Chapter 40 Circulatory System Flashcards
Where is hemoglobin found?
red blood cells
Plasma
fluid portion of blood
Characteristics of Hemoglobin
- tetrameric
- contains 4 hemes
True or False: All animals have a circulatory system.
False
True or False: In mammals, deoxygenated blood is kept separate from oxygenated blood due to the presence of two circuits.
True
In the human heart, blood is pumped from the left ventricle into the ____.
aorta
In mammals, blood in the pulmonary vein is ___.
oxygenated
True or False: Cardiac muscles are striated.
True
Most of the CO2 (carbon dioxide) in the blood _____.
has been converted to bicarbonate and dissolved in plasma
In mammals (ie humans), oxygen is primarily transported in the blood _____.
bound to hemoglobin in red blood cells
True or False: Oxygen binds to the iron that is found in the heme group of hemoglobin.
True
What are the 3 components of the circulatory system?
- pump (heart)
- fluid (blood)
- tubes (blood vessels)
Function of the Circulatory System
carries nutrients, gases, and metabolic wastes around the body
2 Types of Circulatory Systems
open and closed
Does an open circulatory system contain a heart?
YES
What is another word for blood in open circulatory systems?
hemolymph
Is there a distinction between blood and extracellular fluid in open circulatory systems?
NO
What does hemolymph do in open circulatory systems?
bathes cells directly by being emptied into cavities and coming into direct contact with tissues
True or False: Blood is in the vessels in closed circulatory systems.
True
Examples of Animals with Closed Circulatory Systems
- vertebrates
- annelids
- cephalopods
True or False: The heart is more muscular in a closed circulatory system.
True
What is the blood separate from in closed circulatory systems?
intersitital fluid
What animals lack a circulatory system?
- sponges
- some invertebrates
Why do some animals lack a circulatory system?
- low metabolic rates
- short diffusion distances
Why do larger and more active animals need a circulatory system?
- higher metabolic waste
- cannot get nutrients via diffusion
- Extracellular fluid is where cells get nutrients and dump wastes
What are the two types of extracellular fluid in animals with closed circulatory systems?
- plasma in the system itself
- interstitial fluid between cells
3 Advantages of Having a Closed Circulatory System
- fluid moves more quickly
- blood flow can be controlled
- specialized cells and molecules aid in transport
Do all closed circulatory systems have the same structure?
NO
Steps of Blood Flow in a Closed Circulatory System
1) Right Ventricle
2) Pulmonary Artery
3) Lungs
4) Pulmonary Vein to Left Atrium
5) Left Ventricle
6) Aorta
7 and 8) Tissues
9 and 10) Inferior and Superior Vena Cava
11) Right Atrium
A cardiac cycle is one ___.
contraction and relaxation
True or False: Both sides of the heart contract at the same time.
True
What contracts first, the ventricles or the atria?
atria
Systole
contract
Diastole
relaxation
What is the function of valves in hearts and veins?
prevent backwards blood flow
Cardiac Diastole
all chambers are relaxed and the blood flows into the heart
Atrial Systole, Ventricular Diastole
atria contract, pushing blood into the ventricles
Atrial Diastole, Ventricular Systole
after the atria relax, the ventricles contract, pushing blood out of the heart
Pacemaker Cells
initiate action potentials in the heart
True or False: Input is required from the nervous system for action potentials in the heart.
False
Where is the pacemaker located?
sinoatrial node of the right atrium
Characteristics of the Atrioventricular Node
- where electrical signal passes to get to the ventricles
- slows down the electrical signal to give atria time to contract
Purkinje Fibers
conducting fibers
Where does the heartbeat originate?
the valves opening and closing in the cardiac muscle
What is the function of intercalated discs in cardiac muscle?
enable the coordinated function of the heart cells to allow the heart to beat
Which blood vessel is the smallest?
capillaries
Which kind of blood vessel has the largest cross sectional area?
capillaries
Which blood vessel has the highest blood pressure?
Arteries
Which blood vessel class has the lowest blood pressure?
veins
Which blood vessel has the lowest velocity?
capillaries
What does the size of the tube in blood vessels determine?
how fast the blood is moving
True or False: Arteries and veins are the largest blood vessels.
True
Where does the exchange of gases, nutrients, etc. occur in the circulatory system?
capillaries
Why is slow blood flow important to tissues receiving nutrients, gases, etc?
slow blood flow allows more time for things to move in and out of the bloodstream
Blood is a type of _______ tissue.
connective
Hematocrit
volume of blood composed of cells
What does hematocrit include?
red blood cells, white blood cells, platelets
What is another word for red blood cells?
Erythrocytes
Where are red blood cells produced?
bone marrow
What controls the production of red blood cells?
Erythropoetin
Erythropoetin
hormone produced by the kidney in response to hypoxia
Hypoxia
low blood oxygen
What do red blood cells contain?
hemoglobin
Where are red blood cells broken down and stored?
spleen
Leukocytes are involved with ___.
immune responses
Characteristics of Leukocytes (White Blood Cells)
- destroy foreign cells and pathogens
- produce antibodies
- involved in allergic reactions
Platelets are invovled with ___.
clotting
Platelets
cell fragments
Where do platelets come from?
megakaryocytes
Megakaryocyte
large cell that stays in bone marrow
Trace of Electrical Signal Through the Heart
- 1) Starts in pacemaker
- 2) electrical impulse travels through atria
- 3) electrical impulse travels through atrioventricular node
- 4) impulse travels through purkinje fibers
- 5) ventricular contraction starts at apex
