<span>Planets closest approach to the sun is associated with the term perihelion. </span>
Answer:
Three different kinds of muscles are -:
- <u>SKELETAL MUSCELES </u>
- <u>CARDIAC MUSCLES </u>
- <u>SMOOTH MUSCLES</u>
Explanation:
- <u>SKELETAL MUSCLES -: </u>There are long, cylindrical, and striated skeletal muscle cells. They are multi-nucleated, which means they have more than one nucleus. This is because from the fusion of embryonic myoblasts, they are created. Each nucleus controls the sarcoplasm's metabolic demands around it. There are high energy requirements for skeletal muscle cells, because they contain several mitochondria in order to generate adequate ATP. <u>Examples of skeletal muscles: arms and legs- </u>T<u>he muscles that belong to the arms and legs feature in pairs. Abdomen and Back- These muscles are connected to the various sets of skeletal muscles that run across the torso.</u>
- <u>CARDIAC MUSCLES -</u>: Cardiomyocytes have a short and narrow outline and are fairly rectangular. They are about 0.02 mm wide and 0.1 mm (millimetres) long, respectively. There are many sarcosomes in cardiomyocytes, which provide the required energy for contraction. Cardiomyocytes usually contain a single nucleus, unlike skeletal muscle cells. Cardiomyocytes, although they contain more sarcosomes, normally contain the same cell organelles as skeletal muscle cells.<u> example - cardiac muscle is present in heart. </u>
- <u>SMOOTH MUSCLES -:</u> Smooth muscle cells have a single central nucleus and are spindle-shaped. They range in length from 10 to 600 μm (micrometers), and are the tiniest type of muscle cell. In the expansion of organs like the kidneys , lungs, and vagina, they are elastic and therefore essential. As in cardiac and skeletal muscle, the myofibrils of smooth muscle cells are not aligned, meaning they are not striated, hence the term smooth. <u>example of smooth muscles -: Walls of blood vessels , Walls of stomach ,
Ureters , Intestines , In the aorta (tunica media layer), Iris of the eye. ,Prostate and Gastrointestinal Tract.</u>
Leeches are parasitic because they suck blood not giving any benifit but harm.
Over a liter of water is reabsorbed by the colon
History of Boston is described below.
Explanation:
- When workers cut down Copp's hill the only thing they left untouched was the old three-acre burying ground. The city built a retaining wall around the graveyard to prevent it from eroding. In 1814, the Boston and Roxbury Mill Corporation built the Boston & Roxbury Mill Dam across the back bay
- Originally called Tremontaine for the three hills in the area, the Puritans later changed the settlement's name to Boston, after the town in Lincolnshire, England, from which many Puritans originated.
- South Boston, which was front and center in the battle, is no longer that close-knit old school “tough-as-nail” Irish Catholic enclave. “Southie,” as it is still fondly referred to, houses the world today flaunting some of the best restaurants and expensive housing in the city
- Boston was founded in 1630 by English Puritans fleeing religious persecution. On 29 March 1630 a fleet of 11 ships carrying 700 people sailed from England to Massachusetts. They were led by John Winthrop (1588-1649). At first the people settled at Charlestown, which had been founded the year before.
- Much of Boston's coastline is man-made land. The original shoreline, from 1630, is visible in dark green on this map. Land made between 1630 and 1995 is light green.Boston is a safe city, but as with any major city, you should take the usual safety precautions. Stay in well-populated areas, travel with others, especially at night, and keep track of your belongings. The tourist areas in Boston are generally safe, but some areas deserve mention.
