Chapter 8.1 Flashcards
How are nutrients spread throughout the cells organelles?
Through a process called cytoplasmic streaming which requires energy from ATP
What is the 1st main function of the circulatory system?
Transports gases (from the respiratory system), nutrient molecules (from the digestive system), and waste materials (from the excretory system)
What is the 2nd main function of the circulatory system?
Regulates external temperature and transports hormones
What is most of the bodies heat generated by?
The motor system
What are hormones?
Reaction triggering chemicals that are produced by the endocrine system
What is the 3rd main function of the circulatory system?
Prevents against blood loss from injury and against disease-causing microbes or toxic substances introduced into the body
What is are the 3 major components of the circulatory system?
Heart, blood vessels, and the blood
What is the heart?
An organ that pushes blood through the body with its pumping action and generates blood flow
What are blood vessels?
Roadways through which blood moves
What do the heart and blood vessels comprise?
The cardiovascular system
What does the blood do?
Carries nutrients, oxygen, carbon dioxide, water, wastes and many other materials
What are the functions of the heart?
Pumping blood through the body
Keeping oxygen rich blood separate from oxygen poor blood
Ensuring blood flows only in one direction throughout the body
What are the walls of the heart made up of?
Cardiac muscle tissue
Why can’t you consciously affect your heartbeat?
Because contractions are rhythmical and involuntary
How do the muscle cells stop themselves from becoming fatigued?
They take brief breaks in milliseconds before they contract
How many chambers does the human heart have?
4
What are the top 2 chambers of the heart called?
Atria (atrium singular)
What do atria fill with?
Blood returning from either the body or the lungs
What are the bottom 2 chambers of the heart called?
Ventricles
What do the ventricles do?
Receive blood from the Atria and pump it either out to the body or the lungs
What are the atria and ventricles separated by?
Thick muscular walls called the septum
What does the right side of the heart do?
Receives blood coming back from the body and then pumps the blood out to the lungs
What blood vessels open into the right atrium?
The vena cava
What does the superior vena cava do?
Collects oxygen poor blood coming from the tissues in the head, chest and arms
What does the inferior vena cava do?
Collects oxygen poor blood coming from tissues elsewhere in the body
Where does oxygen poor blood flow?
Either from the superior or inferior vena cava into the right atrium and then into the right ventricle. Then out into the pulmonary trunk before entering the left and right pulmonary arteries. From there it goes to the lung
What does the left side of the heart do?
Receives oxygen rich blood from the left and right lungs and pumps this blood out to the body.
How does blood flow from the lungs to the heart?
From the lungs it flows through the pulmonary veins to the left atrium. The left atrium pumps the blood into the left ventricle which sends it to the aorta
How many valves does the heart have?
4
What do valves do in the heart?
Ensure blood flows in the correct direction in the heart
What are the atria and ventricles separated by?
The atrioventricular valves
What is the atrioventricular valve on the right side called?
The tricuspid valve because it it made of 3 flaps
What is the atrioventricular valve on the left side called?
The bicuspid valve because it only has 2 flaps
What are the non atrioventricular valves in the heart called?
Semilunar valves because of their half moon shape
What are the 3 main types of blood vessels?
Arteries
Veins
Capillaries
What is the function of arteries?
They carry oxygen rich blood away from the heart
What is the function of veins?
Carry oxygen poor blood toward the heart
What joins arteries and veins?
Capillaries
What happens when blood travels from an artery to a capillary?
Gases, nutrients, and other materials are transferred to tissue cells and wastes move into the blood
What happens after blood moves from a capillary into vein?
The blood goes towards the heart
What is unique to an artery?
They have elastic walls
Why do arteries have elastic walls?
This allows an artery to expand as a wave of blood surges through it during the contraction of the ventricles and snap back during the relaxation of ventricles