Circulatory System: Blood Vessels and Blood

What is the difference between an arteriole and metarteriole?

*Arteriole: small resistance arteries and only have one to three layers of smooth muscles *Metarterioles: short vessels that link to arterioles and capillaries

Describe the anatomy of a capillary.

*Capillary: composed of only endothelium and basal lamina. Though of as "business end" of cardiovascular system because all the rest of the system exits to serve the exchange process that occurs here.

Name the three classes of arteries and the characteristics of each. Where would each be located?

*Conducting arteries: biggest arteries. Expand during ventricular systole to recieve blood nd recoil during diastole. *Distributing arteries: 40 layers of smooth muscle, constituting about 3/4 of wall thickness *Resistance arteries: 25 layers of smooth. Uncle and are relatively little elastic tissue

Name the three types of capillaries and the function of each.

*Continuous Capillaries: occur in most tissues, such as skeletal. Endothelial cells are held together by by tight junctions that form a continuous tube. *Fenestrated Capillaries: have endothelial cells riddled with holes called filtration pores. Allow for rapid passage of small molecules but still retain most proteins and larger particles in bloodstream. *Sinusoids (discontinuous capillaries): irregular blood filled spaces of the liver,bone marrow, spleen and other organs.

Name the three types of granular leukocytes. What is the function of each?

*Neutrophils: Most abundant. Responds to bacterial infections and destroys it by phagocytizing and digesting them or releasing a toxin. *Eosinophils: Secrete chemicals that weaken or destroy relatively large parasites. They phagocytize and dispose of inflammatory chemicals, antigen-anitbody complexes and allergens. *Basophils: The rarest. Secrete two chemicals that aid in the body's defense process which is Histamine and harpine. -Histamine: vasolidator that widens the blood vessels more permeable so that blood components such as neutrophils and clotting proteins can get into the CT more quickly -Harpine: anticoagulent that inhibits blood clotting and thus promotes the mobility of other WBC's in the area. They also release chemical signals that attract eosinophils and neutrophils to a site of infection

What is the effect of constriction of a pre-capillary sphincter?

*Precapillary sphincter: encircles entrance to one capillary. Constriction of these sphincters reduces or shuts off blood flow through their repetitive capillaries and diverts blood to tissues or organs somewhere else.

Anastomosis.

A cross-connection between adjacent channels, tubes, fibers, or other parts of a network.

What is hemoglobin? What is its function?

A red protein responsible for transporting oxygen in the blood of vertebrates. Its molecule comprises four subunits, each containing an iron atom bound to a heme group.

What two pairs of blood vessels bring blood to the brain?

Anterior cerebral arteries Posterior cerebral arteries

The aorta would be an example of what type of artery? What about the popliteal artery?

Aorta: Conducting artery Popliteal: Distributing artery

Why are arteries considered resistance vessels?

Arteries of the cardiovascular system They are relatively strong, resilient tissue structure that resists the high blood pressure in the arteries as blood is ejected into them.

Name the three blood vessels that exit from the aortic arch?

Brachiocephalic trunk, Right common carotid Artery, Left subclavian artery

What is Hemostasis?

Cessation of bleeding. Stopping of a flow of blood.

From what cell are thrombocytes derived? Describe the characteristics of a thrombocyte.

Derive from megakaryocytes. They have no nucleus

What are the three types of embolism?

Embolus, thromboembolism, air embloism

Which major arteries are paired? (ie. Have a right and left artery)

External carotid artery Internal carotid artery Common carotid artery

Explain the path of a red blood cell from the heart to a capillary and back.

Heart->Arteries->Capillaries->Veins->Heart. Blood usually passes through only network of capillaries from the time it leaves the heart until the time it returns, but their are exceptions, notably portal systems and anastomoses.

What is the difference between the hepatic veins and hepatic portal vein?

Hepatic vein: drain the liver, extending, extending a short distance from its superior surface to the IVC Hepatic Portal Vein: continuation beyond the convergence of the splenic and superior mesentric veins.

The pulmonary arteries carry deoxygenated blood from the heart to the lungs. Why are these called arteries?

In the pulmonary circuit it is the only route in the body where the arteries carry oxygen poor blood and veins carry oxygen rich blood.

Capillary bed

Interweaving network of capillaries supplying organs and tissues. The more metabolically active a cell or environment is, the more capillaries are required to supply nutrients and carry away waste products.

What are the functions of blood?

It supplies essential nutrients to cells, such as amino acids, fatty acids, and glucose. Its white blood cells have antibodies which defend us from infection and foreign bodies. It has specialized cells, such as platelets, which help the blood to clot (coagulate) when we are bleeding

Name the two types of agranular leukocytes. What is the function of each?

Monocytes: largest of the WBC. Rises in inflammation and viral infections. Only work after leaving the bloodstream and transforming into large tissues. Macrophages: Highly phagocytic. They destroy dead or dying host and foreign cells, pathogenic chemicals and microorganism and other foreign matter.

What is the most common type of leukocyte? What is the term for the production of leukocytes?

Neutrohils Leukopoiesis

What is the common name for a thrombocyte?

Platelets

Name the classes of veins and the characteristics of each.

Post capillary venules: smallest of veins, beginning with diameter. More porous than capillaries. Exchange fluids with surrounding tissues. Muscular venues: recieve blood from post capillary venules. Medium veins: tunica interna with endothelium, basement membrane, loose CT, sometimes internal elastic lamina. Venous sinuses: very thin walls, large lumen and no smooth muscle Large veins: smooth muscles in all three tunica

What is an Embolism?

Presence of any abnormal object traveling through the blood stream such as an air bubble, agglutinated RBC's bacteria, or a traveling blood clot.

What veins combine to form the hepatic portal vein? What is the function of this vein?

Recieves from the blood draining from the abdominal digestive tract. Such as: inf & sup mesentric vein Splenic vein Pancreatic vein

In the systemic circuit, where is the most volume of blood located? Give two reasons for this.

Systemic circuit Supplies blood to every organ of the body including other parts of the lungs and the wall of the heart itself

Portal system

The system of blood vessels consisting of the portal vein with its tributaries and branches.

What is the function of a thrombocyte?

To facilitate blood clotting - the purpose of which is to prevent loss of body fluids.

Name the outer layer of a blood vessel. In what type of vessels would the vasa vasorum be found?

Tunica externa Found in small vessels

Name the layer of a blood vessel which is adjacent to the lumen. With what type of tissue is this layer lined?

Tunica interna Simple squamous called *endothelium

Name the middle layer of a blood vessel. What is the primary type of tissue in this layer? What is its function? Larger arteries contain what other type of tissue. What is the function of this other tissue?

Tunica media, thickest. Function: strengthens the vessels and prevents blood pressure from rupturing them and it produces vasomotion, changes in vessel diameter May sometimes contain elestic tissue

What is the anatomic difference between a vein and venous sinus? Name two examples of venous sinuses we have learned this semester.

Vein: relatively Thin walled and flaccid, expand easily to accommodate an increased volume of blood. Bigger capacity than arteries. Venous Sinus: especially thin.