Download Core 3- The Body in Motion

Core 3- The Body in Motion
DESCRIPTION
• 25% of preliminary course time.
• Examines the scientific foundations of human movement. Students explore how the body moves and why it moves in
particular ways. Students focus on the relationship between anatomy, physiology, fitness, biomechanics and efficient
human movement.
• Students investigate 4, critical questions:
1. How do anatomical structures influence the way the body moves?
2. How does the cardiorespiratory system respond to movement?
3. What aspects of physical fitness influence movement efficiency?
4. How are biomechanical principles reflected in the way we move?
OBJECTIVES AND OUTCOMES
A student develops:
• Knowledge and understanding about the way the body moves (P7, P8, P9),
• An ability to take action to improve participation and performance in physical activity (P10, Pll).
• An ability to apply the skills of critical thinking, research and analysis (P16, PI 7).
A student:
P7 Explains how body structures influence die way the body moves.
P8 Describes the components of physical fitness and explains how they are monitored.
P9 Describes biomechanical factors that influence the efficiency of the body in motion.
P10 Plans for participation in physical activity to satisfy a range of individual needs.
PI 1 Assesses and monitors physical fitness levels and physical activity patterns.
P16 Utilises a range of sources to draw conclusions about health and physical activity concepts.
P17 Analyses factors influencing movement and patterns of participation.
HOW THE BODY FUNCTIONS
Anatomy and Physiology
Define Anatomy:-
Define Physiology:-
Anatomical Position:-
Structural Levels of the Body’s Organisation
Comment on:
Chemical Level
Cellular Level
Tissue Level
Organ Level
System Level
Organismic Level
Homeostasis is when:-
The Body Systems
There are 11 major body systems. In the table below list the systems and briefly state what each one does.
System
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
Role In Homeostasis
Describing the Body Structures
Label with as much detail as possible
Anatomy General Terms
Anterior
Posterior
Superior
Inferior
Medial
Lateral
Proximal
Distal
Prone
Supine
Superficial
Deep
Coronal Plane
Sagittal Plane
Transverse Plane
Anatomical Position
How do anatomical structures influence the way the body moves?
Major skeletal bones
The skeletal system consists of 206 bones and fulfils six major functions. These are:
1. Acting as a supporting structure
2. Protecting internal organs, for example, the brain, which is protected by the skull, the heart, which is protected by
the ribs and the sternum, and the spinal cord, which is protected by the vertebral column
3. Providing attachment points for muscles, for example, the deltoid muscle in the shoulder, which is attached to the
clavicle and scapula bones as well as to the humerus
4. Enabling movement to occur when muscles contract and pull on the bones, for example, the deltoid muscle
which, when it contracts, pulls on the humerus and the upper arm moves.
5. Acting as a storage facility for important minerals, such as calcium
6. Acting as a production facility for blood cells.
Bones comprising the skeletal system will be one of six types. The size and/or shape generally define the type of bone
and these factors will help determine its function.
Type of Bone
1. Long
2. Short
3. Flat
4. Irregular
Example
Major Function
Other types of bones include sessamoid bones, which are the patella, and sutural bones, which are located in the skull.
These types of bones are named according to their location rather than their size or shape.
Skeletal bones
The Human Skeleton is made up of 2 main sections – The Axial Skeleton and The Appendicular Skeleton
Axial Skeleton
Provides a central support axis; is made up of the bones that lie around the long axis of the body.
Skull - cranium, facial bones
Vertebral column
The vertebral column consists of 33 bones that have intervertebral discs or cushions between them.
The bones are categorised as:

Cervical (neck), consisting of the seven smallest vertebrae (C1–7)

Thoracic (upper back), consisting of 12 vertebrae (T1–12)

Lumbar (lower back), consisting of the five largest and strongest vertebrae (L1–5)

Sacral (rump), consisting of five vertebrae fused together (the sacrum) coccyx
(tailbone), made up of four vertebrae fused together.
The bones of the vertebral column protect the spinal cord as well as providing support and
movement. The large number of joints, their supporting discs and their structure contribute to
the flexibility of the spinal column and its ability to absorb impact.
The thorax
The thorax is made up of:
 Sternum (breastbone), which serves as an attachment for
most of the ribs.
 Twelve pairs of ribs join the thoracic vertebrae at the back.
At the front, pairs of ribs are attached to the sternum. Two
pairs of ribs are unattached or ‘floating’.
Appendicular Skeleton
Includes the bones of limbs and girdle bones (pelvic and shoulder) which connect the limbs to the axial skeleton, Eg
 Shoulder Girdle - clavicle
(collar bone), Scapula (shoulder
blade)
 Upper Limb (Arm, wrist and
hand) - humerus, radius, ulna,
carpals, metacarpals, phalanges
 Lower Limb (leg, foot) - femur
(thighbone), patella (kneecap),
tibia (shin bone), fibula, tarsals,
metatarsals, phalanges
 Pelvis / Pelvic Girdle illium,
ischium, pubis
In relation to movement, the long bones of the arms and legs, and the short bones of the wrist/fingers and ankles/ toes
are crucial. When muscles contract and pull on long bones a large amount of force can be generated due to the large
lever length. (Note: muscular strength and power are important factors also). This is the reason why coaches instruct
plovers to 'straighten their arms' when striking a ball such as in softball, cricket and tennis.
Short bones help with accuracy needed for fine motor movements. For example, when throwing a ball the contraction of
muscles attached to the long bones of the arm help generate force, but the muscles attached to me wrist and fingers play
a significant role as the ball leaves the hand in determining the accuracy of the throw.
Your tasks:
1 Identify the major functions of the skeletal system.
2 Explain how the skeletal system contributes to movement.
3 Describe four types of bones.
4 Explain how different types of bones can influence movement.
Joint Structures and Joint Actions
A joint occurs where two or more bones meet or where a cartilage joins a bone. A joint can also be called an articulation.
Skeletal movement can only occur at a joint, although not all joints enable movement to occur.
Fibrous joints, (immovable joints), occur where Fibrous membranes hold the bones
tightly together and all movement is restricted, for example, between the radius and
the ulna.
Cartilaginous joints, (slightly
moveable Joints), occur where
some features present enable
limited movement, for example,
between the vertebrae.
Synovial joints, (freely moveable joints), occur where features are present that enable easy movement, for example,
shoulder, elbow, hip. Knee
Synovial Joint Features
 Ligaments, which are relatively inelastic fibrous bands that join one bone to another bone, thus increasing the
stability of the joint.
 Tendons, which join muscles to the bone, thus enabling movement
 Articular cartilage, which is a firm, elastic connective tissue that covers the ends of each bone, thus reducing
friction
 Synovial fluid, which is contained in smalt sacs called bursae and lubricates the joint, thus reducing friction.
Types of Joints
There are six types of synovial joints. Label the diagrams below with the correct joints.
Type of Synovial Joint
Hinge
Pivot
Condyloid
Saddle
Gliding
Ball and Socket
Example
Knee, elbow, finger
Rotation of the head/neck
Wrist
Thumb
Hand- (carpals), Foot (tarsals)
Hip, Shoulder
Range of Movement
Uniaxial- back and forth
Uniaxial- turning and rotation
Biaxial- side to side and back and forth
Biaxial- side to side and back and forth
Biaxial- side to side and back and forth
Triaxial- side to side back and forth and rotational
Your Tasks:1. Explain why skeletal movements can only occur at a joint.
2. Outline features present in synovial joints.
3. Look at the diagrams then, suggest the reasons how structural damage could
occur in a knee.
4. Review MRI and X Rays to view knee structure and damage.
5. Identify sporting examples in which knee ligament injury is prevalent. Suggest
reasons for this prevalence.
Movement General Terms
Description
Flexion
Extension
Abduction
Adduction
Circumduction
Rotation
Supination
Pronation
Inversion
Eversion
Sporting Example
Joint Actions – In the boxes below draw relevant diagrams for:
Flexion
Extension
Plantar Flexion
Dorsi Flexion
Abduction / Adduction
Rotation – Lateral / Medial
Supination / Pronation
Inversion / Eversion
Explain the following:
Elevation:
Depression:
Circumduction:
Muscles
Terms
Origin:Insertion:Action:Agonist:Antagonist:Muscle Types
Skeletal Muscle
Smooth Muscle
Cardiac Muscle
Located
Features/
Function
Skeletal Muscle Functions List and briefly explain
1.
2.
3.
Muscles have four distinct characteristics These enable them to do there job in the body.
1. Excitability
2. Contractibility
3. Extensibility
4. Elasticity
Muscle Actions and Types of Contractions
Muscle Actions – agonist, antagonist, stabilisers
• The role of muscles is to contract and when they contract we move. For movement to occur a muscle must exert a pull
on bones. Muscles are only capable of a pulling action and not a pushing action.
• Muscles Shorten (Contract) causing joint movement, then Lengthen (Relax) as opposing muscles pull the joint back into
position- Muscles can only contract and relax.
• When the muscle contracts it causes movement - This is called muscle action.
• Muscles perform one of three actions when performing a movement:
 Agonist
 Antagonist
 Stabilisers
Agonist (Prime Mover) - the muscle shortens (contracts). The agonist muscle is the one causing the major
action / movement.
Antagonist - the muscle lengthens (relaxes). The antagonist muscle is opposite to the agonist muscle. The muscle
must relax and lengthen to allow the agonist to contract, thus helping lo
control an action.
• The agonist works as a pair with me antagonist muscle. The 2 roles are
interchangeable depending on the direction of the movement. Antagonists
cause an opposite action to that caused by the agonist.
• The process where one muscle contracts (shortens) while its opposite
muscle relaxes (lengthens) is called reciprocal inhibition. This allows for a
smooth and efficient movement. If both muscles were to contract at the
same time, the weaker of the two would tear.
Examples of agonist and antagonist actions:
Muscle Action
Flexion of arm at
elbow
Extension of arm at
elbow
Agonist Muscle
Antagonist Muscle
Stabilisers These muscles act at a joint to stabilize it, giving the muscles a fixed base. The muscle shortens very little during its
contraction, causing minimal movement. This allows the action lo be carried out correctly and allows other joints to
work more effectively.
 Stabiliser muscles act to hold a muscle in a stable position.
eg, when running The torso is held upright so that the arms and legs can move efficiently. Muscles of the stomach (rectus
abdominus) and back (erector spinae) are contracted simultaneously to hold (stabilise) the torso.
Types of Contractions- Concentric, Eccentric, Isometric
When a muscle is stimulated it attempts to contract against external forces. There are 3 main types of muscle contraction:
Isotonic (concentric and eccentric) contractions

are dynamic as the length of the muscle changes (shortens or lengthens)

muscles develop tension (force) when the fibres shorten or
lengthen, as the force developed by the muscle is > the load
(resistance) to be lifted
There are 2 types of isotonic contractions:
Concentric- the force produced by the agonist muscle as it
contracts (shortens)eg ___________________________
_____________________________________________
Eccentric- the force developed by the antagonist muscle as it
relaxes (lengthens). Generally when a muscle is responsible for
the controlled lowering of a load it will be an eccentric muscle
contraction, eg. ___________________________________
________________________________________________
Muscles work in pairs. The agonist muscle shortens during a
contraction. While it is contracting, the opposite antagonist muscle
is lengthening. The antagonist controls the speed of the
movement, preventing forceful contraction that may result in injury
to the joint. It is important to develop both the agonist and
antagonist muscles equally. Strengthening only one muscle group
leads to imbalance in muscular strength between opposing muscle
groups resulting in the possibility of injury.
Isometric- are static as the length of the muscle does not
change despite the application of tension. Effort is made, but the muscle length does not change because the resistance
is too great, eg._______________________________________________________________________________
Produce force in a held or fixed position and are highly specific to joint angles
Isometric contractions are important in those activities which require strength in fixed positions, eg. some gym events,
windsurfing, rock climbing.
Movement or exercise
Muscle
Type of Contraction
Structure of Muscle Tissue
A). Muscle:
Consists of bundles of muscle cells, connective tissues, nerves, and blood supply.
B). Fascicle:
Consists of muscle cells separated by connective tissue.
C). Muscle Fiber: Cell
Elongated, multinucleated cell with a striated appearance.
sarcolemma = plasma membrane
D). Myofibril: Organelle
Complex organelle that has contractile abilitiy
E). Sarcomere: Contractile unit
How Does the Cardiorespiratory System Respond to Movement?
Circulation
Circulation occurs when the blood flows constantly around the body from the heart to the cells and then returns to the
heart. The continual and fresh supply of oxygen and nutrients which the tissues of the body require is provided by the
blood.
When you breathe in oxygen (which is carried in your blood), your lungs and air passages allow oxygen to be transported
first to the heart, then to the muscles and other important organs. At the same time, this system removes carbon dioxide
and other waste products from the blood via the lungs, where it is exhaled.
The structures which blood flows through belong to the circulatory system. (Cardiovascular system)
The Circulatory System consists of:

Blood

The Heart

Blood vessels (arteries, capillaries and veins)
The Respiratory System is also part of the circulatory system.
The lungs are part of the blood vessel network as they consist of arteries, capillaries and veins.
Respiration involves the following:
When oxygen is breathed in, the lungs and air passages provide the system with oxygen to be transported to the heart muscles - other important organs. At the same time this system removes carbon dioxide and other waste products from
the blood via the lungs where it is exhaled.
The efficiency of the circulatory system can be affected by many factors:- regular physical activity can improve its
efficiency, while illness can decrease its efficiency.
Components of Blood
Complex liquid that flows through the blood vessels that makes up the circulatory system

Thicker than water

Makes up approximately 8% of total body weight
Male (average size) ------5-6 litres of blood in their body
Females---------------------4-5 litres of blood in their body
The main functions of blood are:1. Protects the body against blood loss through clotting
2. Protects the body against germs that cause infection
3. Regulated normal body temperature through cooling and heating of its water content.
4. Transports oxygen from the lungs to tissues throughout the body and removes carbon dioxide from cells to the
lungs; it also transports important nutrients, waste products and hormones through the body.
Blood is made up of a liquid component called plasma (55%) and a solid component of red and white blood cells and
platelets (45%). The components of blood are:-
Red blood cells (Erythrocytes)
Contain haemoglobin (red pigment which gives blood its red colour)

 Haemoglobin combines with oxygen and carries it to
muscles and other cells of the body; it also carries
some Carbon dioxide which is transported to the
lungs where it is released and exhaled
 Red blood cells (Erythrocytes) out number White
blood cells (Leukocytes) by about 700 to 1.
White blood cells (Leukocytes)
 Important in the body’s defence against infection
Platelets
 Responsible for blood clotting and repair of slightly
damaged blood vessels
Plasma
 Yellow coloured liquid
 What remains when red and white blood cells are removed from the blood
 Made up of water (90%); nutrients; enzymes and hormones, such as testosterone and oestrogen; fibrinogen (a
special protein which plays an essential role in the process of blood clotting); waste products; electrolytes such as
sodium and potassium.
Structure and Function of the Heart, Arteries, Veins, Capillaries and
Pulmonary Circulation
Transport vessels (arteries, veins and capillaries) carry blood from
the________, around the body and return it to the heart.
The right side of the heart receives ____________ blood from all
parts of the body and pumps it to the________. The circuit of blood
to and from the lungs is called pulmonary circulation.
The left side of the heart receives oxygenated blood from the lungs
and pumps it around the________. The circuit of blood to and from
the body is called systemic circulation
Deoxygenated blood –
blood without oxygen and with carbon dioxide
Oxygenated blood –
blood with oxygen
1. Circulation of blood: (starting at right atrium)
right _______ receives deoxygenated blood from the body
2. Right ventricle receives blood from the right atrium and pumps
this blood to the lungs through the _____________ arteries.
3. While in the lungs deoxygenated blood passes through the
pulmonary artery into the ___________ where the blood gives
up _________________ and takes up __________
4. Oxygenated blood is returned from the pulmonary _______ in
the lungs to the left atrium
5. Left ____________ receives blood from the left atrium and
pumps this into the __________ and then the arteries
6. Oxygenated blood flows to all extremities of the body through
arteries, then_____________.
7. Blood enters capillaries where oxygen and nutrients are given
up to the _______ and carbon dioxide and other ________ products are removed from the cells
8. Capillaries carry deoxygenated blood to the venules, then ______ and finally to the superior and _______ vena cava
(superior vena cava - vein which transports blood from the upper body, head and arms; inferior vena cava - vein
which transports blood from the lower body)
9. Vena cava return deoxygenated blood from the body
to the ________ atrium
One complete __________ (aka the cardiac cycle)
requires the blood to enter and leave the heart
_________ - once on the right side and once on the left.
In a normal heartbeat the 2 atria ________ while the 2
ventricles relax. Then when the 2 ventricles contract the
2 atria relax
As blood ______ both atria, it empties from the
ventricles, then the atria contract the force blood into
the__________. The atria then relax and fill with blood
from the_________. At the same time the ventricles
contract forcing blood into the__________. This cycle is
then repeated.
body
vein
waste
ventricles
pulmonary
arterioles
veins
deoxygenated
ventricle
right
atrium
arteries
cells
fills
carbon dioxide
aorta
heart
contract
twice
capillaries
heartbeat
lungs
oxygen
inferior
veins
Label these diagrams with as much detail as you can. Make sure you indicate the direction of the blood flow and label or
major veins and arteries and where they are either taking to blood to or bringing it in from.
The Heart
The heart is a _________ which acts as a pump to push blood through the body.
It is held in place in the ________ cavity by the pericardium. It lies between the _______ and above the diaphragm, and
is protected by the ribs and__________. The ______________ is like a plastic bag which covers and protects the heart.
The heart beats about 70 times per minute at rest; this amounts to about 12000 litres of _______ a day
The heart has 4 _____________
The top 2 chambers - right and left______: separated by a thin wall; each atrium receives blood coming back to the heart
The bottom 2 chambers - right and left ventricles: separated by a thick wall called the__________: both ventricles pump
blood out of the heart to the body.
Ventricle walls are thicker than the atria walls because of their stronger action when pumping blood away from the heart.
The wall surrounding the left ventricle is the ____________because it is responsible for pumping blood to the extremities
of the body.








Bicuspid (mitral) valve is found between the left atrium and left ventricle
Tricuspid valve is found between the right atrium and right ventricle
These valves prevent blood from flowing back (backflow) from the ventricle into the atrium
Each atrium receives blood coming back to the heart and each ventricle pumps blood out of the heart
Right atrium receives deoxygenated blood from the 2 major veins - the inferior and superior vena cava
Left atrium receives oxygenated blood from the pulmonary veins
Right ventricle sends deoxygenated blood to the lungs through the pulmonary artery
Left ventricle sends oxygenated blood to the extremities of the body through the main artery of the body called the
aorta
 The heart and direction of blood flow:
thickest
pericardium
septum
chest
sternum
chambers
muscle
atriums
lungs
blood
Arteries, Veins and Capillaries
Arteries carry oxygenated blood away from the heart
The aorta and the pulmonary artery are the major arteries leading from the heart. These branch into smaller arteries
which branch into even smaller arterioles which branch into even smaller capillaries.
Draw labelled diagrams in the spaces below each to show the above info:
The aorta is the major artery carrying blood filled with oxygen from the left ventricle to the body
The pulmonary artery carries blood from the right ventricle to the lungs to collect oxygen
 Capillaries are the link between the arterioles and veins. Capillaries allow the exchange of oxygen, carbon dioxide,
nutrients, hormones and waste products between the blood and specific tissues. Capillaries rejoin to form tiny
venules.
 Venules collect deoxygenated blood from the capillaries and transfer it to the veins. The veins rejoin to form the larger
superior vena cava and inferior vena cava which both carry this blood back to the right side of the heart.
 Arteries, capillaries and veins lead into and out of the following areas:- heart, lungs, head and neck, upper limbs,
thoracic and abdominal wall, liver, gastrointestinal tract, pelvis, lower limbs
Resting heart rates (HR)
Heart rate refers to the number of times the heart beats per___________; measured by taking a pulse reading where an
___________ lies near the surface of the skin - carotid (neck), radial (thumb side of wrist), brachial (inside armpit),
temporal (just above eye), ___________ (groin); usually taken with the first 2 fingers, as the _________has its own pulse.
__________ HR is approximately 70 bpm (beats per minute); children have a higher heart rate than________, with
infants having an average rate of 120 bpm; _________ athletes can be as low as 40 bpm.
Maximal HR is the maximum amount that your HR should increase to when exercising. Above this could be dangerous;
decreases with age; Max HR = 220 - AGE
Influences on resting HR:








____________ - increases HR; lowers resting HR
Eating - HR is raised after __________
Body position - moving from a lying to a ___________ position can increase HR by 12 bpm
Emotional stress - fear or excitement increases HR similar to the response to exercise
Gender- resting HR of adult __________ can be 5-10 beats faster than adult males
Age - resting HR increases with age; maximal HR decreases with age
Laughing - increases HR
___________ - increases HR
Effect of exercise on the heart:
 HR increases quickly —-> continues to rise —> reaches a plateau / or levels off
 The time it takes for it plateau will depend on the ____________ of effort
 2-3 minutes straight after exercise, HR ____________ rapidly ---> declines more slowly
 Decline is determined by the intensity and duration of the completed exercise
 Direct, linear relationship between intensity of exercise and HR; greater the intensity, higher the HR
 As ___________ improves HR usually reduces for the same intensity of exercise
 Training decreases resting HR
##Based on what you know draw a graph of a Heart rate during and after exercise. HR x Time y
females
decreases
Resting
artery
standing
trained
Smoking
femoral
Exercise
minute
meals
adults
fitness
thumb
intensity
Blood Pressure
Measures the amount of pressure on the artery walls by the blood as it is pumped by the heart
 Flow and pressure of blood in the arteries rises with each contraction of the
heart and falls when it relaxes and refills; hence, it has 2 phases - systolic and
diastolic
 Reflects the quantity of blood being pushed out of the heart (cardiac output) and
the ease or difficulty of how blood passes through the arteries
 Usually greatest as the heart beats (blood is pushed away from the heart) and
weakest as the heart relaxes and the chambers refill with blood
 Measured at the time of greatest pressure (systolic pressure / contraction
phase) and weakest pressure (diastolic pressure / relaxation phase)
 Varies in response to posture (lying or standing), breathing, emotions, exercise,
sleep; temporary rises due to excitement, stress or physical activity are normal
and BP returns to normal with rest.
Blood Pressure and Exercise
During exercise BP increases as a result of an increase in cardiac output; BP increase is mostly due to an increase in the
systolic pressure; there is also an increase in the diameter of the arterioles supplying blood to the working muscles -—>
a decrease in resistance in the arteries and blood will drain into the capillaries: this reduces any real change to diastolic
pressure.
Over time, exercise has been shown to reduce BP in many people who have been diagnosed with hypertension
Systolic:“The highest pressure recorded when blood is forced into the arteries
during contraction of the left ventricle.”
Diastolic:“The minimum pressure recorded when heart is relaxing and filling.”
Measuring Blood Pressure
Measured using a sphygmomanometer and a stethoscope;
-expressed as systolic over diastolic, mm of mercury (mm Hg);
-acceptable range is 120 / 80 (+ or -10)
~BP = Svstolic 120 mm Hg ± 10mm Hg
Diastolic 80 mm Hg ± 10 mm Hg
Inflatable cuff is attached to a gauge which records the pressure in the cuff; cuff is firmly wrapped around the upper arm
above the elbow. It is inflated with a hand pump. This squeezes the artery under the cuff until the blood flow stops.
The stethoscope is placed over the artery just below the cuff at the elbow; cuff pressure is carefully released while
watching the slowly falling mercury in the gauge; a thudding sound is heard with each heartbeat as the blood returns to
the artery past the cuff; 2 very distinct sounds are also heard
1st sound - the peak of blood pressure; systolic blood pressure reading; note the position in the gauge.
-air continues to be released from the cuff until blood flow returns to the artery and the thudding sounds can no longer be
heard
2nd sound - the lowest pressure within the artery; diastolic blood pressure reading; note the position in the gauge when
the sounds disappear.
Sphygmomanometer:-
Blood Pressure and Health
Low BP
<110 / 70
Healthy BP
110-130 /
70-90
High BP
130-160 /
90-95
Hypertension
>160 / >95
Respiration
Structure and function of the respiratory system (bronchi, bronchioles, lungs, alveoli)
Cardiorespiratory system =
Cardiovascular system
(Heart and blood vessels)
and
Respiratory system
(Lungs and air passages)
Functions of the respiratory system:- responsible for the uptake of oxygen and transfer of this oxygen into the blood.
Removal of carbon dioxide and other waste products from the body.
Can be divided into 2 sections which take the form of an upside down tree
Base of the tree - nose / nasal cavity and mouth where air is drawn from the atmosphere down into the pharynx (throat),
past the larynx (voice box), and into the trachea (windpipe)
Trachea acts like an air filler and is lined with cilia (liny hairs) and mucus (fluid), which help catch and move foreign
particles away from the lungs.
Branches of the tree - the trachea branches to the right and left bronchus and air moves through each bronchus into the
lungs.
There are 2 lungs, one on the right side and left side of the chest cavity: protected by the ribcage and are separated by
the heart, blood vessels and the oesophagus (food passage); diaphragm (muscle) separates the lungs from the stomach
Once in the lungs the air moves into smaller and smaller bronchi and then into even smaller branches called
bronchioles (these form the internal structure of the lungs): air moves from the bronchioles into tiny air sacs called
alveolar sacs and into smaller air sacs called alveoli (very ends of the bronchioles covered in capillaries; have the
appearance of grapes)
Oxygen is transferred in the capillaries and exchanged for carbon dioxide; oxygen is then returned to the heart
and carbon dioxide is exhaled.
Total surface area of alveoli = 1 m2 / kg of body weight, eg. 65 kg person = 65m2 in of alveoli surface area (nearly 1/2 a
tennis court)
Lung Function
Inspiration- air moves in
Expiration- air moves out
Lung ventilation
At rest about 6 litres of air is ventilated per minute we breathe about 12 to 18 breaths per minute
Physical activity increases ventilation due to the increase in demand for oxygen by working muscles and the need for
carbon dioxide to be removed from the body.
Exchange of gases
The exchange of oxygen and carbon dioxide occurs in the capillaries
within the alveoli: caused by the differences in concentration of
oxygen and carbon dioxide between the blood and the air; gases
move from high to low concentration areas. called ____________
The air (inspiration) that arrives in the alveoli has a high concentration
of oxygen and a low concentration of carbon dioxide: blood that
arrives in the capillaries of the alveoli has a high concentration of
carbon dioxide and a low concentration of oxygen -—> carbon
dioxide moves from the blood into the alveoli to be exhaled and the
oxygen moves into the blood where it is returned to the heart.
In muscle the process is reversed: the muscle fibres are covered by
capillaries which are low in oxygen and high in carbon dioxide: the
capillaries are high in oxygen and low in carbon dioxide -—> oxygen
moves into the muscles and carbon dioxide is transported to the
lungs to be exhaled.
Immediate effect of exercise on respiration
Ventilation increases slightly before exercise begins: possibly due to
the expectation of exercise <—-lungs being stimulated by the brain.
During exercise there is a rapid increase in ventilation within a few
seconds of starting
If exercise is not performed at a maximal level (sub maximal) the rise
in ventilation levels off
If exercise is performed at maximal level ventilation will continue to
rise until exercise is stopped
When exercise is stopped there is a sudden decrease in ventilation, followed by a further gradual decrease until resting
ventilation is reached.
Draw a graph that indicates the effect of exercise on respiration in the box below.
Label the graph. Explain what this graph means.