Organization in Animals TOPIC 2 Flashcards
Why do cells differentiate and become specialised
Because the organisms develop different ways of exchanging materials
Define tissues
A group of cells with similar structure and functions
Define organs
Groups of tissues that preform a particular function
What does epithelial tissue do
it lines the inside of organs
What does muscular tissue do
it contracts and relaxes to bring about movement
What do glandular tissues do
Make and secrete chemicals like enzymes and hormones
Define organ system
Different organs combine to form organ systems to carry out major functions in the body
Define organisms
An organism is made up of organ systems that work together
Define Cell
The smallest unit of all living organisms that are the basic building blocks of all living organisms
Define Organelle
A specialized structure inside a cell that carries out a specific function within the cell
Why do multicellular organisms have a double circulatory system
To ensure all the nutrients are delivered to all the cells and that waste products are efficiently removed
Why can’t multicellular organisms not just rely on diffusion
Because the distance molecules need to travel is too big and the rate of delivery and removal would be too slow to meet the cells demands
What are the three components that make up the circulatory system
- heart
- blood vessels
- blood
What does the heart do in the circulatory system
the muscle contracts to generate a force to move the blood
What do the blood vessels do in the circulatory system
they are tubular structures that carry blood through all organs and tissues of the body
What does the blood do in the circulatory system
It is the transport medium that carries nutrients and hormones to the tissues and organs and removes the waste products from them
What is meant by double circulatory system
The blood passes through the heart twice per complete circuit around the body
What are the two routes the blood has to take to complete a circuit around the body
- The pulmonary circuit
- The systemic circuit
What is the pulmonary circuit
Where deoxygenated blood passes from the right ventricle to the lungs and then back to the heart oxygenated
What is the systemic circuit
where oxygenated blood passes from the left ventricle to the rest of the body and then returns to the heart deoxygenated
How is cardiac muscle different to skeletal muscle
- It never fatigues
- It doesn’t need impulses from the nervous system to contract - the heart does it itself
Why does the heart contract
to generate a force that moves the blood around the body in a double circulatory system
What happens to the blood when it goes to the lungs
Gas exchange occurs
Where are valves present in the heart
- between the atria & the ventricles
- at the start of the aorta
- at the end of the vena cava