Answer:
1. Ends of the respiratory branches are called alveoli.
2. C. To control blood flow to different areas of the body depending on activities
Explanation:
1. The trachea divides into left and right primary bronchi which in turn divide multiple times upon entering the lungs and make the bronchial tree.
The final branches of the bronchial tree are the terminal bronchioles that lead to alveoli. The alveoli are the balloon-shaped structures and serve as the site of gas exchange between the blood and inhaled air.
2. The opening and closing of sphincters of capillary beds regulate the direction of blood flow. The opening of sphincters allows the blood to flow into associated branches of capillary beds while closed sphincters direct the blood from arterioles to venules via thoroughfare channel.
This local change in blood flow is responsible for the autoregulation of blood flow to different tissues to match their respective metabolic demands. For example, during physical activity, more blood is directed to skeletal and cardiac muscles.
Synchroniser switch is in the "on" position.
I believe it is because the sun is directly over us which cause more heat since it is beating down. be sure to get a second opinion
Answer:
d) They would bind glucocorticoids, and initiate estrogen-dependent synthesis
Explanation:
Both Glucocorticoids and estrogens Hormones have important but distinct physiologic functions. These two hormones belongs to the two classes of steroid hormones. Both of these hormones binds to their specific receptors.
DNA binding domain is the domain that after activation by external factors such as hormones express the specific proteins by binding to specific region of the DNA.
As DNA binding domain of a glucocorticoid receptor is altered with DNA binding domain of estrogen receptor so it means binding site of the glucocorticoid hormone for glucocorticoid receptor remains the same and binds to glucocorticoids but on binding it activates the estrogen DNA binding domain which further binds to specific region in the DNA which initiates estrogen dependent synthesis.
Striated muscles contain repeating sarcomeres of overlapping arrays of long, thin actin and thicker myosin filaments. Myosin filaments contains the myosin heads, which are enzymes that can bind to actin, split and make use of the energy from ATP. When muscle contraction starts, myosin heads bind to actin, change their configuration on actin, liberating the products of ATP hydrolysis and causing slide of the actin and myosin filaments. The action of the proteins troponin and tropomyosin on the actin filaments regulates vertebrae striated muscle contraction. The release of calcium ions from the sarcoplasmic reticulum is triggered by the nervous stimulation which causes depolarization of muscle membrane. Calcium ions bind to troponin and thus cause or allow the tropomyosin strands on the actin filament to move so that the part of the actin surface where myosin heads need to bind is uncovered. Contraction then occurs and only stops when the sarcoplasmic reticulum pumps calcium out of the muscle interior.
So basically, what triggers the uncovering of the myosin binding site on actin is the calcium ions binding to troponin and changing configuration.