Answer:
- Blood travels at a higher velocity in arteries than in veins.
- The volume of blood flow in the arteries and arterioles is greater than the volume of blood flow through the capillaries
- Blood pressure is higher in arteries than in veins.
- The total cross-sectional area of the capillaries is greater than the total cross-sectional area of the venules and veins
Explanation:
The lumen of arteries is larger than that of arterioles and capillaries. However, even though they have a smaller lumen compared to veins, their walls are thicker to bear the pressure of the blood as it is pumped by the heart to the tissues. Therefore the blood pressure and velocity of blood in arteries (that pump blood away from the heart) is higher than in capillaries and veins. Veins take blood back to the heart from tissues hence this blood is under lower pressure and velocity. This is why veins have valves to prevent the back-flow of blood against gravity.
Due to the large cross-section area of capillaries the blood flow is here is slower hence giving time for blood to linger a bit so there is an exchange of materials between the blood plasma and the interstitial fluids that nourish the cells.
3,000 kilijoules.
You go from 300,000 at the first trophic level to 30,000 at the second trophic level, and finally 3,000 at teh third.
Answer:
In Lincoln Elementary School.
Explanation:
I advise them to send Jackson to Lincoln Elementary School which has 95% vaccination rate for MMR because there is less chances of having measles to Jackson as compared to Oak Crest Elementary School having 80% vaccination rate for MMR. Yes, Jackson is at risk of contracting measles because of no immunity acquire against measles disease by its body. The vaccine can provides immunity to Jackson from the disease but he can't take it due to allergy.
Answer:
The correct answer is: Pupil.
Explanation:
- Light enters inside the side through a small opening in the iris of the eye which is called the Pupil.
- The outer most part of the eye Cornea and the outer chamber aqueous humor are both transparent and allow light to refract through them.
- The Iris, which a circular and thin comes next to the cornea and aqueous humor. It is reponsible for regulating the amount of light that can reach the retina by altering the pupil size.
- The change in the size of the pupil is mediated by muscles in the iris.
- There are two types of muscles, radial muscles and circular muscles.
- In bright light, the radial muscles of the iris relax while the circular muscles contract. This decreases the pupil size allowing less light to pass into the retina.
- In dim light, radial muscles of the iris contract while the circular muscles relax. This increases the pupil size allowing more light to pass into the retina.
