Answer: 1. Blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium of the heart. As the atrium contracts, blood flows from your right atrium into your right ventricle through the open tricuspid valve.
2. Plasma is the main component of blood and consists mostly of water, with proteins, ions, nutrients, and wastes mixed in. Red blood cells are responsible for carrying oxygen and carbon dioxide. Platelets are responsible for blood clotting. White blood cells are part of the immune system and function in immune response.
3.Within the bone marrow, all blood cells originate from a single type of unspecialized cell called a stem cell. When a stem cell divides, it first becomes an immature red blood cell, white blood cell, or platelet-producing cell.
4. Epinephrine and norepinephrine, hormones secreted by the adrenal medulla, raise blood pressure by increasing heart rate and the contractility of the heart muscles and by causing vasoconstriction of arteries and veins. These hormones are secreted as part of the fight‐or‐flight response.
Answer:
True
Explanation:
because Ganglia were the evolutionary precursor to the centralized concentration of neurons that we now call a brain.
Answer:
Mucus
Explanation:
The protein present in the saliva is known as mucin .
When mucin mixes with water , it turns out to be a slippery substance , known as mucus.
The inner linning of the body produces a slippery and a stringy fluid called the muscus .
The importance of mucus is -
Mucus acts as a protective layer , its acts as a moisturizing layer , to keep the organs from drying out.
Human body produces approximately 1 to 1.5 liters per day.
The most natural approach to get enough Vitamin D is through regular sun exposure. Aim for 10 to 30 minutes of midday sunshine many times per week to maintain appropriate blood levels. Those with darker complexion may require a little more.
<h3>
What is Vitamin D ?</h3>
According to the National Institutes of Health, two to three times per week, between five and thirty minutes of unprotected sun exposure to your face, arms, legs, or back between the hours of 10 a.m. and 3 p.m. is sufficient for your body to produce all of the D3 it requires. Vitamin D synthesis can be inhibited by sunscreen.
Your skin tone, age, dietary habits, and the environment in which you reside all have a role. In general, scientists believe that 5 to 15 minutes, or up to 30 minutes if you have dark skin, is approximately right to get the most benefit without endangering your health. If you wear sunscreen, you can spend more time outside and yet receive the same result.
In the continental United States, UV rays are typically highest between 10 a.m. and 4 p.m. (9 a.m. to 3 p.m. standard time). The UV Index predicts each day's UV ray intensity. Avoid overexposing your skin to the sun if your area's UV index is 3 or higher.
To know more about Vitamin D please click here : brainly.com/question/4551554
#SPJ13
