Lesson 1 - Overview of Transport Flashcards
Cells need ______ and ______
Oxygen and Glucose
What are the functions of the system?
- ) Transport - Oxygen, Carbon Dioxide, Nutrients, Hormones and Wastes
- ) Regulation - pH and body temperature
- ) Protection - From blood loss (through clotting) and against infections
(Not all animals have circulatory systems that fulfill all of these functions)
What is an Artery?
Vessel that carries high pressure blood away from the heart. They must be rigid and have thick walls to withstand the pressure.
What is a vein?
Veins return blood back to the heart. They have low pressure blood and thin walls.
What is a capillary?
A capillary is so tiny that only one red blood cell can fit through at a time. They are in between arteries and veins. Diffusion occurs through capillaries and they are the site of exchange, which is why they are so small.
What are the differences in the lumen size of an artery and a vein?
Artery
- Thick Wall
- Smaller Lumen
- Folded inner wall (like an accordion) to allow stretch
Vein
- Thin Wall
- Larger Lumen
- Collects blood to return to heart
What are epithelial cells?
Specialized cells that line the surface of things.
What are endothelial cells?
Inside layer of cells
What is the tunica interna?
The innermost layer of an artery or vein (present in all vessels). It is made up of a layer of endothelial cells and is supported by an internal elastic lamina (a layer of elastic tissue that forms the outermost part of the tunica interna).
What is the tunica intermedia?
The middle layer of an artery of vein. It is thicker in arteries and made of smooth muscle and elastic tissue.
What is the tunica externa?
The outermost layer of a blood vessel, which is thicker in arteries. It is a tougher and fibrous layer that prevents the walls from ballooning when pressure is high.
