I  Heart (�the pump�)  


           A.  Precise location

           B.  Coverings and layers

                        1.  pericardial sac

                                    a.  fibrous pericardium and parietal layer of serous pericardium

                        2.  pericardial cavity (containing pericardial fluid)

                        3.  epicardium (visceral layer of serous pericardium)

                        4.  myocardium

                        5.  endocardium

            C.  Structure

                        1.  atria

                        2.  ventricles

                        3.  septa

            D.  Flow of blood through the heart         (animation of blood flow through the heart)            

                        1.  right heart; pulmonary circuit     

                        2.  left heart; systemic circuit           (heart transplant practice)  

            E.  Valves

                        1.  atrioventricular:  tricuspid and bicuspid (mitral)

                        2.  semilunar:  pulmonary and aortic

                        3.  function

                        4.  abnormalities

                                    a.  stenosis

                                    b.  insufficiency

            E.  Coronary circulation

                        1.  coronary arteries ---> coronary sinus

                        2.  myocardial infarction (MI)     

                                    a.  angioplasty       

                                    b.  bypass surgery

            F.  Fetal circulation

1.  umbilical vessels

                        2.  avoid lungs

                                    a.  foramen ovale ---> fossa ovalis

                                    b.  ductus arteriosus ---> ligamentum arteriosum



                    At the end of this unit you should be able to:



- describe the location of the heart in the thoracic cavity

- identify the protective covering of the heart and the three layers of the heart wall

- compare the structure and the function of the right heart and the left heart

- explain how the atrio-ventricular valves prevent backflow

- explain how the semilunar valves prevent backflow

- explain stenosis and insufficiency of a heart valve

- list the structures the blood flows through in the pulmonary circulation pathway

- list the structures the blood flows through in the systemic circulation pathway

- list the structures the blood flows through in the coronary circulation pathway

- list the structures the blood flows through in the fetal circulation

- explain the reasons for the fetal circulation pathway




II  Blood Vessels   ("the pipes")

            A.  General vessel structure

                        1.  lumen

                        2.  tunics

                                    a.  tunica intima

                                    b.  tunica media

                                                1.  neural innervation

                                    c.  tunica adventitia

                                                1.  vasa vasorum

            B.  Arteries (high pressure vessels)

            C.  Arterioles (regulating vessels)

            D.  Capillaries (exchange vessels)

                         1. capillary beds: meta-arteriole, thoroughfare channel, precapillary sphincter
                         2. types: continuous, fenestrated, sinusoids, impermeable



                                    Arrows indicate RBCs moving single file through capillaries in         ?     tissue.



            E.  Veins (storage vessels)


 III   Circulation

            A.  Pulmonary circuit

            B.  Systemic circuit

            C.  Fetal circulation

            D.  Coronary circulation

            E.  Portal circulation

                        1.  definition

                        2.  hepatic portal circulation

                                    a.  pathway

                                    b.  function

                        3.  hypophyseal portal circulation

                                    a.  pathway

                                    b.  function

            F.  Collateral circulation


                        1.  anastomoses

                                    a.  structure

                                    b.  function

                                    c.  examples

                                                1.  stomach

                                                2.  scapula



At the end of this unit, you should be able to :

    -  describe the three tunics that make up the wall of the blood vessels

    -  compare the structure and functions of arteries, arterioles, capillaries and veins

    -  describe a capillary bed and how it can be bypassed

    -  contrast the four types of capillaries and where they are found in the body

    -  explain the skeletal-muscle pump and why it is necessary

    -  define a portal circulation and describe a portal system in the body, structure and function

    -  define collateral circulation and anastomosis and explain the necessity of this type of circulation

    -  give an example of collateral circulation in the body



                                                                         LINK TO CROSSWORD PUZZLE




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Last Updated: 1/16/19