cardiac and respiration Flashcards
what is meant by ‘breathing’
Physical process of inhalation
describe the process of inspiration/inhalation
External intercostals contract –> ribcage moves up and out
Diaphragm contracts and flattens
Volume of thoracic cavity increases
- Lungs inflate, increasing volume in the lungs
- Therefore decreasing pressure
- Air travels from H-L pressure into the lungs
describe the process of expiration/exhalation
Internal intercostals contract –> ribcage moves down and in
Diaphragm relaxes and forms a dome shape
Volume of thoracic cavity decreases
- Lungs deflate, decreasing volume in the lungs
- Therefore increasing pressure
- Air travels from HL pressure out of the lungs
explain the structure of the lungs
Covered by the pleural membrane
The inner layer is attached to the lungs and the outer layer attached to the thoracic cavity
Between the 2 layers is the pleural fluid
It’s attached to the thoracic cavity and reduces friction, protects them as we breathe
explain the structure and function of the nasal cavity
Divides into 2 sides, each side has 3 shelves
Contains chemo receptors
Cilia hairs filter. Blood capillaries warms. Mucous moistens.
what is the function of the larynx
Allows for speech, vocal cords vibrate to make sound.
explain the structure and function of the trachea
Made of c-shaped bands of cartilage that give flexibility and support
Lined with mucous membrane and cells with cilia to trap any solid particles
Cilia beat to move mucous and trapped particles upwards
explain the structure and function of the bronchi
Pass air from the trachea into each lung.
Contains cartilage rings and a ciliated mucus membrane
Two bronchi branch from the trachea, one left and one right
explain the structure and function of the bronchioles
Very fine tubes that pass air from bronchi to alveoli.
End in tiny air sacs, the alveoli.
explain the structure and function of the alveoli
Tiny air sacs at the end of bronchioles
Site of gas exchange
On the outside of an alveolus is a dense network of blood capillaries
One cell layer thick
Cells are moist to increase the rate of diffusion
The huge surface area allows efficient exchange of gasses
define gas exchange
Process of oxygen diffusing from the alveoli into the blood and carbon dioxide diffusing from the blood into the alveoli in the lungs.
explain the process of gas exchange
Deoxygenated blood comes from the heart via pulmonary artery. There is a high concentration of C02 in the blood capillaries and a low concentration in the alveolus.
Inspired air in the alveolus contains a high concentration of oxygen, and low in the blood capillaries.
Via the process of diffusion carbon dioxide moves from the capillaries (high concentration) to the alveolus (low concentration).
O2 moves from the Alveolus (high concentration) to the blood capillaries (low concentration).
Oxygenated blood in the capillaries returns to the heart via pulmonary veins.
C02 in the alveolus is expired.
why are the lungs well suited to the process of gas exchange
- Alveoli give the lungs a huge internal surface area, so large amounts of gas can be exchanged more efficiently and quickly
- Each alveolus is well supplied kwith blood vessels, so that as much blood as possible is close to air
- Alveoli and capillary cell walls are 1 cell thick, so molecules don’t have to travel far when moving in or out of the blood
- Lung volume can be changed by movements of respiratory muscles, so air is made to flow in and out of the lungs
list 2 disorders of the respiratory system
emphysema
asthma
explain what emphysema is
Caused by long term exposure to irritating particles in the air taken into the lungs
Irritating particles cause damage to alveoli
They lose elasticity and are replaced with fibrous tissue and may break down, reducing surface area for gas exchange
Lungs become constantly inflated and breathing out is a voluntary effort
Symptoms: frequent coughing/wheezing, cough produces mucous, tightness in chest, shortness in breath especially in physical activity
Treatment: cannot be cured, once lung damage begins progression of disease cannot be stopped
explain what asthma is
Difficulty breathing caused by narrowing of airways
Occurs due to: smooth muscles contracting: blocking airways, mucous filling airway, narrowing the tube
Triggers include: respiratory infections, cigarette smoke, allergens e.g. dust, pollen and animals
During asthma attack muscles surrounding the bronchi spasm and cause narrowing of air passages, therefore difficult breathing
Irritation of membrane lining passage secretes excess mucous, restricting movement of air
Gas exchange is reduced and blood doesn’t carry normal amount of oxygen
Symptoms: difficulty breathing, severe chest pain, coughing and wheezing
Treatment: bronchodilator, inhaler, anti-inflammatory medication
explain the carrying of oxygen gas
3% is dissolved in blood (plasma)
97& dissolved in oxyhaemoglobin
- At the alveoli oxygen enters into RBCs and attatches to
the ‘haem’ part of the haemoglobin molecule - At the cells oxygen breaks off the haemoglobin
molecule and enters fluid outside of the cell, the moves
into the cell
explain the carrying of carbon dioxide gas
8% dissolved in blood (plasma)
22% dissolved in the ‘globin’ part of haemoglobin in RBCs
- At the cells 22% of CO2 attached to the globin part of
the haemoglobin molecule - At the alveoli CO2 breaks away and moves into the
alveoli to be exhaled
70% converted into bicarbonate ions
- CO2 diffuses out of cell and react with water around
the cell to form carbonic acid
- Carbonic acid ionises to produce H+ ions and HCO3-
ions
- At the alveoli this reaction reverses
what is the chemical equation for the conversion of carbon dioxide gas into bicarbonate ions
CO2 + H2O (double arrow) H2CO3 (double arrow) H+ + HCO-3
what are the functions of the circulatory system
Body’s main transport system
Link between cellular requirement inside the body and outside environment that supplies these requirements
Blood is the transport link between cells and all the body systems
Some important functions of blood are:
- Transporting oxygen, nutrients and hormones to cells
- Transporting carbon dioxide and waste away from cells
- Maintaining pH and water & ion concentration of body
fluids
- Distribution of heat and maintaining body temperature
explain the structure of the heart
Pump that pushes blood around the body
Located between the lungs in the mediastinum & behind and slightly to the left of the sternum
Conical shape approximately 12 cm long, 9 cm at its widest and 6 cm wide
It is enclosed in the pericardium (its membrane)
Wall of heart is made of cardiac muscle
Right side: collects deoxygenated blood from the body and pumps it to the lungs
Left side: collects oxygenate blood from the lungs and pumps it around the body
Each side is separated into 2 chambers: atria & ventricles
what is the purpose of the pericardium
- Holds heart in place
- Allows for movement
- Prevents overstretching
explain the structure, function and percentage composition of red blood cells in blood
composition in blood: 45%
Biconcave disc shape
No nuclei: more room to carry haemoglobin that binds with oxygen
Flexible: fit through capillaries
Carry oxygen, bound to the protein haemoglobin
Live for approximately 120 days
Produced in red bone marrow
destroyed in liver and spleen
explain the structure, function and percentage composition of white blood cells in blood
composition: <1%
Larger than RBC but fewer
2 types:
- Granulocytes: granular cytoplasm and spherical
nucleus
- Monocytes and lymphocytes: agranular cytoplasm and
spherical nucleus
Able to change shape
Removes dead/injured cells and invading organisms/pathogens
