1. Overview of Function of the Cardiovascular System Flashcards
What are the main functions of the cardiovascular system? (5)
BULK FLOW SYSTEM
- O2 and CO2
- nutrients
- metabolites
- hormones
- heat (thermoregulation to periphearies)
How many heart beats are there in 70 years of a human life?
over 2.5 billion (incredibly reliable)
Why is the heart so remarkably flexible? (what features show this?)
- pump can vary output
- vessels can redirect blood
- vessels can store blood (stored in venules which can be released into circulation when needed)
Esp. during exercise
What are 2 circulations in the heart?
- systemic
- pulmonary
Both pumps have reverse functions
What does the right side of the heart pump blood into?
into the lungs
What does the left side of the heart pump blood into?
into the other body areas
Is output from both sides of the heart equal?
yes, it must be equal since pumps are in series and both must deliver same amount of blood to maintain the balance
How are most vascular beds arranged?
in PARALLEL fashion
What is an exception for blood not travelling in parallel fashion but in series directly to another location without dilution in parallel circulation?
blood travelling from HYPOTHALAMUS to PITUITARY GLAND
What is another exception of blood not travelling in parallel but directly from one location to the next without dilution in circulation?
from GUT to LIVER (nutrients absorbed in gut can be directly transported to liver without having to go through parallel circulation)
What is the cardiac output in a normal circulation?
5L/min
What does cardiac output correspond to?
oxygen consumption (roughly proportional)
Does the brain have more cardiac output or use more oxygen consumption?
MORE oxygen consumption (18%)than cardiac output (13%) for complex tasks
Does the heart have more cardiac output or use more oxygen consumption?
MORE oxygen consumption (10%) than cardiac output (4%)
Does the skeletal muscle have more cardiac output or use more oxygen consumption?
Both cardiac output and oxygen consumption is equal (20%)
Does the skin have more cardiac output or use more oxygen consumption?
MORE cardiac output (9%) than oxygen consumption (2%) for flexible thermoregulation
Do the kidneys have more cardiac output or use more oxygen consumption?
MORE cardiac output (20%) than oxygen consumption (6%) for metabolic requirement for filtration
Do abdominal organs have more cardiac output or use more oxygen consumption?
MORE oxygen consumption (30%) than cardiac output (24%)
Why is heart so susceptible to cardiac diseases in terms of its cardiac output and oxygen consumption?
Only receives 4% of its cardiac output but uses 10% of the body’s o2 therefore it can’t always satisfy its oxygen requirements which is why it’s so susceptible to disease