Block B Lecture 3: Exercise - Physiology and Pharmacology Flashcards
How do you calculate flow?
Change in pressure / Resistance
(Lecture 3, Slide 4)
What is Po2?
The concentration of oxygen
(Lecture 3, Slide 4)
Where does gas exchange occur and what 2 gases are exchanged and what direction?
It occurs between the alveoli and the blood (and eventually the tissues), and O2 is put into the blood whereas CO2 is taken out
(Lecture 3, Slide 5)
What are the 5 steps of gas exchange?
Ventilation
Diffusion
Bulk flow
Diffusion
End-point
(Lecture 3, Slide 5)
What occurs in the ventilation stage of gas exchange?
Bulk flow exchange of air
(4L/min at alveoli)
(Lecture 3, Slide 5)
What occurs in the first diffusion stage of gas exchange?
Diffusion of O2 and CO2 occurs at lung capillaries
(Lecture 3, Slide 5)
What drives diffusion in gas exchange?
Concentration gradients
(Lecture 3, Slide 5)
What occurs in the bulk flow phase of gas exchange?
Transport of O2 and CO2 through circulation
(Lecture 3, Slide 5)
What occurs in the second diffusion stage of gas exchange?
Diffusion of O2 and Co2 at tissues
(Lecture 3, Slide 5)
What occurs in the end-point stage of gas exchange?
Cells use O2 and produce CO2
(Lecture 3, Slide 5)
How much oxygen does 5L of arterial blood contain?
1L
(Lecture 3, Slide 6)
5Ls of arterial blood contains 1L of O2, how much of this is physically dissolved and how much is bound to haemoglobin?
15 mil physically dissolved, 985 ml bound to haemoglobin
(Lecture 3, Slide 6)
What curve does haemoglobin make on a oxyhaemoglobin dissociation curve (Conc of oxygen vs haemoglobin O2 saturation)?
Sigmoidal
(Lecture 3, Slide 7)
What is the sigmoidal curve that haemoglobin makes on an oxyhaemoglobin dissociation curve (conc of oxygen vs haemoglobin O2 saturation) useful for?
Rapid transfer of oxygen into tissue that is using up oxygen
(Lecture 3, Slide 7)
What is the difference in the oxyhaemoglobin dissociation curve of foetal haemoglobin compared to normal?
It moves the curve to the left and makes it steeper
(Lecture 3, Slide 8)
What 2 things does lower pH (from increased Co2) and higher temperature do the oxygen haemoglobin curve?
it shifts it to the right and makes it less steep
(Lecture 3, Slide 8)
What 3 physiological conditions are present in more metabolically active tissue and what do these result in?
Lower PO2
Higher PCo2
Higher temperature
All leading to greater O2 unloading
(Lecture 3, Slide 8)
What happens when breathing in and out?
In: Diaphragm and external intercostal muscles contract
Out: abdominal organs press upwards and lung elasticity recoils
(Lecture 3, Slide 9)
What is the role of carotid chemoreceptors?
To pick up chemical inputs that stimulate ventilation and to act as excitatory input to medulla inspiratory neurons
(Lecture 3, Slide 10)
What 3 chemical inputs stimulate ventilation?
Decreased arterial Po2
Increased production of non-Co2 acids
Increased Arterial PCo2
(Lecture 3, Slide 10)
What effect do α adrenoreceptor agonists have on smooth muscle?
They cause vascular smooth muscle contraction
(Lecture 3, Slide 11)
What effect do ß adrenoreceptor agonists have on smooth muscle?
Pulmonary smooth muscle relaxation
(Lecture 3, Slide 11)
What is the difference in pulmonary and vascular smooth muscle?
Pulmonary smooth muscle is found in walls walls of bronchi and bronchioles in the respiratory system
Vascular smooth muscle is found in the walls of blood vessels throughout the body, including all types of veins and arteries
(Lecture 3, Slide 11)
What does supplementary O2 increase?
The driving force for O2 uptake
(Lecture 3, Slide 11)
How do deaths from opioid abuse occur?
As they decrease activity of neurons in the medulla that drive breathing
(Lecture 3, Slide 11)
What does carbon monoxide poisoning result in?
Haemoglobin binds CO more readily than O2 and also loses co-operativity when it does - resulting in no oxygen reaching tissues
(Lecture 3, Slide 11)
What nerves control the skeletal muscle?
Somatic motor nerves
(Lecture 3, Slide 12)
What does an action potential in muscle increase the concetration of and what does this lead to?
An increase in calcium (Ca2+) ions , resulting in contraction
(Lecture 3, Slide 12)
What is a skeletal muscle fibre also known as?
A muscle cell
(Lecture 3, Slide 12)
How many nuclei and myofibrils exist per skeletal muscle fibre?
Multiple nuclei and hundreds of myofibrils
(Lecture 3, Slide 12)
What are myofibrils?
Very fine contractile fibres
(Lecture 3, Slide 12)
What are myofibrils made of?
Thick (myosin) and thin (actin + troponin) myofilaments
(Lecture 3, Slide 12)
What are 2 organelles contained in skeletal muscle fibres that are specific to these cells?
Transverse-tubules
Sarcoplasmic reticulum
(Lecture 3, Slide 14)
What is the role of transverse-tubles?
Extend plasmalemma (cell/plasma membrane) deep into the cell
(Lecture 3, Slide 14)