cardiovascular system
DESCRIPTION
Cardiovascular System. Biology 2122 Chapter 18. Heart Anatomy. Location : Mediastinum Coverings ( Pericardium ) Fibrous and Serous layers Serous (Parietal and Visceral = epicardium ) Heart Wall (Layers) Epicardium ; Myocardium; Endocardium. Chambers. Atria - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Cardiovascular System](https://reader035.vdocument.in/reader035/viewer/2022062717/56812a6c550346895d8df02c/html5/thumbnails/1.jpg)
Cardiovascular System
Biology 2122Chapter 18
![Page 2: Cardiovascular System](https://reader035.vdocument.in/reader035/viewer/2022062717/56812a6c550346895d8df02c/html5/thumbnails/2.jpg)
Heart Anatomy Location: Mediastinum
Coverings (Pericardium)
– Fibrous and Serous layers
– Serous (Parietal and Visceral = epicardium)
Heart Wall (Layers)
– Epicardium; Myocardium; Endocardium
![Page 3: Cardiovascular System](https://reader035.vdocument.in/reader035/viewer/2022062717/56812a6c550346895d8df02c/html5/thumbnails/3.jpg)
Chambers Atria
– Pectinate muscles; auricles – Superior and Inferior Vena Cava
• Right-side
– Deoxygenated Blood • Coronary sinus/Pulmonary veins
Ventricles – Trabeculae carneae/Papillary muscles– Pulmonary Trunk– Aorta
Circulation – Pulmonary vs. Systemic
![Page 4: Cardiovascular System](https://reader035.vdocument.in/reader035/viewer/2022062717/56812a6c550346895d8df02c/html5/thumbnails/4.jpg)
![Page 5: Cardiovascular System](https://reader035.vdocument.in/reader035/viewer/2022062717/56812a6c550346895d8df02c/html5/thumbnails/5.jpg)
Coronary CirculationArterial – Left Coronary Artery
– Anterior Interventricular • “Left Anterior Descending”
– Circumflex
Arterial – Right Coronary Artery– Marginal artery– Posterior Interventricular artery
Venous– Cardiac veins– Coronary sinus
• Great, middle, small cardiac veins
Angina pectoris and Myocardial Infarctions
![Page 6: Cardiovascular System](https://reader035.vdocument.in/reader035/viewer/2022062717/56812a6c550346895d8df02c/html5/thumbnails/6.jpg)
Heart Valves • Atrioventricular Valves
– Prevents backflow – chordae tendineae – Tricuspid (right)– Mitral (left)
• Semilunar Valves– Aortic – Semilunar
• Stenosis
• Heart Animation
![Page 7: Cardiovascular System](https://reader035.vdocument.in/reader035/viewer/2022062717/56812a6c550346895d8df02c/html5/thumbnails/7.jpg)
Microscopic - Cardiac Tissue Histology• Cardiac Tissue
– Striated – Branching– Uninucleated – Intercalated discs
• Gap junctions
– Functional Syncytium
– High in mitochondria
![Page 8: Cardiovascular System](https://reader035.vdocument.in/reader035/viewer/2022062717/56812a6c550346895d8df02c/html5/thumbnails/8.jpg)
Cardiac Tissue - Contraction• Autorhythmic Cells
• Heart Contracts as a unit– Ion passage through gap junctions– Steady and rhythmical waves of depolarization
• Depolarization – Longer absolute refractory periods – 250 ms
• Similar to depolarization events in skeletal muscle – Differs in Ca++ release (SR)
![Page 9: Cardiovascular System](https://reader035.vdocument.in/reader035/viewer/2022062717/56812a6c550346895d8df02c/html5/thumbnails/9.jpg)
Intrinsic Conduction System Sets basic or normal rhythm
– Autorhythmic Cells
Sequence of Excitation 1.SA node (right atria)
– “pacemaker”
2.Atrioventricular node – Above tricuspid valve
3.Atrioventrical bundle– “bundle of his” – Superior interventricular septum
4.Bundle branches
5. Purkinje fibers – Apex
•Intrinsic Conduction System Animation
![Page 10: Cardiovascular System](https://reader035.vdocument.in/reader035/viewer/2022062717/56812a6c550346895d8df02c/html5/thumbnails/10.jpg)
Disorders 1. Arrhythmias
2. Fibrillation
3. Heart Block
![Page 11: Cardiovascular System](https://reader035.vdocument.in/reader035/viewer/2022062717/56812a6c550346895d8df02c/html5/thumbnails/11.jpg)
Extrinsic Innervation and Control • Autonomic Nervous System
– Sympathetic Effects – Parasympathetic Effects
• Cardiac centers – Medulla Oblongata
– Cardioacceleratory Center • Sympathetic (T1-T5) • Innervate SA and AV nodes
– Cardioinhibitory Center • Vagus Nerve• To SA and AV nodes
![Page 12: Cardiovascular System](https://reader035.vdocument.in/reader035/viewer/2022062717/56812a6c550346895d8df02c/html5/thumbnails/12.jpg)
Electrocardiogram
EKG lead placements
![Page 13: Cardiovascular System](https://reader035.vdocument.in/reader035/viewer/2022062717/56812a6c550346895d8df02c/html5/thumbnails/13.jpg)
Electrocardiography• The Electrocardiogram (ECG)
• Waves 1. P-Wave
– Depolarization (Atrial contraction) – SA node
2. QRS – Ventricular depolarization – Ventricular contraction
3. T-Wave – Ventricular repolarization
![Page 14: Cardiovascular System](https://reader035.vdocument.in/reader035/viewer/2022062717/56812a6c550346895d8df02c/html5/thumbnails/14.jpg)
Electrocardiography
P-Q Interval
S-T Segment
Q-T Interval
![Page 15: Cardiovascular System](https://reader035.vdocument.in/reader035/viewer/2022062717/56812a6c550346895d8df02c/html5/thumbnails/15.jpg)
Abnormal ECG
Heart Block – Some P-waves not conducted through (see more P-waves)
Non-functional SA Node
![Page 16: Cardiovascular System](https://reader035.vdocument.in/reader035/viewer/2022062717/56812a6c550346895d8df02c/html5/thumbnails/16.jpg)
Heart Sound • “Lub-Dub”
• Lub– AV valve closure
• Dub– SL valves snap shut – Ventricular relaxation
• Heart Murmer
![Page 17: Cardiovascular System](https://reader035.vdocument.in/reader035/viewer/2022062717/56812a6c550346895d8df02c/html5/thumbnails/17.jpg)
Cardiac Cycle Systole vs diastole
The cardiac cycle involves all events associated with blood flow through the heart during one complete heartbeat
Ventricular filling: Mid-Late Diastole ◦EDV (end diastole volume)
Ventricular Systole◦ESV (end systolic volume)
Isovolumetric Relaxation – Early diastole
![Page 18: Cardiovascular System](https://reader035.vdocument.in/reader035/viewer/2022062717/56812a6c550346895d8df02c/html5/thumbnails/18.jpg)
Cardiac Cycle
Cardiac Cycle Animation
![Page 19: Cardiovascular System](https://reader035.vdocument.in/reader035/viewer/2022062717/56812a6c550346895d8df02c/html5/thumbnails/19.jpg)
Cardiac OutputCO is defined as the amount of blood pumped out by each ventricle in one minute.
calculated as the product of stroke volume and rate
HR X SV = 5.25 L/min
Stroke volume - volume of blood pumped out by one ventricle with each beat
CO is variableincreases in response to special demands like exercise
The difference between resting CO and maximal CO is called cardiac reserve. In trained athletes it is 7 times that of normal (35 L/min)
![Page 20: Cardiovascular System](https://reader035.vdocument.in/reader035/viewer/2022062717/56812a6c550346895d8df02c/html5/thumbnails/20.jpg)
Stroke Volume RegulationSV is the difference between EDV (blood in ventricle during diastole) and ESV (blood in ventricle during systole)
Normal SV = 70 ml/beat
Depends on the following factors◦Preload (Frank-Starling Law)◦Contractility◦Afterload
![Page 21: Cardiovascular System](https://reader035.vdocument.in/reader035/viewer/2022062717/56812a6c550346895d8df02c/html5/thumbnails/21.jpg)
Regulation of Stroke Volume 1. Preload
– Frank-Starling Law – Cardiac muscle cells stretched to optimal
length before contraction
2. Contractility– Independent of stretch– Greater Ca++ influx – Increased leads to greater SV
3. Afterload– Back pressure on aortic and pulmonary
valves – Overcome pressure for ventricles to be able
to eject blood
![Page 22: Cardiovascular System](https://reader035.vdocument.in/reader035/viewer/2022062717/56812a6c550346895d8df02c/html5/thumbnails/22.jpg)
Regulation of Heart Rate 1. Autonomic Nervous System
2. Chemical Regulation – Hormones (Epinephrine and Thyroxine) – Ions
• Calcium (Hypo- and Hypercalcemia)• Potassium (Hypo- and Hyperkalemia)
• Disorders/Imbalances 1. Tachycardia and Bradycardia
2. Congestive Heart failure