Lecture 1 (Test 2) Flashcards
What is the primary function of the cardiovascular system in response to blood loss?
To maintain arterial pressure and cardiac output to deliver nutrients
This involves multiple systems working together to ensure blood is delivered where needed.
What happens to blood when a person stands up from a seated position without reflexes?
Blood pools in the legs
This can lead to a drop in blood pressure if not counteracted by reflexes.
Which nervous system typically responds to positional changes in blood circulation?
Sympathetic Nervous System (SNS)
The SNS responds almost instantaneously to changes in position to maintain blood pressure.
Where are the carotid baroreceptors located?
At the bifurcation of the carotid artery (carotid sinus)
These baroreceptors are crucial for monitoring blood pressure.
What is the role of norepinephrine (NorEpi) in the cardiovascular system?
It regulates systemic vascular resistance (SVR) and contractility
NorEpi is the main pressor in the cardiovascular system.
Which organs are prioritized for blood flow during low blood pressure situations?
- Coronary circulation
- Central nervous system
- Kidneys
These organs are protected during circulatory compromises.
What is the function of vasopressin in response to low blood pressure?
To increase systemic vascular resistance (SVR)
Vasopressin release is typically triggered by changes in osmolarity.
What does the Renin-Angiotensin-Aldosterone System (RAAS) regulate?
Blood pressure and fluid balance
RAAS plays a critical role in maintaining blood pressure during emergencies.
What happens when compensatory mechanisms like Angiotensin 2 are taken away?
The ability of the system to maintain cardiac output and blood pressure is impaired
This can lead to severe consequences for blood circulation.
What are the low-pressure circulation areas of the body where stretch receptors are located?
Stretch receptors in large veins and atria
These receptors respond to increases in blood volume.
What is the effect of increased stretch in the atria on kidney function?
It increases urine output
This is a compensatory mechanism to reduce blood volume.
What is Atrial Natriuretic Peptide (ANP) and its role?
A hormone released from the right atrium that promotes sodium and water excretion
ANP helps to decrease blood volume when the atria are overstretched.
What does Brain-Type Natriuretic Peptide (BNP) indicate?
It indicates ventricular stretch and heart failure status
Elevated BNP levels suggest worsening heart failure.
What happens to BNP levels when heart failure treatment is effective?
BNP levels decrease
This indicates reduced strain on the ventricles.
What is the consequence of having a high blood volume in terms of blood flow?
Slower circulation and increased risk of clotting
Sluggish blood flow can lead to coagulation problems.
What role do the kidneys play in response to excessive blood volume?
They increase urine output to reduce blood volume
This is part of the body’s mechanism to prevent overdistension.
What is the normal blood volume in a healthy adult?
Approximately 5 liters
This includes both plasma and hematocrit.
What is the plasma portion of the blood volume?
About 3 liters
Plasma is the liquid component of blood.
What is the oncotic pressure of the blood primarily composed of?
- Albumin
- Fibrinogen
- Immunoglobulins
Oncotic pressure helps to maintain fluid balance in the vascular system.
What happens if about 20% of blood volume is lost?
It can be serious but not immediately fatal
The body has compensatory mechanisms to handle moderate blood loss.
What is the interstitium’s volume in relation to blood?
3/4s - 4/5s is the interstitium
What is the hematocrit value mentioned?
0.4
What is the oncotic pressure of the blood?
28 millimeters mercury
What primarily makes up the oncotic pressure?
- Albumin
- Fibrinogen
- Immunoglobulins
- Antibodies
- Coagulation factors
