circulatory system #1 Flashcards
what are the three main functions of the circulatory system?
- transport
- homeostasis
- protection
what does the transport function of the circulatory system consist of?
transports gases, hormones, nutrient molecules and waste materials
what does the homeostasis function of the circulatory system consist of?
regulates internal temperature and transporting hormones
what does the protection function of the circulatory system consist of?
protects against blood loss from injury and protects against disease
what are the two circuits of the circulatory system?
- pulmonary
2. systemic
what is the pulmonary circuit?
- blood moving between the heart and lungs
- blood gets pumped to the lungs to pick up oxygen and release carbon dioxide, the newly oxygenated blood then gets sent back to the heart
what is the systemic circuit?
- blood pumped from the heart to the rest of the body
- oxygen rich blood returns to the left ventricle from the lungs, blood is then pumped from the heart to the rest of the body where the oxygen is dropped off
what is the coronary pathway?
oxygenated blood pumped from the heart to the heart tissues
where does the coronary artery originate?
the aorta
what circuit is blood moving between the heart and lungs
pulmonary circuit
what circuit is blood pumped from the heart to the rest of the body?
systemic circuit
what pathway is blood being pumped from the heart to the rest of the heart?
coronary pathway
what type of muscle is the heart composed of?
cardiac muscle
are heart contractions voluntary or involuntary?
involuntary
what is the average bpm of an adult?
70 bpm
what is the pericardium?
a fluid filled sac that surrounds the heart, it acts as a shock absorber and prevents friction
where is the heart located?
it is located in the centre of the chest in between the lungs, tipped slightly to the left
how many lobes does each lung have?
right lung: 3 lobes
left lung: 2 lobes (room for the heart)
what is the heart’s main function?
pumping blood through the body
how many pumps does the heart have?
2
how much blood does the heart pump every minute?
5L every minute
what can affect someone’s bpm?
stress, diet or exercise (or health issues)
how many chambers does the heart have?
4 chambers – 2 atria, 2 ventricles
what direction do arteries carry blood?
away from the heart
what direction do veins carry blood?
to the heart
what are atria?
chambers at the top of the heart that fill with blood returning to the heart
what does the left atrium do?
collects blood returning from the lungs
what does the right atrium do?
collects blood returning from the body
what are ventricles?
chambers at the bottom of the heart that receive blood from the atria and pump it out
what does the right ventricle do?
pumps blood to the lungs
what does the left ventricle do?
pumps blood to the body
what is the septum?
a muscular wall that separates the left and right sides of the heart
what are pulmonary arteries?
- blood vessel that carry DEOXYGENATED blood from the right ventricle to the lungs
what are pulmonary veins?
- blood vessels that carry OXYGENATED blood back from the lungs to the left atrium
what is the superior vena cava?
a vein that collects the deoxygenated blood from the head, chest and arms and dumps the blood into the right atrium
what is the inferior vena cava?
a vein that collects deoxygenated blood from the central and lower body and dumps it into the right atrium
what is the aorta?
- largest blood vessel in the body
- artery that stems from the left ventricle
- carries oxygenated blood
what are the branches of the aorta?
- coronary artery (feeds heart)
- left and right carotid arteries (feeds brain and torso)
what is the largest blood vessel in the body?
the aorta
how many valves does the heart have?
4 – 2 atrioventricular, 2 semilunar
what are the atrioventricular valves?
- there are two, the tricuspid and the bicuspid
- they separate the atrium from the ventricle
what is the tricuspid valve?
- has three flaps
- separates right atrium from right ventricle
what is the bicuspid valve?
- has two flaps
- separates the left atrium from the left ventricle
- aka. mitral valve
what are chordae tendinae?
connective tissue that support valves
what are papillary muscles?
the muscle that attaches to the chordae tendinae
what are semilunar valves?
- half moon shape
- found in the pulmonary trunk and aorta
- 2 of them - pulmonary/ aortic
what is the pulmonary semilunar valve?
- controls blood flow from the right ventricle to the pulmonary trunk, and eventually the lungs
what is the aortic semilunar valve?
- controls blood flow from the left ventricle to the aorta, and eventually the entire body
what are heart sounds?
the sound of valves closing
as ventricles contract what happens?
the SL valves open and the AV valves close
when do SL valves open?
when the ventricles contract
as the ventricles relax what happens?
AV valves open and SL valves close
when do AV valves open?
when the ventricles relax
what sound do we hear when the SL valves open and the AV valves close?
“LUB”
what sound do we hear when the AV valves open and the SL valves close?
“DUB”
what happens when heart valves are defective?
blood leaks back through valves
why is the muscle on the left side of the heart thicker?
because the left ventricle must pump blood to the entire body
