Circulatory Systems Flashcards
What do cells need to allows exchange of gases and nutrients?
sufficient surface area
What does diffusion put limits on?
Stay small
Thin Tissue Layers
What do circulatory systems do?
move fluid through body to quickly carry materials
What do circulatory systems employ?
bulk flow of circulatory fluid to carry materials from one place to another in the body quickly and efficiently
What are the three basic components of all circulatory systems?
Circulatory Fluid: Hemolymph or Blood carrying dissolved gases and nutrients
Tube (Vessels): short or long
Muscular Pump: the heart, provides force to move fluid
What are open circulatory systems?
organs in body that are directly bathed in hemolymph pumped by the heart through short vessels that are empty into the Coelom. Direct contact allows exchanges. Heart contraction creates negative prcssure that draws the fluid back through pores to complete circulation
What are closed circulatory systems?
blood is transferred through blood vessels
blood is confined to vessels that separate it from interstitial fluid in the coelom
Heart pumps fluid through larger vessels that branch into smaller vessels
Smaller vessels infiltrate the tissues and organs to bring gases/nutrients to individual cells
What are the three types of blood vessels?
arteries: carry blood from heart by branching into Arterioles and Capillaries
capillaries: infiltrate organs, thus allowing diffusion into cells
veins: capillaries merge into venues/veins to carry blood towards the heart
Describe arteries.
They have an endothelium, layer of cells that reduces resistance to flow
surrounded by smooth muscle followed by connective tissue
has thicker walls than veins due to high pressure of blood pumped from the heart
Describe capillaries.
branch from arterioles, which branch from arteries, and from capillary beds
highly branched vessels can bring blood to the organs and exchange molecules into cells via diffusion
capillaries are think and are only surrounded by an extracellular layer of basal lamina
Describe veins.
capillaries merge into venues, that then merge into veins that bring blood back to the heart
also have endothelium that is surrounded by smooth muscle then connective tissue
muscle contraction and valves are needed to move blood since they’re under a lower pressure
Where is velocity of blood the slowest?
in capillary beds due to the large total cross-sectional area where zones of high resistance exist
Slow flow is beneficial so diffusion can efficiently occur
What is the heart made of?
cardiac muscle
acts as the pump that moves the blood through the vessels
What are the chamber types of the heart?
atria: chamber where blood enters heart
ventricle: chamber that pumps blood out of the heart when contracted
What are the goals of the cardiovascular system?
gas exchange: deliver oxygen, remove carbon dioxide
energy balance: deliver nutrients and remove waste
osmoregulation: carry waters, ions, and hormones