Respiratory System Flashcards
What are the functions of the Respiratory System (4)
- Gas exchange O2 and CO2
Oxygen is needed for cell respiration
Carbon Dioxide is a waste product of cell respiration.
Inhaling creates O2 and we exhale CO2 - Warming, cooling and moistening of the air going into our lungs
e.g cold air may tighten the muscles causing them to constrict also can challenge internal temperature. - Removal of inhales particles (immunity)
Removal of Larger particles are in the nose
Smaller particles are removed by using the mucociliary escalator
Alveola macrophages in the alveoli - Voice production and Olfaction (smell)
Where do we find our immune system in the respiratory tract?
In the respiratory tract the tonsils are our immune tissues, tonsils are clusters of white blood cells. We also have white blood cells in the alveoli
Define the mucociliary escalator
Goblet cells and cilia in the respiratory tract that help remove particles
What are macrophages
White blood cells
What are Alveoli
Air sacs in the lungs
Describe the membrane lining the respiratory tract?
It is a ciliated epithelial membrane that contains mucous secreting goblet cells
What does the RT Mucous membrane do/
Mucus traps inhaled particles and acts as a surfactant it also has antimicrobial properties.
Cilia move the particle-laden mucus towards the Oesophagus where it is either coughed up or swallowed, protecting the lungs from pathogens. This mechanism is called the Mucociliary escalator
What mechanism is the first line of defence in the body?
Mucociliary escalator
What is the most common way that the mucociliary escalator is damaged?
Smoking and pollutants
What is cell respiration
How the we make ATP
Explain external respiration
The exchange of gases between the blood and the lungs (air) Pulmonary arteries carry blood around the alveoli.
What is air inhaled and exhaled called?
Ventilation
What is a surfactant
Lowers the surface area of a liquid, allowing easier spreading
What is celllular respiration
It is a metabolic process whereby energy (atp) is obtained by metabolising carbohydrates, fats and proteins.
What is internal respiration
Exchange of gases between blood and cells.
What do we need to produce aerobic respiration
Glucose, amino acids and fatty acids that mix with Oxygen creating lots of ATP
What do we need to produce anaerobic respiration
We use glucose we split the glucose up and extract as much ATP as possible.
Define the nasal cavity
Nasal cavity is the first contact organ in the respiratory system and conditions air.
What is the structure of the nasal cavity
It is an irregular cavity, divided by a septum bordered posteriorly by skull bones. Internally is has 3 nasal concha (turbinites) - these are shelves that increase surface area and trap water during exhalation
What are the functions of the nasal cavity
Filter air - Hairs and cilia trap particles, protect the epithelium cilia beat towards the mough
Nasal concha (turbinites) spin air within the nasal cavity which filters air and encourages particles to become trapped in the mucous.
Warming air - strong vascularity of mucosa
Humidification - air travels over the moist mucosa
Sneezing reflex - in case of mucosal irritation
Olfactory function - Olfactory receptors
Define the paranasal sinuses
They are air filled cavities with certain facial and cranial bones.
What are the paranasal sinuses lined with
They are lined with mucous membrane that is continuous with the mucosa lining. Secretions drain into the nasal cavity
What is the name of the 4 sinuses
Frontal, ethmoid, sphenoid and maxillary
What 4 functions do the sinuses perform/
Resonance in speech
Lightening of cranial mass
Nasolacrimal ducts drain tears from the eyes (naso lac rimal
Moistening/humidifying the air
Describe the pharynx
Is a straight muscular tube that connects the nose and the throat. It is 13cm long and sits anterior to the cervical spine terminating at the larynx
Name the 3 anatomical parts of the Pharynx
Nasopharynx
Oropharynx
Laryngopharynx
What does the Pharynx contain
Nasopharynx is connected by tubes to the middle ear. These tubes are called Eustachion tubes and allow equalisation of pressure.
They also contain clusters of immune tissue called the adenoids also known as the nasopharyngeal tonsils.
What are the 7 functions of the Pharynx
Passageway for food and air
Warming and humidifying
Taste (we use tongue and pharynx)
Hearing
Equalisation of pressure
Immune protection tonsils (nasopharyngeal tonsils)
Speech (resonance)
What thickens and strengthens the vocal cords
Testosterone
Define the Larynx
The Larynx is the voice box (adams apple) it connects the laryngopharynx with the trachea
What does the larynx consist of
Consists of 9 pieces of cartilage (including thyroid cartilage, epiglottis and vocal cords
What are the vocal cords composed of
Mucous membrane foldings that are stretched horizontially
Laryngeal muscles attach to the vocal cords and when contracted stretch them. How does our voice differ from relaxed or contracted
Relaxed - loose cords - low tone
Contracted - tight cords - High tone
What are the functions of the Larynx
Production of sound (vocal cords) and speech (cheeks, lips and tongue)
Protection - the epiglottis closes of the trachea during swallowing and prevents food entering the lungs
Air passageway
Warming and humidifying
Describe the Trachea
The Trachea (wind pipe) is roughly 12cm long and made up of incomplete C shaped rings of hyaline cartilage.
The incomplete rings of hyaline cartilage are connected by smooth muscle called the trachealis
Why do we have incomplete C shaped rings in our Trachea
To ensure we keep the trachea open and never in a situation that we cant get oxygen into our lungs or remove carbon dioxide
What is the smooth muscle called in the trachea
Trachealis
What is the sympathetic response and what does it cause in the trachea
Fight or flight response, we need more oxygen so we have tracheal dilation
What is the parasympathetic response and what does it cause in the trachea
rest and digest - we need less oxygen so we have tracheal constriction
Name 4 functions of the Trachea
Airflow - C shaped rings keep the trachea open preventing food going into the lungs.
Mucociliary Escalator - traps inhaled particles and moves them from the respiratory system
Cough reflex
Warming, humidifying and filtering air (its usually warm and humid by this point)
What happens in the coughing reflex
Epithelial receptors in the respiratory tract are highly sensitive to chemical/mechanical stimuli. The coughing reflex starts when irritation to the mucous membrane occurs.
Stimulates sensitive nerve endings in the larynx, trachea and bronch
A nerve impulse is sent via the vagus nerve to the respiratory center and brain stem
This causes deep inhalation and closure of the glottis and vocal cords the abdominal and respiratory muscles contract causing forced removal or irritation.
What does aspirate mean
to inhale something
What does it mean for something to be innervated by
to be stimulated by
What does carina mean
ridge
Describe the Bronchi
The Trachea divides into the left and right bronchi at vertebral level T5 and deliver air into the lungs.
The Bronchi contain cartilage rings maintain an open airway. They are lined with ciliated epithelium.
The right bronchi is more vertical, shorter and wider hence an aspirated particle is more likely to enter the right lung
What are Bronchi lined with
Ciliated epithelium
What is the Carina
Where the trachea divides into the bronchi an internal ridge called the carina is formed. This is the most sensitive structure in the respiratory system and triggers the cough reflex.
What is the most sensitive structure in the respiratory system
Carina
What are the Bronchioles
The Bronchioles are continuations of the Bronchi
What is the structure of Bronchioles
They have no cartilage in their structure and instead contain smooth muscle. They lead directly to the alveoli where gas exchange happens.
What role does the nervous system play in air entry to the bronchi
The Sympathetic nervous system stimulates- Bronchodilation thus more air can be taken in.
The parasympathetic nervous system encourages Bronchoconstriction during a restful state.
Where to the Broncholies terminate
At the Alveolar sacs
In Alveoli how are gases exchanged
between air and the blood (capillaries and alveoli)
Explain how Oxygen moves in gas exchange
Oxygen moves from the alveoli to the blood after breathing in. The blood then becomes oxygenated.
Explain how Carbon Dioxide moves in gas exchange
Carbon Dioxide moves from the blood after being delivered through the pulmonary artery to the alveoli where it is then exhaled.
The movement of gases happens via xxxxxxx
Diffusion (down the concentration gradient)
Describe type 1 Alveolar cells
Simple epithelial cells, which cover 90%
Describe type 1 Alveolar cells
Simple epithelial cells covering 90% of the surface area of Alveoli. They are very thin to support exchange of gases.
Describe type 2 Alveolar cells
Alveolar cells secrete a fluid called pulmonary surfactant. This reduces the surface area preventing alveolar collapse. The fluid also allows for gases to move through it.
There are 3 types of Alveolar cells, type 1 type 2 and xxxx describe what these cells do
Alveolar Macrophages - They are strategically located white blood cells (leukocytes) that engulf and destroy microbes from entering the alveoli.
What would happen if we didn’t have pulmonary surfactant?
The lungs would not remain inflated and we would struggle to breathe.
What does the term gestation mean
time when the foetus develops
What does pulmonary surfactant do?
Keeps alveoli open by reducing the surface tension within the alveoli, preventing them from collapsing and reducing the pressure required to re-inflate them.
What is Pulmonary Surfactant made up of?
A mixture of lipids and protiens that forms a surface film in Alveoli
The protein part of Pulmonary surfactant is xxxxxx and resides in the xxxxx xxxx. Whilst the lipid component is xxxxxx and faces the xxxxx
Hydrophillic
Alveolar fluid
Hydrophobic
Air
How many weeks gestation is pulmonary surfactant produced
Not until 34 weeks.
What are the 4 surfaces of the lung
Apex (above the clavicle)
Base over the diaphragm
Costal (rib) surface
Medial surface
How many lobes do we have in 1. left lung 2. right lung
Right lung has 3 left has 2
Define the Pluera
The pluera are serous membranes that surround the lungs
What is the structure of the pleura
Contains visceral (inner) and parietal (outer) layer with a pleural cavity inbetween.
The visceral and parietal layer forms a double layer separated by 5-10ml of serous fluid that prevents friction
Where do the pleura adhere too and why?
They adhere to the lungs so the lungs are sucked to the pleura (passive dilation) which helps expansion of the lungs.
What occurs when damage to the pleura allows air into the pleural cavity?
Pneumothorax (collapse lung)
What is the process of ventilation
Process in which O2 and CO2 are transported to and from the lungs.
How many breaths per minute in a normal cycle of ventilation
12- 15 breaths
What are the 2 main phases of ventilation and how long for each?
Inspiration/Inhalation 2 secs or Expiration/Exhalation 3 secs followed by a brief pause.
What are the 2 areas breathing can come from?
What area is preferred for breathing and why for both?
Abdominal (diaphragmatic) breathing - Preferred
Helps in massaging the digestive organs and gut
Better movement of O2 into the lungs
Encouraging return of the blood via the veins
Encourage lymphatic drainage
Stimulates and activates the vagus nerve (part of the parasympathetic nervous system
(rest and digest)
The vagus nerve promotes digestion
Upper rib breathing - generally when people are stressed, muscles in the clavicle, shoulder and upper neck become very fatigued and muscles can shorten.
Why is it important to breathe in through your nose?
If we don’t use our nose to breathe, air will enter cold and will be unfiltered which can lead to problems deeper in the respiratory tract.
What are the 2 primary muscles of ventilation, where are they found and what do they do?
Intercostal muscles - Internal and external
Attached between the ribs at right angles
contraction pulls ribs upwards (inhalation) expanding outward and increasing size of rib cage.
Diaphragm - Attached to the lower ribs, sternum and lumbar spine. A domed muscle that separates the thoracic and abdominal cavity. Contraction moves the diaphragm into the abdomen and draws air into the lungs.
Define secondary muscles of ventilation and where are they mainly found.
also called accessory muscles that assist in breathing found mainly in the neck and chest.
Give 3 examples of secondary muscles of ventilation?
Sternocleidomastiod, Trapezius and the Scalenes
What can happen when we use secondary muscles of ventilation
These muscles are often over-recruited especially in patients suffering with breathlessness e.g asthmatics the muscles shorten and fatigue.
In inspiration/inhalation what is the process?
It is an active process requiring muscles. Negative pressure in the thoracic cavity causes air to enter lungs down a pressure gradient
In Expiration/exhalation what is the process.
It is typically a passive process - the muscles relax and is aided by the elastic recoil of the pluera and the lungs.
When can exhalation become active?
Should only be active when forceful breathing. If elasticity is lost for example in pulmonary fibrosis exhalation can become active with the recruitment of internal intercostal and abdominal muscles
What is our lung volume in litres?
6 litres
What percentage of lung capacity to we use in tidal volume?
10%
What is tidal volume
Lung capacity at normal volume
What individuals tend to have a larger lung volume
Men, non smokers, taller individuals and athletes
Why does oxygen enter the blood easily
It has a strong affinity (attraction) with Haemoglobin oxygen will enter the blood and bind to the haemoglobin molecules
What use do we have in the body for nitrogen breathed in through the air
Nitrogen doesn’t bind to haemoglobin and it is not used or created by the body.
What percentage of oxygen to we inspire and expire
Inspire - 21%
Expire - 16%
What percentage of nitrogen to we inspire and expire
inspire 78%
Expire 78%
What percentage of Carbon Dioxide to we inspire and expire
Inspire - 0.04%
Expire - 4%
Explain Haemoglobin
A pigment that binds oxygen using a mineral called Iron
What is it called when plenty of Oxygen is bound to Haemoglobin
Oxyhaemoglobin
What is the name given to when Haemoglobin lacks Oxygen
Deoxyhaemoglobin
What percentage of Oxygen is transported by Haemoglobin in red blood cells
98.5%
How many molecules of Oxygen can one blood cell carry
1 billion molecules of Oxygen
What happens to the 1.5% of oxygen that isn’t transported by Haemoglobin.
It is dissolved in the plasma and transported
