Monday 21st May 2018

The Body – Anatomy and Physiology

Lesson 11

Left Atrium

The

Cardiac

Cycle

Left Atrium Back to the heart via the pulmonary vein

Distributed around the body via arteries

Capillaries at the Alveoli (lungs)–

Gaseous exchange delivering Carbon

Dioxide and collecting Oxygen

Capillaries at Muscles and organs –

Gaseous exchange delivering Oxygen

and collecting Carbon Dioxide

Through the Aorta

Back to the heart via veins Left Ventricle

Through the Vena Cava Into Right Atrium

Right VentricleOut of the Pulmonary Artery to the

Lungs

Extension

1) Colour all oxygenated sections red, deoxygenated

sections blue and areas of gaseous exchange

purple

2) 2) Add additional details i.e. location of valves,

other key anatomy, description of blood vessels etc

Task – complete the cycle in the correct order

Starter Left Atrium

Left Ventricle

Through the Aorta

Distributed around the body via arteries

Capillaries at Muscles and organs – Gaseous exchange delivering

Oxygen and collecting Carbon Dioxide

Back to the heart via veins

Through the Vena Cava

Into Right Atrium

Right Ventricle

Out of the Pulmonary Artery to the Lungs

Capillaries at the Alveoli (lungs)–

Gaseous exchange delivering Carbon

Dioxide and collecting Oxygen

Back to the heart via the pulmonary vein

The

Cardiac

Cycle

Starter Left Atrium

Left Ventricle

Through the Aorta

Distributed around the body via arteries

Capillaries at Muscles and organs – Gaseous exchange delivering

Oxygen and collecting Carbon Dioxide

Back to the heart via veins

Through the Vena Cava

Into Right Atrium

Right Ventricle

Out of the Pulmonary Artery to the Lungs

Capillaries at the Alveoli (lungs)–

Gaseous exchange delivering Carbon

Dioxide and collecting Oxygen

Back to the heart via the pulmonary vein

The

Cardiac

Cycle

Today’s lesson –Associated topics to cardio/ respiratory system

• Redistribution of blood

• The Cardiac Cycle

• Cardiac Output/ Stroke Volume

• Measuring breathing volumes

• Interpretation of data

Redistribution of blood during exercise

During exercise, blood flow to muscles increase to meet the increase in oxygen demand. This redirection of blood flow to the areas where it is most needed is known as a vascular shunt.

The body uses two mechanisms to control this redistribution. Vasoconstriction (narrowing) and Vasodilation (expanding) is used to redistribute blood to essential areas of the body while decreasing blood flow to others.

Where? Why?

Vasodilation

Vasoconstriction

Redistribution of blood during exerciseConsider where blood is needed/ sent when we exercise and where it is pulled from

Where? Why?

Vasodilation WorkingMuscles

To deliver more oxygen and other nutrients such as glucose/ fats to working muscles to create energy. Also to starve off effects of lactic acid.

Skin surface To ensure we don’t overheat the warm blood is shunted to the surface of the skin in order for it to be cooled down by the air. This makes us appear red.

Vasoconstriction Non working muscles

These receive minimal blood flow as they require no additional energy

Internal organs eg stomach

Only essential body functions are completed when exercising. Instead the blood flow is reduced to ensure these organs to not overheat whilst exercising.

Redistribution of blood during exerciseConsider where blood is needed/ sent when we exercise and where it is pulled from

There are 2 stages to each heart beat:

The Cardiac Cycle

1) Diastole (Filling) 2) Systole (Ejection)

The filling of the heart and subsequent emptying follows a particular sequence.

Diastole

The heart filling with

blood.

-----------------

The heart is relaxing

Systole

The heart emptying.

-------------------

The heart contracts

Cardiac output, stroke volume and heart rate

The short term effects of exercise on the cardiovascular system:

1. Increase in heart rate2. Increase in stroke volume3. Increase in cardiac output

Heart rate is the number of beats per minute made by our heart.

It can be measured via a heart monitor or by counting the number of times our arteries ‘pulse’ per minute (or part of).

We can feel our pulse where an artery runs close to the surface of the skin- for example - Radial Artery (wrist) or Carotid Artery (neck)

Cardiac output, stroke volume and heart rate

The short term effects of exercise on the cardiovascular system:

1. Increase in heart rate2. Increase in stroke volume3. Increase in cardiac output

Stroke volume is the amount of blood

pumped out of the left ventricle per beat.

The stroke volumes for each ventricle

are generally equal, both being

approximately 70 mL in a healthy 70-kg

man

Cardiac output, stroke volume and heart rate

The short term effects of exercise on the cardiovascular system:

1. Increase in heart rate2. Increase in stroke volume3. Increase in cardiac output

Cardiac output is the amount of blood pumped out of the

left ventricle of the heart per minute.

The cardiac output is usually expressed in liters/minute.

For someone weighing about 70 kg (154 lbs), the cardiac

output at rest is about 5 liters/minute.

cardiac output = stroke volume × heart rate

Breathing volumes

Tidal volume:

This is the amount you breathe in and out in one normal breath.

Name Tidal volume at rest (ml)

Tidal volume during exercise (ml)

James 500 3500

Exercise causes an increase in breathing rate and depth. This is due to a greater need for oxygen in the body and removal of carbon dioxide.

Tidal volume can increase up to 5-9 times higher than at rest to cope with exercise demands.

Interpretation of a spirometer trace

Lung volumes can be shown on a spirometer trace and will change during exercise.

Inspiratory Reserve Volume

The volume able to be forcibly inspired during normal breathingThis decreases during exercise.

Expiratory Reserve VolumeThe volume able to forcibly expired, after a normal breatheThis decreases slightly during exercise.

Residual VolumeThe volume of air that remains in the lungs after forced maximum expiration. No change to this volume during exercise.

Interpreting heart rate data & graphs

The table below shows an athletes cardiovascular and respiratory measurement taken at rest and during exercise.

Describe what the tables tell you? Discuss why these changes have taken place?

Heart rate (bpm)

Strokevolume (ml)

Breathing rate (number per min)

Muscle temperature

72 60 18 Normal

Heart rate (bpm)

Strokevolume (ml)

Breathing rate (number per min)

Muscle temperature

156 140 48 Hot

Rest

During exercise

Interpreting heart rate data & graphs

Plot the information shown in the table onto graph paper to show how heart rate has changed over time. Label the axes and join up the points to make a line graph.

Describe what the graph tells you?

Time (minutes) 2 4 6 8 10 12 14

Heart rate (beats per minute)

68 80 104 120 120 140 90

Homework for the holidays – REVISION!!!!!Y10 Exam: Monday 18 June – 1.30pmAll content from paper 1 and paper 2 since September

Paper 1 – AG

• Health and Fitness

• Components of Fitness

• Fitness Testing

• Training Types (inc injury prevention, seasons, safety, training zones, warming up/ cooling down etc)

• Effects of exercise

• Skeletal/ Muscular Systems

• Movement analysis

• Circulatory/ Respiratory Systems