Week 5 Respiratory system Flashcards
What is the purpose of the respiratory system
Gas exchange (CO2/O2) between environment and body Regulation of acid-base balance during exercise
What is pulmonary respiration?
External ventilation, exchange of O2 and CO2 in the lungs
What is cellular respiration?
Internal, utilization of O2 and CO2 production by the tissues.
What is the definition of ventilation
Ventilation is mechanical process of moving air into (inspiration) and out of (expiration) the lungs
What is the definition of diffusion
Movement of O2/CO2 molecules between the lungs and blood at the alveolus.
What is the defence system in the respiration system
Warming of air - lungs are very sensitive and dont want cold air (done in conduction zone)
Mucus - traps particles
Cilia - spit or swallow
Macrophages - in alveoli, eat foreign bodies.
What are the components of the conduction zone and what does it do
Trachea, bronchial tree and bronchioles
Conducts air to respiratory zone and warms and filters air
What are the components of the respiratory zone and what does it do
Respiratory bronchioles and alveolar sacs
Exchanges of gases between air and blood
What does the intrapulmonary pressure and diaphragm do in both inspiration and expiration
Inspiration - pressure lowered, diaphragm pushed downward, ribs lifted upward
Expiration - pressure increased, diaphragm relaxed and ribs pulled downward.
What are the respiratory muscles involved in inspiration (4)
- Sternocleidomastoid
- scalenes
- external/internal intercoastals
- diaphragm
What are the respiratory muscles involved in expiration (3)
- Internal intercoastals
- external/internal obliques
- transverse/rectus abdominus
Define tidal volume, alveolar ventilation and dead space ventilation
Tidal volume is the amount of air moved per breath
Alveolar ventilation is volume of air that reaches respiratory zone
Dead space ventilation is volume of air remaining in conducting airways
What is Dalton’s Law
The total pressure of a gas mixture is equal to the sum of the pressure that each gas would exert independently
What are the partial pressures of O2 and CO2 (PO2 and PCO2) in the:
- Atmospheric air
- Alveolar air
- Pulmonary veins
- Systemic arteries
- PO2 = 159, PCO2 = 0.2
- PO2 = 105, PCO2 = 40
3 & 4. PO2 = 100, PCO2 = 40
What are the partial pressures of O2 and CO2 (PO2 and PCO2) in the:
- Tissues
- Systemic veins
- Pulmonary arteries
All 3 are
PO2 = 40
PCO2 = 46
How is oxygen transported in the blood and what increases the amount of oxygen being able to be transported?
Haemoglobin transfers oxygen in the blood. Haemoglobin is in the RBCs. Haemoglobin can carry four oxygen molecules. High altitude training increases haemoglobin count. Myoglobin is what O2 binds to in haemoglobin.
What is haemoglobin-oxygen saturation affected by
PO2, pH, temperature and PCO2 and PO2 binding.
How is CO2 transported (3)
- Dissolved in blood plasma (7-10%)
- As bicarbonate ions resulting from dissociation of carbonic acid (60-70%)
- Bound to amino groups on haemoglobin (carbonaminohemoglobin) 20-33%
What happens to the artery-vein difference of O2 during rest and exercise
At rest 20mL of O2 per 100mL blood is taken from artery and 4-5mL O2 is taken by capillaries and 15-16mL O2 is taken by veins to go back to lungs
During exercise 15mL O2 is taken by capillaries to go to muscle while 5mL is taken by veins back to lungs
What are the factors determining O2 uptake/delivery (3)
Oxygen content of blood
Amount of blood flow
Local conditions in muscle (pH, temp).
Describe pons and medulla oblongata regarding regulation of pulmonary ventilation
They control the rate and depth of the breathing by sending impulses to respiratory muscles
Receive majority of input control signals from periphery
List the regulators of pulmonary ventilation (8)
- Central control - pons and medulla oblangata
- Chemical changes (PCO2, PO2, H+)
- Chemoreceptors
- Muscle mechanoreceptors
- Conscious control
- Dyspnea/Hyperpnea
- Hyperventilation
- Valsava manouevere
What is dyspnea and hypersnea
Dyspnea - Shortness of breathing
Hypersnea - Increase in breathing
What is valsava manouevere
Breathing in and not allowing air to escape, during extensive period can reduce cardiac output
What is ventilatory breakpoint
The point during intensive exercise at which ventilation increases disproportionally to the O2 consumption. When work rate exceeds 50-75% VO2 max, O2 delivery can no longer match intensity. This results in energy being derived from anaerobic glycolysis
What is anaerobic threshold
Point during exercise of progressively increasing intensity at which metabolism becomes increasingly more anaerobic
What are buffers in the blood (4)
Bicarbonate
Haemoglobin
Proteins
Phosphates
What are chemical buffers in the body
HCO3-
Phosphate
Proteins
List the respiratory structure anatomy (9)
- Nasal cavity
- Nostril
- Mouth
- Larynx
- Trachea
- Right/left bronchus
- Right/left lung
- Pharanx
- Diaphragm
Name respiratory factors involved in acid-base balance (4)
- important chemical H+ buffers in body
- Pulmonary ventilation removes H+ from blood by the HCO3- reaction
- Kidney - long term regulation, secrete Cl- and conserve Na+ and K+
- Acute - reuptake and oxidation of Lac- into contracting and non-contracting tissue
Does ventilation limit performance?
Respiratory muscles are more resistant to fatigue than other muscles during heavy exercise (even though they take a lot of O2).
Pulmonary ventilation isnt usually a limiting factor apart from in some elite athletes and people with asthma.
