Circulatory System Flashcards
can single-celled organisms gain oxygen and glucose directly
Single-celled organisms can gain oxygen and glucose directly from their surroundings, and the molecules can diffuse to all parts of the cell quickly due to short diffusion distances
Why do larger organisms require mass transport system
The diffusion distances involved are too great
Large organisms often have high energy requirements, so the delivery of reactants for metabolism needs to happen quickly
what does mass transport system allow
Bring substances quickly from one exchange site to another
Maintain diffusion gradients at exchange sites
Ensure effective cell activity by supplying reactants and removing waste products
how are atoms composed in water
hydrogen and oxygen. One atom of oxygen combines with two atoms of hydrogen by sharing electrons; this is covalent bonding
The sharing of the electrons is uneven between the oxygen and hydrogen atoms
what does oxygen atom attract in H2O bond
he oxygen atom attracts the electrons more strongly than the hydrogen atoms, resulting in a weak negatively charged region on the oxygen atom (δ-) and a weak positively charged region on the hydrogen atoms (δ+)
This separation of charge due to the electrons in the covalent bonds being unevenly shared is called a dipole
When a molecule has one end that is negatively charged and one end that is positively charged it is said to be a polar molecule
Water is a polar molecule
why does water dipole nature make it good at transporting
Water is cohesive making it good to transport substances
Water is a solvent
explain cohesion and adhesion in water
Hydrogen bonds between water molecules allow for strong cohesion between water molecules
Water is also able to hydrogen bond to other molecules; this is known as adhesion
The forces of cohesion and adhesion within a body of water and between water and its surroundings means that water flows easily
why is water a solvent
since polar molecule many ions will dissolve in it
Water molecules surround charged particles; the positive parts of water are attracted to negatively charged particles and the negative parts of water are attracted to positively charged particles
The surrounded molecules break apart
The ions surrounded by water molecules have dissolved
what happens in closed circulatory system
blood is pumped around the body and is always contained within a network of blood vessels
what happens in open circulatory system
the blood, or blood equivalent, is inside the body cavity and bathes the organs
what does the right side of the heart pump
deoxygenated blood to the lungs for gas exchange; this is the pulmonary circulatory system
what does the left side of the heart pump
Blood then returns to the left side of the heart, so that oxygenated blood can be pumped at high pressure around the body; this is the systemic circulatory system
what is the heart divided into
four chambers
The two top chambers are atria
The bottom two chambers are ventricles
what are the left and ride side of the heart separated by
a wall of muscular tissue called the septum
what are the right atrium and right ventricle separated by
atrioventricular (AV) valve known as the tricuspid valve
what are the left atrium and ventricle separated by
another AV known as the bicuspid valve
what are right ventricle and pulmonary artery separated by
semilunar valve known as pulmonary valve
what are left ventricle and aorta seperated by
another SL valve known as the aortic valve
what are valves attached to
heart walls by valve tendons, or cords; these prevent the valves from flipping inside out under high pressure
what is the function and structure of the left ventricle
thicker muscle than right for strong contraction to pump blood around the body.
what is the function of AV valves
prevent back flow of blood from ventricles to atria
what is the function of the semi lunar valves
prevent back flow of blood from aorta or pulmonary artery to the ventricles
what two blood vessels bring blood into heart
vena cava: blood from body
pulmonary vein: from lungs
what two blood vessels take blood away from the heart
The pulmonary artery takes blood to the lungs
The aorta takes blood to the body
what is coronary arteries
a series of blood vessels in the muscle of the heart
what are arterioles
arteries branch into narrower blood vessels called arterioles which transport blood into capillaries
what are venules
these narrow blood vessels transport blood from capillaries into veins