Anatomy CVS 2

Question 1

Describe the structure of blood vessels in the terms of layers

Answer 1

Tunica externa, media and intima (from out to in)

Question 2

What is the tunica intima made up from?

Answer 2

Epithelium, connective tissue and BM

Question 3

What is the tunica externa made up from?

Answer 3

Fibrous connective tissue

Question 4

WHat is the tunica media made up from?

Answer 4

Muscle and elastic tissue

Question 5

Compare the diameter and thickness of the arteries with vein

include the media and adventita

Answer 5

Arteries smaller diameter than accompanying vein

Arteries thicker wall than accompanying vein

Arteries thick media thin adventitia

Veins thin media thick adventitia

Question 6

Which vessel has the largest total cross sectional area?

Answer 6

Capillaries

Question 7

Describe elastic arteries and give examples

Answer 7

Elastic – large conducting – eg: aorta, common carotid,

pulmonary

Question 8

Describe the muscular arteries

Answer 8

Muscular – distributing arteries – eg: coronary arteries, radial, femoral

Question 9

Describe the arterioles arteries

Answer 9

terminal branches which supply blood to capillary bed

Question 10

Name the 3 different types of arteries?

Answer 10

Elastic, muscular and arterioles

Question 11

Describe the histology of elastic arteries

Answer 11

Can see elastic fibres ( blue) that are wavy obscuring th emuscle in the T media
Doesnt have IEL and OEL

Question 12

Describe the muscular arteries histology

Answer 12

Thick T media has smooth muscle cells
No elastic laminae between muscle cells in T. media

Has IEL and OEL

Question 13

Where is the elastic lamina in muscular arteries?

Answer 13

Elastic fibres are concentrated in 2 well defined sheets called the internal elastic lamina (IEL) just under epithelium

Question 14

Where do you see the external/outer elastic lamina in muscular arteries?

Answer 14

and the thin external/outer elastic lamina (OEL) between T.media & T. adventitia

Question 15

Describe the histology behind arterioles

Answer 15

The smaller muscular arteries gradually change histologically to become arterioles

No IEL

Only 1-2 layers of smooth muscle in T. media

No T. adventitia

Has nerves around it to control the diameter

Question 16

What can arterioles control and how?

Answer 16

Rich sympathetic nerve innervation

Control blood flow to capillary beds (local)

Control blood pressure (systemic)

Question 17

Describe the shape and histology of capillaries

Answer 17

Capillaries tiny and consist of single squamous epithelial cells turned initself

Therefore very thin walled
T. intima only – endothelium on BM
No T. media
No T. adventitia

Can have Pericytes

Question 18

What is Pericytes?

Answer 18

incomplete layer of cells surrounding basement membrane – have contractile properties which help control flow of blood in the capillaries.

Question 19

Is BP high or low in capillaries?

Answer 19

Average diameter – 4-15µ

Sum of diameters of all capillaries in body > diameter of aorta. Therefore blood pressure in capillaries is LOW!

Question 20

Describe the 3 types of capillary

Answer 20

Continuous - complete basal lamina
Fenestrated - compelte basal lamina and fenestrated endothelial lining
Discontinuous - fenestrated endothelial lining and incompelte basal lamina

Question 21

Describe the structure of continuous capillary and where it can be found

Answer 21

Can control what is exchanged
Material must pass through cell, or between cell (junctions can control)

Selective transport mechanisms

Eg. in muscle

Question 22

Describe the structure of fenestrated capillary and where it can be found

Answer 22

Have fenestrations (or pores)

Fenestrations up to 100μm

With or without protein diaphragms

Diaphragms filter molecules by MW &/or charge

Eg. endocrine glands, kidney renal corpuscle

Question 23

Describe the structure of discontinous capillary and where it can be found

Answer 23

Gaps between endothelial cells (and basement membrane)

Allow free passage of fluid and cells

Eg. liver, spleen, bone marrow

Question 24

What do the capillary bed and ateriovenous shunts allow? And give example

Answer 24

Bypasses capillary beds eg: skin for thermoregulation

Question 25

Describe the structure of veins and its histology

Answer 25

Structure:
T.intima is thin
IEL and OEL thin or absent
T.media v thin or absent
T adventitia  - collagenous tissue

Valves – to prevent back flow = endothelial projections into lumen

Question 26

Whats the differene between superficial and deep veins

Answer 26

Differences most obvious in lower limb

Superficial
Thick walled
No surrounding support

Deep
Thin walled
Surrounding support from deep fascia and muscles

Question 27

Describe the lympathic system and its function

Answer 27

Drains tissue fluid lost from blood capillaries

Question 28

Where are the nodes found for the lymphatic system?

Answer 28

Nodes found alongside major veins and around origins of major arteries

Question 29

Where specifically is the lympathic clinically important in?

Answer 29

Tumor cell metastases

Question 30

Describe the histology and structure behind lymph capillaries?

Answer 30

Blind-ended capillaries

Lined by very thin endothelium

No fenestrations

Absent / rudimentary basal lamina

Lumen maintained at –ve hydrostatic pressure

Anchoring filaments – fine collagenous filaments link endothelial cell to surrounding tissue keeping lumen open

No red blood cells in lumen

Question 31

Whats the main key difference between lymph capillaries vs venules?

Answer 31

Presence of blood cells

• should have NO blood cells

Question 32

What is the nerve supply of skin?

Answer 32

ONLY sympathetic

Question 33

What is the nerve supply of the heart?

Answer 33

Sympathetic + parasympathetic