The Structure and Function of the Heart - charlestonbiology

The Structure and Function of the Heart - charlestonbiology

The Structure and Function of the Heart Higher Human Physiology and Health 1 What do you know now? From your previous N5 or maybe S1/2 work label the diagram of the heart and write any facts you know.

What you are learning? Revising the heart structure and function The cardiac cycle and output Cardiac conduction and heart beat Cardiac pressures 2 superior vena cava pulmonary veins

AV valve mitral AV valve tricuspid inferior vena cava 3 The Heart - external

4 The Heart - internal 5 Cardiac cycle 6

Systole / Diastole Systole when part of the heart is contracting either atria or ventricles Diastole when part of the heart is relaxing either atria or ventricles Both atria contract or relax at the same time Both ventricles contract or relax at the same time Atria and ventricles can be relaxed at same time Atrio-ventricular valves (AV) and semi-lunar valves (SL) are forced open or kept closed depending on systole or diastole of

atria or ventricles Valves allow flow of blood in one direction through the heart 7 Measuring cardiac output Cardiac output = heart rate x stroke volume CO HR SV Cardiac output is the volume of blood pumped through each

ventricle per minute Heart rate is the number of times the heart beats per minute Stroke volume is the volume of blood pumped through a ventricle at each beat Each ventricle pumps the same volume of blood to aorta or pulmonary artery respectively 8 Cardiac output

9 Valves and heart sounds Heart sounds come from the closing of valves and sounds like LUB/DUB AV valve closes and gives the LUB sound SL valve closes and gives the DUB sound Heart murmurs can be heard and are defective valves

10 Heart sounds 11 Cardiac cycle 12

Cardiac cycle and pressure changes Atria contract (systole) pushing blood into ventricle via AV valve, SL valve is closed Ventricles contract (systole) closing the AV valve. Blood is pumped out into aorta or pulmonary artery via SL valve All relax (diastole) SL valves closed 13 Cardiac conducting system

Heart beat originates in the heart But it is regulated by nervous and hormonal control Sinoatrial node Atrioventricular node 14 Cardiac conducting system

Sinoatrial node (SAN) ii right atrium controls contractions and timing of beat Impulses from SAN radiate across atria Impulses from SAN transmitted to atrioventricular node (AVN) at base of atria Conducting fibres pass down centrally and branch left and right across ventricles Impulses sent to ventricular muscle fibres starting at apex (bottom) moving upwards Atrial systole first then ventricular systole next (coordinated)

15 Measuring heart impulses Impulses are electrical so can be measured by electrocardiogram (ECG) Electrodes placed on skin 3 distinct phases P wave atrial excitation from SAN QRS complex ventricle excitation T wave electrical recovery of ventricles

16 17 Abnormal ECGs CPR Defibrillator 18

Regulation and control of heart beat Nervous Control centre located in medulla Autonomic nervous system

Cardio accelerator centre sympathetic nerve increases heart rate Cardio inhibitor centre parasympathetic nerve decreases heart rate Impulses sent to SAN Relative number of impulses determines heart beat Hormonal Sympathetic nerve acts on adrenal gland It releases norepinephrine (noradrenaline) speeding up heart rate

Parasympathetic nerve releases acetylcholine slowing heart rate 19 Measuring blood pressure Blood pressure is the force put on walls of blood vessels Measured in the aorta Systolic pressure as left ventricle pushes blood out into aorta (pulse detected)

Diastolic pressure as left ventricular contraction has stopped (pulse not detected) Measured in mm of mercury (Hg) Typically 120 mm Hg for systolic 70 mm Hg for diastolic in young adult (120 over 70) Mercury manometer 20 Digital syphgmomanometer

21 22 Hypertension High blood pressure Caused by many factors: being overweight, lack of exercise, diet of fatty foods, too much salt, excessive alcohol, high levels of stress

Measurements of 140 over 90 mm Hg for extended periods when resting Hypertension increases risks of coronary heart disease and strokes 23 What you should know

Know the heart structure and function Know what cardiac output is how to calculate it Know what the cardiac cycle is and describe it Know how the cardiac cycle is controlled Know how the cardiac cycle can be measured

Know what blood pressure is and how it can be measured Consolidate your learning Read appropriate pages from textbook, complete questions in textbook, complete summary, make own notes, complete scholar work 24

Recently Viewed Presentations

  • Key Findings of the 2014 REUWS Update Study

    Key Findings of the 2014 REUWS Update Study

    On average the homes use 753,000 BTU/Mo for heating water. Maximum was 1.06 MBTU in Tacoma. Minimum was 321,000 BTU in Scottsdale. Showers are the #1 hot water user, followed by faucet use. Clothes washing is a relatively small hot...
  • Semicolons and Colons

    Semicolons and Colons

    Comma, Colons, and Semicolons Punctuation Lesson Who Cares? Using punctuation is like pausing between words and ideas when you speak. Imagine if you didn't take pause between words and sentences when speaking.
  • Fun Quiz - Gering High School

    Fun Quiz - Gering High School

    You have finished the fun quiz. Good. I like Edward Norton also. Nice. I am also a fight club fan. Yes. That is Eddie Murphy in the movie Vampire in Brooklyn. A fish shouldn't be with that group of animals....
  • Why Cant we see Sounds? By applying the
  • Présentation PowerPoint - Grenoble INP

    Présentation PowerPoint - Grenoble INP

    Traitement à l'acide nitrique ou par meulage. Plonger la lame de cuivre dans une solution salée (avec une lame d'aluminium) ou de nitrate de Plomb (avec une lame de Plomb). Relier les deux lames à un ampèremètre. Allumer la lampe...
  • Com 346

    Com 346

    The Basics Human-Computer Interaction (HCI) Usability refers to how easy or difficult it is to get around a web site, CD-ROM, or other interactive environment. Navigation is the way we get around inside a site. Ituitive Experience Expected ways to...

    Intensive Interaction is based on work by Nind and Hewett (e.g. Hewett & Nind, 1998; Nind & Hewett, 2006). Its use with children and adults appears widespread in the UK and Australia, and increasingly elsewhere, supported by training courses, conferences...
  • Tablet PC Workshop

    Tablet PC Workshop

    Tablet PC Workshop Group "A" Researchers 7/20/2005 Progress Since Last Year Good discussion between interaction researchers and recognition researchers UIST AAAI Workshop ICMI Eurographics Workshop How About Next Year?