Circulation and gas exchange Flashcards
Name the three cellular components of blood
Red blood cells
White blood cells
Platelets
What are all the components of blood? (4)
- Cells
- Plasma
- Biomolecules (proteins, hormones, CHO)
- Inorganic salts
Blood plasma makes up what percentage of of whole blood?
About 55%
This is the substance within blood that buffers the pH and contributes to osmotic balance and regulation of the cell membrane potential
Inorganic salts
What are the functions of the blood plasma? (3)
- Transports nutrients around the body
- Transports proteins, hormones, and Ab
- Removes metabolic waste compounds
This is the percentage of red blood cells relative to the total blood volume
hematocrit
What is the characteristic shape that RBC’s have?
Bi-concave, or doughnut shape
What is the purpose of the RBC’s special shape?
Has a large surface area for gas exchange, and it s allow flexible enough to allow them to travel through narrow capillaries
The bi-concave shape of RBC’s is achieved via a mesh-like network of the protein called
Spectrin
What is the primary component of the RBC cytoskeleton that interacts with cell membrane proteins?
Spectrin
What is the effect of Spectrin gene abnormalities?
Spherical shape and fragile RBC’s
RBC plasma membrane composition is aymmetrical with mainly ________ charged phospholipids on the inner part of the lipid bilayer.
negatively
What is the significance of the negatively charged phospholipids in the RBC plasma membrane?
Important in cell signalling communication
Abnormally low concentration of O2 in the blood
Hypoxaemia
Abnormally high concentration of CO2 in the blood
Hypercapnea or Hypercarbia
Respiratory rate (RR) x the tidal volume (TV)
Minute Ventilation (VE)
Negatively charged molecule
Anion
Positively charged molecule
Cation
Dazed/drunk type state caused by abnormally high levels of nitrogen in the blood, such as from deep sea diving
Nitrogen narcosis
Shortness of breath, trouble breathing
dyspnea
Interruption in breathing during sleep
Sleep apnoea
Pulmonary embolus
Blood clot in the lungs
Pain caused by inflammation of the parietal pleura, most pronounced with deep breathing, coughing, sneezing, or laughing
Pleuritic chest pain
Abnormal lung sound caused by inflamed pleural layers rubbing together with breathing
Pleural rub
Abnormally low levels of CO2 in the blood
Hypocapnoea
Abbreviation for perfusion
Q
V/Q ratio
Ventilation / Perfusion
Partial pressure of oxygen in the alveoli is represented as
PA O2
Partial pressure of oxygen in arterial blood is represented by
Pa O2
The difference between the PA O2 and the Pa O2
A-a gradient
What are the four types of hypoxia?
- Hypoxic (or hypoxaemic)
- Anaemic
- Stagnant (or circulatory)
- Histoxic (or cytotoxic)
What are the five mechanisms of hypoxia?
- Hypoventilation
- Low FiO2 (fraction of inspired oxygen)
- Diffusion impairment
- Shunt
- V/Q mismatch
What are the three types of hypoxia that result in a reduced ability to DELIVER oxygen?
- Hypoxic
- Anaemic
- Stagnant
What is the type of hypoxia that results from an inability to utilise oxygen?
Cytotoxic/histotoxic
Hypoventilation results in what changes in blood gasses?
An increase in carbon dioxide
What is the relationship between FiO2 and altitude?
Fi O2 will decrease with increased altitude
What percentage of air is made up of oxygen?
21%
What is the partial pressure of inspired oxygen at sea level? (Fi O2)?
about 150 mm Hg or 20 kPA
What would cause a diffusion impairment?
Diffusion impairment is caused by the thickening of the interstitum due to collagen deposition and fibrosis of the lungs, which stops oxygen from diffusing.
How wide is the interstitial space between the alveoli and the capillary?
0.5 micrometres (double check this answer)
What is the optimal V/Q ratio?
0.8
Name two conditions mentioned in lecture that would result in a V/Q mismatch.
- Pneumonia (reduced ventilation relative to blood flow)
2. PE (reduced blood flow relative to ventilation)
This is a system where nutrients are transported from the intestines to the liver
The hepatic portal system
This is the system where hormones are rapidly transported and exchanged between the hypothalamus and the anterior pituitary gland
The hypophyseal portal system
Name two important structural components of hepatic circulation
Liver lobule and sinusoid
Which vein arises from the gastrointestinal tract and supplies 70% of the circulation in the liver?
The portal vein
What three arteries make up the splanchnic circulation?
Celiac artery
Superior mesenteric
Inferior mesenteric
(All branch off the aorta)
What is part of the circulatory system called that provides blood to the liver, spleen, stomach, pancreas, small intestine, and large intestine?
The splanchnic circulation
Circulatory flow to skeletal muscle can increase up to _____ fold during exercise
100
What happens to blood flow in the kidneys and GI tract when adrenaline and the sympathetic nervous system is activated?
blood flow is reduced
What happens to cerebral blood flow when adrenaline and the sympathetic nervous system is activated?
Cerebral blood flow should be maintained
During exercise, what local regulatory factors can override the sympathetic vasoconstrictor influences in skeletal muscle?
CO2 K+ H+ Lactate NO
This concept refers to the diminished vasoconstriction during increases in sympathetic activity within the active skeletal muscle
Functional sympatholysis
diminished vasoconstriction during increases in sympathetic activity within the active skeletal muscle
thermoregulation
Thermoregulation is under the autonomic control of the ____________ nervous system.
sympathetic
Which region of the brain contains receptors that control the body temperature within a tight range?
Hypothalamus
These circulatory structures within the skin redirect blood flow to either towards the surface or the core in order to maintain the body’s core temperature.
Arterio-venous anastamoses
Sympathetic activity _________ surface capillaries during cold or fight/flight response, and ___________ them in heat and exercise.
closes, opens
Through what two mechanisms is cutaneous blood flow adjusted to maintain body temperature?
- Arterial dilation/constriction
2. Activity of AV anastamoses
Abbreviation for atmospheric pressure
P atm
Abbreviation for the pressure of oxygen in the alveoli
PA O2
Abbreviation for the arterial partial pressure of oxygen
Pa O2
Abbreviation for the arterial partial pressure of carbon dioxide
Pa CO2
Abbreviation for the venous partial pressure of carbon dioxide
Pv CO2
Medical term for reduced partial pressure of oxygen in arterial blood
hypoxaemia
What does Sa O2 measure?
The percent saturation of haemoglobin with oxygen
This is haemoglobin with carbon monoxide bound to it
carboxyhaemoglobin
