Pages 356-363 © 2015 Pearson Education, Inc.. Includes the heart and the blood vessels Functions:...
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Transcript of Pages 356-363 © 2015 Pearson Education, Inc.. Includes the heart and the blood vessels Functions:...
Pages 356-363
© 2015 Pearson Education, Inc.
Includes the heart and the blood vessels Functions:
◦ Deliver oxygen/nutrients to cells/tissues◦ Remove carbon dioxide/waste products
Blood is the transport vehicle
© 2015 Pearson Education, Inc.
Location◦ Thoracic cavity◦ between the lungs within the inferior mediastinum
(the central chamber of the thorax) Orientation
◦ Pointed apex directed toward left hip◦ Base points toward right shoulder
About the size of a human fist
© 2015 Pearson Education, Inc.
(a)
Superiorvena cava
Pulmonarytrunk
Diaphragm
Aorta
Left lung
Pericardium(cut)
Apex ofheart
(b)
Diaphragm
2nd rib
Midsternal line
Sternum
The heart is enclosed by the pericardium
Pericardium—a double-walled (2 layered) sac
◦ Fibrous pericardium is loose and superficial◦ Serous membrane is deep to the fibrous pericardium and
composed of two layers:1. Parietal pericardium: outside layer that lines the inner
surface of the fibrous pericardium2. Visceral pericardium: lies directly on heart; also known
as the epicardium
◦ Serous fluid fills the space between the layers of pericardium
lubricates; prevents friction from the beating heart
© 2015 Pearson Education, Inc.
Pericardium
Myocardium
Pulmonarytrunk
Fibrous pericardium
Parietal layer ofserous pericardium
Pericardial cavityEpicardium(visceral layerof serouspericardium)
MyocardiumEndocardium
Heart chamber
Heartwall
Three layers comprise the walls of the heart:1. Epicardium Most superficial; connective tissue (This is the visceral pericardium)
2. Myocardium Middle layer- the one that contracts Mostly cardiac muscle
Desmosomes hold cells together gap junctions allow electrical wave to flow cell to cell
3. Endocardium Inner layer known as endothelium
Endothelial cells are a layer of thin squamous cells with vascularity A specialized type of epithelial cell
© 2015 Pearson Education, Inc.
Pericardium
Myocardium
Pulmonarytrunk
Fibrous pericardium
Parietal layer ofserous pericardium
Pericardial cavityEpicardium(visceral layerof serouspericardium)
MyocardiumEndocardium
Heart chamber
Heartwall
Right and left side are separate pumps Four chambers:
Atria -right and left (on top) Receiving chambers
Ventricles -right and left (on bottom) Discharging chambers
© 2015 Pearson Education, Inc.
(b) Frontal section showing interior chambers and valves.
Left atrium
Left ventricle
Right atrium
Right ventricle
Interventricular septum ◦ Separates the two ventricles
Interatrial septum ◦ Separates the two atria
© 2015 Pearson Education, Inc.
Left pulmonary artery
Superior vena cava
(b) Frontal section showing interior chambers and valves.
Aorta
Left atrium
Left pulmonary veins
Pulmonary semilunarvalve
Left atrioventricularvalve (bicuspid valve)
Aortic semilunar valve
Left ventricle
Interventricular septum
Myocardium
Visceral pericardium(epicardium)
Right pulmonaryartery
Right atrium
Right pulmonaryveins
Fossa ovalis
Right atrioventricularvalve (tricuspid valve)
Right ventricle
Chordae tendineae
Inferior vena cava
Oxygen-poor blood flows from the right side of the heart to the lungs
Oxygen-rich blood returns to the left side of the heart from the lungs
© 2015 Pearson Education, Inc.
Oxygen-rich blood flows from the left side of the heart (via the aorta) to body tissues
(oxygen is used at the cellular level; carbon dioxide is returned to circulation via veins for elimination from the body)
Oxygen-poor blood returns to the right side of the heart via the superior vena cava
© 2015 Pearson Education, Inc.
Capillary bedsof lungs wheregas exchangeoccurs
Venae cavae
Pulmonary veins
Aorta and branches
Leftatrium
Leftventricle
Heart
Capillary bedsof all body tissueswhere gas exchangeoccurs
Pulmonaryarteries
Pulmonary Circuit
Rightatrium
Rightventricle
Systemic Circuit
KEY:
Oxygen-rich, CO2-poor blood
Oxygen-poor, CO2-rich blood
Four valves:◦ Atrioventricular (AV) valves—between atria and
ventricles Bicuspid (mitral) valve (left side of heart) Tricuspid valve (right side of heart)
◦ Semilunar valves—between ventricle and artery Pulmonary semilunar valve Aortic semilunar valve
© 2015 Pearson Education, Inc.
Allow for unidirectional flow; prevent backflow
Open/close in response to pressure changes in heart
Leaky valves are ok… to a degree Valves that cannot close correctly cannot
prevent backflow Valves that are damaged (due to infection)
require more forceful contraction This leads to a weak heart and potential heart failure
This link shows a summary of the process of blood flow: http://highered.mheducation.com/sites/0072495855/student_vie
w0/chapter22/animation__the_cardiac_cycle__quiz_2_.html
This link shows a step by step process of flow: http://www.sumanasinc.com/webcontent/anima
tions/content/humanheart.html
This link shows a valve replacement!! Very cool https://www.youtube.com/watch?v=C-sIdppyaP
Q
The heart has its own circulatory system
Coronary arteries—branch from the aorta to supply the heart muscle with oxygenated blood
Cardiac veins—drain the myocardium of blood and dump into the Coronary sinus (located posterior and inferior)
From the sinus, blood empties into the right atrium and is returned to pulmonary circulation for re-oxygenation at the lungs
© 2015 Pearson Education, Inc.
Superior vena cava
Right pulmonary artery
Pulmonary trunk
Right pulmonaryveins
Right atrium
Right coronary artery
Anterior cardiac vein
Right ventricle
Small cardiac vein
Inferior vena cava
Aortic arch
Left pulmonary artery
Left pulmonary veins
Left atrium
Left coronary artery
Left ventricle
Great cardiac vein
Apex