Download presentation
Presentation is loading. Please wait.
Published byGabriel Wright Modified over 8 years ago
1
The Heart Circulatory System Ms. Lowrie Advanced Biology 11
2
7.5 – The Mammalian Heart Muscular pump In circulatory system Technically: Two parallel pumps Synchronized Separated by a thick wall of muscle Septum
3
Two Pumps Right Side Right atrium & ventricle Pulmonary circulation: Receives deoxygenated blood from body Sends to lungs Think: LUNGS! Left Side Left atrium & ventricle Systemic circulation: Receives oxygenated blood from lungs Sends to body tissues and cells Think: BODY!
4
Heart Chambers Four chambers or “rooms” Two atria and two ventricles Atria Thin walls Receive blood from veins Pump blood to ventricles Ventricles Thick walls Receive blood from atria Pump blood out of heart To body or lungs
5
Blood Flow in Heart Into heart Atria Ventricles Leaves heart Like the alphabet … A comes before V
6
The heart has valves too!? Just like veins! Prevents backflow of blood Atrioventricular (AV): Between artia & ventricles Semilunar: Between ventricles & arteries
7
Major Veins & Arteries Vena cava are VeINs Come INto heart from body Superior vena cava From upper body Inferior vena cava From lower body Aorta is an Artery Go Away from heart to body Aorta To upper body Descending aorta To lower body Coronary arteries Supply heart with oxygen and nutrients
8
Label Heart Diagram (pg 257) L pulmonary vein R atrium (from upper body) (from lower body) (to upper body) semilunar AV (to lower body)
9
Task Use notes & pages 256–258 & 261–262 Answer: A: Practice Questions: #1-4 (pg 258) B: Practice Questions: #2, 3 (pg 263) C: Section Questions: # 1, 5 & 6 (pg 263)
10
Questions?
11
Blood Flow Blood Flow in the Heart Grab blue & red colouring utensils!
12
7.6 – Setting the Heart’s Tempo Cardiac muscle is different from skeletal muscles Composed of myogenic muscle Muscles that contract without external nerve stimulation
13
The Heart’s Tempo “Node” = bundle of specialized nerves Sinoatrial (SA) node Located where vena cava enter right atrium Acts as pacemaker Sends nerve impulse to AV node Atria contract
14
The Heart’s Tempo (cont.) Atrioventricular (AV) node Located at AV valve in right atrium Sends nerve impulse through septum to ventricles Through Purkinje fibres Ventricles contract
15
Heart Rate & Communication Controlled by autonomic nervous system Sympathetic nervous system: Increases rate under stress Prepares for increased energy demands Parasympathetic nervous system: Decreases rate after stress Controls rate during rest
16
Electrocardiogram (ECG) Electrical impulses displayed on a graph P wave = atrial contraction QRS wave = ventricular contraction T wave = ventricular recovery Flat lines = @ rest
17
Abnormal ECG What has gone wrong? normal ECG
18
7.7 – Heart Sounds lubb-dubb caused by heart valves closing Diastole (relaxation): Atria fill with blood & contract AV valves open Blood enters ventricles & contract AV valves close lubb Blood pushed into arteries through semilunar valves
19
Heart Sounds Systole (contraction): Ventricles relax & increase in volume Blood drawn toward ventricles from arteries Semilunar valves close dubb Blood stays in arteries
20
7.8 – Blood Pressure Measured by a sphygmomanometer “Blood pressure cuff”
21
Blood Pressure (cont.) Measures 2 pressures: When ventricles contract (systolic) When ventricles relax (diastolic) Normal blood pressure = 120/80 Systolic = 120mm Hg Diastolic = 80mm Hg
22
Blood Pressure Can Change Varies by artery Decreases with distance from ventricles
23
Blood Pressure Regulation 1. Cardiac output Any increase = increase blood pressure 2. Arteriolar resistance Arteriole diameter: Constriction (more blood in artery) Increase blood pressure Dilation (less blood in artery) Decrease blood pressure
24
Blood Pressure Regulation (cont.) If CO 2 & lactic acid build-up Anaerobic respiration Smooth muscles relax Arterioles dilate Delivers more oxygen to tissues Homeostasis!
25
Blood Pressure Problems If too low: Reduces capacity to move blood Circulation problems Adjustment: Sympathetic (speed up) increased Cardiac output increased Arterioles constrict Decrease outflow from arteries
26
Blood Pressure Problems If too high: Can weaken artery May rupture vessel Adjustment: Sympathetic (speed up) decreased Parasympathetic (slow down) increased Cardiac output decreased Arterioles dilate Increase outflow from arteries
27
Concept Map Use terms: 1. Capillaries 2. Diastolic 3. Heart 4. Pulmonary artery 5. Pulmonary vein 6. Sphygmomanometer 7. Systolic 8. Vein 9. Vena cava
28
Any Questions???
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.