Chapter 3 (the cardiovascular and respiratory systems) Flashcards
1
Q
Aerobic
A
a process taking place in the presence of oxygen
2
Q
Anaerobic
A
a process taking place with insufficient oxygen
3
Q
Deoxygenated blood
A
blood depleted of oxygen
4
Q
Oxygentaded blood
A
Blood saturated/loaded with oxygen
5
Q
Function of the Respiratory system
A
Takes in oxygen and removes the carbon dioxide
6
Q
function of the Heart
A
receives blood from the lungs and acting as a double pump forces the blood around vascular system to the lungs and body tissues/ muscles
7
Q
The function of the vascular system
A
Blood and blood vessels which transport and direct oxygen and carbon dioxide to and from the lungs, heart and body (body tissue/muscles)
8
Q
Blood
A
Blood carries all the vital ingredients needed for muscle growth. blood accounts for approximately 8% of total body weight
9
Q
What is blood made up of?
A
Blood is made up of blood cells and platelets floating in plasma.
10
Q
Plasma
A
Plasma= 55% of blood volume 90% of which is water.
Dissolved in plasma we may find; salt, glucose, fatty acids, blood proteins, waste products, enzymes, hormones, gasses such Carbon dioxide and oxygen
11
Q
What are the 3 types of blood cells?
A
- Red blood cells- erythrocytes
- white blood cells- leukocytes
- Platelets
12
Q
Red blood cells
A
Biconcave disks just small enough to pass through capillary. They form about 95% of the blood cells. Their main function is to transport oxygen and carbon dioxide. They contain a protein called hemoglobin.
13
Q
Haemoglobin
A
is a protein found in red blood cells which has a high affinity for carbon monoxide, carbon dioxide and oxygen.
- can carry 4 molecules of oxygen and transport 97% of the oxygen( remaining 3% is dissolved into plasma)
- haemoglobin can also carry carbon dioxide (20% carried this way)
- highest affinity for carbon monoxide, meaning it will pick this gas up in preference to the other two.
14
Q
White blood cells
A
*less than 1% of blood volume
there are 5 different types of leukocytes. The function of the white blood cells are to protect body from bacterial viruses and foreign bodies
15
Q
Platelets
A
small cell fragments that help clot the blood. form less than 1% of blood volume,
16
Q
Blood flow through the heart
A
- superior and inferior cava- deoxygenated blood enters heart through the superior and inferior cava into the right atrium.
- Pulmonary artery- deoxygenated blood from the the right ventricle pumps the blood through the pulmonary artery to the lungs
- Pulmonary veins (x4)- oxygenated blood from the lungs enters the left atrium via the pulmonary veins
- Aorta- oxygenated blood from the left ventricle is pumped to the whole body through the aorta
17
Q
Pulmonary
A
Linked to the lungs
18
Q
The structure of the heart
A
- about the size of a clenched fist
- Lies within the Pericardial cavity
- Pericardial cavity forms part of the mediastinum which is part of the thoracic cavity
- 4 types of chambers- 2 top chambers atria, w bottom chambers- ventricles
- close to lungs the right side of heart has little work to do compared with left side
- Left side of the heart is larger
- Hear is surrounded by a closed sac called the pericardium filled with pericardial fluid.
- fluid is needed to reduce effects of friction as heart is continually moving
- heart has 3 layers; Endocardium, myocardium and epicardium
19
Q
Endocardium
A
Is the inner layer of the heart, smooth tissue to allow uninterrupted blood flow through the heart.
20
Q
Myocardium
A
Is the middle layer of the heart. cardiac muscle tissue, highly specialised, similar to skeletal muscle in appearance single nucleus, containing many mitochondria due to fatigue. cardial cells connected by intercalated discs allowing a coordinated wave of contraction to occur when heart is stimulated.
21
Q
Epicardium
A
is the outer layer of the heart, thinner layer of pericardium. made of strong fibrous tissue that helps protect the heart.
22
Q
cardiac cycle
A
events of one heart beat
23
Q
Systemic circulation
A
-is the circulation of oxygenated blood from the left ventricle to the tissue of the body and return of deoxygenated blood from the tissue of the body to the right atrium.
24
Q
Pulmonary circulation
A
is circulation of deoxygenated blood from the right ventricle to the lungs and the return of oxygenated blood from the lungs to the left atrium
25
Right side of the heart during cardiac cycle
1. deoxygenated blood flows into the right atrium from superior and inferior vena cava.
2. left and right ventricles relax - blood from atria flow into them
3. the atria contracts to ensure the ventricles are completely filled
4. the ventricles then contract aortic valves close to prevent back flow) blood pushed out of ventricles
5. blood pushed out of ventricles through the semilunar valves into aorta and pulmonary artery
6. ventricles relax semilunar valves closed, preventing back flow
7. the atria relax and fill again - process repeats.
26
Left side of the heart during cardiac cycle
1. oxygenated blood flows into the left atrium via the pulmonary vein for the lungs.
2. left and right ventricles relax - blood from atria flow into them
3. the atria contracts to ensure the ventricles are completely filled
4. the ventricles then contract aortic valves close to prevent back flow) blood pushed out of ventricles
5. blood pushed out of ventricles through the semilunar valves into aorta and pulmonary artery
6. ventricles relax semilunar valves closed, preventing back flow
7. the atria relax and fill again - process repeats.
27
Cardiac cycle
* at rest takes 0.8 seconds to complete on cycle.*
the cardiac cycle involves rhythmic contraction and relaxation of the heart muscle. the contraction phase is known as systole and takes approximately 0.3 seconds at rest. The relaxation phase is known as the diastole last roughly around 0.5 seconds at rest.
28
The conduction system of the heart
1. the muscle pump of the heart needs to make it contract
2. cardiac muscles need to create a wave-like contraction
3. this is so the atria contractract before the ventricle.
4.blood need to flow down from atria to ventricles and then up from ventricles out of aorta and pulmonary artery
5.The heart generates its own electrical impulse - cardiac impulse
6. wave of contraction is initiated by the sinoatrial node (SA node)- pacemaker in the wall of the left atrium
7. SA node controlled by autonomic nervous system atria contraction
8. impulse spreads over ventricles from the bottom (apex) of heart.
9.this achieved by atrioventricular (AV) node in the atrioventricular septum
10. impulse from the atria to AV node down a specialized bundles of nerve tissue - the bundle of his
11 impulse carried to apex of heart, specialised fibers branch into purkinje fibres
12 Purkinje fibers extend upwards and across the ventricles
29
The process of diastole and systole
Diastole:
1.Both atria fill with blood. aortic valves are closed
2. arterial blood pressure rises above ventricular pressure blood pressure.
3. rising blood pressure forces aortic valves open and blood passively pushes into both ventricles and semilunar valves are closed
Atrial systole
4.Both atria contract actively forcing the remaining blood into the ventricles Semilunar valves remain closed
Ventricular systole
5 both ventricles contract increasing ventricular pressure
6.aortic and pulmonary valves (semilunar) are forced open aortic valves closed
7. blood forced out into aorta and pulmonary artery. at res 40-50% of blood is ejected
8.Diastole of next cardiac cycle begins semilunar valves closed preventing back flow from aorta and pulmonary artery
30
Heart rate (HR)
the heart rate represents the number of times the heart ventricles beats in one minute. *average resting heart rates are 70-72 bpm's
31
How is maximal hear rate calculated?
220 - age = Max HR
32
Stroke volume
is the volume of blood ejected from ventricles each heart beat. the stroke volume is the difference in the volume of blood in the ventricle before and after ventricular contraction.Average resting sv is approximately 70 ml
33
End-diastolic volume & End-systolic volume
- (EDV)is the volume of blood in ventricles before contraction (systole) after filling. average 130 ml
- (ESV) volume of blood remaining in the ventricles after contraction (systole)
34
How to calculate stroke volume?
Stroke volume = end-diastolic volume - end-systolic
35
How can stroke volume vary?
Blood in:
1. how much blood is being returned to the heart (venous return)
2. how far the ventricles will stretch (remember muscle tissue is elastic)
Blood out:
3)the contractility of ventricles
4) the pressure in the main arteries leading from the heart
36
Heart rates response to submaximal exercise
1. adrenalin released into the body system causing anticipatory rise of heart. the sinoatrial node is stimulated to increase HR
2. increase with intensity but reaches a plateau during submaximal work, represent steady state optimal HR for meeting demand for oxygen at the specific intensity
3. Decreased rapidly immediately after exercise stops due to a decrease in the demand for oxygen from the working muscles.
4) gradually and more slowly decrease, but still remains elevated towards resting values to allow the body to recover. the oxygen debt.
37
Heart rates response to maximal exercise
1. adrenalin released into the body system causing anticipatory rise of heart. the sinoatrial node is stimulated to increase HR
2. increase as exercise intensity increases
3. increase but slow down just prior to maximal HR values are reached
4. decrease as exercise intensity decreases
5. A much slower and longer recovery towards resting values due to greater oxygen debt
38
Oxygen debt
Additional oxygen consumption during recovery above that usually required when at rest
39
Cardiac output
* Q=SV x HR
Cardiac output increases directly in line with exercise intensity
-resting values 5L/min
-Maximal values 20-40 l/min (high trained athletes)
resting/submax/max
SV= 60-80 ml/ 80 - 100(ut) 160-200ml(t)/ 100-120ml(ut)160- 200(t)
HR=70-72 bpm/100-130 bpm/ 220 - age
Q= 5l/min / 10 l/mi / 20-40 l/min
40
Cardiac output response to exercise
1.At onset of exercise q is increased bu the increase in SV & HR.
2.when exercises intensity increases 40-60% of maximal intensity sv begins to plateau.
3 any further increase in Q is due to an increase in HR
41
Cardiovascular drift
is the gradual decrease in sv and increase in the HR prolonged exercise. An increase in body temperature results in venous return. *Sweating will cause a slight decrease in blood volume
42
Cardiac control centre
(CCC)
- The medulla obligor in the brain contains the cardiac control centre, which is primary responsible for regulating heart rate via the stimulus of the sinoatrial node.
- the ccc is controlled by the autonomic nervous system (ANS), meaning that it is under involuntary control and consists of sensory and motor nerves from either the sympathetic or parasympathetic nervous system
43
What are the 3 parts to neral control?
Proprio receptors
Chemoreceptors
Baroreceptors
44
Proprio receptors
Proprio receptors are receptors found in the muscles, tendons and joints. they inform the CC that motor activity has increased
45
Chemoreceptors
Chemoreceptors are receptors which are sensitive to the chemical changes, in muscles, aorta and carotid arteries. inform the CC that lactic acid and carbon dioxide levels have increased and oxygen and ph levels have decreased.
46
Receptors
centre receptors that detect changes in the body.
47
Baroreceptors
Baroreceptors are sensitive to the stretch within the blood vessel wall, in aorta and carotid arteries. inform the CCC that blood pressure has increased
48
Sensory nerves
transmit information detected by settler towards the central nervous system (CNS), example chemoreceptors of parts pp O2 to and pp CO2 (pp = partial pressure)
49
Medulla oblongata
part of the brain (CNS) responsible for regulating respiration, heart rate and blood vessels
50
Autonomic nervous
system control bodies and voluntary internal functions
51
Motor nerves
from the central nervous system posse instructions to the body parts =, example muscles, to contract.
52
Central control centre & autonomic nervous system
CCC & ANS
sympathetic nerves Parasympathetic nerves
increase HR + SV Decrease HR
Via accelerator Via vagus nerve to:
nerve to:
SA NODE
53
Neural control during exercise
```
neural information delivered to the CCC. CCC responds by stimulating SA node via the sympathetic ns (cardiac accelerator nerve) this increases HR and SV
when exercise stops neural factors gradually reverse Info to CCC
Parasympathetic ns (vagus nerve) sends messages for SA node to decrease HR
```
54
Hormonal control
Before and during exercise adrenalin is released into the bloodstream from the adrenal glands. Adrenalin directly stimulates the sinoatrial node. this increases Heart rate and the strength of ventricular Contraction. this will therefore increase SV
55
Intrinsic control
Before and after exercise there are a number of intrinsic factors that affect control of the HR
56
What happens during exercise?
1. temperature increases
- nerve impulse speed is increased this increases Heart rate
2. Venous return increased
- this directly increases EDV and Therefore SV (starling's law
57
What happens after exercise?
1. Tempera decreases therefore HR decreases
| 2. Venous return will decrease and therefore EDV decreases as well as SV decreases (starling's law)
58
What are the two parts to the Cardiovascular system?
1.Vascular System
2 Circulatory networks:
-Pulmonary circulation
-Systemic circulatory
59
Vascular system
is where blood vessels transport oxygen and nutrients to the working muscles and transport blood to the lungs and heart. As well as transport CO2
60
Circulatory networks
1. Pulmonary circulation: deoxygenated blood leaves right ventricles. travels through the pulmonary artery to the lungs. oxygenated blood leaves the lungs via the pulmonary vein and enters the left atrium
2. Systemic circulatory : oxygenated blood leaves the left ventricles via the aorta. blood travels through a system of blood vessels; arteries and arterioles until it reaches the capillary beds at working muscles tissues or organs. once gaseous exchange has occurred, deoxygenated blood travels through the capillary beds to the venules and veins via the inferior and superior vena cava the blood enters the right atrium.
61
What makes up the blood vessel structure?
1. Arteries or Arterioles
2. capillaries
3. veins or venules
62
Arteries or Arterioles
Transport oxygenated blood away from the heart towards tissues/muscles
- 3 layers
- large middle layer of smooth muscles to allow them to vasodilate and vasoconstrict to alter their shape/size to regulate blood flow.
- Arterioles have a ring of smooth muscle surrounding the entry to the capillaries where they control blood flow. called precapillary sphincter they can vasodilate / vasoconstrict
63
capillaries
Bring blood directly in contact with the tissues where O2 and CO2 are exchanged
- 1 layer
- very thin, one-cell-thick layer allowing gaseous exchange
64
veins or venules
Transport deoxygenated blood back towards the heart
- 3 layers
- larger veins have pocket valves to prevent the back flow of blood and direct it in one direction back to the heart
- veins & venules have a much thinner muscular layer allowing them to venodilaet and vasoconstrict to lesser extent than arteries.they have a thicker outer which helps support the blood in the pocket valves
65
Venous return
the transport of blood from the capillary back to the hear(right atrium) through venules veins, superior and inferior vena cava.
66
Starling's law of heart
Stroke volume (sv) is dependent on venous return (VR)
- i.e if VR increases, SV increases
- i.e if VR decreases, SV decreases
67
Smooth muscle
is involuntary muscle with blood vessels allowing them to constrict or dilated
68
Vasodilate
arterial blood vessels widening
69
Vasoconstrict
Arterial blood vessels narrowing
70
Venodilate
venous blood vessels widening
71
venoconstrict
venous blood vessel narrowing
72
how is the Venous return maintained?What are the 5 mechanisms?
1. Pocket valves
2. Muscle pump
3. Respiratory pump
4. Smooth muscle
5. Gravity
73
Pocket valves
are one way valves, prevent backflow, direct blood towards the heart
74
Muscle pump
are veins which lie between skeletal muscle. when muscle contracts and releases this helps push or squeeze blood back to the heart
75
Respiratory pump
During exercise this is deeper and faster. this pressure change in the thorax and abdomen. pressure is increased in the abdomen, the large veins in abdomen are squeezed, helping to force blood back to heart
76
Smooth muscle
Contraction and relaxation cause the smooth muscle t squeeze blood back towards the heart (smooth muscle is the middle layer of veins)
77
Gravity
blood from upper body is aided by gravity as it returns to the heart.
78
blood pooling
- VR requires a force to push blood back to the heart
- if insufficient pressure, blood will 'sit' in pocket valves
- Feels like heavy legs: increased cardiac output sent to muscles in legs actually pools with insufficient pressure to return it to the heart.
79
What is sufficient to maintain Venous return at rest?
Pocket valves gravity and smooth muscles are sufficient to maintain venous return at rest but not sufficient enough during or immediately after exercise.
80
What is needed to maintain venous return after and during exercise?
pocket valves, gravity and additional mechanisms of skeletal and respiratory pumps must be used to maintain venous return. this is done through active cool down:
- elevated respiratory rate maintains respiratory pump -continued skeletal muscles contraction maintains muscle pump.
81
what are the impacts of venous returns on the quality of performance?
1. stalin's law, a reduce in stroke volume or cardiac output decreases oxygen transport to the working muscles, reducing the ability to contract or work anaerobically
2. Net effects: reduction on exercise intensity or muscle will work anaerobically and induce quicker muscle fatigue
3. A good venous return will speed up recovery and therefore allow performers to work and exercise for longer
82
Distribution of cardiac output (Q) at rest
At rest:
- only 15-20% of resting Q supplied to the muscles
remaining 80-85% of Q is supplied to the body's organs
83
Distribution of cardiac output (Q) during exercise
during exercise:
- 80-85% of Q is supplied to the working muscles as exercise intensity increases
- remaining 15-20% of Q is supplied to the body organs
- blood supply to the brain is maintained
84
Vasomotor control centre
Vasomotor control centre (VCC) is located in the medulla oblongata regulating the redistribution of Q by controlling the vascular shunt mechanism
-Chemoreceptors and baroreceptors stimulate the VCC
_ VCC increases or decreases the stimulation via the sympathetic nervous system either vasodilate or vasoconstrict the pre-capillary sphincters and arterioles supplying muscles and organs (Vascular shunt mechanism)
85
O2 - how is it transported?
O2:
- 97% carried within protein hemoglobin
- This is packed with Red blood cells and called oxyhaemoglobin (HbO2)
- 3% is carried within blood plasma
86
CO2 - how is it transported?
CO2:
- 70% combines with water and Red blood cells to make carbonic acid
- 33% combines with haemoglobin as carbaminohemoglobin (HbCO2)
- 7% dissolved in plasma
87
What are the effects of having a good O2 and CO2 transports?
- prolongs the duration of anaerobic and especially aerobic activity.
- Delays anaerobic thresholds
- this increases the possible intensity/ work rate for activity
- Speeds up recovery during and after exercise
88
What are the effects of a warm up?
- Increase in blood flow due to vascular shunt mechanism via:
1. Vasoconstriction of arterial + precapillary sphincters to organs. decreasing blood flow to organs
2. vasodilate of muscle arterioles + precapillary sphincters increasing blood flow delivery to working muscles
3. Increase in body temperature increasing the transport of enzymes required for energy systems and muscle contraction:
- decrease blood viscosity improving blood flow
- increase the dissociation of oxygen from heamoglobin in muscle tissue
4. decrease onset of blood lactate accumulation due to the early onset of anaerobic work when a warm up is not done
89
What are the effects of a cool down?
1. keeps metabolic activity elevated which gradually decreases HR and respiration
2. Maintains respiratory/muscle pumps which:
- prevent blood pooling
- maintains venous return
3. Maintains blood flow (SV and Q) to supply oxygen maintaining blood pressure
4. keeps capillaries dilated to flush muscles with oxygenated blood and muscle lactic acid and carbon dioxide
90
what are the impacts of smoking on O2 transport?
1. Tobacco smoke contains CO, which haemoglobin in the red blood cell will prefer over oxygen. this would reduce HbO2 association reducing maximal oxygen intake reducing good supply of oxygen to working muscles and lactic threshold will decrease .
91
Blood pressure (Bp)
blood pressure is the pressure exerted by the blood against (arterial) blood vessel walls
Bp is expressed as systolic/diastolic
average resting Bp is 120 mmHg/80 mmHg (millimeters of mercury)
92
What is used to measure blood pressure?
A sphygmomanometer
93
How else can blood pressure be expressed?
Blood press expressed as = Blood flow (Q) x Resistance
94
Systolic pressure
the force exerted by the blood on the arterial walls during ventricular contraction
95
Diastolic blood pressure
the force exerted by the blood on the arteral walls during ventricular relaxion
96
Resistance
the friction of the blood cells travelling against te blool vessel walls. this is viscosity (fluid friction)
97
How does Blood pressure alter?
arteries can vasodilate and vasoconstrict, due t smooth muscle layer. this explains how blood presure can alter. bp decreases when arteries vasodilates BP will increase when they vasoconstrict. the body regulates and controls Bp in this way but also controls Q redistribution via vascular shunt mechanism
98
Hypertension
Hypertension is a long term high Bp. treatment is normally provided if Bp exceeds 140 mmHg / 90 mmHg, but 160/95 is more commonly regarde as real hyper tension
99
Effects of Hypertension
1. hypertension affects the ability to control/ maintain a normal resting BP
2. increased workload on heart
3. accelerates atherosclerosis and arteriosus
4. arterial damage, increases risk of stroke and heart failure.
100
CHD
generic term for summarising coronary heart diseases
101
Sedentary
physical inactive lifestyle
102
What are the different common CHD?
1. Arteriosclerosis
2. Atherosclerosis
3. Angina
4. Heart attack
103
Arteriosclerosis
a loss of elasticity, thickening/ hardening of the arteries which reduces efficiency to vasodilate/ vasocontrict.
104
Atherosclerosis
is a form of Arteriosclerosis that involves change in the lining of arteries. high levels of cholesterol and fat deposits accumulate within artery walls forming fatty plaque, lumen of artery progressively narrows.
105
Angina
partial blockage of the coronary artery causing intense chest pain which occurs when inadequate O2 supply to heart muscles walls (usually small are). deprives areas of heart of o2 and blood
106
Heart attack
more severe or sudden or total restriction in O2/ blood supply to a part of the heart muscle wall. caused by blood clots from larger coronary arteries that get stuck in smaller ones, acts as a plug.
107
Respiratory system
the primary aim of the respiratory system is to supply O2 to working muscles via gaseous exchange in the lungs, to remove CO2 from blood. i.e respiratory system bring blood in contact with atmospheric air so that O2 can be taken in and CO2 removed
108
What are the # main processes linked via the heart and vascular system
1. pulmonary ventilation
2. external respiration
3. internal respiration
109
pulmonary ventilation
the breathing of air into and out of the lungs
110
external respiration
exchange of O2 and CO2 between the lungs and blood
111
internal respiration
exchange of O2 and CO2 between blood and muscle tissue
112
what are the 5 mechanics of respiration
1. muscles- actively or passively relax to cause
2. movement - of the ribs and sternum and abdomen, which causes
3. Thoracic cavity volume- to either increase or decrease, which in turn causes
4. lung air pressure- to either increase or decrease, which causes
5. inspiration or expiration- air breathed in or out.
113
Explain the process of inspiration at rest?
1. diaphragm contracts -active. external intercostals contract- active
2. diaphragm flattens/ pushed down ribs/ sternum moves up and out
3. thoracic cavity volume increases
4. lung air pressure decreases below atmospheric air (outside)
5. air rushes into lungs
114
Explain the process of inspiration during exercise
1. diaphragm contracts - external intercostals contract. sternocleidomastoid contracts pectoralis minor contract
2. diaphragm flattens with more force increased lifting of ribs and sternum
3. increased thoracic cavity volume
4. lower air pressure in lungs
5. more air rushes into lungs`
115
Explain the process of expiration at rest
1. diaphragm relaxes -passive. external intercostals relax- passive
2. diaphragm pushed upward ribs/ sternum moves in and down
3. thoracic cavity volume decreases
4. lung air pressure increases above atmospheric air (outside)
5. air rushes out of lungs
116
Explain the process of expiration during exercise
1. diaphragm relaxes - external intercostals relaxes. internal intercostals contract (active) rectus abdominus/ obliques contract (active)
2. diaphragm pushed up harder with more force ribs and sternum pulled in and down
3. greater decrease in thoracic cavity volume
4. Higher air pressure in lungs
5. more air pushed out of the lungs
117
What are the 3 volumes required to find out the respiratory volumes at rest?
1 tidal volume (TV)
2 frequency (f)
3 minute ventilation (VE)
118
tidal volume
the volume of air inspired or expired per breath - approximately 500 ml during breathing at rest
119
frequency
the number of breaths taken in one minute- approximately 12-15 breaths during breathing at rest
120
minute ventilation
the volume of air inspired or expired in one minute. VE can be calculated by multiplying the tidal volume with the frequency of breaths in one minute
121
what is the formula to find minute ventilation?
VE= TV x f
122
Pulmonary ventilation
is the breathing in and out, follows a common pathway through the respiratory structures before oxygen (o2) and carbon dioxide are exchanged in the lungs.
123
What is the advantage of breathing through your nose?
helps to moisten, filter and warm up air aided by ciliated mucus lining and blood capillaries within the walls of the respiratory structure before it enters the lungs; this improves the exchange of oxygen and carbon dioxide. From the nose the air passes through the pharynx, larynx and trachea before entering the lungs
124
Gaseous exchange
refers to the exchange of gases, namely oxygen and carbon dioxide and relies on a process called diffusion
125
Diffusion
is the movement of gases from an area of high pressure to an area of low press the difference between the high and low pressure is called the diffusion gradient
126
Diffusion gradient
the bigger the gradient the greater the diffusion and gaseous exchange that takes place
127
What is the route of air through the respiratory structure?
Air enters through the nasal/ oral cavity don through the pharynx, larynx and trachea. it then travels through to the left and right bronchi then into the bronchiole, alveoli duct, alveoli sac and finally into the alveolus.
128
Lobes of the lungs
lobes are simply divisions of each lung, the right lung has three lobes and the left two- this is to accommodate the location of the heart
the left+right bronchi branch further forming bronchioles, which branch into each lobe of the lungs. bronchioles terminate into alveoli ducts leading to alveoli sacs of grape like clusters of tiny air sacs. sacs are known as alveolus and is the actual site of gas exchange.
129
How do alveoli increase the efficiency of gas exchange?
1. formating a vast surface (half the size of a tennis courts) for gaseous exchange to take place.
2. having a single-cell layer of thin epithelial cells,reducing the distance for gas exchange with:
- moist lining of water helping to dissolve and exchange oxygen
- an extensive network of narrow alveoli capillaries producing a short diffusion path
- alveoli capillaries have a single -cell layer reducing the distance for exchange
130
Pulmonary pleura
the lungs have a pulmonary pleura, double walled sacs consisting of two membranes filled with pleural fluid which helps reduce friction between the ribs and lungs during breathing. the outer layer attaches to the ribs and the inner layer to the lungs this to make sure they move with the chest.
131
Partial pressure
is the pressure a gas exerts within a mixture of gases
132
Myoglobin
red pigment in muscles that stores and transports O2 to mitochondria within muscles
133
What are the effects on the respiratory system at altitude.
1. has a significant effect upon performance and is a recognised ergogenic training aid
2. At high altitude the pp of oxygen decreases and this has a series of knock on effects which decreases the efficiency of the respiratory process
134
Ergogenic
anything that improves performance
135
negative effects of the respiratory system due to high altitude
1. decreased oxygen in the alveoli = hypoxia
2. decrease p O2 causes a reduction in the diffusion gradient
3.decrease in O2 and Hb association (HbO@) during external respiration
4. resulting in decreased O2 transport in the blood
5 causing a reduction in the oxygen available to muscles- due to reduction in diffusion gradient
6. net effect decreased VO2 max which decreases aerobic performance and increases the onset of muscular fatigue
136
hypoxia
due to reduce PP in the atmospheric altitude
137
VO2 max
Maximal oxygen consumption
138
positive effects of the respiratory system due to high altitude
1. hypoxic conditions lead body to adapt. Erythropoietin (EPO) is released into the body in larger amounts
2. EPO stimulates RBC production + capillarisation
3. return to sea level means o2 carrying capacity has increased (VO2max) i.e aerobic performance has increased
