Cardiac Muscle Cell

Cardiac Muscle Cells (cardiomyocytes)

Classified under the Skeletal Muscle Tissue

Function:
In the heart there are two types of cells, cardiomyocytes and the cardiac pacemaker cells. the cardiomyocytes make up the valves in the heart such as the atria and the ventricles and are responsible for the contracting and expanding of the heart. They are crucial in the proper beating and pumping of blood that the heart is responsible for. The cardiac pacemaker cells carry the electrical impulses that control the frequency of the beating of the heart.

Structure:
The cardiac cells are striated (striped) and contain a single nucleus and multiple mitochondria. The cardiac muscles cells have a unique branched shape that allows them to be in constant contact with 3-4 other cardiac muscle cells. At the end of each of the cardiac muscle cells are membranes called the intercalated disks. These form tight unions with the neighboring cells so that the cardiac muscle cells do not separate when pumping the blood. Inside the cardiac muscle cell there are thick dark filaments of myosin that are layered upon thin filaments of a light colored protein called actin. When the muscle fibers contract the myosin pulls together the actin fibers and contracts the cell.




sources:
https://en.wikipedia.org/wiki/Cardiac_muscle_cell

http://www.innerbody.com/image_musc01/musc71.html

https://upload.wikimedia.org/wikipedia/commons/7/7e/1020_Cardiac_Muscle.jpg

http://www.getbodysmart.com/ap/circulatorysystem/heart/anatomy/cardiac_muscle/tutorial.html

Sweetness Lab

Today we completed the sweetness lab in class. Basically we gathered the different types of basic carbohydrates and tasted them for sweetness. The ones that we tasted were sucrose, glucose, fructose, galactose, maltose, lactose, starch, and cellulose. The ones that were most sweet were the sucrose, fructose, and glucose, while maltose, galactose, and lactose were somewhat sweet, while starch and cellulose were not sweet at all. This displays a unique relationship between the sweetness of the carbohydrate and its structure. To put this in basic terms, the monosaccharides were the most sweet while the polysaccharides were the least sweet. The relationship exists that the more rings in the carbohydrate the less sweet it becomes. Glucose, fructose, and sucrose are all commonly used in my diet. Almost all the sweeteners I use, are sucrose, and the fruits that I eat are fructose. Galactose, Maltose, and Lactose are all carbohydrates that relate to dairy products such as milk. Finally starches are found in foods such as potatoes, while cellulose are found in vegetables. Human taste is a complicated mechanism. The human tongue can differentiate between five basic tastes, sweetness, sourness, bitterness, saltiness, and umami. The tongue has many taste buds on it that act as different receptors to these different tastes. These appear as the bumps on your tongue. These taste buds basically have microscopic hairs on them that are extremely sensitive. These send signals to the brain about how something tastes. However, your nose also plays an extremely important part when it comes to taste. The nose contains special cells in its upper part that send signals to the brain about different smells. When you chew something the molecules of the food travel up the nose as well and stimulate these receptors as well as those on your tongue. The both of these working together contribute to the overall taste of a food. The receptors on the nose however, contribute much more to the taste of the food, as a result if you do not breathe through your nose when you eat a food, the food tastes much blander.


https://en.wikipedia.org/wiki/Taste

http://kidshealth.org/kid/talk/qa/taste_buds.html