AP Unit 6 Lesson 1 - Circulatory Structures/Functions + BP

Circulatory System

• Blood brings nutrients (oxygen, glucose) to cells and brings wastes (C02) away from cells via circulation

Circulatory System pt. 2

• Aorta / Artery / Arteriole

  • Colour: Red (some exceptions)

  • Carries blood away from the heart

  • Contains O2 blood + nutrients

Circulatory System pt. 3

• Vena Cava / Vein / Venule

  • Colour: Blue (some exceptions)

  • Carries blood towards the heart

  • Contains dO2 blood and waste

Circulatory System pt. 4

● Pulmonary Circulation: blood circulation in heart and lungs

• dO2 blood travels from heart → lungs via arteries

• O2 blood travels from lungs → heart via veins

● Systemic Circulation: blood circulation in the body

• O2 blood travels from heart → body via arteries

• dO2 blood travels from body → heart via veins

Pulmonary Circulation - Heart Anatomy Diagram

Pulmonary Circulation of Blood Flow Diagram

Pulmonary Circulation of Blood Flow Text

• 1. Deoxygenated blood enters Right Atrium via Superior / Inferior Vena Cava

• 2. Right Atrium contracts, forces blood through Tricuspid Valve into Right Ventricle

Pulmonary Circulation of Blood Flow Text pt. 2

3. Right Ventricle contracts, blood travels through Pulmonary Valve into Pulmonary Artery

4. Pulmonary Arteries take deoxygenated blood to capillaries of lungs where they are oxygenated (CO2 out, O2 in; via diffusion)

Pulmonary Circulation of Blood Flow Text pt. 3

5. Oxygenated blood then moves to Left Atrium through Pulmonary Veins

6. Left Atrium contracts, forcing blood through Mitral Valve into Left Ventricle

7. Left Ventricle contracts, forces blood through Aortic Valve into Aorta then to the rest of the body

Pulmonary Circulation - The Beat

• Septum: separates oxygenated & deoxygenated blood

• Chordae Tendineae: fibrous strings that support atrioventricular valves

Pulmonary Circulation - The Beat pt. 2

• Heartbeat Sounds

  • Lub: AV valves close after atria push blood into ventricles (start of heartbeat)

  • Dub: Semilunar valves close after ventricles pump blood out (end of heartbeat)

  • Heart Murmurs: occur when there are problems with valves closing

Heart Needs Blood Too

• Coronary Arteries: branches off the aorta and wraps around heart to supply blood to the heart muscles

• Cardiac Veins: dump blood with heart muscle wastes into right atrium

Controlling the Heartbeat + Diagram

• Nodal Tissues: exhibit characteristics of both nerves & muscles, allowing the heart to beat without conscious control

Controlling the Heartbeat pt. 2

• Medulla Oblongata: contains a cardiac control center that can alter Heart Rate (HR) via an autonomic nervous system

• Adrenal Medulla: releases protein hormone epinephrine (adrenaline) to increase HR in response to stress

Controlling the Heartbeat pt. 3

• Reading an Electrocardiogram (ECG)

• P wave: Atria contract

• QRS wave: Ventricles contract & Atria relax

• T wave: Ventricles relax

Blood Pressure

• Systole: Contraction of Heart Muscle

• Diastole: Relaxation of Heart Muscle

• Sphygmomanometers are used to measure Systolic / Diastolic BP

  • Normal: 120 / 80

Blood Pressure - Conditions

• Hypertension: Blood pressure is higher than normal

• Hypotension: Blood pressure is lower than normal

Blood Pressure - Conditions pt. 2

• Atherosclerosis: hardening of arteries due to plaque buildup from saturated fats / cholesterol

• Aneurysm: a bulge or ballooning in the wall of a blood vessel due to a weakened area

Blood Pressure - Conditions pt. 3

• Angina Pectoris: Radiating pain in left arm due to insufficient blood flow

• Thrombus: Stationary clot attached to blood vessel wall that slows blood flow

Blood Pressure - Conditions pt. 4

• Embolus: Thrombus - dislodged, moves along with blood

• Embolism: Embolus - gets stuck, entirely blocking blood flow

• Stroke: portion of brain dies due to lack of oxygen