 47

run deep within ciliary stroma fenestrated capillaries blood supply for aqueous humor

Question 48

posterior ciliary arteries are located where? what type of capillaries? blood supply for?

Answer 48

run within each ciliary process (not as deep as anterior) continuous capillaries blood supply for ciliary muscle

Question 49

recurrent arterioles run back toward what? here they anastomose with what? what type of capillaries? what do they supply?

Answer 49

ora serrata where they anastomose with anterior branches of choroidal circulation from short posterior ciliary arteries. fenestrated capillaries because dealing with choroid. blood to the ant choroid.

Question 50

what is the purpose of the cilioretinal artery? what does it supply? branches from where? what percent of the population has it?

Answer 50

spares central vision in cases of central retinal artery occlusion. supplies macula. branches from choroid or circle of zinn to retina 15-50%

Question 51

which vein drains venous blood out of the iris? which veins drain the posterior uvea?

Answer 51

anterior ciliary vein (runs with the anterior ciliary arteries, drains all anterior uvea) vortex veins

Question 52

how many vortex veins per eye? where are they located?

Answer 52

4 (can have up to 6) | one in each quadrant of the posterior eye.

Question 53

central retinal vein drains blood from? travels parallel with?

Answer 53

retina | central retinal artery

Question 54

the vortex veins exit how many mm posterior to the equator (middle of globe)?

Answer 54

6mm

Question 55

superior opthalamic vein is the result of which two veins joining together? which structures does it drain blood from?

Answer 55

angular and supraorbital veins | superior structures

Question 56

inferior opthalamic vein begins as what vein? inferior opthalamic vein may form which two branches when draining?

Answer 56

plexus 1. empty into superior opthalamic vein then cavernous or straight to cavernous 2. AND into pterygoid plexus

Question 57

the central retinal vein leaves the optic nerve how far behind the lamina cribosa? what does it travel alongside with? what does it join up with (two options)?

Answer 57

10mm alongside central retinal artery (parallel) joins superior opthalamic vein or into cavernous sinus.

Question 58

what does the lateral palpebral artery supply? what does it branch from?

Answer 58

supplies superior and inferior eyelid (laterally) derived from lacrimal artery

Question 59

what does the medial palpebral artery supply? what does it branch from? once it enters the lids, what happens?

Answer 59

superior and inferior eyelid (medially) opthalamic artery it branches into two branches forming two arches in the eye

Question 60

both the lateral and medial palpberal arteries anastomose to form what?

Answer 60

palpebral arcades.

Question 61

Anterior conjunctiva artery (medial) branch of? provides vascular supply for first 1-2mm of what?

Answer 61

anterior ciliary artery | bulbar conjunctiva just beyond the cornea

Question 62

posterior conjunctiva artery (peripheral) branches from what? (this branch supplies what?) posterior conjunctiva artery provides vascular supply to what?

Answer 62

peripheral arterial arch (supplies palpebral conjunctiva) | vascular supply to bulbar conjunctiva

Question 63

both the anterior conjunctiva artery and psoterior are branches of?

Answer 63

anterior ciliary arteries.