The integumentary system is the largest organ in the body. The integumentary system is composed of the skin and the structures related to the skin, which include the hair, the finger nails, the sensory receptors and the glands. This system has an important function since it provides protection to the body, helps to maintain body temperature, and contains sensory receptors. The skin being the largest organ makes up approximately 15 percent of the body’s total weight.1 The skin has two layers called epidermis and the dermis. The epidermis is the skins most superficial layer and it is composed of stratified squamous epithelial tissue.2 The epidermis is divided into four or five general layer called the strata.
The total thickness of the epidermis is usually about 0.5 - 1 mm. At the lowermost portion of the epidermis are immature, rapidly dividing keratinocytes. As they mature, keratinocytes lose water, flatten out and move upward. Eventually, at the end of their life cylce, they reach the uppermost layer of the epidermis called stratum corneum. Stratum corneum consists mainly of dead keratinocytes, hardened proteins (keratin) and lipids, forming a protective crust.
DERMATOLOGY Skin is the largest organ of the body, covering and protecting the entire surface of the body. The total surface area of skin is around 3000 sq inches or roughly around 19,355 sq cm depending on age, height, and body size. The skin, along with its derivatives, nails, hair, sweat glands, and sebaceous glands forms the integumentary system. Besides providing protection to the body the skin has a host of other functions to be performed like regulating body temperature, immune protection, sensations of touch, heat, cold, and pain through the sensory nerve endings, communicating with external openings of numerous other body systems like digestive system, urogenital system, and respiratory system via mucous membranes and also one of the most important function of acting as a storage house of energy by collection of adipose tissue, which is the principal fat depot in the body. It is the first line of defense of our body against any organism.
It is the interface between the body and the rest of the world. It shields us from harmful organisms and protects us from physical and mechanical injury. “Skin accounts for 10-15% body mass which is about 6-8 lbs and covers more than 20 square feet. Our Skin has a ph balance of 4.0-6.5, this acid mantle helps regulate normal skin flora which acts as a barrier to bacteria, other micro organisms and infections.” (Baranoski, S. Ayello, E., and Tomic-Canic, M. 2008). Skin has a thickness of 0.5mm-6mm, it is thickest on our hands and soles of the feet and thinnest at our eyelids.
45 2 points Question 4 The protein in blood that regulates osmotic pressure and pH is albumin True False 2 points Question 5 All of the following are PLASMA blood proteins EXCEPT 1. albumin 2. hemoglobin 3. fibrinogen 4. globulin 2 points Question 6 Which element in hemoglobin binds oxygen 1. calcium 2. zinc 3. iron 4. iodine 2 points Question 7 How many red blood cells in blood and how many white blood cells? 1. 4-6 million / 10-200 2. 1-2 million / 100-10,000 3. 4-6 million / 4,800 -10,800 4.
Connective tissue proper has two subclasses, loose connective tissue and dense connective tissues. Loose connective tissue is made up or three different types, areolar, adipose and reticular. Dense connective tissue is made up of three different types as well, dense regular, dense irregular and elastic. The functions of areolar connective tissue include: supporting and binding to other tissues, holding body fluids, defending against infection and storing nutrients as fats. This specific tissues has an arrangement made up of loose fibers.
Provide physical protection Control permeability Provide sensation Produce specialized secretions There are various specialized types of epithelia. They can be sorted by cell shape and the number of cells between the basement membrane and the exposed surface of the epithelium. The three basic shapes of epithelial are squamous, cuboidal, and columnar. If the basement membrane is only covered by one layer of cells it is called a simple epithelium. If the basement membrane is cover by several layers of cells it is called stratified epithelium.
Adhesion of platelets is stimulated by the damage tissue; Platelets do not adhere to the endothelium that lines healthy blood vessels and the heart. The endothelium is very smooth and coated with prostacyclin. Release reaction is when the platelets grow long pseudopods that adhere to the vessels and to other platelets. They will contract, draw the wall of vessel together and the platelets will aggregate. Therefore, platelets undergo degranulation the exocytosis of their cytoplasmic granules and release of factors that promote hemostasis.
1) Most of your bone mass is made up of hydroxyapatite, which is a compound of calcium and phosphorus, and accounts for about 65%. This is 99% of your body’s calcium and about 85% of your body’s phosphorus. Although these are the most abundant there are many other minerals in the bones such as magnesium, fluoride and potassium to name a few. This is why the skeletal system is also known as the “mineral reserve”. Whenever a mineral is needed hormone signals are sent to the bones and the mineral that is needed is released into the blood stream.
Compare and contrast the functions of each tissue type. Why do some areas of our body have stratified squamous epithelium and other areas have simple squamous epithelium? Epithelial tissues - It protects us, and it absorbs with the stomach and intestinal lining Connective tissues - Support, surround, connect other tissues, Protect organs, Transport fluids and dissolved materials Muscle tissues - Responsible for body movement, Moves blood, and food waste through body’s organs, Responsible for digestion. There are three types smooth, skeletal and cardiac muscle tissues. Nervous tissues - Conducts impulses organs from neurons.