2025 - pe unit 1 half of exam

cardiorespiratory

cardiovascular system

• consists of heart, blood vessels, blood

cardiovascular system - pulmonary circuit

• blood flow between heart and lungs

• Pulmonary circulation is the blood that circulates between the heart and lungs. It starts in the right ventricles, where deoxygenated blood is pumped through the pulmonary arteries to the lungs. The lungs then oxygenate the blood (through respiratory system – pulmonary diffusion at alveoli-capillary interphase) and the lungs bring back oxygenated blood through the pulmonary veins into the left atria.

cardiovascular system - systematic circuit

• blood flow between heart and body

• Systematic circulation is the blood that circulates between the heart and the body. It starts in the left ventricle, where oxygenated blood is pumped through the aorta to the body. (The body uses the oxygen in the blood for cellular respiration, which creates co2). The body then brings back this deoxygenated blood to the right atrium.

cardiovascular system - functions of cardiovascular system

• circulates blood

• brings o2, water and nutrients to cells

• removes co2 and other wastes from cells

• thermoregulation + hydration

• fight disease

• blood clotting

cardiovascular system - heart structure

superior vena cava - vein that brings deoxygenated blood from upper body to right atrium

inferior vena cava - vein that brings deoxygenated blood from lower body to right atrium

right atrium - recieves deoxygenated blood from veins and pushes into right ventricle

tricuspid valve - valve between right atrium and right ventricle

right ventricle - recieves deoxygenated blood from atrium and pushes into pulmonary artery

pulmonic valve - valve between right ventricle and pulmonary artery

pulmonary artery - brings deoxygenated blood from right ventricle to lungs (there’s two because they need to go to each lung)

blood gets oxygenated and loses carbon dioxide in lungs

pulmonary veins - receives oxygenated blood from lungs (there’s two because they come from each lung)

bicuspid/mitral valve -

left ventricle -

aortic valve -

aorta -

cardiovascular system - valves

prevent backflow

cardiovascular system - viscosity

low viscosity = water

high viscosity = syrup

cardiovascular system - stroke volume, heart rate + cardiac output

• heart rate - measured in bpm

• stroke volume - the volume of blood pumped from the left ventricle per beat

• cardiac output - represents how much blood the heart pumps per minute

• cardiac output increases during excercise to deliver more required oxygen to working muscles. this is because both heart rate and stroke volume increase.

• cardiac output (Q) = heart rate x stroke volume

cardiovascular system - blood vessels

• arteries - carry oxygen rich blood away from the heart (except for pulmonary arteries). have large, thick elastic walls

• veins - carry oxygen poor blood back to the heart (except for pulmonary veins)

• capillaries - smallest blood vessels that are the site of gaseous they connect arterioles and venules

cardiovascular system - max heart rate

220 - age

cardiovascular system - redistribution of blood flow

• during excercise, blood flow is redistributed through vasodilation (widening of blood vessels to working muslces) and vasoconstriction (narrowing to non-essential organs such as the digestive system

• (expand more on this in acute responses)

blood components - red blood cells

• function - carry oxygen

blood components - white blood cells

• function - fight infection

blood components - platelets

• function - clot blood

blood components - plasma

• function - transport nutrients/waste

respiratory system

mouth / nose + nasal passage → oral cavity → larynx → pharynx → trachea → left/right bronchus → bronchioles → alveoli → capillaries → pulmonary venules

• also includes diaphragm, intercostal muscles, ribs, lungs

respiratory system - inspiration

respiratory system - expiration

respiratory system - gaseous exchange

respiratory system - respiratory rate, tidal volume, ventillation/minute ventilation

• respiratory rate - 

• tidal volume - the amount of air inhaled and exhaled per breath

• minute ventilation - represents the total air breathed per minute

• minute ventilation (VE) = respiratory rate x tidal volume

acute responses to excercise - how do the cardiovascular and respiratory systems work together to transport oxygen around the body during excercise

acute responses to excercise - how do heart rate, stroke volume and cardiac output change during excercise

submaximal intensties

maximal intensities

muscle fibre types

• slow twitch (type I) - low force, high endurance. marathon runners

• fast twitch (type II) - high force, low endurance. sprinters