Anatomy of Lungs, Airways and Blood Supply Flashcards
what gas exchanges is the respiratory system involved in?
oxygen added to the blood from the air, carbon dioxide removed from the blood into the air
what chemical balance does the respiratory system help maintain?
acid base balance, regulation of body pH
what protective function does the respiratory system have?
protection from infection
other function which will come up in the exam 100%?
communication via speech
what does the body do with the oxygen? why does it need to remove carbon dioxide?
the body produces energy by burning oxygen and releases carbon dioxide as a waste product
what is the name of this combustion process?
cellular respiration
how does the cardiovascular system help the respiratory system?
by transporting the oxygen acquired by the respiratory system to the tissues, and transporting the CO2 produces by the cells to the respiratory system
what is the name of the movement of gases allowed by the integration of the two systems?
“external respiration” allows movement of gases between the air and the body’s cells
which direction does the pulmonary artery flow in? what blood does it carry? what system is it part of?
artery = away from heart, it carries oxygen-poor blood as it is part of the pulmonary circulation
which direction does the pulmonary vein flow in? what blood does it carry? what system is it part of?
vein = towards the heart, it carries oxygen-rich blood as it is part of the pulmonary circulation
which circulation differs from the pulmonary one, and how does it differ? (a circulation’s starting point is the heart)
the system circulation (delivers O2, picks up CO2 to the cells) has an opposite function to the pulmonary one (delivers CO2, picks up O2)
where does the first exchange of external respiration take place?
between atmosphere and lung
where does the second exchange of external respiration take place?
between lung and blood
where does the third exchange of external respiration take place?
between blood (system capillaries) and cells
what are the changes which occur in the respiratory system when the demand for energy by working muscles rises?
rate and depth of breathing speeds up (more O2 acquired, more CO2 disposed of)
what are the changes which occur in the cardiovasculary system when the demand for energy by working muscles rises?
heart rate and force contraction speeds up (more O2 delivered to muscle via blood, more CO2 removed from muscle via blood)
what do the similarities between the two responses prove?
an integration of the respiratory and cardiovascular system
in a steady state; how does the volume of oxygen exchanged in the lungs per unit of time compare with the net volume of oxygen exchanged in the tissues?
the net volumes are equal
what about carbon dioxide?
same (net volumes are equal)
what does this equation prevent?
gas build up. integration of both systems ensures supply = demand
what is the average volume of oxygen exchanged per minute?
250 mL of oxygen exchanged (then to be consumed)
what is the average volume of carbon dioxide exchanged per minute?
200 mL carbon dioxide exchanged (having been produced)
what is the resting breathing rate in adults?
10-20 breaths/min
what is the breathing rate at maximum exercise in adults
40-45 breaths/min
which part of the respiratory system is shared with the digestive system?
the pharynx/throat (MEMO: farynx = food)
which part of the respiratory system contains the vocal chords?
the larynx
what happens in the nose?
cilia and mucus trap particle, warm and moistens the air
what does the epiglottis do?
prevents food from entering the larynx
what is the trachea made of?
small rings of cartilage that support and protect it
where does the trachea lead to?
the bronchus (left and right bronchi)
where do the bronchus lead to?
inside the lungs
what composes the upper respiratory system?
mouth, nasal cavity, pharynx, larynx (vocal cords, tongue, oesophagus?)
what composes the lower respiratory system?
trachea, right and left bronchus, right and left lung (diaphragm?)
what is the lower respiratory system bordered with?
enclosed in thorax, bounded by the ribs, spine and diaphragm
how are the bronchi angles (where the trachea branches off into bronchus) asymmetrical and what are the implication of this?
R bronchi branches off at a more acute angle, this makes aspirated foreign bodies more likely lodge there
inside the lung: how does the bronchus branch?
each bronchi branches into 22 times, each branch terminating in a cluster of alveoli
after a certain degree of branching, the airways change structure. How?
the airways no longer have any cartilage, their potency is maintained by dark physical forces (they are then called bronchioles)
what is the point of gas exchange called?
the alveoli
all airways are covered with what regulatory body? how does this regulation take place?
smooth muscle, which enables contraction/ relaxation therefore decreasing/ increasing diameter thus increasing/ decreasing resistance to airflow
what is a lung lobule?
cluster of alveoli surrounded by elastic fibres and a network of capillaries (branching from either a branch of the pulmonary vein or the pulmonary artery ). There are also some lymphatic vessels present
what 2 type of cells compose the alveoli?
type 1 pneumocytes for gas exchange (97% of alveolar surface), type 2 pneumocytes for surfactant synthesis
what other cells do we find in/near the alveoli?
elastic fibres and endothelial cells of capillary are found between the alveoli, as well as alveolar macrophages
what is the purpose of elastic fibres?
recoil
where do the alveolar macrophages come from, what do they do and where are they going?
they come from blood monocytes (like all macrophages), they gather residual dirt and then escape to pharynx or lymph nodes
what is surfactant?
phospholipids and proteins produced by type 2 pneumocytes which reduces surface tension at alveolar surface and therefore reduces the work of breathing
TRUE/FALSE: the alveoli has average sized walls
FALSE they have very thin walls and huge surface area
TRUE/FALSE: the walls of the upper airways has average sized walls
WHAT EVEN is average all we know is the walls of the upper airways are too thick to allow gases to cross (function is purely conduction of air to and from the alveoli)
what is the air in the airways known as?
it cannot participate in gas exchange (walls too thick) -> anatomical dead space
does a large alveolar surface area enhance gas exchange?
Of course
Lining of respiratory tract: what is its epithelium like? how does it differ from alveolar epithelium?
resipiratory tract: pseudo-stratified (appearance of being stratified but all cells reach basement membrane), ciliated (has cilia), columnar (rectangle)
alveoli: simple squamous (one layer of flattened cells) epithelium
what else is the respiratory tract lined with?
glands, mucous, cilia, lymph nodes, nutritive blood vessels
how does the respiratory tract vary as it goes from nose to alveoli?
epithelium becomes more squamous, the mucous cells are lost first, the mucous cells are lost second
what is the purpose of mucous?
moistens air, trap particles, provides large surface area for cilia to act on
what cells produce mucous?
goblet cells and subepithelial cells
