Histology Chapter 11 - Circulatory System

Front 1

What are the general functions of the circulatory system?

Back 1

transporting oxygen and nutrients
moving Co2
excreting waste products
distributing heat
moving clotting elements
circulating elements of the immune system
deliering hormones

Front 2

True or false? The circulatory system includes the cardiovascular and lymphatic vascular system

Back 2

True

Front 3

What layers make up the wall of the heart? Be able to identify the se layers in the slide.

Back 3

outer epicardium
middle myocardium
inner endocardium

Front 4

What are the layers of the epicardium? Describe these layers and its histology.

Back 4

Epicardium is the outer wall of the heart
Epicardium has a single layer of simple squamous epithelium (mesothelium) called the visceral pericardium/pleura
Under that thin layer is CT with some SM and vasovasorum for the coronary arteries
The visceral pericardium is continuous with cells lining the inner part of the of the pericardial sac called the partietal pericardium/pleura

Front 5

What is the function of the epicardium?

Back 5

the secrete a lubricant fluid that can prevent friction when the heart beats/ contracts

Front 6

Describe the myocardial cells.

Back 6

striated cardiac muscle with small blood vessels and nerve fibers and intersitital tissue. Contain 1-2 centrally located nuclei and intercalated discs.

Front 7

What are the functions of the myocardial cells?

Back 7

They have an endocrine function along with contraction of the atria. These cells have sacs filled with peptide hormone, atrial natriuretic peptide (ANP)

Front 8

What is the purpose of ANP and where is it secreted? What does it do and where is it produced?

Back 8

It's secreted into the interstitial tissue and diffuses into vascular channels around the cardiac muscles cells. It is an antagonist to renin and produced by cells in the kidney. ANP lowers the BP by causing th body to excrete high sodium concentrations

Front 9

Where does the endocardium line? What is continuous with?

Back 9

Inside 4 chambers of the heart. Continuous with the tunica intima of the great vessels.

Front 10

Describe the histology of the endocardium?

Back 10

Contains a single layer of endothelial cells, underlying basal lamina, and a thin layer of CT with elastic and collagen fibers with some SM.

Front 11

What is the subendocardium

Back 11

additional layer of CT containing veins, nerves, and branches of the impulse conducting system

Front 12

What are purkinje fibers in terms of histology?

Back 12

modified cardiac myoctyes. They contain accumulations of glycogen and abundance of mitochondria.

Front 13

Where does the AV bundle of His run and branch as?

Back 13

Runs down the interventricular septum and branches into the purkinje fibers.

Front 14

Where do the semilunar valves insert into?

Back 14

Into the annulus fibrosus of the fibrous cardiac skeleton

Front 15

What vessels are included in macrovasculature

Back 15

large elestic arteries, conducting arteries, conduction veins, muscular/distributing arteries, muscular/distributing veins, arterioles

Front 16

What vessels are included in microvasculature?

Back 16

arterioles, capillaries, postcapillary venules, and lymphatics

Front 17

What are the resposibliites

Back 17

carry bllod from heart to muscular arteries which conduct the blood to other organs.

Front 18

Give examples of elastic arteries

Back 18

aorta, common carotid, subclaian, and renal arteries.

Front 19

What are the general layers of blood vessels?

Back 19

tunica intima, tunica media, and tunica adventitia

Front 20

For elastic arteries, what is difficult to distinguish in terms of the layers?

Back 20

difficult to see the internal elastic lamina between t he tunica media and tunia interna.

Front 21

Which layer of the elastic artery is fenestrated and descibeits histology?

Back 21

Tunica media - elastic tissue and smooth muscle is fenestrated

Front 22

How do elastic arteries maintain blood pressure?

Back 22

distention and recoiling od elastic sheets bekingblood flow more uniformly

Front 23

How are the cells arranged in the tunica intima layer?

Back 23

Lining membrane - lined with simple squamous endothelial cells that are joined by tight junctions and communicating junctions.
(under that) subendothelial zone of CT - contains collagen, few elastin fibrils, and smooth muscle fibers
(under that) dense internal elastic lamina

Front 24

Describe the layers of the tunica media of the large arteries.

Back 24

Thickest layer
Contains sheets of elastic tissue where in between there is SM fibers and CT of collagen fibrils and ground substance
The elastic sheets are fenestrated

Front 25

What do smooth muscle cells of the intima and media of large elastic arteries have the capability of doing?

Back 25

Can sontract and synthesize

Front 26

Describe the adventitia layer of the elastic arteries.

Back 26

thick and consists of collagen fibrils, fibroblasts, and macrophages. Contains a network of elastic fibrils. Adventitia will blend in with the CT of the body wall. THey have a smaller-caliber blood vessels and autonomic nerve fibers. Contain vasa vasorum.

Front 27

What does the vas

Back 27

Supplies adventitia and outer portion of the tunica media. The inner half relies on diffusion of substance from the lumen.

Front 28

Describe the layers of the large muscular veins

Back 28

- Thick tunica media with several smooth muscle layers that are separated by bundles of collagen fibrils
- tunica intima is thin
- internal elastic lamina is absent
- tunica intima contains longitudinal oriented SM fibers which are loosely arranged

Front 29

Describe the venous valves

Back 29

- projections of the tunica intima into the lumen
- semilunar in shapre
- consists of core CT and lined on both sides by endothelial cells
directed toward flow of blood and swing shut to prevent backflow
- keep flow of venous blood towards heart

Front 30

Describe the layers of the muscular arteries

Back 30

- tunica adventitia - thin-walled
- endothelial cells are close to the internal elastic lamina that appear white and wavy
- basal lamina - only CT between endothelium and elastic membrane
- there is an internal and external lamina

Front 31

Describe the tunica media in a vein

Back 31

tunica media is much thinner than corresponding arteries and tunica adventitia is thickest of 3 coats of veins