respiratory system Flashcards
what are the respiratory systems functions?
allows you to talk and smell.
warms air to match your body temperature
delivers oxygen to the cells in the body
removes waste gases inc c02
protects airways from harmful substances
what does the nasal cavity do?
an entry point for air.
what is the structure of the nasal cavity?
lined with mucous membranes and tiny hair like structures called cila.
what does cilia do in the nasal cavity?
helps filter, warm and humidify the air before it reaches the lungs.
after the nasal cavity where does air pass through?
the pharynx
what is the pharynx there for?
a pathway for both air and food
what does the pharynx connect to?
the nasal cavity and the mouth to the larynx
what is the larynx?
commonly known as the voice box. produces sound
where is the larynx located?
below the pharynx
what is the structure of the epiglottis?
a flap like structure, covers the entrance to the larynx during swallowing to prevent food or liquids from entering he respiratory tract.
what is the trachea?
tube like structure that extends from the layrnx and divides into main bronchi
what is the structure of the trachea?
c shaped rings of cartilage which helps to maintain its open structure and prevent collapse during breathing
what is the bronchi and bronchioles?
the main branches that arise from the trachea and lead to the lungs. then further divide into smaller bronchioles forming a branching network within the lungs
what is the alveoli?
tiny grape like sacs located at the ends of the bronchioles within the lungs. they are the primary sites of gas exchange
what is the structure of alveoli?
the wall of the alveoli are thin and surrounded by a dense network of cappilliaries.
what happens in the alveoli?
oxygen from inhaled air diffuses across the alveolar walls into the bloodstream. while carbon dioxide a waste product moves from the blood stream into the alveoli to be exhaled
what is the lungs and what does it do?
two organs that remove oxygen from the air and pass it into your blood. the lungs then delivers oxygen to all your organs and other tissues
what is the diaphragm and intercostal muscles?
a dome shaped muscle located beneath the lungs and the intercostal muscles have a crucial role in respiration
during inhaltion what happens to the diahragm and intercostal muscles?
the diaghram contracts and moves downwards. while the intercostal muscles expand the ribcage
during exhaltion what happens to the diahragm and intercostal muscles?
they relax allowing for the expulsion of air.
What does the respiartory system work with the cardiovascular doing?
they ensure the exchange of carbon dioxide and oxygen between the lungs and body systems
what is the function of the lungs?
gas exchange, removing waste products, oxygenating the body’s cells, supports the body’s energy and PH balance
what conditions can cause inflammation, swelling and irritation to the respiratory system?
allergies, asthma, infection, disease, aging and damagge.
what is asthma?
a chronic long term disorder that causes inflammation in the airways. making breathing difficult
what are 2 types of respiratory infection and what happens?
the flu or cold. these can lead to pneumonia- inflammation. or bronchitis- inflammation of the bronchial tubes.
what respiratory diseases are there and what can they result?
include lung cancer and COPD. these can harm the respiratory ability to deliver oxygen throughout the body and filter waste gas.
when oxygen is inhaled where does it diffuse across?
the thin walls of the air sacs in the lungs alveoli.
what cells carry the oxygen to various tissues and organ in the body.
red blood cells.
what is cellular respiration and what is included in the celluar respiaration chemical reacton?
breaks down glucose to energy
the chemical reaction for cellular respiration involves glucose and oxygen as inputs, and produces carbon dioxide, water, and energy (ATP) as outputs.
at the same time oxygen is being carried to the organs what is happening with co2?
its being diffused from the tissues into the cappilaries and transported back to the lungs to be exhaled.
what does oxygen bind with?
hemoglobin (found in red blood cells). forming oxyhemoglobin
what does oxyhemoglobin allow?
for efficient transportation of oxygen from the lungs to the body tissues, where it is required for energy production
how does the respiratory system help regulate the acid base balence in the body?
by removing co2 which is a acidic waste product. when the co2 levels increase the resp rate increases to restore the balence
how does the respiartory system help speech?
air passing through the larynx and vocal cords cause them to vibrate generating sound waves that are then modified by other structures to produce speech.
what is the conducting zone in the respiratory system?
the nose, nasopharynx, larynx, trachea, and a whole series of successive narrowing segments of bronchi and bronchioles.
what is the respiratory zone?
respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli
what does the conducting zone do?
at 37 degrees
Mucus secreted by cells of the conducting zone structures serves to trap small particles in the inspired air and thereby performs a filtration function.
This mucus is moved along at a rate of 1 to 2 centimeters per minute by cilia projecting from the tops of epithelial cells that line the conducting zone.
There are about 300 cilia per cell that beat in a coordinated fashion to move mucus toward the pharynx, where it can either be swallowed or expectorated.
what happens in the respiratory zone?
Gas exchange in the lungs occurs across an estimated 300 million tiny (0.25 to 0.50 mm in diameter) air sacs, known as alveoli.
Their enormous number provides a large surface area (60 to 80 square meters, or about 760 square feet) for diffusion of gases.
The diffusion rate is further increased by the fact that each alveolus is only one cell-layer thick, so that the total “air-blood barrier” is only two cells across (an alveolar cell and a capillary endothelial cell), or about 2 µm.
what is dead space?
is the volume of air contained within the conductive airways of the respiratory system. Nose trachea, bronchioles, alveolar duct, alveolar sac and alveoli. Dead space should be 0 in a healthy human. Dead space and anatomical dead space is equal. Dead space indicates the lung status.
explain physiological dead space
atatomical dead space- gas doesnt reach bronchials+alveoli. stays in conducting zone
+
alveoli dead space- makes it to the alveoli but no blood present for gaseous exchange to take place
how much dead space is there per 1kg of body weight?
2ml
what happens to the inspiratory muscles during respiration?
The external intercostal: raise the rib cage
Sternocleidomastoid muscles: which lift upward on the sternum
anterior serrati: lift many of the rib
Scaleni: lift the first two ribs
what is lung capacity?
the sum of two or more lung volumes.
what is the tidal volume?
the volume of gas inspired or expired in an unforced respiratory cycle.
what is inspiratory reserve volume? (about 300ml)
the maxinum volume of gas that can be inspired during forced breathing in addition to tidal volume
what is expiratory reserve volume (about 1100ml)
the maximum volume of gas that can be expired during forced breathing in addition to tidal volume
what is residual volume (about 1200ml)
the volume of gas remaining in the lungs after a maximum expiration.
what does total lung capacity (5800ml) VC+RV mean?
the total amount of gas in the lungs after a maximum inspiration
what does the vital capacity (4600ml) IRV+TV+ERV mean
the maximum amount of gas that can be expired after a maximum inspiration
what does inspiratory capacity mean?
the maximum amount of gas that can be inspired after a normal tidal expiration
what does functional residual capacity (2300ml) mean?
the amount of gas remaining in the lungs after a normal tidal expiration.
what is lung compliance?
Lung compliance can be defined as the change in lung volume per change in transpulmonary pressure, expressed symbolically as ΔV/ΔP.
It is the ability of the lungs to expand, or it is the expansibility of lungs.
Determination of compliance is useful as it is the measure of stiffness of lungs. Stiffer the lungs, less is the compliance.
what is the function of surfactant?
Surfactant reduces the surface tension in the alveoli of lungs and prevents collapsing tendency of lungs.
how does surfactant work?
The surfactant molecules become interspersed between water molecules at the water-air interface of the alveoli, thereby reducing the attractive forces (hydrogen bonds) between water molecules that produce the surface tension. Thus, because of surfactant, the surface tension in the alveoli is reduced
what is 2 extra functions of surfanctant?
It plays an important role in the inflation of lungs after birth.
Another important function of surfactant is its role in defense within the lungs against infection and inflammation. Hydrophilic proteins SPA and SPD destroy the bacteria and viruses by means of opsonization.
what is the thickness of the respiratory membrane?
The overall thickness of the respiratory membrane in some areas is as little as 0.2 micrometer, and it averages about 0.6 micrometer, except where there are cell nuclei. The total surface area about 70 square meters.
where does gas exchange happen in the lungs
Gas exchange between the alveolar air and the pulmonary blood occurs through the membranes of all the terminal portions of the lungs, known as the respiratory membrane or pulmonary membrane.
what is ficks law?
Fick’s Law describes the relationship between the rate of diffusion and the three factors that affect diffusion.
It states that ‘the rate of diffusion is proportional to both the surface area and concentration difference and is inversely proportional to the thickness of the membrane’.
what are the factors which affect diffusion?
membrane surface area, membrane thickness, solubility of gas and weight of gas
what are the 3 component’s of the brain stem called in the respiratory centre?
pneumoatic area, apneustic area, rhythmicity area.
where is the respiratory centred located?
in the brain stem
what does the phneumotaxic do in the brain stem?
sending inhibitory impulses to the inspiratory centre, stopping the process of inspiration, and thereby maintaining and regulating the inspiratory volume and respiratory rate
what does the apneustic center do?
sends signals to the dorsal group in the medulla to delay the ‘switch off, the inspiratory off switch (IOS) signal of the inspiratory ramp provided by the pneumotaxic center. It controls the intensity of breathing, giving positive impulses to the neurons involved with inhalation.
what does the rhythmicity area do in the brain stem?
controls the basic rhythm of breathing through the activity of the inspiratory and expiratory areas.
what does the medulla oblongata do?
send signals to the muscles that control respiration to cause breathing to occur.
what stimulates the insipratory muscles to contract?
the nerve impulses to the diaphragm and external intercostal muscles for 2 seconds
what allows the inspiratory muscles to relax after contracting?
the neurons stop firing for 3 seconds which allows the muscles to relax. the elastic recoil of the lungs and chest walls leads to expiration
explain the nervous regulation after the lungs inflate
baroreceptors in lung tissue detect this stretching and generate sensory impulses to the medulla; these impulses begin to depress the inspiration center. This is called the Hering-Breuer inflation reflex, which also helps prevent overinflation of the lungs.
what is chemical regulation?
the effect of blood ph and blood levels of o2 and co2 on breathing
what are chemoreceptors?
special nerve cells or receptors that sense changes in the chemical composition of the blood.
what are the 2 groups of chemoreceptors and what do they do?
Chemoreceptors are special nerve cells that detect changes in the chemical composition of the blood and send information to the brain to regulate cardiovascular and respiratory functions. There are two major types, which are peripheral and central chemoreceptors.
what do central chemoreceptors do?
specialised cells on the ventrolateral surface of the medulla.
detect the hydrogen concentration and when we get too many hydrogen ions we send a signal to the respiratory center to help increase the respiratory rate.
what are peripheral chemoreceptors?
the carotid and aortic bodies respond to changes in aterial p02, pc02 and ph.
protecting the brain from hypoxia and ensuring that the breathing is always appropriate for metabolism
