Chapter 49 - The Circulatory System Flashcards
Which groups lack a separate circulatory system?
- Sponges
- Cnidarians
- Nematodes
Why do sponges, cnidarians, and nematodes lack a circulatory system?
They are small enough, having a small surface area, that oxygen and nutrients can get to all the cells through diffusion
No distinction between circulating and extracellular fluid
Open Circulatory Sytem
The fluid in an open circulatory system
Hemolymph
Distinct circulatory fluid (blood) enclosed in vessels and transported away from and back to the heart
Closed Circulatory System
Path of blood in fish circulation
- Body
- Heart
- Gills
- Body
Who evolved a circulation system first?
Fish
Who evolved the first chamber pump heart?
Fishes
How are the fishes heart set up?
Four structures are arranged one after the other to form two muscular pumping chambers.
The two muscular pumping chambers in a fish
Atrium and Ventricle
Which chamber of the fishes heart is the stronger?
Ventricle because they have to pump blood to the whole body
Land vertebrates have lungs that require what?
Double Circulation
The two circulation systems in a land vertebrates
- Pulmonary Circulation
2. Systematic Circulation
The flow in pulmonary circulation
- Heart
- Lungs
- Heart
The flow in systemic circulation
- Heart
- Body
- Heart
Amphibian/Reptile Circulation have how many chambers in their heart?
Three chambered heart
What does the three chambered heart consist of?
Two atria and one ventricle
Amphibians obtain additional oxygen through ______
Cutaneous Respiration
In a three chambered heart, oxygenated and deoxygenated blood ________
Mix but very little
Mammals and archosaurs have how many chambers in their heart?
Four chambered heart
The anatomy of the four chambered
Two separate atria and two separate ventricle
The heart has two pairs of valves
- Atrioventricular (AV) Valves
2. Semilunar Valves
Guard the openings between atria and ventricles. Left and right or bicuspid and tricuspid.
Atrioventricular (AV) Valves
Overview of blood flow in the heart
- Superior Vena Cava
- Right Atrium
- Atrioventricular Valves
- Right Ventricle
- Pulmonary Artery
- Lungs (Get Oxygen)
- Pulmonary Veins
- Left Atrium
- Bicuspid Valve
- Left Ventricle
- Aortic Valve (Aorta)
- To the rest of the body
Guard the exits from the ventricles to the arterial system
Semilunar Valve
Two parts of the semilunar valve
- Pulmonary Valve (right)
2. Aortic Valve (left)
Supply the heart muscle itself
Coronary arteries
Brings blood back to the heart
Cardiac Veins
Valves open and close as the heart goes through the cardiac cycle of rest called __________
Diastole
Valves open and close as the heart goes through the cardiac cycle and contracts called the _________
Systole
The heart contracts starting at the _______
Sinoatrial (SA) Node
Three characteristics of the Sinoatrial (SA) Node
- In the right atrium
- Acts as a pacemaker for the rest of the heart
- Produces spontaneous action potentials that proliferate down the heart and causes a heartbeat
Blood leaves the heart through _______
Arteries
__________ are the finest, microscopic branches of the arterial tree
Arterioles
Blood from arterioles enters the ________
Capillaries
Blood from capillaries collects in the _______
Venules
The blood from the venules leads to larger vessels, called _______-
Veins
What carries the blood back to the heart?
Veins
Order of blood flow through vessels
- Arterioles
- Arteries
- Capillaries (Oxygen exchange happens)
- Venules
- Veins
Arteries and veins are composed of four tissue layers
- Endothelium (Epithelium)
- Elastic Fibers
- Smooth Muscle
- Connective Tissue
Are composed of only a single layer of enothelial cells
Capillaries
What is the job of capillaries?
Allow rapid exchange of gases and metabolites between blood and body cells
Has vasoconstrictions and vasodilations
Arteries and Arterioles
Contraction of the smooth muscle layer
Vasoconstriction
Relaxation of the smooth muscles layer results in
Vasodilation
- Have thinner layer of smooth muscles than arteries
- Return blood to the heart with help of skeletal muscle contractions and one way venous valves
Veins and venules
___________ return blood to the heart with help of skeletal muscle contractions and one way venous valves called ________
- Veins and venules
2. Venous Valves
Two cardiovascular diseases
- Heart Attacks
2. Stroke
Three facts about heart attacks
- Also called Myocardial Infarctions
- Main cause of cardiovascular deaths in U.S.
- Insufficient supply of blood to the heart
What causes a stroke?
Interference with blood supply to the brain
Is a connective tissue composed of a fluid matrix, called plasma, within which are found different cells and formed elements.
Blood
The fluid matrix in blood
Plasma
What is in the plasma?
Different cells and formed elements
The functions of circulating blood are
- Transportation of materials
- Regulation of body functions
- Protection from injury and invasion
What percentage of the plasma is water?
92%
What solute are in the plasma?
Nutrients Wastes Hormones Ions Proteins
If protein is removed, the plasma is called _______
Serum
The formed elements include ______________
Red Blood Cells
White Blood Cells
Platelets
Another name for red blood cells
Erythrocytes
Red blood cells of vertebrates contain _________
Hemoglobin
A pigment that binds and transports oxygen
Hemoglobin
Another name for while blood cells
Leukocytes
Amount of red blood cells in blood?
5 million per microliter of blood
Percentage of white blood cells in blood
Less than 1% of blood cells
Three defining characteristics of leukocytes
- Larger than erythrocytes
- Have nuclei
- Can migrate out of capillaries
Are cell fragments that pinch off from larger cells in the bone marrow
- Function in the formation of blood clots
Platelets
All of the elements of blood develop from _________-
Pluripotent Stem Cells
Is blood cell production
Hematopoiesis
