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251 Cards in this Set
- Front
- Back
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Function of nasal cavity? |
Traps dust, bacteria and other debris. Humidifies incoming air. Contains lysozyme to destroy bacteria. Warms incoming air. |
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Structure of nasal cavity? |
Lined by a mucous membrane. Contains lysozyme. Contains ciliated cells. Contains sensory nerve endings. Rich plexuses of blood capillaries and thin walled veins. |
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Functions of respiratory system? |
External gas exchange- oxygen and carbon dioxide are exchanged between air in alveoli and blood pH regulation- by regulating blood carbon dioxide concentration Sense of smell Voice production Aids venous and lymph return-the flow of venous blood and lymph back to the heart |
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Anatomy of respiratory system? |
Clear, open path for air to travel from the atmosphere into the lungs. Compliant (stretchy) structures move in and out to enable air movement and distribution. Large surface area in the lungs for rapid diffusion of gases into the blood. |
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Physiology of respiratory system? |
Creates pressure gradients to cause air flow. Filter and humidify air particles and entry of microbes into lungs so that airways and lungs aren't damaged. Ensure oxygen and carbon dioxide are efficiently exchanged between the atmosphere and the blood. |
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What are the air passages to the alveoli? |
Nose, pharynx, larynx, trachea, bronchi, bronchioles, alveoli |
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What is the nose divided into? |
External nose and nasal cavity |
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What is the external nose made of? |
Bone and hyaline cartilage |
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What are the external openings of the nose? |
Nostrils/nares |
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What are the nostrils bound by? |
Bound laterally by flared alae |
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How much mucus does the nasal cavity mucous membrane produce a day? |
1L |
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What does the mucus contain to destroy bacteria? |
Lysozyme |
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What is the purpose of the mucus? |
Destroys bacteria and traps dust and other debris. Also humidifies incoming air |
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What is the purpose of the ciliated cells in the nasal cavity? |
Create gentle currents that moves contaminated mucus posteriorly towards the pharynx where it is swallowed |
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What triggers sneezing? |
Sensory nerve endings are stimulated by irritating particles like dust and pollen |
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What do the blood capillaries and veins in the nasal cavity do? |
Warm incoming air |
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What is the cranial nerve for smell? |
Olfactory nerve |
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Where are olfactory sensory neurons located? |
Superior nasal cavity |
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What are the olfactory sensory neurons stimulated by? |
Odour |
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How do their axons travel to the brain? |
Travel upwards through holes in the bone |
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What is the nasal cavity divided into? |
The nostrils by a septum which is part bone and part hyaline cartilage. The nasal conchae project from the lateral wall. |
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What do the nasal conchae do? |
Increase surface area Generate turbulence to help warm, moisten and filter inspired air. |
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What are the paranasal sinuses? |
Are cavities in certain cranial and facial bones. |
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What is the function of paranasal sinuses? |
Lighten the skull Act as voice resonators Produce mucus for nasal cavity |
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How are the paranasal sinuses drained? |
By the suctioning effect of nose blowing |
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What are some homeostatic imbalances of the nasal cavity? |
Viral, bacterial infections and allergens cause inflammation of the mucous membranes of nasal cavity. Sinusitis- when infections spread to the paranasal sinuses. |
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What happens during nasal cavity inflammation from infections/allergens? |
Excess mucus production Nasal congestion Postnasal drip |
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What happens during sinusitis? |
Infectious material blocks the passageway The air is absorbed creating a vacuum This causes sinus headaches over the inflamed area. |
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What is the pharynx? |
A funnel-shaped muscular passage for food, drink and air. |
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What are the 3 parts of the pharynx? |
Nasopharynx Oropharynx Laryngopharynx |
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Where is the nasopharynx located? |
Posterior to the nasal cavity |
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What is the nasopharynx a passage for? |
Air only |
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What does the nasopharynx consist of? |
The soft palate and the pharyngeal tonsil (adenoids). The lateral wall contains the opening of the Eustachian/auditory tube |
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Function of pharyngeal tonsil? |
Trap and destroy airborne pathogens |
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Function of soft palate? |
During swallowing the soft palate moves superiorly to prevent food from entering the nasal cavity. |
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What is the oropharynx a passage for? |
Food and air |
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Where is the oropharynx located? |
Posterior to the oral cavity |
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What does the oropharynx contain? |
Pair of palatine tonsils and a lingual tonsil |
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What is the laryngopharynx a passage for? |
Food and air |
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Where is the laryngopharynx located? |
Opens in the larynx anteriorly and opens into the oesophagus posteriorly |
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What does the upper respiratory tract consist of? |
Nasal cavity and pharynx |
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What does the lower respiratory tract consist of? |
Larynx, trachea, primary bronchi, secondary bronchi, tertiary bronchi, bronchioles and alveoli |
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What happens when air passes from the laryngopharynx to the larynx? |
It leaves the upper respiratory tract and enters the lower respiratory tract |
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How many alveoli are in each lung? |
150 million |
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What is the larynx? |
A passageway which connects the laryngopharynx to the trachea. |
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What is the larynx composed of? |
9 pieces of hyaline cartilage |
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Which piece of cartilage in the larynx is the largest? |
Thyroid cartilage |
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What is the glottis? |
Consists of the vocal cords and the opening between them. |
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Function of the vocal cords? |
Vibrate to produce sound |
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What is the epiglottis? |
A flap of elastic cartilage |
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Where is the epiglottis located? |
Anchored to the anterior rim of the thyroid cartilage |
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What is the epiglottis covered with? |
Mucous membrane |
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Function of the epiglottis? |
Guards the entrance of the glottis. |
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What is the epiglottis doing during breathing? |
Held open anteriorly |
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What is the epiglottis doing when swallowing? |
It is pulled backward to close off the glottic opening |
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Functions of the larynx? |
Passage for air The epiglottis acts as a switching mechanism to prevent food and drink entering the larynx during swallowing Vocal cords produce sound Initiate a cough reflex to expel dust, food etc. which enters the larynx |
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What is a homeostatic imbalance of the larynx? |
Laryngitis- inflammation of the vocal cords. |
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What happens during laryngitis? |
The vocal cords swell, interfering with vibration. They then produce hoarse sounds or just a whisper. |
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What are the causes of laryngitis? |
Infection, overuse of voice or irritants such as cigarette smoke |
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What is the trachea? |
A tubular passage for air |
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How long is the trachea? |
12cm |
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How wide is the trachea? |
2.5cm |
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Where is the trachea located? |
Extends from the larynx in the neck and divides into the two main bronchi at mid-thorax. It is anterior to the oesophagus |
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What is the structure of the trachea? |
Consist of a mucosal lining containing ciliated pseudostratified epithelium containing goblet cells. Contains elastic tissue to make the trachea flexible. The sub-mucosal layer under this contains 16-20 c-shaped cartilage rings. |
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What is the purpose of the cilia in the trachea? |
Propels debris-laden mucus toward the pharynx |
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What is the purpose of the c-shaped rings of cartilage in the trachea? |
Provides support and keeps the trachea open so it doesn't have to be re-inflated each time air moves through it. |
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Why are the cartilage rings in the trachea c-shaped? |
They allow the trachea room for expansion |
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Which area of the trachea triggers coughing? |
The mucosa at the carina |
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Why does the carina trigger coughing? |
It is extremely sensitive and violent coughing is triggered when a foreign object touches it. |
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What does smoking do to the cilia? |
Damages and destroys the cilia |
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Why do the muscles of the trachea contract during coughing? |
To help expel mucus |
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What happens to the air by the time it reaches the end of the trachea? |
It is warm, clean from most impurities and saturated with water vapour in preparation for gas exchange |
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What are the 3 levels of the bronchi? |
Primary, secondary and tertiary |
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What is the structure of the primary bronchi? |
Rings of c-shaped cartilage, right bronchus is shorter, wider and more vertical than the left. |
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What is the structure of the secondary bronchi? |
The left lung has 2 secondary bronchi and the right lung has 3. The rings of cartilage are replaced by strips of cartilage. |
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What is the structure of tertiary bronchi? |
Contain strips of cartilage. |
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What do the secondary bronchi do? |
Supply the lobes of each lung |
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What do the tertiary bronchi do? |
Supply the segments within the lobes of each lung |
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What is the structure of the bronchioles? |
Cartilage is replaced by smooth muscle and mucus producing cells and cilia are sparse. |
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Function of the bronchioles? |
Connect the tertiary bronchi to the alveoli. Controls bronchoconstriction and bronchodilaton |
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What is the reduction or impairment to airflow through the bronchioles heard as? |
Adventitious sound |
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What are the progressive changes in the bronchi and bronchioles? |
Pseudostratified ciliated columnar epithelium is replaced by simple cuboidal epithelium in smallest bronchioles. The cartilaginous rings become more sparse and eventually disappear altogether leading into smooth muscle. |
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What happens to airborne debris at the bronchiole/alveolar level? |
Must be removed by macrophages in the alveoli |
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What does sympathetic stimulation do to the bronchioles? |
Causes bronchodilation by relaxing smooth muscle and enabling more air in through a larger airway |
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What happens during exercise? |
SNS activity increases, adrenaline release is increased and lung ventilation improves |
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What does parasympathetic stimulation do to the bronchioles? |
Causes bronchoconstriction and reduces airflow when resting or due to histamine release during allergic reactions |
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What effect does asthma have on the bronchioles? |
The bronchioles are narrowed by asthma |
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What are the effects of asthma? |
Smooth muscle spasm, excess mucus production, swelling and inflammation and wheezing |
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What is the anatomy of the lungs? |
Paired, cone-shaped organs. Separated from each other by the heart and other structures of the mediastinum. |
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Location of the lungs? |
In the mediastinum of the thoracic cavity, the apex of the lung is superior and extends slightly above the clavicle. The concave base of the lungs rests on the diaphragm |
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Which lung is smaller? |
The left lung is 10% smaller than the right. |
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What is on the mediastinal surface of each lung? |
The hilum |
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What is the hilum of the lung? |
An entry and exit point for the bronchi, blood vessels, lymphatic vessels and nerves. |
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How many lobes does each lung have? |
The left has 2 and the right has 3 |
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What are the lobes divided by? |
Deep grooves called fissures. |
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What is each lung enclosed by? |
A pleural membrane |
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Which pleura covers the lung |
Visceral pleura |
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Which pleura covers lines the wall of the thoracic cavity? |
Parietal pleura |
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What does the pleural cavity contain? |
A small amount of serous fluid |
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What is the function of the serous fluid of the pleural cavity? |
Reduces friction as they slide across one another during breathing movements and pleural fluid causes the membranes to adhere to each other |
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What is mechanical coupling? |
The pleura adheres to the chest wall and to the lung producing mechanical coupling for the two layers to move together lifting up the lung during inspiration and allow it to fall during expiration. |
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What does elasticity do? |
Reduces the work of breathing |
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What does lung tissue consist of? |
Mostly air spaces and elastic connective tissue. |
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What is the blood supply of the lungs? |
Pulmonary arteries and pulmonary veins. A low pressure, high volume circuit. All of the blood passes through the lungs-once each minute. |
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What are the pulmonary lobules? |
Each lobe of the lung has many lobules. |
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What are the lobules wrapped in? |
Elastic connective tissue |
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What do the pulmonary lobules contain? |
A lymphatic vessel, an arteriole, a venule, a terminal bronchiole, an alveolar sac consisting of alveoli |
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How many alveoli are there altogether? |
300 million |
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What do the alveoli provide? |
A very large surface area for gas exchange |
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What are the alveoli lined with? |
Simple squamous epithelium to optimise diffusion |
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What surrounds each alveolus? |
A rich supply of capillaries |
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What do some of the alveolar cells secrete? |
A fluid that keeps the alveoli moist and contains surfactant to lower surface tension |
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What is the purpose of surfactant? |
Makes breathing easier (increasing compliance) and prevents alveolar collapse |
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What do alveolar macrophages do? |
Remove particles from the alveoli. |
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Where does oxygen diffuse from? |
From an area of high oxygen concentration in the alveoli to an area of low concentration in the capillaries |
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When does diffusion work? |
Only works efficiently over short distances |
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What allows for rapid diffusion in the respiratory system? |
Thin layers between the alveoli and capillaries |
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When does gas exchange occur? |
When air from the atmosphere reaches the alveoli |
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What allows for rapid diffusion in the respiratory system? |
Thin layers between the alveoli and capillaries |
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What are 3 factors that affect the rate of airflow and ease of breathing? |
Surface tension in the alveoli Compliance of the lungs Airways resistance |
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What is surface tension? |
A thin, watery liquid film lines the surface of the alveoli and exerts a force called surface tension. |
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When does surface tension occur? |
When water and air meet |
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What does surface tension do? |
Draws the liquid molecules closer together and reduces their contact with air molecules and resists any force that tends to increase he surface area of the liquid |
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What would happen if the film was pure water? |
The alveoli would collapse inwards between breaths |
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What other substance does the film contain? |
Surfactant |
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What is surfactant? |
A detergent-like complex of lipids and proteins which reduces surface tension |
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When does surface tension occur? |
When water and air meet |
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What is the function of surfactant? |
Prevents the alveoli from collapsing Reduces the energy needed to expand the lungs during each inspiration |
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What is lung compliance? |
Is the ease with which the lungs and thoracic wall can be expanded. |
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What does high compliance do? |
Makes ventilation easier |
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What does low compliance do? |
Makes ventilation harder |
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What does lung compliance depend on? |
On the elasticity of the lung tissue and surface tension inside the alveoli |
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What do healthy lungs have in terms of compliance? |
High compliance which favours efficient ventilation and ease of breathing because lung distensibility is usually high and surfactant keeps surface tension low |
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What is airway resistance? |
The resistance to air flow in the respiratory passages |
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What is airway resistance caused by? |
By friction between the air and the air passages |
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What increases resistance? |
Obstructing the airways and/or reducing the diameter of the airways |
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What does greater resistance cause? |
More pressure and more work is required to force air through the airways |
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What is the smooth muscle in the bronchioles sensitive to? |
Neural controls |
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What does sympathetic stimulation do to the bronchioles? |
Dilated the bronchioles and decreases mucus secretion |
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What does parasympathetic stimulation do to the bronchioles? |
Constricts the bronchioles and increases mucus secretion |
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What factors make breathing easier? |
Open, unobstructed airway Minimal resistance to airflow Ability to move the diaphragm and ribs Compliant lungs Clear alveolar-capillary interface for diffusion |
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What factors cause difficulty with breathing? |
Obstruction to airflow Constriction from spasm (asthma) Injury/obstruction to diaphragm/ribs Stiff lungs (inflammation or loss of surfactant) Alveoli contain secretions/fluid (pneumonia) |
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How does air move? |
From an area of high pressure to an area of low pressure |
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How does air move into the lungs? |
When there is low pressure inside the lungs |
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How does air move out of the lungs? |
When the pressure inside the lungs is high |
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What is the best way to alter pressure? |
Change the volume |
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What does halving the volume do? |
Doubles the pressure |
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What happens to the thoracic cavity pressure when the volume is expanded? |
It decreases |
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What does it mean when the pressure of the thoracic cavity is low? |
The pressure outside the body is higher than the pressure inside the lungs. |
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What will happen when the pressure inside the lungs is lower than the pressure outside the body? |
Air will flow from an area of high pressure outside the body to an area of lower pressure inside the lungs |
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What do we have to do to breathe in? |
Increase the volume of the thoracic cavity |
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What happens to the diaphragm during inhalation? |
It contracts and is pulled downward |
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What happens to the diaphragm during exhalation? |
It relaxes |
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How do we increase the volume of the thoracic cavity? |
The phrenic nerve stimulates the diaphragm to contract downward and flatten. This increases the height of the thoracic cavity. The intercostal nerve stimulates the external intercostal muscles which then contract and pulls the sternum and ribcage superiorly swinging the ribs outward. This increases the anterior, posterior and lateral dimensions of the thoracic cavity thus increasing the volume. |
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How do we decrease the volume of the thoracic cavity? |
When the phrenic nerve and intercostal nerve stop sending impulses, the diaphragm and external intercostal muscles relax. The diaphragm relaxes upwards and onwards, the lungs recoil and the volume of the thoracic cavity decreases. |
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What happens when the volume of the thoracic cavity is decreased? |
The pressure inside the lungs is higher than the pressure outside the body. Air will move from an area of higher pressure in the lungs to an area of lower pressure outside the body. |
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What percentage of the change in volume and pressure is the diaphragm responsible for? |
75% |
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What is tidal volume? |
The usual volume of air that enters or exits the lung during normal quiet breathing |
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What is the normal tidal volume? |
500mL |
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Why do the lungs expand when the chest cavity expands? |
The parietal layer of the pleural membrane is fixed to the chest wall. The visceral layer adheres to the lungs. The fluid between them makes them adhere to each other. |
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What occurs during normal inspiration? |
The diaphragm and external intercostal contract This increases the volume of thoracic cavity Decreases the pressure in cavity Air flows into the lungs down pressure gradient |
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What happens during normal expiration? |
Normal expiration is passive and depends on the natural elasticity of the lungs. Inspiratory muscles relax causing chest and lungs to recoil. Decreases the volume of cavity Increases pressure of cavity Air flows out of lungs down pressure gradient |
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What muscles are involved with forced inspiration? |
Sternocleidomastoid muscles, scalene and pectoralis minor muscles |
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What happens during forced inspiration? |
Sternocleidomastoid muscles raise the sternum and scalene and pectoralis minor muscles elevate the 2nd-5th ribs. |
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What happens during forced inspiration? |
Sternocleidomastoid muscles raise the sternum and scalene and pectoralis minor muscles elevate the 2nd-5th ribs. |
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What muscles are involved with forced expiration? |
Internal intercostals and abdominal muscles |
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What happens during forced inspiration? |
Sternocleidomastoid muscles raise the sternum and scalene and pectoralis minor muscles elevate the 2nd-5th ribs. |
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What happens during forced expiration? |
The internal intercostals and abdominal muscles contract, this pulls the ribs down and forces the diaphragm up. It occurs during exercise or playing a wind instrument. |
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What muscles are involved in normal inspiration? |
Diaphragm and external intercostal muscles |
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What muscles are involved in normal expiration? |
None |
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What does a spirometer do? |
Evaluates loss of respiratory function and monitors improvement or deterioration of respiratory disorders |
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What is residual volume? |
Is the volume of air remaining in the lungs after maximal exhalation |
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What is vital capacity? |
Is the maximum volume of air that can be expelled after a maximal inspiration |
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What is total lung capacity? |
Is the sum of vital capacity and residual volume |
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What is forced exploratory volume in one second? (FEV1) |
Is the volume of air forcibly exhaled during the first second of exhalation after maximal inhalation |
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What is peak flow? |
Is the maximum rate of expiration (L/min) |
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What is peak flow used for? |
Used to evaluate airway obstruction in asthma and lung disease |
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What does respiration refer to? |
The exchange of gases |
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What is external respiration? |
The exchange of oxygen and carbon dioxide between the alveoli and the lung capillaries. |
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What is internal respiration? |
The exchange of oxygen and carbon dioxide between the systemic capillaries and the body tissues |
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What are the factors that promote external respiration? |
Short diffusion distance between the alveoli and the capillaries. Large surface area Abundance of capillaries Moist alveolar surface |
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How does short diffusion distance promote external respiration? |
Allows the exchange to be very efficient and rapid |
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How thick is the respiratory membrane in healthy lungs? |
0.5-1 micrometer thick. |
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How large is the surface area of the alveoli? |
70m2 |
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How does larger surface area promote external respiration? |
The greater the surface area the more gas that can diffuse across it in a given time |
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How long does it take for exchange of oxygen and carbon dioxide between alveoli and capillaries? |
0.25 seconds |
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How does abundance of capillaries promote external respiration? |
Allows for adequate transit time for blood through the capillaries. |
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How does a moist alveolar surface promote external respiration? |
Allows the respiratory gases to dissolve, gases dissolve before diffusion |
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What are some homeostatic imbalances relating to diffusion? |
Thickness of the respiratory membrane increases if the lungs become waterlogged and oedematous (pneumonia or heart failure) doesn't allow enough time for adequate gas exchange and tissues may suffer hypoxia. Some pulmonary diseases drastically reduce alveolar surface area such as emphysema or tumours. |
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What partial pressure gradients do? |
Drive oxygen and carbon dioxide across the membrane |
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What is a partial pressure gradient? |
The atmosphere is composed of nitrogen, oxygen and carbon dioxide, water vapour and other gases. The partial pressure of a gas is directly proportional to the percentage of that gas in the total mixture. |
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What is the most important factor that determines how much oxygen combines with haemoglobin? |
Partial pressure of oxygen |
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What will happen if there is a greater difference in partial pressure of oxygen? |
Oxygen will combine with haemoglobin faster until the haemoglobin molecules are fully saturated |
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Is the partial pressure of oxygen higher in the alveoli or the pulmonary capillaries? |
Alveoli |
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Is the partial pressure of carbon dioxide higher in the blood or the alveoli? |
Blood |
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What happens if there is a larger difference in partial pressure of carbon dioxide? |
Diffusion will occur faster between the alveoli and the capillaries |
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How much oxygen is transported by haemoglobin? |
98.5% |
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How much oxygen is dissolved in plasma? |
1.5% |
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What is haemoglobin called when it has 4 oxygen molecules? |
Oxyhaemoglobin |
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What does pulse oximetry measure? |
The oxygen saturation percentage of haemoglobin |
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How does haemoglobin release oxygen to resting tissues? |
As haemoglobin flows through systemic capillaries where partial pressure of oxygen is lower, it releases a small amount of oxygen and venous blood is about 75% saturated. This provides a safe reserve if needed |
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What does pulse oximetry measure? |
The oxygen saturation percentage of haemoglobin |
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How does haemoglobin release oxygen to resting tissues? |
As haemoglobin flows through systemic capillaries where partial pressure of oxygen is lower, it releases a small amount of oxygen and venous blood is about 75% saturated. This provides a safe reserve if needed |
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How does haemoglobin release oxygen in active tissues? |
Haemoglobin releases a much greater percentage of oxygen in tissues with a low partial pressure of oxygen because these tissues need it most (contracting skeletal muscle) |
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What dictates where haemoglobin releases oxygen? |
Partial pressure of oxygen |
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What are the 4 main factors that cause haemoglobin to release oxygen? |
Oxygen level is low Carbon dioxide level is high Temperature is high pH is low |
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What are two causes of hypoxia? |
Low partial pressure of oxygen in blood due to airway obstruction, high altitude or fluid in lungs. Levels will be low/normal Anaemia- levels will be low/normal |
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How is carbon dioxide transported? |
Carbon dioxide diffuses from cells into blood. 70% is carried as bicarbonate ions, 7% is dissolved in plasma, 23% is bound to haemoglobin in red blood cells. |
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What does carbon dioxide bind to in haemoglobin? |
Amino acids |
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What centre controls rate and depth of breathing? |
Respiratory centre in medulla oblongata and pons |
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What does the respiratory centre do? |
Controls rate and depth of breathing and sends impulses to the diaphragm and external intercostal muscles via phrenic nerves and intercostal nerves |
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What can modify the basic rhythm of breathing? |
Cerebral cortex. |
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What is the expiratory centre? |
A centre in the medulla oblongata that is usually inactive during quiet breathing but during forced exhalation it sends impulses to the internal intercostal muscles and abdominal muscles |
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What 4 factors can basic breathing rhythm be modified by? |
Conscious decision to alter breathing Chemical stimuli (changes in partial of CO2, changes in hydrogen concentration, large decreases in pO2) The inflation reflex Other influences |
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How can we voluntarily alter our breathing pattern? |
By holding our breath. This is only limited control. |
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What is the most powerful respiratory stimulant? |
Rising carbon dioxide levels |
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What detects rising carbon dioxide levels? |
Receptors in the medulla oblongata, aorta and common carotid arteries |
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What lowers carbon dioxide levels back to normal? |
The respiratory centre increases the rate and depth of breathing to expel more carbon dioxide and lower levels back to normal |
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How is a rise in hydrogen levels detected? |
Receptors in the aortic arch and carotid arteries (blood pH) and medulla oblongata (pH of CSF) |
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What lowers carbon dioxide levels back to normal? |
The respiratory centre increases the rate and depth of breathing to expel more carbon dioxide and lower levels back to normal |
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How is a rise in hydrogen levels detected? |
Receptors in the aortic arch and carotid arteries (blood pH) and medulla oblongata (pH of CSF) |
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How are hydrogen levels returned to normal? |
The respiratory centre can increase rate and depth of breathing to expel more carbon dioxide which lowers hydrogen levels and raises pH |
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What happens when there is a fall in hydrogen? |
There is an excess of bicarbonate ions and too little hydrogen ions. |
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What lowers carbon dioxide levels back to normal? |
The respiratory centre increases the rate and depth of breathing to expel more carbon dioxide and lower levels back to normal |
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How are hydrogen levels returned to normal? |
The respiratory centre can increase rate and depth of breathing to expel more carbon dioxide which lowers hydrogen levels and raises pH |
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What happens when there is a fall in hydrogen? |
There is an excess of bicarbonate ions and too little hydrogen ions. |
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How is alkalosis corrected? |
The respiratory centre decreases rate and depth of breathing to gain higher levels of carbon dioxide and hydrogen and raise pH. |
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How is large drops in oxygen levels detected? |
Receptors in the medulla oblongata, aorta and common carotid arteries. They only respond to a large drop in partial pressure of oxygen |
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What is the purpose of the inflation reflex? |
It prevents over inflation of the lungs |
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How is over stretching of the lungs detected? |
By stretch receptors in the bronchi and bronchioles |
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What happens during the inflation reflex? |
When stimulated, the receptors send impulses to the medulla oblongata and pons which inhibits further inspiration. Exhalation then follows |
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How does the limbic system affect respiration? |
Anticipation of activity or emotional excitement increases respiration. |
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How does temperature affect respiration? |
Rise- during exercise or fever increases respiration Sudden cold stimulus cause apnoea (absence of breathing) |
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How does the limbic system affect respiration? |
Anticipation of activity or emotional excitement increases respiration. |
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How does pain affect respiration? |
Prolonged somatic pain increases respiration |
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How does the limbic system affect respiration? |
Anticipation of activity or emotional excitement increases respiration. |
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How does temperature affect respiration? |
Rise- during exercise or fever increases respiration Sudden cold stimulus cause apnoea (absence of breathing) |
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How does pain affect respiration? |
Prolonged somatic pain increases respiration |
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How does blood pressure affect respiration? |
A sudden rise in blood pressure decreases respiration. A sudden drop in blood pressure increases respiration |
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How does temperature affect respiration? |
Rise- during exercise or fever increases respiration Sudden cold stimulus cause apnoea (absence of breathing) |
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How does pain affect respiration? |
Prolonged somatic pain increases respiration |
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How does blood pressure affect respiration? |
A sudden rise in blood pressure decreases respiration. A sudden drop in blood pressure increases respiration |
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How do medications affect respiration? |
Medications such as morphine can depress respiratory function |
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How does temperature affect respiration? |
Rise- during exercise or fever increases respiration Sudden cold stimulus cause apnoea (absence of breathing) |
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How does pain affect respiration? |
Prolonged somatic pain increases respiration |
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How does blood pressure affect respiration? |
A sudden rise in blood pressure decreases respiration. A sudden drop in blood pressure increases respiration |
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How do medications affect respiration? |
Medications such as morphine can depress respiratory function |
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What are the other influences that affect respiration? |
Limbic system Temperature Blood pressure Pain Medications |
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What does the respiratory centre receive impulses from during exercise? |
Proprioceptors in muscles and joints, primary motor area and neural stimuli. |
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What does arterial blood gas sampling measure? |
Hydrogen, bicarbonate and pH. Partial pressure of carbon dioxide and oxygen |
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What are the effects of ageing on the respiratory system? |
Airways and tissues of respiratory system become less elastic and more rigid Thorax becomes more rigid Elasticity of lungs decreases Vital capacity declines Decrease in blood oxygen level Reduces ability to perform vigorous exercises like running Sleep apnoea is more common More susceptible to pulmonary disorders like pneumonia and bronchitis due to reduced action of cilia and decreased activity of alveolar macrophages |
