Respiratory System Flashcards
(8 cards)
STRUCTURE OF THE RESPIRATORY SYSTEM
Nasal Cavity- Air enters the body through the nose when we breathe in.
Mouth- Air enters the body through the mouth when we breathe in.
Trachea- This is the tube that carries air from the mouth/nose down into the lungs
Rings of cartilage within the walls of the trachea ensure that it remains open to allow air movement.
Bronchus- A pair of smaller tubes that branch from the trachea, allowing air to travel between the trachea and the lungs.
Bronchioles- Smaller tubes that branch from the bronchi, carrying air into the alveoli.
Alveoli- Tiny air sacs located at the end of the bronchioles
Gases are exchanged here between the air and the blood.
Lungs- The network of organs and tissues that allow you to breathe.
Diaphragm- A muscle that helps you inhale and exhale.
FUNCTIONS OF THE RESPIRATORY SYSTEM
Inspiration (breathing in)- The diaphragm contracts and moves downwards. The intercostal muscles contract and move the ribs upwards and outwards. This increases the size of the chest and decreases the air pressure inside it which sucks air into the lungs.
When exercise begins, inspiration can be assisted by the pectoral muscles and the sternocleidomastoid which help to lift the ribs up and out even further.
Expiration (breathing out)-The diaphragm relaxes and moves back to its domed shape. The intercostal muscles relax so the ribs move inwards and downwards under their own weight. This decreases the size of the chest and increases the air pressure in the chest so air is forced out of the lungs.
During exercise, this passive process of relaxation becomes active as the abdominal muscles pull the ribs downwards and inwards even further.
Function of Gaseous Exchange
Gaseous Exchange- Gaseous exchange occurs at the alveoli in the lungs and takes place by diffusion. The alveoli are surrounded by capillaries so oxygen and carbon dioxide diffuse between the air in the alveoli and the blood in the capillaries.
Diffusion is the movement of gas from an area of high concentration to an area of low concentration.
There is a high concentration of oxygen in the alveoli and a low concentration of oxygen in the blood, so oxygen diffuses from the alveoli into the blood.
There is a high concentration of carbon dioxide in the blood and a low concentration in the alveoli, so carbon dioxide diffuses from the blood into the alveoli.
LUNG VOLUMES
Total Lung Volume- The total amount of air that the lungs can hold after the biggest possible breath in. Residual Volume- The volume of air remaining in the lungs after maximum forceful expiration.
Inspiratory Reserve Volume- The maximum amount of additional air that can be taken into the lungs after a normal breath.
Respiratory Rate- The number of breaths taken per minute. It increases as soon as we start exercise in order to get more oxygen in.
Vital Capacity- The maximum amount of air that can be breathed out after breathing in as much air as possible.
Tidal Volume- The amount of air breathed in with each normal breath.
Expiratory Reserve Volume- The maximum amount of additional air that can be forced out of the lungs after a normal breath.
Minute Volume- The amount or volume of air inspired or expired in one minute.
SHORT TERM EFFECTS OF EXERCISE ON THE RESPIRATORY SYSTEM (Responses)
Increased Breathing Rate During exercise your muscles demand more oxygen (aerobic energy system). You also produce more carbon dioxide- this stimulates faster and deeper breathing. At the start of exercise there is an immediate and significant increase in breathing rate. After several minutes of aerobic exercise breathing continues to rise but at a slower rate and it levels off if the exercise intensity remains constant. Increased Tidal Volume This increases to allow more air to pass through the lungs removing waste products helping to keep up with the demands placed on the body. During strenuous exercise tidal volume can increase by three times its resting level. Because minute ventilation depends on breathing rate and tidal volume this can increase by approximately 15 times its resting values.
LONG TERM EFFECTS OF EXERCISE ON THE RESPIRATORY SYSTEM (Adaptions)
Increased Vital Capacity As an adaptation to long term exercise your respiratory muscles are stronger and therefore can forcibly inhale and exhale more air per breath. This will give working muscles more oxygen needed to perform well. Increased Strength Of Respiratory Muscles The diaphragm and intercoastal muscles increase in strength which allows greater expansion of the chest cavity. This means it is easier to take deeper breaths drawing more air into the body. Increased In Oxygen And Carbon Dioxide Diffusion Your respiratory system adapts to training and becomes more efficient at diffusion across the membranes. This means you can train for longer and harder as your muscles will be supplied with more oxygen.
RESPIRATORY SYSTEM ISSUES
Asthma- Asthma is a common lung condition that causes occasional breathing difficulties. It is caused by inflammation, narrowed and muscles tighten around the airways. This makes it harder for air to flow out of your airways when you breathe out.
Altitude and partial pressure- The percentage of oxygen in inspired air is constant at different altitudes, the fall in atmospheric pressure at higher altitude decreases the partial pressure of inspired oxygen and hence the driving pressure for gas exchange in the lungs.
CONTROL OF BREATHING
Medulla Oblongata-Medulla Oblongata sends a message to the respiratory control centre. This made up of expiratory control centre (dorsal respiratory group) Inspiratory control centre (ventral respiratory group).
Sensory Receptors- Detect change in internal environments and operate through the autonomic nervous system. Chemoreceptors- Present throughout the body to detect changes in levels of chemicals such as carbon dioxide for respiration. Thermoreceptors- Present in all tissues to detect temperature changes. Baroreceptors- Found mainly in the walls of the arteries to detect changes in blood pressure.
Proprioceptors- Found in muscles and tendons to detect changes in body position.
