Answer:
1) True
Explanation:
Cells of Sinoatrial (SA) node make up the auto rhythmic cells of heart as in normal physiological conditions , SA-node is responsible to set the pace of the rest of the heart (pacemaker) at a rate of 70 to 80 beats per minute.
The cells of SA node has the ability to self-excite thus able to generate action potential without external stimulation by nerve cells. Thus they initiate the cardiac cycle providing the conduction system.
Hence the statement , SA nodal cells are unique in that they exhibit autorhythmicity, meaning they are capable of depolarizing and firing an action potential spontaneously without any external influence, is true.
Explanation:
When your doing a physical activity like running Anaerobic respiration is used.
Answer:
Both prokaryotic and eukaryotic cells have structures in common. All cells have a plasma membrane, ribosomes, cytoplasm, and DNA. The plasma membrane, or cell membrane, is the phospholipid layer that surrounds the cell and protects it from the outside environment.
Explanation:
LDL (low-density lipoprotein) carry cholesterol from the liver to the tissues and can contribute to the formation of plaque that builds up in the arteries.
<h3>What are lipids?</h3>
Lipids are soluble in fat and to circulate in the blood, which is an aqueous medium, they form lipoprotein complexes called lipoproteins, these constitute a transport medium and circulating reservoir for lipids.
<h3>Characteristics of LDL (low-density lipoprotein)</h3>
- Low-density lipoproteins, composed of 50% triglycerides, are the ones that transport the lipids synthesized in the liver to other parts of the body.
- LDL, composed mainly of cholesterol, when in excess, also deposits it on the walls of the arteries, contributing to the formation of plaque.
Therefore, we can conclude that excess LDL (low-density lipoprotein) poses a health risk because it facilitates the accumulation of fat in the arteries.
Learn more about lipoproteins here: brainly.com/question/16170788
