chapter 1b Flashcards
What is the trachea?
Windpipe, carries air from the mouth and nose to the lungs
What are the lungs?
Pair of large, spongy organs optimised for gas exchange between our blood and the air
What is the bronchi?
tube leading from trachea to each lung, carry air
What are bronchioles?
Airways in the lungs that lead air from the bronchi to the alveoli.
What is the alveoli?
Many tiny air sacs in the lungs which allow for rapid gas exchange
What is alveoli surrounded by?
network of capillaries
What is gaseous exchange?
The delivery of oxygen from the lungs to the bloodstream, and the elimination of carbon dioxide from the bloodstream to the lungs. Takes place by diffusion, CO2 and O2 move down a concentration gradient from a high to low concentration. O2has a high concentration in the alveoli, so diffuses into the capillaries (forms oxyhemoglobin) . CO2 has a high concentration in the capillaries, so diffuses into the alveoli
What structured does air pass through as it moves from the mouth to the alveoli?
Trachea, bronchi, bronchioles
What is the function of cilia?
Catch particles or dust, which are then removed by coughing
keeps trachea open
What is haemoglobin?
a globular protein which is an oxygen-carrying pigment found in red blood cells, makes the blood red. Haemoglobin is a two-way respiratory carrier, transporting oxygen from the lungs to the tissues and facilitating the return transport of carbon dioxide
What is oxyhaemoglobin?
A chemical formed when haemoglobin bonds to oxygen
Define inspiration
intake of air into lungs, caused by increasing volume of chest cavity
Define expiration
expulsion of air from lungs, caused by reducing volume of chest cavity
What are the pectoral and sternocleidomastoid muscles?
The muscles which help increase the size of the chest cavity, allowing more air to enter during respiration
What are the abdominal muscles?
The muscles which help force air out of the lungs and so speed up expiration
What is tidal volume?
The volume of air breathed in (or out) during a normal breath at rest rate
What is inspiratory reserve volume?
The additional air that can be forcibly inhaled after the inspiration of a normal tidal volume
What is expiratory reserve volume?
The additional air that can exhaled after the expiration of a normal tidal volume
What is residual volume?
the volume of air that remains in the lungs after maximal expiration
What is the pathway of air?
nose/mouth, trachea, bronchi, bronchioles, alveoli/capillaries, lungs, blood
What factors help the process of diffusion?
-the alveoli are very small, large SA for the exchange of gas
- the surface of alveoli and walks of capillaries are very thin, also helps with gas exchange
- alveoli and capillaries are touching each other, short distance for diffusion
- each alveolus is surrounded by a network of blood capillaries, rich supply of gas and blood to diffuse into/from
Name the breathing muscles
diaphragm, external intercostals, internal intercostals
name the breathing muscles used to expire air during exercise
Abdominals
name the breathing muscles used to inspire air during exercise
pectorals and sternocleidomastoid muscles
How is air expired during rest?
the diaphragm and intercostals relax and the chest cavity returns to its normal/resting size
What is a spirometer?
instrument used to measure respiratory volumes and lung capacities
Which lung volume is used to increase the amount of air breathed in?
inspiratory reserve volume
What is the name of the amount of air left in the lungs after a full expiration?
residual volume
Define artery
Artery- blood vessel carrying blood away from the heart, blood is at highest pressure here, elastic and have a pulse (stretch as blood surges through and then return to normal, shape)
Define vein
a blood vessel that returns blood to the heart, contain valves to prevent back flow of blood, no pulse
Define capillaries
Very thin blood vessels with thin walls, allow gas exchange to happen and link arteries and veins
What is vasoconstriction?
Reducing the diameter of small arteries to reduce blood flow to tissues
What is vasodilation?
Increasing the diameter of small arteries to increase blood flow to tissues
What is the function of elastic tissue in arteries?
Recoil/return to shape and maintain blood pressure
Why are capillaries thin walled?
allow diffusion
Define atria
Upper chambers of the heart that collect blood from the veins
Define ventricles
Lower chambers of the heart which pump blood out of the heart to the arteries
Define cardiac cycle
Sequence of events when the heart beats
Define diastole
Term used to describe the relaxation phase of the cardiac cycld
Define systole
Term used to describe the contraction phase of the cardiac cycel
What happens in the diastole?
ventricles relax and fill with blood
What happens in the systole?
ventricles contract and blood pumps to the arteries
Describe what happens in the cardiac cycle
- Ventricles relax, atria contract-blood flows to ventricles so ventricular pressure increases
- Ventricles contract, atria relax-ventricular pressure increases further, AV (atrioventricular) valves close, SL valves open + blood forced out into arteries
- Ventricles relax, atria relax-SL valves close, atria start to fill + atrial pressure increases until AV valves open so blood flows passively into ventricles REPEAT
What is cardiac output?
Volume of blood ejected by the heart per min
What is cardiac output formula?
Cardiac output = heart rate x stroke volume
How can heart rate be increased?
Usually increases before exercise due to the expectation of exercise (anticipatory rise)
How can stroke volume be increased?
By the heart contracting with more force and so pushing more blood out with each beat
What is the function of the heart (atrioventricular) valves?
prevent backflow of blood
Describe the passage of blood from the right atrium to the lungs
From right atrium; through atrioventricular valve; to right ventricle; systole; through pulmonary artery to lungs.
Describe the passage of blood from the lungs to the left ventricle
From lungs through pulmonary veins; into left atrium; through atrioventricular valves; to left ventricle.
What is stroke volume?
Volume of blood leaving the heart per beat
