SA Node<span> which is also known as the sinus node, is the natural pacemaker of
the heart. It controls the heart rate by generating electrical impulses
and then sending electrical signals through the heart muscle, causing
the heart to contract and pump blood throughout the body. </span>
The SA Node is located in the outer layer of the right atrium of the heart, near the superior vena cava. It is made up of a group of cells (myocytes) positioned on the
wall of the right atrium, at the center of the heart and near the
entrance of the superior vena cava. These cells contract at a rate of
about 70-80 times per minute, which make up the natural heart beat.
Answer:
Neurilemma
Explanation:
Schwann cells are the neuroglia that produces myelin sheaths. There is a formation of multiple layers of the glial plasma membrane around axons. The cytoplasm and nucleus of Schwann cells from the outermost layer while the inner part has multiple layers of the Schwann cell membrane. The outer nucleated cytoplasmic layer of the Schwann cell that encloses the myelin sheath is called neurolemma. It is found only around axons in the PNS. Its function is to serve in the regeneration of injured axons by the formation of a regeneration tube.
Answer:
Check if the rock layer has fossils in it.
Explanation:
The rock layer from the inside out and the fossils will tell you how old the rock is.
Answer:
(C) 10 times more acidic than distilled water.
Explanation:
The pH scale is logarithmic, meaning a pH difference of one is a difference of 10 times.
Answer:
c) adrenocorticotropic hormone (ACTH).
Explanation:
A tropic hormone is defined as the hormone which is secreted from one gland and acts on another gland. ACTH is released by anterior portion of our pituitary gland during the condition of biological stress. After it is released, it acts on adrenal gland so that adrenal gland could secrete another hormone named as cortisol (steroid hormone). In response to stress, cortisol increases blood sugar level, elevates brain's use of glucose etc. so as to counter stressful situation.
Apart from this cortisol also helps in regulating our metabolism, reduces inflammation and controls salt and water balance.
