Unit 4: Cardiovascular System (Part 1) Flashcards
What is the general problem with being multicellular?
you are very big!
What are some characteristics of multicellular organisms
- very large in size
- outer layer interacts with the environment
- requires oxygen and nutrients from the environment because we cannot generate them ourselves
- rate of diffusion of oxygen and nutrients is limited by distance
What is the solution of diffusion limitation in multicellular organisms
- cardiovascular system for substance transport in body
- transported by blood flow throughout the body
- bulk flow rather than diffusion***
What materials are transported from the external environment to tissues
nutrients, water, and gases
What materials are transported between tissues of the body
wastes, nutrients, and hormones
What materials are transported from body to the external environment
metabolic wastes, gases, and heat
What’re the components of the cardiovascular system
- heart: the pump of the system
- blood vessels: the vasculature (figure 15.3)
- blood cells and plasma: the fluid (figure 16.3)
Where are the blood vessels attached to the heart
the base of the heart
What is the apex of the heart
the pointy inferior end of the heart
What can be compared to the heart when discussing shape
an ice cream cone
- the base is where the important components are attached (like ice cream on the base of a cone)
- the apex is the pointy inferior end (like the pointy end of the cone)
What are the components of the blood?
~ 42% red blood cells (most dense)
<1% white blood cells (medium density)
~58% plasma (least dense)
What is another term for the region not containing erythrocytes
the Buffy coat
What components are found in the Buffy coat
platelets and white blood cells (neutrophils, basophils, eosinophils, lymphocytes, monocytes, etc.)
What are erythrocytes
red blood cells
What are leukocytes
white blood cells
What does the pneumonic NLMEB mean
“never let monkeys eat bananas” - the types of leukocytes
- neutrophils, lymphocytes, monocytes, eosinophils, basophils
What is the pericardium
the tough membraneous sac surrounding the heart
- made up of two layers with a small amount of fluid between them that acts as a lubricant (called pericardial fluid)
What are coronary arteries
supply oxygenated blood to the heart
- the heart has a very high oxygen demand; depends on adequate blood flow
- lack of blood supply to the heart results in a heart attack (myocardial infarction)
Describe the components of the internal anatomy of the heart and how blood travels throughout each part of the system
Left atrium: receives oxygenated blood from pulmonary veins, and sends it to the left ventricle
Left ventricle: receives blood from the left atrium, and sends blood to the body via the aorta
Right atrium: receives deoxygenated blood from the venae cavae (plural vena cava since we have 2), and sends it to the right ventricle
Right ventricle: receives blood from the right atrium, and sends it to the lungs
Valves: ensure blood flow is unidirectional (eg. atrioventricular (AV) valves, and semilunar valves)
(review figure 14.5 - note: the right pulmonary veins are not shown in this figure, but remember they are there!)
(review figure 14.1)
Draw/recall the pathway of blood through the heart!
include atrium(s), ventricle(s), valve(s), etc. and review figures 14.1 & 14.5 for clarification
What is the pulmonary circuit
blood flows from heart to the lungs for oxygen
What are the two types of AV valve
tricuspid (right side) and biscuspid (mitral) (left side)
(figure 4.3)
What are the two types of semilunar valve
aortic and pulmonary (figure 4.3)
The base of the heart is….
a. found at the bottom of the heart
b. found at the top of the heart
c. where major vessels attach
d. a and c
e. b and c
*in class review question
e. found at the top of the heart, and where the major vessels attach
Which type of valve DOES require cords for support
AV valves - chordae tendinae
(semilunar do not due to their shape)
*review figure 4.3 course notes
What are the two paths of blood flow through the body
pulmonary circuit and systemic circuit
(review figure 4.4 course notes)
When the ventricle contracts, the AV valves are ________, and the semilunar valves are __________
closed, open
What is the purpose of the chordae tendinae
prevents valves from being pushed back into atrium
When the ventricle is relaxed, the AV valves are ________, and the semilunar valves are ________
open, closed
What is the pulmonary circuit consisting of
blood vessels in the lungs and those that connect lungs to the heart
What is the path of the pulmonary circuit
- blood flows from right atrium to right ventricle; which is then pumped to pulmonary arteries in the lungs
- lungs have many small capillaries to increase oxygen transfer (increased resistance = decreased pressure of blood)
- oxygenated blood has low pressure; needs to return to heart via the pulmonary veins to left atrium
(review figure 14.1)
What is the aftermath capability of the pulmonary circuit
breathing
What does the systemic circuit involve
the remaining organs in the body (aside from lungs in pulmonary circuit)
What is the path of the systemic circuit
- blood flows from left atrium to left ventricle; which is then pumped to aorta, pumped to arteries, and pumped to capillary networks throughout the body
- oxygen diffuses from the blood into capillary networks, then flows to venues and larger veins
- oxygen-poor blood has low pressure; needs to return to heart through superior and inferior vena cavas and to the heart
(review figure 14.1)
What increases the pressure of blood in critical points of the double circuit
the heart
(review figure 15.1)
Arteries carry blood _________ the heart
away (think a-artieries = a-away)
Veins carry blood ___________ the heart
towards
How’s the heart different from other muscles in relation to the nervous system
the heart does not need signalling from the nervous system to contract
What specialized cells are found in the heart and what do they do
auto rhythmic cells (pacemaker cells)
- generate action potentials to create contraction without help from the nervous system
Where are pacemaker/autorhythmic cells found
the SA node (sinoatrial node), in the right atrium near the superior vena cava
(figure 14.15 *in purple)
Pacemaker cells have _____________ ___________ ____________
unstable membrane potential
What are unstable membrane potentials
slow potential that drifts upwards from -60mV until it reaches threshold and initiates action potential
(review figure 14.14)