Investigations of the Circulatory System Presented by: Tiesha Miller and Jillian McClennen
What is the Circulatory System The circulatory system is the network of flexible tubes that carry blood throughout the body. The circulatory system includes the heart, lungs, arteries, arterioles (small arteries), and capillaries (very tiny blood vessels). The blood vessels carry oxygen- and nutrient-rich blood throughout the body.
High blood pressure results from the tightening of very small arteries called arterioles. Arterioles are important because they regulator the blood flow throughout the body.
The arterioles tighten (or constrict), the heart works harder to pump blood through the smaller space, and the pressure inside the vessels grows.
Pressure and Capillaries
The pressure of arterial blood is largely dissipated when the blood enters the capillaries.
Capillaries are tiny vessels with a diameter just about that of a red blood cell. The number of capillaries supplied by a single arteriole is so great that the total cross-sectional area available for the flow of blood is increased.
Blood Pressure Continued
The pressure of the blood when it enters the capillaries decreases, which is why human capillaries do not get destroyed from high blood pressure.
Ventricular contraction creates pressure in the arteries. This pressure travels throughout body as a pulse
the two types of pulses included: Systolic pressure is active pressure and Diastolic pressure is passive pressure.
Major Evolutionary Trends in the Circulatory System
The major evolutionary trends include organisms with an open heart system and closed heart systems, the amount of chambers in the heart has increased; the possession of hemoglobin in the blood now present in order to get the blood to pump faster throughout the body.
The development of veins, capillaries, and arteries that control the exchange of oxygen and deoxygenated blood and they also transport heat, and control the blood pressure.
Representation of Circulatory system
Circulatory system in 5 Representative Animals Cnideria Nematode Annelida Mollusca Chondrichthye
Cnideria Has an open circulatory system. In this type of system, there is neither a true heart nor capillaries. Blood vessels that act as pumps to force the blood along.
Continuation These vessels join directly with open sinuses. "Blood," actually a combination of blood and interstitial fluid called 'hemolymph', is forced from the blood vessels into large sinuses, where it actually baths the internal organs.
Nematode In nematodes, there is a circulatory system but they have pseudocoel fluids that accomplish a similar circulation throughout the body.
Annelids have a closed circulatory system with more than one heart that pumps in large vessels that branch into smaller vessels flowing through the organs. Blood is confined to vessels and interstitial fluid do not fuse, and muscular vessels that function as hearts.
have an open circulatory system pumped through the heart, and released directly into spaces in the tissues and it returns to the gills back to the heart.
blood-filled space is known as a hemocoel ("blood cavity").
In the mollusks, the hemocoel has largely replaced the coelom, which is reduced to a small area around the heart and to the cavities of the organs of reproduction and excretion.
Circulatory system in 5 Representative Animals Osteichthyes Amphibians Reptiles Human Aves
Osteichthyes Osteichthyes have a two chamber heart. They have one atrium & one ventricle. An atrium receives blood into the heart and drives it into a ventricle for pumping the blood away from the heart. The ventricle muscular chamber pumps blood out of the heart and into the circulatory system. The pumped blood goes to the gills of the Osteichthyes.
Through this process oxygen spreads out into the capillaries and carbon dioxide is released.
The capillaries end up converging into arteries that will eventually carry out blood throughout the body and organs. Blood flows through the capillary beds and drops blood pressure. Capillary beds are extremely small blood vessel located within the tissues of the body.
In a cycle, blood flows throughout the body, tissues and organs.
Amphibians and Reptiles Amphibians and Reptiles have a three chamber heart which consists of a right and left ventricle, atrium, systemic circuit and a pulmonary circuit. In a systemic circuit, blood exits the heart through the aorta, travels through the organs of the body by assistance from the arteries, and then returns to the heart through the systemic veins.
In a pulmonary circuit, blood travels from the right ventricle through the pulmonary artery into the lungs. This is where carbon dioxide is exchanged for oxygen.
How does the Human Heart beat and how is the heart beat regulated?
The heart's four chambers are controlled by an electrical impulse.
A chamber of the heart contracts when an electrical impulse moves across it. These electrical gestures begin in a small parcel of highly specialized cells in the right atrium or the sinoatrial node (SA node), also called the sinus node.
The SA controls how often the heart beats. There are alterations in reactions to emotional and hormonal influences. This also lets the heart rate respond to varying stressors
Humans and Aves are consisted of a four chamber heart.
They both have 2 atria & 2 ventricles. This gives them the ability to complete separation of oxygenated and deoxygenated blood. This allows an easy access of oxygen to travel through the body and cells. The right side of the heart drives pulmonary circulation while the other dives systemic circulation.
Through evolutionary changes in the circulatory system many organism struggles to survive in certain environments just because of this system.
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