Anatomy and non-respiratory functions
Describe the path the air takes from the outside to the alveoli?
Identify the respiratory and non-respiratory structures along the way
Nasal cavity -> pharynx -> trachea -> lung -> bronchus -> bronchiole -> alveoli
nose, mouth, diaphragm, esophagus, epiglottis, etc..
Identify and describe common volume metrics in respiratory physiology?
FRC - Functional residual capacity = air left after normal expiration
ERV - Expiratory reserve volume = volume that can be forced expiration
VC - Vital capacity = Amount of air between max intake and forced expiration
RV - residual volume = amount of air in the lungs after forced expiration
TLC - Total lung capacity = full amount of air that can be held
TV - Tidal volume = amount of air for normal inspiration and expiration
IRV - Inspiratory reserve volume = Amount of space left to fill the lungs after normal inspiration
IC - Inspiratory capacity = Amount of air taken in on forced inspiration
Understand and explain the concept of "negative pressure building"?
- describe the sequential steps involved in achieving inspiration and expiration, along with the forces at play during each step
Air is pulled into the lungs, NOT pushed
air travels from a place of high pressure to a place of lower pressure
inspiration = Respiratory muscles contracts, thoracic cavity expands, intrapleural pressure decreases, lung volume increases, alveolar pressure drops, air moves from high pressure to low pressure
expiration = Respiratory muscles relax, thoracic cavity decreases its volume passively, Lung volume decreases, alveolar pressure increases, air moves from high pressure to low pressure area
Describe the path oxygen takes from alveoli to tissue?
- explain why/how the O2 is moving from one structure/place to the next
Gas goes from places of high to low PP
So oxygen binds to things like Hb in order to keep the PP levels where they need to be
Name the structures in the brain that control ventilation and describe each of their roles?
Medulla - Dorsal respiratory group (inspiratory neurons for quiet breathing), Ventral respiratory group (inspiratory and expiratory neurons)
Describe the anatomical particularities of obligate nasal breathers?
Prey animals or herbivores - spend lots of time with their head down and eat
they can chew feed and smell for predators at the same time without interuption
Define the concept of "dead space" and its implications?
Anatomical dead space = air remaining in the conducting airways
physiological dead space = anatomical dead space + alveolar air with no blood supply
Equipment dead space = Anything that increases respiratory tract volume
Explain the role of the pleural cavity in facilitating ventilation?
- Define and explain what happens during a pneumothorax
Pneumothorax - caused by a hole in chest or lung, loss of sub-atmospheric pressure in the pleural cavity, lungs don't stick to the thorax and collapse, lungs don't expand on inspiration, so no air flow
Intrapleural fluids cohesiveness - water on the 2 pleural surfaces makes them super resistant to pulling = as the lung recoils, lower pressure in intrapleural cavity
Explain how exercise changes conditions leading to increased O2 diffusion?
PP gradient gets larger, Surface area for exchange increases, Thickness of the membrane is reduced, Coefficient of diffusion is increased
Your muscles are using up oxygen since they are using up energy, which means that if you exercise consistently your body will adapt to allow more sites of gas exchange to account for increased O2 use
Understand the way the body monitors respiration (structures and parameters monitored)
Peripheral chemoreceptors - carotid bodies, aortic bodies (sensors can detect hypoxia quick) (also respond to H+)
Central chemoreceptors - located near the medulla, respond to Po2, Pco2, and H+, although arterial H+ can't penetrate the blood brain barrier
List the muscles involved in inspiration and forced expiration?
Inspiration - Diaphragm (primary muscle), External intercostal muscles (pull ribs up and out), Accessory muscles in the neck (deep breath)
Expiration - Abdominal muscles (increase pressure and push diaphragm up), Internal intercostal muscles (pulls ribs in and down)
Define the 4 commonly used metrics for measuring lung function?
FEV1 = forced expiratory volume in 1 sec
FEV1% = FEV1/VC
PIF = peak inspiratory flow
PEF = peak expiratory flow
Define and explain lung elasticity and lung compliance. Provide examples of conditions in which the two are at play?
- Explain the role of surfactant
Elasticity = refers to how easily the lung recoils after being stretched
Surfactant - reduces the surface tension but maintains recoil so that lung doesn't collapse
Compliance = how much effort is required to stretch the lungs by a given amount - low compliance means more effort during inspiration is required, high compliance means more effort during expiration is required
Explain how O2 and CO2 are transported?
move down pressure gradients
Respiratory pigment to transport O2 is very common throughout the animal kingdom - Hb
PP only counts with gas molecules that are dissolved, gas molecules that are bound don't count
CO2 has 3 main ways of transport - 5-10% dissolved in blood, 25-30% bound to Hb, 60-70% turned to bicarbonate
Understand how the body controls blood flow to optimize gas exchange?
Bronchial circulation - Oxygenated blood from left ventricle and aorta, supplies O2 to bronchial smooth muscles and connective tissues, small percentage of cardiac output
Pulmonary circulation - Deoxygenated blood from right ventricle and pulmonary artery, large volume of blood, low pressure, low resistance, all for gas exchange
List the 7 non-respiratory functions of the respiratory system?
Regulation of water loss and heat exchange
circulation
acid-base balance
defense
removal, (in)activation of muscles
olfaction
sound production
Be able to diagnose obstructive vs. restrictive lung disease from a pneumogram?
Obstructive = issue breathing out - asthma, emphysema, chronic bronchitis, cystic fibrosis = Damage to the lung narrowing of airways makes air come out more slowly
Restrictive = hard time breathing in - pulmonary fibrosis, obesity, muscular dystrophy = Often caused by stiffness of the lung or anything that restricts lung expansion
Define and explain the concept of airway resistance?
- provide examples of conditions dealing with airway resistance issues
- Discuss the brachycephalic syndrome
How much airflow gets through, or lack there of - trouble breathing
asthma, COPD, chronic bronchitis
Brachycephalic syndrome = narrow nostrils, elongated soft palate, hypoplastic trachea, everted laryngeal saccules - restriction of air flow causes respiratory distress
Understand what an oxygen dissociation curve is?
- How do we get the s shape
- Give examples and discuss the physiological changes happening during a right and left shift in the curve
How much O2 is attached to hb
S shape shows how easy or hard it is for oxygen to attached or release from Hb
lower pH shifts curve to the right, higher temp shifts curve to right, organic phosphate (high altitude) shifts to right (Easier for O2 to attach and release)
CO shifts curve to left (makes it harder to get O2 to attach or release)
Understand the basic differences between bird and mammal lungs?
Birds have 2 rigid lungs, parabronchi open up into capillaries instead of alveoli, have air sacs connected to respiratory system
Bird respiration is more efficient
Describe the structures/organs involved in respiratory immunity and their respective functions?
Mucociliary escalator
Alveolar macrophages - can be inhibited by stress and corticosteroid hormones
Explain how respiratory pigments (Hb, and Mb) lead to increased gas exchange?
Hb allows O2 to travel in the blood without changing PP
idk what else
Discuss the cost of respiration?
3-5% of resting metabolic rate is for respiration
During exercise muscles need more O2, which means more ventilation is required
Give examples of a gas transport dysfunction?
Cyanide poisoning
Nitrate poisoning
Understand how the avian respiratory systems achieves a more efficient respiration?
air is continuously flowing passed the capillaries
gas gets transferred from air to blood via a cross current exchange
the air blood barrier is at least 30-40% thinner than for mammals
the capillary blood volume per gram of body weight is 20% greater in birds
the exchange area per gram body weight about 10 times that of mammals