Answer: The SA node
Answer choices are:
<span>A. </span>The AV node
<span>B. </span>The SA node
<span>C. </span>The purkinje fibers
<span>D. </span>The AV bundle
The SA node<span> is the heart's natural pacemaker consisting of a cluster of cells located in the upper part of the wall of the right atrium. (the right upper chamber of the heart). The electrical impulses are produced and sent out from there to regulate heartbeat. This is also called the sinus code. </span>
Smaller cube (1 cm X 1 cm X 1 cm)
<span>The surface area of one side = 1 cm X 1 cm = 1 <span>cm2</span></span>
<span>There are 6 sides, total SA = 6 X 1 <span>cm2</span> = 6 <span>cm2</span></span>
<span>Volume = 1 cm X 1 cm X 1 cm = 1 cubic cm (1 <span>cm3</span>)</span>
<span>Surface to Volume Ratio = 6 <span>cm2</span>/1 <span>cm3</span> = 6 <span>cm2/cm3</span></span>
Larger cube (6 cm X 6 cm X 6 cm)
<span>The surface area of one side = 6 cm X 6 cm = 36 <span>cm2</span></span>
<span>There are 6 sides, the total SA = 6 X 36 <span>cm2</span> = 216 <span>cm2</span></span>
<span>Volume = 6 cm X 6 cm X 6 cm = 216 <span>cm3</span></span>
<span>Surface to Volume Ratio = 216 <span>cm2</span>/216 <span>cm3</span> = 1 <span>cm2/cm3</span></span>
<span> </span>
A molecule is a group of two or more atoms held together by chemical bonds. A compound is a substance which is formed by two or more different types of elements which are united chemically in a fixed proportion. All molecules are not compounds. All compounds are molecules.
Answer:
Topographically SN is classified into:
1. Central SN- made up of the brain and spinal cord
2. Peripheral SN- made up of nerves (31 pairs of spinal nerves, 12 pairs of cranial nerves), nerve plexuses and nerve ganglia
Structural Dpdv
1. Somatic SN \ of relationship life
2. Vegetative SN a) sympathetic- acts in unusual conditions (eg stress, fear)
b) parasympathetic- acts in normal life conditions
Explanation:
You cant answer this without looking at the diagram. sorry.
