Respiratory System Flashcards
what is the purpose of the respiratory system?
to exchange gases. In aerobic organisms oxygen needs to be brought to the cells and carbon dioxide has to be removed
how many parts is the human respiratory system split into
2; the upper and lower respiratory system
what parts make up the upper respiratory system
- nose and nasal cavity
- pharynx
- oral cavity
- epiglottis
- trachea
- larynx
nose and nasal cavity
- a hollow area inside the nose where air enters
- hairs line the nose and trap dirt
- air is warmed and moistened
mucus is secreted to trap dirt
Pharynx
- common tube that connects and oral cavity to the trachea and esophagus
- carries food and air
Oral cavity
also allows air to enter the body going to lungs
Epiglottis
- a flap of cartilage that covers the glottis when food is swallowed
- the glottis is the hole that is opening from the pharynx to the trachea
Larynx
Voice box makes sounds as air passes
what parts make up the lower respiratory system
- Bronchi
- Bronchiole
- Alveoli
- Diaphragm
- Intercostal Muscles
- Pleura
Bronchi
- the trachea divides into the right bronchus and left bronchus
- like the trachea bronchi are held open with rings of cartilage
Bronchiole
- many bronchioles branch off from the bronchi
- bronchioles are not held open with cartilage rings
Alveoli
- tiny damp hollow sacs covered outside with capillaries
- gas exchange occurs across the alveoli membrane by diffusion
carbon dioxide goes from the blood into the alveoli and oxygen enters the blood from alveoli - the singular is alveolus
- flattening all your alveoli would cover a tennis court
- this huge surface area increases the amount of gas exchange possible
Diaphragm
- strong muscle separating the thoracic cavity from the abdominal cavity
- contracts along with intercostal muscles to produce breathing movement
Intercostal Muscles
- intercostal muscles are attached to the ribs
Pleura
- each lung is covered in tissue called pleuron (singular)
- pleurisy is an infection of the pleura (plural)
How many breathes do we take a day
17 000 to 29 000
3-4 L of air is captured in your lungs when you take a deep breath
what are the 4 components of respiration?
- ventilation or breathing
- external respiration
- internal respiration
- cellular respiration
What does ventilation or breathing consist of
- involves both inhalation and exhalation
- gas exchange between the lungs and the external environment
what does external respiration consist of
- has exchange between alveoli and blood at the respiratory membrane
what is the respiratory membrane
the space between the wall of alveoli and the capillaries
what does internal respiration consist of
gas exchange between blood in capillaries and cells or tissues of the body
what does cellular respiration consist of
- process happens inside the cells of all tissues
- energy = ATP - energy currency of cell
Glucose + oxygen = carbon dioxide + water + ATP - 36 Atp molecules are made per glucose
reactions take place in the cytoplasm and mitochondria of all living cells
Functions of the respiratory system
- defending the body against micro-organisms
- produces sounds for speaking
- regulating pH
- maintains homeostasis through a negative feedback loop
- respiratory, circulatory and nervous system works to maintain homeostasis
Nasal cavity and oral cavity locations
where air enters the body
Nasal cavity function
- has lots of blood capillaries to warm the air to body temp when entering
- lined with mucus- secreting cells
- mucus helps moisten and filter air
- mucus, nose hair and cilia filter out large particles and debris
- sinuses help warm and moisten nasal passages
Oral cavity function
most filtering/ warming of air doesn’t happen in the mouth
Pharynx 2
- common path for air and food
- branches into esophagus (eating) and trachea (breathing)
- epiglottis flaps down when swallowing to prevent food from entering lungs
where is the epiglottis located
in the Pharynx
above the larynx closeby
what happens when air and food go down the wrong tubes
it causes coughing, choking and burping
Larynx 2
- made from several “incomplete rings of cartilage”
- produces sound
how does the larynx produce sound
- when muscles cause the vocal cord to contract, the air passing between them vibrates and produces sound
Trachea
- hollow tube allowing the passage of air from the pharynx to the lungs
- surrounded by C-shaped cartilage rings to provide support/ prevent collapse
What are the cells of the trachea lined with
- mucus producing cells and cilia
- mucus trap dust and other airborne particles that are swept up and out of the passageway by cilia with a wave like motion
- mucus will be swallowed or expelled by coughing or sneezing
What are the Bronchi
- two main branches from the trachea leading to the left and right lungs
- lined with cilia and mucus for continued filtering, even though most debris is removed in nasal and tracheal cavities
- branch into smaller and smaller tubes called bronchioles
- at the end of the bronchioles are alveoli that deliver air to all regions of the lung
- cilia and mucus line only line the larger bronchioles
Alveoli 2
- grape-like clusters of tiny hollow air sacs found at the end of the smallest bronchioles
- surrounded by a network of capillaries
- 150 million alveoli per lung (larger surface area for gas exchange)
How thick are the walls that make up the respiratory membrane?
- each wall is one cell thick
- allows gas exchange to easily happen through diffusion across the cell membranes
What is gas exchange
the process whereby body cells obtain oxygen and gets rid of carbon dioxide
where are capillaries located
2 locations
the alveoli in the lungs
the tissue in the body cells
what is diffusion gradient
relationship which a dissolved substance moves from a region of high concentration to a region of low concentration
Gas exchange in the lungs
- alveoli have high concentration of oxygen
- RBCs coming to the alveoli have low concentration of oxygen
- oxygen diffuses from alveoli into the hemoglobin in the RBCs
what is the mechanism of ventilation
-external and internal intercostal muscle
- muscles between ribs that raise/depress the rib cage, changing pressure inside the chest cavity
what happens to the external intercostals
contract & expand chest cavity
what happens to the internal intercostals
relax chest cavity
what is the diaphragm
- large sheet of muscle located beneath the lungs
- primary muscle in breathing
what happens when you inhale
- diaphragm and intercostal muscles contract, making diaphragm move down and rib cage move up and out which causes volume of chest cavity to increase
- increased volume results in low gas pressure inside cavity than outside the body
- air equalizes by rushing into lungs
what happens when you exhale
- diaphragm and intercostal muscles to relax
- diaphragm returns to original position (moves up) and rib cage moves inward
- decreased volume results in higher/ increased gas pressure inside cavity than outside the body
- air equalizes by rushing out of the lungs
what is the rate of breathing determined by
demand for oxygen/ energy and the need to eliminate carbon dioxide
sugar + oxygen = carbon dioxide + water + energy
what gas controls our breathing
CO2
what happens when our breathing is not normal
- the body has homeostasis (levels of CO2 and O2 are balanced)
- CO2 in the increases
- CO2 combines with the water to produce carbonic acid (H2CO3)
- carbonic acid ionizes to form H+ ions and HCO3- ions. Which causes pH to fall below 7.4
- chemoreceptors in medulla oblongata detects the change in pH
- they send a message to the respiratory centre in medulla oblongata which is activated
- breathing rate is increased by the increased movement of the diaphragm & intercostal muscles (to contract more rapidly & forcefully)
- Since breathing rate is increased the excess CO2 is exhaled
- H+ is converted to water and removed from the blood making the pH return to normal
what is Tidal Volume (TV)
- normal breath
- volume of air breathed in and out in one breath
what is Expiratory Reserve Volume (ERV)
- forced exhalation after breathing out
- volume of air that can be forcefully exhaled after normal tidal volume is exhaled
what is Inspiratory Reserve Volume (IRV)
- forced inhalation after breathing in
what is Residual Volume or Reserve Volume (RV)
- air remaining in the lungs after maximum expiration
what is Vital Capacity (VC = TV + IRV + ERV)
- deep breath in and out
- maximum amount of air that can be moved into and out of the lungs less than TLC otherwise lungs would be fully deflated
what is the equation for vital capacity
VC = TV + IRV + ERV
what is Total Lung Capacity
- max volume of air that can be held in the lungs at any given time
- only a fraction of this is used in normal breathing
what is the equation for total lung capacity
TLC = VC + RV or TLC = TV + IRV + ERV + RV
what is anatomical dead space
- space occupied by conduction airways (trachea, bronchi, bronchioles, and even alveoli) that do not participate in gas exchange
what is a respirometer
a device that measures vital capacity
what is the air like at sea level
it is moist meaning that their is a high concentration of O2
what happens when you increase elevation
air becomes less saturated with O2 molecules
what is the relation between the density of molecules and air pressure
as density of molecules decreases the air pressure also decreases
What is partial air pressure
the pressure of each individual gases that make up total pressure of the mixture of gases
what is the atmospheric composition
- oxygen makes 20.9% of the atmosphere
- carbon dioxide
- gases will diffuse across a membrane from high pressure to an area of low concentration till pressures are equal
what is the air pressure in the bloodstream compared to the pressure in the alveoli
air pressure in bloodstream is less than in the alveoli
What are the components of blood
Plasma and Hemoglobin
what is plasma
the liquid component of blood which red blood cells are suspended
what is hemoglobin
an iron rich protein that is found on our red blood cells that bond with oxygen and transport it around the body
What is the function of hemoglobin
- responsible for carrying approximately 98.5% of oxygen and the other 1.5% is carried by the plasma
- when O2 binds to hemoglobin it forms oxyhemoglobin that gives blood a bright red colour
- when red blood is deoxygenated the colour is a darker shade of red
what accumulates in the tissue fluid
- carbon dioxide
- CO2 is the end product of aerobic respiration
What is the partial pressure in the tissue fluid compared to partial pressure in the capillaries
is a bit higher than the partial pressure of CO2 in the capillaries
- it is enough of a difference to allow from diffusion into the bloodstream
what are the 3 ways CO2 is transported into the bloodstream
- 7% of CO2 is left dissolved in the bloodstream
- 20% attaches to hemoglobin and forms carbaminohemoglobin
- remaining 73% reacts with water in the blood plasma to form carbonic acid (H2CO3)
what does carbonic acid separate into
- bicarbonate ions (HCO3-) and hydrogen ion (H+)
- H+ lowers blood pH
hemoglobin releases oxygen to bind with the H+ ion to prevent high levels of ions in the blood - when it gets to our lungs the hydrogen ions separate from hemoglobin and diffuses back into blood plasma
- H+ ions react with blood HCO3- ions to form CO2 and H2O
- results in higher partial pressure inside plasma and CO2 diffuses into alveoli
what effects does altitude have on respiration
- less molecules of oxygen per volume of “air”
- air pressure gradient is less meaning there is going to be lowered rate of diffusion across respiratory membrane meaning less available oxygen to the body
- reduction can lead to altitude sickness (shortness of breath, dizziness, nausea, headache and tiredness)
