The Anatomy Of The Respiratory System Flashcards
Where does the body receive its energy from?
Aerobic respiration carried out by mitochondria forming ATP.
What are the nostrils also known as?
Nares
What separates the two nostrils?
The nasal septum
What is the nasal septum formed of?
Cartilage and the ethmoid bone
What is the roof of the nasal cavity made of?
The cribriform plate of the ethmoid bone, frontal bone and nasal bone
What is the floor of the nasal cavity made of?
The roof of the mouth, consisting of the hard and soft palate
What is the hard palate made of?
The maxilla and palatine bones
What is the soft palate made of?
Involuntary muscle
What is the nasal cavity lined with? (2)
Ciliates columnar epithelium to woft the mucus up to the mouth to be swallowed and digested.
Also contains goblet cells that produce the mucus.
What do the posterior nares opening lead to from the nasal cavity?
Pharynx (Nasopharynx)
What are paranasal sinuses?
They are four groups of tiny cavities in the bones of the face and the cranium, containing air.
What are the four main sinuses and where are they located?
Maxillary sinuses in the lateral walls (cheekbones)
Frontal (lower region of forehead) and sphenoidal (bone behind the nose) sinuses in the roof.
Ethmoidal sinuses in the upper part of the lateral walls. (bridge of nose)
What are sinuses involved in?
In speech and also involved in lightening the skull.
They are cavities containing air.
What is the three respiratory functions of the nose?
Warming of the air.
Humidifies the air.
Filters the air.
What are conchas? (2)
There are three different types: inferior, middle and superior nasal concha.
It is responsible for regulating airflow and increases the surface area in the nasal cavity.
How does the nose warm the air? (3)
The concha, AKA turbinates, are responsible for regulating airflow, and increase the SA of the nasal cavity.
Heat from the blood and respiratory a system warms air to body temp as it passes through.
Follows Charles Law which states that as air gets warmer, it expands meaning you will take shallower breaths in colder weather.
What is Charles’ Law?
The volume of gas is directly proportional to its absolute temperature.
( increase in temp - increase in volume).
How does the nose humidify the air? (2)
Mucus from goblet cells keep mucosa (inner lining of oesophagus moist.
Aid travels down mucosa becoming saturated with water vapour.
Why is it important to humidify the air in the nose? (2)
Air in respiratory tract needs to be moist to keep cilia and alveoli moist in order to work effectively and for efficient gas exchange.
Helps feel the alveoli inflated.
How does the nose keep the air filtered? (3)
Large, foreign particles trapped by hairs at anterior nares.
Smaller particles and bacteria trapped in mucus.
Cilia worts mucus filled with particles to pharynx.
What receptors are used to detect smell and where are they located? (3)
Called olfactory receptors.
Located in superior aspects of the nose.
Stimulated by odours.
What is the mouth also known as?
Oral cavity
Is the oral cavity part of respiratory system?
No
What is the mouth lined with?
Stratified squamous epithelium
What is the need of stratified squamous epithelium?
Protects against wear and tear. Eg. From eating
What structure keeps the membrane of the mouth from drying out?
Mucus secreting goblet glands
What is the roof of the mouth made of?
The hard and soft palate
What is the location of the hard and soft palate?
The hard is anterior to the soft.
The soft is posterior to the hard.
Where does the soft palate continue into?
The uvula
What is the uvula?
Fold of muscle that hangs down.
What happens when you swallow? (2)
Soft palate and uvula move upward to block passage to the nose preventing food and saliva entering the nasal cavity.
This is ineffective when laughing and eating at the same time or vomiting.
Where is the palatine tonsils located?
They are located on the lateral aspects of the palatoglossal arches.
What are palatine tonsils?
They are collections of lymphoid tissue responsible for destroying inhaled and ingested pathogens.
What is the tongue?
It is a voluntary muscle
What is the tongue lined with?
Stratified squamous epithelium and papillae which contains taste buds.
Where are salivary glands located?
Outside the oral cavity
What is saliva responsible for? (4)
Lubrication
Cleaning the mouth (enzyme - eg amylase)
Defence
Chemical digestion of food
What is the main problem with the tongue in unconscious patients?
Can obstruct the airways
How long is the pharynx?
12-14 cm long
Where is the pharynx located? (3)
It lies posteriorly to the nasal cavity, oral cavity and the larynx.
It extends from the posterior aspects of the mouth and the nose to the larynx.
It ends with the 6th thoracic vertebrae.
What is the pharynx split into?
Nasopharynx
Oropharynx
Laryngopharynx
Where is the Nasopharynx located?
Lies posteriorly to the nasal cavity
What does the Nasopharynx contain?
A collection of lymphoid tissue responsible for destroying inhaled and infested pathogens in the posterior portion of the nasal cavity.
What is the lymphoid tissue called in the Nasopharynx?
Nasopharyngeal tonsil AKA adenoids
What does the Nasopharynx also contain alongside the nasopharyngeal tonsils?
The auditory tunes leading into the middle ear
Where is the oropharynx located? (2)
It lies posteriorly to the oral cavity.
It lies inferiorly to the Nasopharynx and superior to the laryngopharynx.
What does the oropharynx partially contain?
Palatine tonsils
Where is the laryngopharynx located?
It lies inferiorly to the oropharynx and posteriorly to the larynx.
It extends to the level of the 6th cervical vertebrae and continues into the oesophagus below.
What structure does the pharynx have?
Smooth muscle
What is the function of the smooth muscle in the pharynx?
Helps keeps the pharynx open
What problems can be faced when the smooth muscles in the pharynx relax during sleep or unconsciousness?
The muscles may cause partial or total obstruction.
What is the pharynx lined with? (2)
Ciliates columnar epithelium in the Nasopharynx.
And stratified squamous epithelium in the oropharynx and the laryngopharynx.
What is the function of the pharynx? (5)
Warms and humidifies the air
Involved in taste (olfactory receptors on roof of nose)
Involved in hearing via the auditory tube
Involved in protection - use of tonsils
Speech - acts as a resonating chamber
What is the purpose of air entering the middle ear via the Nasopharynx?
Leads to air in the middle ear being at the same pressure as the outer ear, protecting the tympanic membrane (eardrum) from changes in atmospheric pressure.
What is the larynx also known as?
The voice box
What is the purpose of the larynx?
It like the laryngopharynx to the trachea
Where is the larynx located?
Posteriorly to the laryngopharynx and the 3rd, 4th, 5th and 6th cervical vertebrae.
What is the structure of the larynx? (4)
Has thyroid cartilage
Cricoid cartilage
Arytenoid cartilage
Epiglottis
What is the thyroid cartilage in the larynx?
Most commonly known as the Adam’s Apple.
Where is the thyroid cartilage located in the larynx?
In lies posteriorly to the neck
What is the thyroid cartilage in the larynx made of?
It is made of hyaline cartilage lined superiority with stratified squamous epithelium (continued from the laryngopharynx) and inferiorly with ciliated columnar epithelium.
Where is the cricoid cartilage located in the larynx?
It lies inferiorly to the thyroid cartilage
What is the cricoid cartilage in the larynx made of?
Hyaline cartilage lined with ciliated columnar epithelium.
What is the shape of the cricoid cartilage in the larynx?
It is shaped like a signet ring, completely encircling the larynx.
Where is the arytenoid cartilage located in the larynx?
Superiorly to the cricoid cartilage.
What shape is the arytenoid cartilage in the larynx?
They are two roughly pyramid shaped hyaline cartilage
What is the purpose of the arytenoid cartilage in the larynx?
Gives attachment to the vocal cords and to the muscles, which is lined with ciliated columnar epithelium.
What is an epiglottis in the larynx?
It is a leaf-shaped fibroelastic cartilage attached by flexible cartilage to the inner surface of the anterior wall of the thyroid cartilage, below the thyroid notch.
What is a thyroid notch?
It is where the anterior wall of the thyroid cartilage is partially divided.
What is the epiglottis lined with?
Stratified squamous epithelium
What happens to the epiglottis in the larynx when you swallow?
It closes over the larynx as the larynx moves upwards during swallowing
What is the purpose of the epiglottis closing over the larynx?
It protects the lungs from accidental inhalation of foreign objects.
What does the interior larynx contain?
The vocal cords which are two folds of mucus membrane that stretch across the laryngeal opening.
What is the space between the vocal cords in the larynx called?
The glottis and it is the narrowest part of the airway in an adult
What happens when the muscles is the vocal cords relax? (3)
Passageway of air coming up through the larynx is clear.
Vocal cords are said to be abducted (opened)
Vibrating the cords in this position produces low-pitched sounds.
What happens when the vocal cords contract? (3)
They stretch out tightly across the larynx.
They are said to be adducted (closed)
When vibrated, the sound produced is high pitched.
What is the term used when the vocal cords in the larynx are not in use?
Adducted (closed)
What is the functions of the larynx? (4)
Production of sound and speech
Protection of the lower respiratory tract from food
Air passage
Humidifies, warms and filters air
What is the trachea? (4)
It is a continuation of the larynx
It extends downwards to the 5th thoracic vertebra
It divides at the carina into the right and left bronchi
It lies anteriorly to the oesophagus
It is the main airway carrying warm, moist air from the nose down into the chest
How long is the trachea?
10-11cm
What is the structure of the trachea? (3)
It has an outer layer of fibroelastic tissue
Has middle layer of smooth muscle encased by bands of hyaline cartilage that are incomplete on posterior wall to allow oesophagus to expand during swallowing and prevent trachea collapsing
Inner layer of ciliated columnar epithelium and goblet cells that waft towards the mouth for secretion
What is the four functions of the trachea?
Patency - the trachea does not collapse due to the rings of cartilage that surrounds it on all but the posterior wall. Movement of the head and neck does not kink the trachea.
Mucociliary escalator - mucus and particles wafted upwards due beating of cilia. Wafted to the larynx where it is either swallowed or cough up.
Cough reflex - nerve endings in trachea become stimulated and initiate closing of glottis. Abdominal muscle contracts, which increased pressure in thoracic cavity, opening the glottis causing expulsion of air and mucus/particles.
Filters, warms and humidifies air.
Where are the lungs located?
On either side of the midline in the thoracic cavity.
Where does the apex of the lungs lie?
It lies above the middle third of the clavicle (collarbone).
What shape is the base and where does it lie?
It is biconcave and semilunar in shape and lies on the upper (thoracic) surface of the diaphragm.
Where does the costal surface lie?
It lies against the ribs, against the costal cartilages and the intercostal muscles.
What is the difference between the left and right lungs?
The right lung has three lobes whilst the left only has two lobes.
What is the space between the lungs called?
The mediastinum
What is the hilum?
It is where the bronchus and vessels enter and leave the lung.
What is the function of the pulmonary artery?
It carries deoxygenated blood from the cells of the body to the lungs for exchange of gases to take place.
Where does the pulmonary veins originate from?
The alveoli
Where does the pulmonary veins leave?
The hilum of the lungs.
What is the function of the pulmonary vein?
It carries oxygenated blood from the lungs to the heart for distribution to cells.
Where are the bronchi formed?
The carina
What is the purpose of the carina?
It is where the trachea is divided into two and are continuations of the air passages.
What does the mediastinum contain?
The heart, vessels, trachea, right and left bronchi, oesophagus, lymph nodes, lymph vessels and nerves.
What is the pleura?
It consists of two closed sacs of serous membrane (one for each lung) which contains serous fluid called pleural fluid.
What is the parietal pleura?
It sticks to the inside of the chest wall and the superior surface of the diaphragm.
What happens to the parietal pleura in the hilum region?
It folds on itself
When the parietal pleura folds on itself in the hilum, what is it called?
Visceral pleura
What is the visceral pleura?
It is stuck to the lung and covers each lobe and passes into the fissures that separate them.
What happens to the visceral pleura in the hilum?
It folds on itself.
When the visceral pleura folds on itself in the hilum, what is it called?
The parietal pleura
What is the pleural cavity?
This is a potential space and contains no air, so pressure within is negative relative to atmospheric pressure.
What does the pleural cavity contain?
Pleural fluid
What is the purpose of the pleural fluid?
It lubricates lung movement when breathing, thus reducing friction.
Why is it beneficial to have two pleura with pleural fluid in between them?
It allows the pleura to glide over each other easily but can only be pulled apart with great difficulty. This is essential for keeping the lung inflated against the inside of the chest wall.
What would happen if the layer of pleura was punctured?
Air would be sucked into the pleural space and part or all of the entire underlying lung would collapse.
What is the lungs composed of?
The bronchi (smaller air passages), alveoli, connective tissue, blood vessels, lymph vessels and nerves, all embedded in an elastic connective tissue matrix.
What is each lobe made of?
Lobules
What is the difference between the left and right bronchus?
The right is shorter, wider and more vertical than the left bronchus.
Why is the left bronchus linger and narrower than the right?
The left has to accommodate the heart. This means that inhaled objects are more likely to pass into the right bronchus than the left.
How long the right bronchus?
It is 2.5cm long.
The right bronchus breaks into how many branches and why?
It divides into three for each lobe.
How long is the left bronchus?
It is about 5cm long
How many beaches does the left bronchus break into?
Two branches, one for each lobe
What is the structure of the bronchi?
It has rings of cartilage that surrounds the smooth muscle and is lined with ciliated epithelium.
As the bronchi becomes bronchioles what happens?
The cartilage disappears and is replaced by smooth muscle. The lining is replaced by flattened non-ciliated epithelium and goblet cells disappear.
What is the purpose of more smooth muscle in the bronchioles?
Allows for efficient expansion and contraction of the smaller air passages, which are less likely to become clogged with mucus.
What is the function of the bronchus/bronchioles? (5)
Expansion and contraction of the smooth muscle regulates airflow into and out of the alveoli.
Warm, humidifies, filters.
Reflex
What are the alveoli commonly known as?
Air sacs
What is the structure of the alveoli? (5)
Has flattened squamous epithelium
Collagen
Elastic fibres
Capillaries
Surfactant
What is the purpose of elastic fibres in ten alveoli?
It is for expansion and elastic recoil of the alveoli controlling the flow of oxygen in and out of the lungs.
Why is the elastic fibres important in the alveoli?
It prevents the alveoli bursting.
What is the purpose of the network of capillaries in the alveoli?
It helps maintain a steep concentration gradient for gaseous exchange.
What do the elastic tissue on the alveoli contain? (4)
Macrophages (removes cellular debris)
Nerves
Blood
Lymph
What is the purpose of the surfactant on the alveoli?
As it is a water based solution, it allows oxygen to dissolve on the surface of the alveoli keeping it inflated.
When is surfactant excreted by the alveoli?
35 weeks gestation (which is why premature babies often need respiratory supper).
What is the percentage of oxygen inspired and expired?
Inspired - 20%
Expired - 16%
What is the percentage of nitrogen inspired and expired?
Inspired - 79%
Expired - 79%
What is the percentage of carbon dioxide inspired and expired?
Inspired - 0.04%
Expired - 4%
What is Charles Law? (2)
The volume of a gas is directly proportional to its absolute temperature.
As air is warmed in the lungs it expands.
Where does bronchioles lead into?
The terminal bronchioles.
Where does the terminal bronchioles lead into?
The alveolar ducts and then the alveoli.
What is the Boyles Law?
The pressure of gas in a closed container is inversely proportional to the volume of a container.
Inspiration and expiration.
What cells secrete surfactant?
Septal cells
What is breathing?
It is pulmonary ventilation that takes place in the lungs and is the movement of air into and out of the lungs.
What is the primary function of breathing?
To supply oxygen and eliminate carbon dioxide.
What are the main muscles of inspiration?
The diaphragm and the external intercostal muscles
Are the muscles of inspiration voluntary or involuntary and why?
Muscles can be contracted voluntarily (eg. Deliberately taking a deep breath for singing) .
Also has an involuntary component (eg. We breath without conscious effort and we cannot hold our breath indefinitely).
How many pairs of external intercostal muscles are there?
11 pairs between 12 ribs
How are external intercostal muscles arranged?
They extend downwards and forwards from the inferior border of the ribs to the superior border of the ribs below and are involved in inspiration.
How are internal intercostal muscles arranged?
They extend downwards and backwards from the inferior border of the rib above to the superior border of the rib below, crossing the external intercostal muscle fibres at right angles.
The internal intercostals are used when expiration becomes active, as in exercise.
What is the shape of the diaphragm?
It is dome-shaped
What happens when the diaphragm contracts?
The muscle fibres shorten and the diaphragm is pulled downwards and flattens towards the 9th thoracic vertebrae from the 8th thoracic vertebrae.
A negative pressure is created in the thoracic cavity below atmospheric pressure, causing air to rush in.
What does the diaphragm form?
It forms the floor of the thoracic cavity, and the roof of the abdominal cavity.
What supplies the diaphragm?
The phrenic nerve
During restful breathing, how much of the work is done by the diaphragm and what is it called?
75%
Diaphragmatic breathing
What are accessory muscles of inspiration?
Additional muscles that can be used when required.
What are the accessory muscles of respiration?
Sternocleidomastoid
Scalene
What is expiration and why does it happen?
It is a passive process and occurs due to relaxation of the muscles and the elastic recoil of the lungs?
What happens during inspiration? (6)
Some shaped diaphragm contacts, flattening and lowering.
External intercostal muscles contract moving the ribs upwards and outwards.
The chest expands.
The volume in the thorax increases.
Pressure decreases in the thorax.
Pressure falls below atmospheric pressure so air is drawn into the lungs down a pressure gradient.
What happens during expiration? (8)
This is a passive process where the muscles relax.
The diaphragm relaxes and returns to its some shape.
External intercostal muscles relax moving ribs downwards and inwards.
The chest recoils.
The elastic fibres in the alveoli recoil.
There’s a decrease in volume in the thorax.
Increase in pressure in the thorax.
Pressure is higher than atmospheric pressure so air moves into the lungs down a pressure gradient.
What happens during forceful expiration? (7)
Uses energy from accessory muscles of expiration.
Internal intercostal muscles contract.
Pulls the ribs downwards and inwards fast.
Abdominal muscles contract forcing diaphragm upwards from resting dome shape.
Decreases thorax volume and increases pressure rapidly.
Air moves into the lungs against a pressure gradient.
What are accessory muscles of expiration?
Forced expiration is helped by the internal intercostal muscles and the abdominal muscles.
What is the cycles of breathing? (3)
Inspiration
Expiration
Pause
How long does inspiration last?
It is an active process lasting 2 seconds.
How long does expiration last?
It is a passive process lasting 3 seconds.
What is tidal volume?
It is the amount of air passing into and out of the lungs during each cycle of breathing (about 500mL at rest.
What is inspiratory reserve volume?
It is the extra volume of air that can be inhaled into the lungs during maximal inspiration, ie. over and above normal inspiration.
What is inspiratory capacity?
The amount of air that can be inspired with maximum effort. It consists of the tidal volume (500mL) plus the inspiratory reserve volume.
What is the functional residual capacity?
The amount of air remaining in the air passages and alveoli at the end of expiration.
Why is functional residual capacity important?
It prevents the collapsing of the alveoli on expiration.
What is expiratory reserve volume?
The largest volume of air that can be expelled from the lungs during maximal expiration.
What is residual volume?
This cannot he measures directly but it is the volume of air remaining in the lungs after forced expiration.
What is vital capacity?
The maximum volume of air that can be moved into and out of the lungs.
What is total lung capacity?
The maximum amount of air the lungs can hold. It represents the sum of vital capacity and the residual volume.
In adults normally around 6 litres.
What is alveolar ventilation?
The volume of air that moves into and out of the alveoli per minute. It is equal to the tidal volume minus anatomical dead space, multiplied by the respiratory rate.
TV - anatomical dead space x respiratory rate = (500-150)mL x 15 per minute
= 5.25 litres per minute
What are the physiological variable that affect breathing? (3)
Elasticity - ability for the lung to return to its normal self.
Compliance - effort required to inflate the alveoli.
Airway resistance - broncho-construction means more effort is required to inflate the lungs.
What is external respiration?
Where oxygen from the air is absorbed into the blood via the capillaries of the lungs.
Carbon dioxide is released from the blood into the lungs for exhalation.
What is inspiration?
Oxygen is absorbed by the cells and the carbon dioxide is carried from the cells into the blood.
What is Daltons Law?
In a mixture of non reacting gases, the total pressure exerted is equal to the sum of the partial pressures of the individual gases.
Why does diffusion occur?
It is due to a different in the partial pressures of a gas on either side of a semi-permeable membrane.
The gas will diffuse from a high to a low partial pressure.
How much oxygen as a percentage is carried in the haemoglobin?
98.5% carried as oxyhaemoglobin
What percentage of oxygen is carried in plasma?
1.5%
What percentage of carbon dioxide is transported in the plasma?
77%
What percentage is carbon dioxide is carried in haemoglobin?
23%
What is Henry’s Law?
The quantity of a gas that will dissolve in a liquid is proportional to the partial pressure of the gas and to its solubility.
So the higher the pressure is, the more has that will dissolve in a liquid.
What is parts of the brain? (6)
Cerebrum
Cerebellum
Midbrain
Pons
Medulla Oblongata
Spinal cord
What parts of the brain make the brain stem?
The midbrain, pons and the medulla oblongata.
What is the “Respiratory (Medullary) Rhythmicity Centre”?
It is a group of nerves in the medulla that controls the respiratory pattern (rate and depth).
What is the purpose of the pneumotaxic area? (3)
It has nerves in the upper pons varolli that transmit inhibitory impulses to the inspiratory area.
It shortens the duration of inspiration.
When the pneumotaxic area is active, breathing rate is rapid.
What is the purpose of the apneustic area? (3)
It has nerves in the lower pons varolli that send stimulatory impulses to the inspiratory area
This activates and prolongs inspiration.
The pneumotaxic area is dominant and can override the apneustic area.
What are chemoreceptors? (3)
They respond to changes of oxygen and carbon dioxide in the blood.
If carbon dioxide rises, the respiratory centre is stimulated and ventilation of the lungs increase.
An increase in CO2 is main stimulus that we have to breath.
Where are chemoreceptors located?
They are located centrally in the medulla and peripherally in the aorta and carotid bodies.
What is the hypoxic drive? (3)
It is a form of respiratory drive that uses oxygen chemoreceptors instead of CO2 to regulate the respiratory cycle.
It encourages breathing.
If there is high levels of oxygen levels the body will decrease the rate of respiration, blunting the hypoxic drive.
What are baroreceptors?
These are pressure receptors located in the bronchi and bronchioles.
What do baroreceptors do? (2)
They prevent over inflation of the lungs by sending impulses to the apneustic area, which inhibits inspiration.
This is known as the Hereing-Breuer reflex.
What is the respiratory rate of an adult?
12-20 bpm
What is the respiratory rate of a 5-11 year old?
20-25bpm
What is the respiratory rate of a 2-5 year old?
25-30bpm
What is the respiratory rate of a 1-2 year old?
25-35bpm
What is the respiratory rate of a 0-12 month old?
30-40bpm
Factors increasing respiratory rate: (4)
Exercise
Illness/infection
Injury
Emotional state
Factors that decrease respiratory rate: (3)
Alcohol
Drug - morphine
Brain injury/stroke
What conditions cause abnormal respiratory movement? (6)
Use of accessory muscles
Anxiety and panic
Kussmals respiration (laboured breathing)
Abnormally fast or slow respirations
Agonal breathing (gasping)
Periods of apnoea
What are some abnormal sounds? (5)
Snoring
Stridor (high pitched breathing)
Wheezing
Rhonchi
Crackles
What can be associated signs and symptoms? (4)
Pallor (pale)
Cyanosis (blue)
Increases capillary refill (time for colour to return)
Decreases oxygen saturations
What are the 6 respiratory terms?
Dyspnoea
Tachypnoea
Orthopnoea
Hypoxia
Anoxia
Haemoptysis
What is dyspnoea?
Difficulty in breathing
What is tachypnoea?
Fast breathing
What is orthopnoea?
Shortness of breath when laying flat.
What is hypoxia?
Lack of oxygen to tissues
What is anoxia?
No oxygen in the tissues
What is haemoptysis?
Coughing up blood from the lungs.
