Chapter 3 - Circulation Flashcards
What is diffusion time proportional to?
Distance^2
What is a circulatory system?
An organ system that transports blood containing nutrients such as oxygen and CO2
What are the three main components of the circulatory system?
- Circulatory fluid
- Blood Vessels
- Muscular Pump (Heart)
What is an open circulatory system?
nutrients and waste are moved through the body by a fluid which flows freely through the body cavity, rather than being contained in veins
What is a closed circulatory system?
Blood is contained within blood vessels at all times
What is the name of the circulatory fluid?
Hemolymph
What animals have an open circulatory system?
Anthropoids and Molluscs
What animals have a closed circulatory system?
All vertebrates, Annelids and Cephlapods
What animals have a single and double circulatory system?
Single - fish
Double - humans, reptiles, amphibians and birds
What animals have a three chambered heart?
Amphibians and reptiles (two atria and one ventricle)
What are the two loops of blood vessels in a human heart?
Pulmonary circulation 9%
Systemic circulation 84%
What is the contraction phase of the heart pumping?
Systole
What is the relaxation phase of the heart?
Diastole
What part of the heart receives deoxygenated blood from the body?
Right atria
What part of the heart pumps deoxygenated blood to the lungs via the pulmonary artery?
Right ventricle
What artery transports blood from the right ventricle to the lungs?
Pulmonary artery
What part of the heart receives oxygenated blood from the lungs via the pulmonary veins?
Left atrium
Which part of the heart pumps oxygenated blood to the body via the aorta?
Left ventricle
What are the atrioventricular valves?
Tricuspid and Mitral (bicuspid) valves
Where would you find the tricuspid valve?
Between the right atria and ventricle
Where would you find the mitral (bicuspid) valve?
Between the left atria and ventricle
What are the semilunar valves?
Aortic and pulmonary valve
Where would you find the aortic valve?
Between the left ventricle and the aorta
Where would you find the pulmonary valve?
Between the right ventricle and pulmonary trunk
What does the coronary sinus do?
Transports deoxygenated blood to the heart via the heart walls aka the hearts own blood supply
What valves contract during systole?
Tricuspid and mitral
What valves contract during diastole?
Aortic and pulmonary
What does autorythmic mean?
Contracts and relaxes without any signal from the nervous system
What controls the coordinated contractions of the heart?
The SA node (pacemaker)
Describe the heart conduction system
SA node > spreads signals through atria > AV delays signals to allow for atria to empty completely of blood before the ventricles contract > bundle branches pass signal to heart apex > purkinje fibres spread signals through ventricle >
SA node > AV Node > bundle branches > Purkinje Fibres
What hormones effect heart rate?
Epinephrine
What hormone speeds up the SA node?
Epinephrine
What gland secretes epinephrine?
Adrenal gland
How much does body temperature at 1oc increase heart rate?
10 beats/minute
What is the autonomic nervous system?
component of the peripheral nervous system regulates involuntary physiologic processes including heart rate, blood pressure, respiration, digestion, and sexual arousal.
What two nerves make up the Autonomic nervous system?
Sympathetic and Parasympathetic
What is the role of the Sympathetic nerves?
Release norepinephrine that increase the heart rate and force of contraction
Where does the sympathetic nerves originate from?
T1- T4 levels of the spinal cord
What is the role of the parasympathetic nerves?
Releases acetylcholine that decreases heart rate and force of contraction
Where does the parasympathetic nerves originate?
The vagus nerve
What arteries supply the heart with blood?
Coronary arteries
What is cardiac output?
Volume of blood pumped through the heart per minute
What is cardiac output dependent on?
Heart rate and stroke volume
What is heart rate?
Number of beats per minute
What is stroke volume?
Amount of blood pumped in a single contraction
What determines blood pressure?
Cardiac output and peripheral resistance
What is atherosclerosis?
Build up of fatty substances in the arterial wall
What is a deep vein thrombosis?
Pooling of blood in the vein causing clotting
Where is the velocity of blood slowest?
In the capillary beds due to the high resistance and large cross sectional area
How to measure pulse pressure?
Systolic pressure - diastolic pressure
What is the role of precapillary spinchters?
Control blood flow between arterioles and venules
What drives fluid out of the capillaries?
Blood Pressure
What drives fluid back into the capillaries?
Blood proteins known as osmotic pressure
True or false - on average there is a net loss from the capillaries
True
What is the equation for net loss in the capillaries?
Fluid out - fluid in mmHg
What pressure drops along the capillaries?
Blood pressure
What is the name for fluid lost by the capillaries?
Lymph
What is the lymphatic system?
A series of drains that returns fluid that has leaked out the capillaries back into the veins
What is Oedema?
Swelling caused by distributions in the flow of lymph
What are lymph nodes?
Organs that filter lymph and play an important role in the body’s defence
What is the respiratory system?
A system of branching ducts that conveys air into the lungs
What is pleural space?
Potential space between the lung and ribs containing pleural fluid
What is the role of pleural fluid?
Prevents friction between the lung and ribs
What is diffusion rate dependant on?
Surface area ( large ) Concentration difference Distance ( short )
Describe the structure of alveoli
Honeycombs surrounded by dense capillary networks
How many alveoli does a human contain?
500 million +
What type of tissue makes up alveoli?
Simple squamous epithelium
What is negative pressure breathing?
When air is drawn into the lungs - DIAPHRAGM moves down
What is normal blood pH?
7.4
What is haemoglobin?
A blood protein that is able to bind with haem to carry oxygen
How many subunits does haemoglobin have?
Four
What do all heam groups contain?
Iron
When would a haemoglobin be said to be 100% saturated?
When all sites have been bound with oxygen
In what cells is haemoglobin contained?
Erythrocytes
What is pO2 levels in the lungs?
100mmhg
What are pO2 levels of tissues at rest?
40mmHg
What is the partial pressure (pO2) of tissues during exercise?
<20%
At what pH does pO2 and haemoglobin reach disassociation?
7.4
What decreases haem subunits affinity for oxygen?
A change in their shape
What are the three ways that carbon dioxide is transported?
5% dissolved CO2
5% attached to haemoglobin and other blood proteins
90% as bicarbonate ions
What is the name of an oxygen storing protein found in mammals such as seals?
Myoglobin
Describe the structure of blood
Cells and cell fragments (platelets) suspended in a liquid matrix called plasma
What is the role of plasma?
Influence blood pH, osmotic pressure, viscosity
They all aid in immunity as antibodies, lipid transports and blood clotting