1. The Cardiovascular System26
The Cardiovascular System

2. Learning Outcomes (cont.)
26.1 Describe the structures of the heart and the function of each.
26.2 Explain the cardiac cycle, including the cardiac conduction system.
26.3 Compare pulmonary and systemic circulation.

3. Learning Outcomes (cont.)
26.4 Differentiate among the different types of blood vessels and their functions.
26.5 Explain blood pressure and tell how it is controlled.
26.6 Describe the causes, signs and symptoms, and treatments of various diseases and disorders of the cardiovascular system.

4. Introduction The cardiovascular system Heart Blood vessels
Sends blood to
Lungs for oxygen
Digestive system for nutrients
Also circulates waste products for removal
Learning Outcomes: Describe the structures of the heart and the function of each.
This system also circulates waste products to certain organ systems so these wastes can be removed from the blood.

5. The Heart Cone-shaped organ Size of a loose fist
Slightly left of the midline
Bordered by
Lungs
Sternum and vertebral column
Diaphragm
Learning Outcomes: Describe the structures of the heart and the function of each.
Located in the mediastinum and extends from the level of the second rib to about the level of the sixth rib.

6. Cardiac Membranes Pericardium Pericardial sac
Covers the heart and large blood vessels
Fibrous outer layer
Visceral pericardium ~ epicardium
Parietal pericardium
Pericardial sac
Pericardial cavity – pericardial fluid
Learning Outcomes: Describe the structures of the heart and the function of each.
Pericardium
Consists of an outer fibrous layer that covers two inner layers.
The visceral pericardium [ epicardium]– the innermost layer
It is also the outer layer of the heart wall.
The parietal pericardium – the layer on top of the visceral pericardium
Pericardial sac – formed by fibrous pericardium and the parietal pericardium
The pericardial cavity
the space between the parietal pericardium and visceral pericardium.
Contains pericardial fluid that reduces friction between the membranes when the heart contracts.  
Cardiac Membranes

7. Cardiac Membranes (cont.)
Learning Outcomes: Describe the structures of the heart and the function of each.
Back

8. The Heart Wall Epicardium Myocardium Endocardium Thin, smooth layer
Contains part of electrical conduction system
Learning Outcomes: Describe the structures of the heart and the function of each.
Epicardium
The visceral pericardium
Contains fat – cushions the heart
Myocardium
Middle layer and thickest layer of the wall
Primarily of cardiac muscle
Endocardium – innermost layer stretches as the heart pumps blood.
Heart Wall

9. Heart Chambers and Valves
Four chambers
Two atria
Upper chambers
Interatrial septum
Atrioventricular septum separates the atria from the ventricles
Two ventricles
Lower chambers
Interventricular septum
Learning Outcomes: Describe the structures of the heart and the function of each.
The heart contains four hollow chambers.
Atria
Thin walled
Receive blood returning to the heart from the lungs and the body
Interartrial septum – walled membrane separating atria
Ventricles
Interventricular septum – separates the ventricles
Function to pump blood into the arteries, which send the blood to the lungs and the body.
The atrioventricular septum is the wall that separates the atria from the ventricles.
Click for View of Heart

10. Heart Chambers and Valves (cont.)
Valves between atria and ventricles
Tricuspid ~ three cusps
Bicuspid ~ two cusps
Valves between ventricles and arteries
Pulmonary semilunar
Aortic semilunar
Learning Outcomes: Describe the structures of the heart and the function of each.
The four valves keep blood flowing in one direction.
Tricuspid Valve [right atrioventricular (AV) valve]
Prevents blood from flowing back into the right atrium when the right ventricle contracts.
Chordae tendineae – cord-like structures that anchor the cusps of the valve to papillary muscles that contract close the valve.
Bicuspid valve [mitral valve or left AV valve]
Prevents blood from flowing back into the left atrium when the left ventricle contracts.
Also has chordae tendineae.
Pulmonary semilunar valve
Between the right ventricle and the trunk of the pulmonary arteries
Prevents blood from flowing back into the right ventricle.
Semilunar – cusps are shaped like a half moon
Aortic semilunar valve
Situated between the left ventricle and the aorta
Prevents blood from flowing back into the left ventricle
Also semilunar
Click for View of Heart

11. The Heart Labeled
Learning Outcomes: Describe the structures of the heart and the function of each.
Back

12. Good Job! Apply Your Knowledge ANSWER: Match the following:
__ Tricuspid valve A. Outermost layer of the heart wall
__ Bicuspid valve B. Covering of the heart and aorta
__ Intraventricular C. Between the right atrium and the right septum ventricle
Ventricles D. Pump blood into the arteries
Pericardium E. Primarily cardiac muscle
Epicardium F. Between the left atrium and the left ventricle
Myocardium G. Inner most layer of the heart wall
Endocardium H. Separates the ventricles C F H D
Learning Outcomes: Describe the structures of the heart and the function of each. B A E G
Good Job!

13. Cardiac Cycle One heart beat = one cardiac cycle
Right atrium contracts  tricuspid valve opens
 blood flows into right ventricle
Left atrium contracts  bicuspid valve closes
 blood flows into left ventricle
Learning Outcome: 26.2 Explain the cardiac cycle, including the cardiac conduction system.
One cardiac cycle consists of one complete cardiac contraction and one complete cardiac relaxation.

14. Cardiac Cycle (cont.) Right ventricle contracts  tricuspid valve
closes  pulmonary semilunar valve opens 
blood is pushed into pulmonary artery
Left ventricle contacts  bicuspid valve closes
 aortic semilunar valve opens  blood is
pushed into aorta
Learning Outcome: 26.2 Explain the cardiac cycle, including the cardiac conduction system. .
Refer to CONNECT to see an animation on Cardiac Cycle

15. Cardiac Cycle (cont.) Influenced by Exercise Parasympathetic nerves
Cardiac control center
Body temperature
Potassium ions
Calcium ions
Learning Outcome: 26.2 Explain the cardiac cycle, including the cardiac conduction system.
Exercise – increases the heart rate because skeletal muscles need more oxygen.
Parasympathetic nerves – (vagus nerve) generally keep the heart rate relatively low.
Sympathetic nerves – increase the heart rate during times of stress.
Cardiac control center – located in the medulla oblongata.
When blood pressure rises, impulses are sent to decrease the heart rate.
When blood pressure falls, impulses are sent to increase the heart rate.
Body temperature – an increase in body temperature usually increases the heart rate.
Potassium ions
A low concentrations of potassium ions in the blood decrease the heart rate
A high concentration causes an arrhythmia.
Calcium ions
Low concentrations of calcium ions in the blood depress heart actions
High concentrations cause heart contractions called titanic contractions –longer than normal contractions

16. Heart Sounds Lubb Dubb Murmur – abnormal heart sound First sound
Occurs when ventricles contract and the tricuspid and bicuspid valves snap shut
Dubb
Second sound
Occurs when atria contract and the pulmonary and aortic valves snap shut
Murmur – abnormal heart sound
Click for Heart Sounds
Learning Outcome: 26.2 Explain the cardiac cycle, including the cardiac conduction system.
During one cardiac cycle, you can hear two heart sounds – lubb and dubb.
If a valve is damaged, it will not close completely and blood leaks back into the atria or ventricles. This produces an abnormal heart sound called a murmur.

17. Cardiac Conduction System
Sinoatrial node
Right atrium
Natural pacemaker
Sends impulse to AV node
Atrioventricular node
Between atria and just above ventricles
Sends impulse to the bundle of His
Learning Outcome: 26.2 Explain the cardiac cycle, including the cardiac conduction system.
The cardiac conduction system sends electrical impulses through the heart stimulating the heart muscle to contract.
Sinoatrial node (SA node)
Natural pacemaker - it generates the heart’s rhythmic contractions.
Generates an impulse that flows to the atrioventricular node.
 Atrioventricular node (AV node) – after the impulse reaches the AV node, the atria contract
Click for Conduction System

18. Cardiac Conduction System (cont.)
Bundle of His
Between ventricles
Right and left bundle branches
Sends impulse to Purkinje fibers
Purkinje fibers
Lateral walls of ventricles
Ventricles contract
Learning Outcome: 26.2 Explain the cardiac cycle, including the cardiac conduction system.
Bundle of His [atrioventricular or AV bundle] – splits into two branches before sending the electrical impulse to the Purkinje fibers.
Purkinje fibers – after the impulse flows through the Purkinje fibers, the ventricles contract and the SA node starts the flow of a new impulse.
An electrocardiogram (ECG or EKG) is performed to determine if the cardiac conduction system is working properly.
Click for Conduction System

19. Cardiac Conduction System (cont.)
Learning Outcome: 26.2 Explain the cardiac cycle, including the cardiac conduction system.
Back

20. Smashing! Apply Your Knowledge ANSWER: Match the following:
__ Right ventricle A. Two branches; sends impulse to Purkinje fibers
__ Left ventricle B. Located in the medulla oblongata
__ Cardiac control C. Contraction pushes blood into the lungs center
__ SA node D. In the lateral walls of ventricles
__ Bundle of His E. Natural pacemaker
__ Purkinje fibers F. Contraction sent blood to the aorta C F B E
Learning Outcome: 26.2 Explain the cardiac cycle, including the cardiac conduction system. A D
Smashing!

21. Circulation Pulmonary circulation Systemic Circulation
In the body, the blood gives oxygen to cells and picks up carbon dioxide. Veins of the body pick up the oxygen-poor blood and empty it into the venae cavae, and the whole system starts all over again with pulmonary circulation.
Circulation
Pulmonary circulation
Oxygenates blood
Removes carbon dioxide
Systemic Circulation
Delivers oxygen and nutrients
Removes carbon dioxide and waste products
Learning Outcome: Compare pulmonary and systemic circulation.
Blood flows through the body through two main circuits.
Pulmonary circulation
The route that blood takes from the heart to the lungs and back to the heart again.
In the lungs, blood picks up oxygen and gets rid of carbon dioxide.
Systemic circulation
The route blood takes from the heart through the body and back to the heart.
The function of this circuit is to deliver oxygen and nutrients to body cells and picks up carbon dioxide and waste products.

22. Pulmonary Circulation Pulmonary Semilunar Valve Aortic Semilunar Valve
Circulation (cont.)
Pulmonary Circulation
Right Atrium
Tricuspid Valve
Right Ventricle
Pulmonary Semilunar Valve
Body
Lungs
Learning Outcome: Compare pulmonary and systemic circulation.
Pulmonary Circulation
Deoxygenated blood that is rich in carbon dioxide enters the right atrium of the heart via the inferior and superior venae cavae.
Blood leaves the ventricles via the pulmonary semilunar valve into the pulmonary trunk which branches into the pulmonary arteries that carry deoxygenated blood to the lungs.
Systemic Circulation
Oxygenated blood from the lungs flows through the left atrium and bicuspid valve into the left ventricle.
When the left ventricle contracts, blood is pushed through the aortic semilunar valve into the aorta.
Veins of the body pick up the oxygen-poor blood and empty it into the venae cavae, and the whole system starts all over again with pulmonary circulation.
Aortic Semilunar Valve
Left Ventricle
Bicuspid Valve
Left Atrium
Systemic Circulation

23. Apply Your Knowledge Correct!
What are the functions of the pulmonary and systemic circulations?
ANSWER: The pulmonary circulation functions to oxygenate the blood and remove carbon dioxide. The systemic circulation delivers oxygen and nutrients to and removes carbon dioxide and waste products from the body’s cells.
Learning Outcome: Compare pulmonary and systemic circulation.
Correct!

24. Blood Vessels
Form a closed pathway that carries blood from the heart to cells and back to the heart
Learning Outcome: Differentiate among the different types of blood vessels and their functions.

25. Arteries and Arterioles
Thick muscular wall
Carry blood under high pressure
Arterioles
Coronary arteries
Supply heart muscle
Coronary sinus
Pulmonary arteries
Heart to lungs
Deoxygenated blood
Aorta
Learning Outcome: Differentiate among the different types of blood vessels and their functions.
Arteries
The strongest blood vessels
Their smooth muscle is thicker than that of other types of blood vessels.
They carry blood away from the heart and are under high pressure.
The muscular wall of an artery constricts to increase blood pressure or dilates to decrease blood pressure.
Arterioles – small branches of arteries.
Coronary Arteries
Supply blood to the tissues of the heart.
Branches down to very small blood vessels called capillaries.
Blood leaving the capillaries in the heart enters the cardiac veins.
Cardiac veins eventually deliver the oxygen-poor blood to the coronary sinus which empties the blood into the right atrium.
Pulmonary arteries carry oxygen-poor blood from the heart to the lungs.
The aorta comes directly off the left ventricle and has many branches that carry blood to the body.
Other arteries are paired – right and left
Refer to Table 26-1 Major Arteries of the Body.

26. Veins and Venules Veins Deoxygenated blood
Skeletal muscle contractions move blood
Valves prevent back flow
Sympathetic nervous system effect
Learning Outcome: Differentiate among the different types of blood vessels and their functions.
Veins
Carry blood toward the heart.
Blood is under no pressure in the veins and does not move very easily.
The movement of blood through veins requires skeletal muscle contractions and valves to prevent blood from flowing backward.
The sympathetic nervous system causes vein walls to constrict forcing blood through the veins if blood pressure gets abnormally low in the arteries.

27. Veins and Venules Venules Pulmonary veins – oxygenated blood
Superior and inferior vena cava
Hepatic portal system
Learning Outcome: Differentiate among the different types of blood vessels and their functions.
Venules
Very small blood vessels formed when capillaries merge.
Venules merge to make veins, the largest of which are the superior and inferior venae cavae.
Most veins in the body carry oxygen-poor blood, except the pulmonary veins, which carry oxygenated blood from the lungs to the heart.
Hepatic portal system
Collection of veins that carry blood to the liver.
The liver processes nutrients in the blood and returns it to general circulation through the hepatic veins.
Refer to Table 26-2 Major Veins of the Body.

28. Capillaries Branches of arterioles Connect arterioles to venules
Exchange vessels
Oxygen and nutrients
Carbon dioxide and waste products
Water
Learning Outcome: Differentiate among the different types of blood vessels and their functions.
Capillaries
The smallest type of blood vessel
They have very thin walls about one cell layer thick allowing substances to pass into and out of capillaries.
Exchange vessels – capillaries are the only blood vessels that allow substances to move in and out of the blood
Precapillary sphincters – control the amount of blood that flows into them
The substances move through the capillary wall through diffusion, filtration, and osmosis.
Oxygen and nutrients diffuse out of the capillary and into body cells.
Carbon dioxide and waste products diffuse out of the cells into the capillary.
Water is forced through the capillary wall via filtration into a body cell.
By the time blood leaves a capillary, it has a high solid concentration and a low water concentration so water back into the capillary by osmosis.

29. Apply Your Knowledge YIPPEE! Match the following:
coronary arteries A. exchange vessels
arterioles B. supply blood to the heart tissues
veins C. largest veins in the body
arteries D. supplies the forearm and hand
capillaries E. carry blood toward heart
vena cavae F. drain the knees
radial artery G. strongest blood vessels
popliteal veins H. small branches of arteries
ARTERIES: B H E G A C
Learning Outcome: Differentiate among the different types of blood vessels and their functions. D F
YIPPEE!

30. Blood Pressure
The force blood exerts on the inner walls of blood vessels
Highest in arteries
Lowest in veins
Rises and falls as ventricles contract and relax
Learning Outcome: Explain blood pressure and tell how it is controlled.
In the clinical setting, blood pressure refers to the pressure in arteries. .

31. Blood Pressure Systolic pressure Diastolic pressure Pulse Systole
Ventricles contract
Blood pressure in arteries greatest
Diastolic pressure
Diastole
Ventricles relax
Blood pressure in arteries lowest
Pulse
Learning Outcome: Explain blood pressure and tell how it is controlled.
Systolic pressure – blood pressure in the arteries when the ventricles contract.
Diastolic pressure – blood pressure in arteries when the ventricles relax.
Reported as Systolic pressure over diastolic pressure – 120/80
Pulse - created as the artery expands when pressure increases and then subsequently relaxes as blood pressure decreases.

32. Blood Pressure (cont.) Factors affecting blood pressure Cardiac output
Blood volume
Vasoconstriction and vasodilation
Blood viscosity
Learning Outcome: Explain blood pressure and tell how it is controlled.
Cardiac output - total amount of blood pumped out of the heart in one minute.
As cardiac output increases and decreases, blood pressure increases and decreases.
With blood loss, blood pressure falls and vasoconstriction helps to raise blood pressure.
If blood pressure is too high, vasodilation decreases the blood pressure.
If blood becomes more viscous, blood pressure will decrease.

33. Blood Pressure (cont.)
Controlled by the amount of blood pumped out of the heart
Starling's law of the heart
Blood entering the left ventricle stretches its wall
The more the wall is stretched the harder it will contract
Learning Outcome: Explain blood pressure and tell how it is controlled.
Blood pressure is controlled to a large extent by the amount of blood pumped out of the heart.
Blood entering the heard should equal the amount pumped out.
Starling’s law of the heart
When blood enters the left ventricle, the wall of the ventricle is stretched.
The more the wall is stretched, the harder it will contract and the more blood it will pump out.
If only a small amount of blood enters the left ventricle, it will not be stretched very much and will not contract very forcefully.

34. Blood Pressure (cont.) Baroreceptors Help regulate blood pressure
Located in the aorta and carotid arteries
Send information to cardiac center in the medulla oblongata
Learning Outcome: Explain blood pressure and tell how it is controlled.
Baroreceptors measure blood pressure.
The cardiac center increases or decreases the heart rate to regulate blood pressure based on information from the baroreceptors.

35. Good Answer! Apply Your Knowledge
What is the difference between the systolic pressure and diastolic pressure?
ANSWER: Systolic pressure is the result of the contraction of the ventricles increasing the pressure in the arteries. Diastolic pressure is the result of the relaxation of the ventricles lowering the pressure in the arteries.
Learning Outcome: Explain blood pressure and tell how it is controlled.
Good Answer!

36. Diseases and Disorders of the Cardiovascular System
Chest pain
Cardiac causes
Myocardial infarction
Angina
Pericarditis
Coronary spasm
Non-cardiac causes
Heartburn
Panic attacks
Pleurisy
Costochondritis
Pulmonary embolism
Sore muscles
Broken ribs
Learning Outcome: Describe the causes, signs and symptoms, and treatments of various diseases and disorders of the cardiovascular system.
Refer to Educating the Patient Feature – Chest Pain
Take all complaints of chest pain seriously!

37. Diseases and Disorders of the Cardiovascular System (cont.)
Description
Aneurysm
A ballooned, weakened arterial wall
Arrhythmias
Abnormal heart rhythms
Endocarditis
Inflammation of the innermost lining of the heart, including valves
Myocarditis
Inflammation of the muscular layer of the heart
Learning Outcome: Describe the causes, signs and symptoms, and treatments of various diseases and disorders of the cardiovascular system.
Aneurysm
Most common locations are the aorta and arteries in the brain, legs, intestines, and spleen.
Most causes are unknown but may include atherosclerosis , congenital conditions, or traumatic injury
Arrhythmias
Most common – atrial fibrillation which is a sporadic and rapid beating of the atria.
Most serious type of heart arrhythmia is ventricular fibrillation, which produces ineffective contractions of the ventricles because electrical impulses of the cardiac conduction system do not flow correctly through the heart.
Endocarditis – caused by bacterial infections
Myocarditis – caused by a viral infection, but it also may be caused by exposure to certain chemicals, allergens, and bacteria.

38. Diseases and Disorders of the Cardiovascular System (cont.)
Description
Pericarditis
Inflammation of the membranes that surround the heart (pericardium)
Congestive heart failure
Weakening of the heart over time; heart is unable to pump enough blood to meet body’s needs
Coronary artery disease (CAD)
Atherosclerosis; narrowing of coronary arteries caused by hardening of the fatty plaque deposits within them
Learning Outcome: Describe the causes, signs and symptoms, and treatments of various diseases and disorders of the cardiovascular system.
Pericarditis
Most commonly caused by complications of viral or bacterial infections.
May also result from heart attacks and chest injuries.
Congestive heart failure – there are many risk factors for this condition as well as congenital heart defects and drugs that weaken the heart
Coronary artery disease (CAD)
Produced by the buildup of fat, cholesterol, and calcium in the arteries.
Risk factors include high levels of LDL cholesterol in the blood, a diet high in fat and cholesterol, smoking, high blood pressure, obesity, a lack of exercise, and diabetes mellitus
Refer to CONNECT to see animations about Heart Failure Overview, Left- Side Heart Failure, Right-Side Heart Failure, and Coronary Artery Disease

39. Diseases and Disorders of the Cardiovascular System (cont.)
Description
Hypertension
High blood pressure; consistent resting blood pressure equal to or greater than 140/90 mm Hg
Mitral valve prolapse
Valve falls into the left atrium during systole; prevents proper closing
Murmurs
Abnormal heart sounds
Learning Outcome: Describe the causes, signs and symptoms, and treatments of various diseases and disorders of the cardiovascular system.
Hypertension
Increases a person’s risk of heart attack, stroke, heart failure, and kidney failure
Known causes and risk factors include narrowing of the arteries, various medications, kidney disease, endocrine disorders, pregnancy, drug use sleep apnea, obesity, smoking, a high-sodium diet, excessive alcohol consumption, stress, and diabetes.
Mitral valve prolapse (MVP)
Blood may flow back into the atrium; may become worse over time
Increases the risk of heart valve infections and endocarditis.
The cause is unknown in most cases. It may be hereditary or due to autonomic nervous system disorders.
Murmurs
Murmurs are graded from 1 to 6, 1 being barely audible.
Not all the causes of heart murmurs are known. In children, the failure of the foramen ovale or ductus arteriosis to close completely after birth can cause murmurs. Other causes include stress and defective heart valves.
Refer to CONNECT to see an animation about Hypertension

40. Diseases and Disorders of the Cardiovascular System (cont.)
Description
Myocardial infarction
Heart attack; damage to cardiac muscle due to a lack of blood supply
Stenosis of the heart valves
The valve does not fully open; aortic stenosis, mitral stenosis
Thrombophlebitis
Blood clots and inflammation develop in a vein
Varicose veins
Twisted, dilated veins
Learning Outcome: Describe the causes, signs and symptoms, and treatments of various diseases and disorders of the cardiovascular system.
Myocardial infarction
The causes and contributing factors include blockage of coronary arteries as a result of atherosclerosis or a blood clot.
Drugs such as cocaine also can cause coronary arteries to spasm.
Stenosis of the heart valves
Blood flow from the heart is decreased, and pressure inside the left ventricle is increased.
Congenital or as a result of rheumatic fever.
Thrombophlebitis
If the blood clot breaks loose becoming an embolus, it can cause a pulmonary embolism, heart attack, or CVA (stroke).
Many risk factors including prolonged inactivity, oral contraceptives and others
Varicose veins
If they occur in the rectum – hemorrhoids
May be caused by prolonged sitting or standing, damage to valves in the veins, a loss of elasticity in the veins, obesity, pregnancy, oral contraceptives, or hormone replacement therapy. Family history may also be a cause.

41. Bravo! Apply Your Knowledge True or false:
A myocardial infarction results from a lack of oxygen to the cardiac muscle
Myocarditis is inflammation of the innermost lining of the heart.
A potentially fatal arrhythmia is ventricular fibrillation.
Murmurs are abnormal heart rhythms.
ANSWER: T F
Endocarditis T
Learning Outcome: Describe the causes, signs and symptoms, and treatments of various diseases and disorders of the cardiovascular system.
sounds F
Bravo!

42. In Summary
26.1 The structures of the heart include the pericardium, epicardium, myocardium, and endocardium.
The chambers of the heart consist of the upper atria and the lower ventricles.
The septa are the interatrial, interventricular, and atrioventricular.
The four valves within the heart are the tricuspid, the bicuspid, the pulmonary semilunar, and the aortic semilunar valves.

43. In Summary (cont.)
26.2 One cardiac cycle consists of one complete heartbeat.
The atria contract and relax together, and the ventricles contract and relax together.
As each chamber contracts, associated valves open and close to control the flow of blood through the heart.
Contractions are initiated by the cardiac conduction system.
26.2 One cardiac cycle consists of one complete heartbeat.
The atria contract and relax together, and the ventricles contract and relax together.
As each chamber contracts, associated valves open and close to control the flow of blood through the heart.
Contractions are initiated by the cardiac conduction system, which consists of the sinoatrial node, the atrioventricular node,
the bundle of His, and Purkinje fibers.

44. In Summary (cont.)
26.3 Pulmonary circulation: Right atrium  tricuspid valve  right ventricle  pulmonary semilunar valve pulmonary trunk  pulmonary arteries  lungs pulmonary veins  left atrium.
Systemic circulation: Left atrium  bicuspid valve left ventricle  aortic semilunar valve  aorta  arteries  arterioles  capillaries  venules  veins  venae cavae  right atrium.

45. In Summary (cont.)
26.4 Types of blood vessels include arteries and arterioles, which bring blood from the heart to the body; capillaries, which act as the connectors between the arterioles and venules.
The largest artery in the body is the aorta. Others arteries are listed in the chapter.
The largest veins in the body are the superior and inferior venae cavae. Others veins are listed in the chapter.
26.4 Types of blood vessels include arteries and arterioles, which bring blood from the heart to the body; veins and venules, which carry blood back from the body to the heart; and capillaries, which act as the connectors between the arterioles and venules.
The largest artery in the body is the aorta. Other major arteries include lingual, facial, occipital, maxillary, ophthalmic, axillary, brachial, ulnar, radial, intercostals, lumbar, external iliac, common iliac, femoral, popliteal, and tibial.
The largest veins in the body are the superior and inferior venae cavae. Other major veins are jugular, brachiocephalic, axillary, brachial, ulnar, radial, intercostals, azygos, gastric, splenic, mesenteric, hepatic portal, hepatic, iliac, femoral, popliteal, and saphenous.

46. In Summary (cont.)
26.5 Blood pressure is the force exerted on the inner wall of blood vessels by blood as it flows through vessels.
It is highest in arteries and lowest in veins. Clinically, blood pressure refers to the force of blood within the arteries.
Blood pressure is largely controlled by the amount of blood pumped out of the heart, but various other events also may raise and lower blood pressure.

47. In Summary (cont.)
26.6 Many different types of cardiac and blood diseases are described within this chapter.
The signs, symptoms, and treatments are as varied as the diseases themselves.
The last section of this chapter outlines the most common of these diseases, their signs and symptoms, as well as their treatments.

48. End of Chapter 26
Your work is to discover your world and then with all your heart give yourself to it.
~ Buddha