The largest organ in the body is skin. The weight of skin is twice as much as the brain, approximately 3-5kg. Skin thickness varies according to function and area of the body. Glands sensitive to temperature changes and a layer of fatty tissue under the surface of the skin are found in the skins thick outer layers. Skin contains many cells that are sensitive to touch, pain, pressure, itching and temperature.
The epidermis is composed of stratified keratinized squamous epithelium and is made up of many layers near the surface of the skin (McLafferty, Hendry, and Farley, 2012). There are four main types of cells in the epidermis, keratinocytes make up 90% of the cells found in this layer. 8% of epidermal cells are made up of melanocytes which produce melanin known as pigment. Langerhans cells and Merkel cells are also contained within the epidermis. The immune response is protected by Langerhans cells and Merkel cells function in the sensation of touch. The epidermis is avascular because it has no blood vessels and uses blood vessels of the dermis for oxygenation, metabolite provision and removal of metabolic waste products.
The epidermis is made up
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An early sign of cell death is when the nuclei is dark. This happens as the fluid is unable to reach them by diffusion, the nutrients and oxygen in the interstitial fluid are gone. In the skin, the stratum spinosum is a multi-layered arrangement of cuboidal cells that sits beneath the stratum granulosum. Adjacent cells are joined by desmosomes, giving them a spiny appearance when the cells shrink during the staining process while the desmosomes hold firm. Their nuclei are often darkened (a condition called pyknosis), which is an early sign of cell death. Their fate is sealed because the nutrients and oxygen in interstitial fluid have become exhausted before the fluid is able to reach them by
To begin we will look at the integumentary system and its entire multitude of functions. The main components of the integumentary system are the skin, hair, nails, glands and nerves. For the purpose of this paper we will focus mainly on the levels of the skin and their functions. While the integumentary
There are 4 different types of tissues in the human body, epithelial, connective, muscular and nervous. One of the main ones to look at with the lymphatic system is epithelial tissue. The epithelial tissues have many functions but the ones that affects the lymphatic system are diffusion and cleaning.
After production, melanin is packaged in membrane bodies called melanosomes. Dark skin has large melanosomes that are in a single state and also contains more melanosomes than lighter skin such as in Europeans. Most Asian skin, on the other hand, has smaller concentrated groups of melanosomes, whereas European skin has the smallest melanosomes, which are combined into bound materials. The spacing and amount of melanosomes are what gives the appearance of skin color due to the dispersal of light hitting the skin.
The integumentary system has five main functions. The five main functions of the integumentary system are protection, regulation, sensation, absorption, and secretion. It consists of the hair, nails, skin, sebaceous and sweat glands. The largest organ of the entire body is the skin. The skin consists of three different layers. The epidermis, the dermis, and the subcutaneous layer, these are the three layers of the skin. There is a layer that is deeper than the skin and contains body fat, that layer is called the hypodermis. Sweat glands are also called sudoriferous glands. One of the functions of the skin is to maintain homeostasis. Synthesis of vitamin D, excretion of urea, excretion of salts and water are a few things that the skin is also capable of. The top layer of the skin is called the epidermis. The epidermis contains five different layers. These layers are the stratum corneum, the stratum lucidum, the stratum spinosum, and the stratum basale. In the epidermis there are four different cell types. The keratinocytes which produce keratin, the merkel cells that are sensitive to touch, the langerhans cells which is a dendritic type off cell, and the melanocytes which produce melanin.
The epidermis, which is the outer layer of the skin, is made up of four to five layers in some parts (Shier, Butler, & Lewis, 2009). In the majority of the areas, just four layers can be differentiated: the stratum basale, stratum spinosum, stratum granulosum, and stratum corneum (p.119). Another layer is the stratum lucidum which can be found in the thicker part of the skin of the palms and ...
Skin cancer is a disease where cancer (malignant) cells are found on the outer layer of the skin (epidermis). The three types of cells found in the epidermis are squamous cells, basal cells, and melanocytes. These cells in time grow to be cancerous. Thus, the three types of skin cancers are squamous cell, basal cell, and melanoma. Melanoma is the most deadliest and destructive type of cancer. (“Skin Cancer” infotrac.com) The number of people with melanoma has risen in Scotland from 3.5 in 1979 to 10.6 per 100,000 in 1998 for men and 7.0 to 13.1 for women. (Miller 945) Squamous cell and Basal cell skin cancer can kill up to 2,200 people a year in the United States. (Sommerfield SIRS.com) Basal cell, being the most common type of skin cancer, is the cancer that about 75 percent of the people have. (“Skin Cancer “ infotrac.com) Melanoma is mostly seen in older men but ever since tanning came in during the 1970’s, it has increased in women 60 percent around the ages 15-29 over the past three decades.(Sommerfield SIRS.com) “And basal cell and squamous cell cancers are increasing at a rate of about 5 percent per year”(Sommerfield SIRS.com).
The word melanoma comes from the Greek words, melas (black) and -oma (tumour). It is a very serious cancer that most often occurs in the skin and less frequently in the eye or in the lining of the nose, mouth, or genitals. Melanoma begins in melanocytes, cells that make a pigment called melanin. Both light- and dark-skinned people have melanin, which gives colour to the skin, hair, and parts of the eye.
In the conclusion, many people opinion would disagree say the heart was the most important part of the body. They didn’t know the only way the heart will working is by the brain, and the neurons are sending signals. Our body are like light switch your turn back on and off, plus you could even restart your body. In other cases, the brain is the most tangled part of the human body. It is the center of alertness and also rules all voluntary and involuntary movement and bodily functions. It can communicates with each part of the body throughout the nervous system, is a network of channels that carry electrochemical signals.
The liver is the largest internal organ in our body, weighing about 3 pounds. It is reddish-brown and rubbery to the touch (WebMD, n.d.). Our liver is one of the most important organs in our bodies. It exists to process nutrients from the food we eat, make proteins, make bile and remove toxins.
List the embryonic germ layers that the epidermis and dermis are derived from (be specific for the dermis). (2 points)
Epithelial tissue covers the surface of the human body and lines most internal cavities. Epithelial tissue is found in the body’s skin, lining of the stomach and intestines, the kidney, and glands, as well as other locations within the body (Amsel, 2012). The two types of epithelial tissue are (1) covering and lining epithelium and (2) glandular epithelium. The covering and lining epithelium are found lining the integumentary, digestive, cardiovascular, and respiratory systems as well as the ventral body cavity and the organs this cavity houses (Hoehn, et al., 2007, p. 118). The glandular epithelium is found within the glands of the entire human body. Not only are their two types of epithelial tissue found in the human body, there are also multiple classifications and various shapes. These classific...
The nervous system is composed of all nerve tissue in the body. This organ system forms a communication and coordination network between all parts of the body. It plays a major role in everyday activities such as breathing, walking even blinking. It is made up of nerve tissues to receive and transmit stimuli to nervous centers and initiate response. Neurons are nerve cells that transmit signals from one location of the body to another. With damage to the nervous system the body would not be able to function properly. The body has to be well taken care of in order to insure proper regulation. The two anatomical divisions that work hand in hand to help regulate the nervous system are the central and peripheral nervous system. According to the Campbell’s seventh edition biology book the nervous system is the most intricately organized data processing system on earth. It is a complex collection of nerves and specialized cells.
The first layer, the epidermis, contains keratin which is a water proof protein. This makes the body water proof and keeps water from entering the body. This layer also consist of two specialized cells, langerhans cells and melanocytes. Langerhans cells are macrophages which is a white blood cell that phagocytize infectious agents. They then travel to lymphatic organs. Melanocytes lye deep in the epidermis, and produces melanin. This is the main pigment for skin color. The second layer, the dermis, is a fibrous connective tissue. It is made up of dense fibrous connective tissue and consist of collagen and elastic fibers. The purpose of the collagen fibers are to allow stretching to prevent tearing of the skin; unlike the elastic fibers which only allows for normal tension for stretching, allowing movement of muscles and joints. As we age, the fibers become weaker causing the skin to wrinkle. The blood vessels in the dermis help
The human body is very complex. It is like a job. You have to do a million things in one day to make it through the day. The body uses nine systems to do all of those jobs. They all have separate functions, but some work together. Each system is also made up of organs. There are many ways to care and protect the systems from the many different problems they can have. There are also many interesting facts about each system.
Because cells are the ‘basic unit of life’, the study of cells, cytology, can be considered one of the most important areas of biological research. Almost every day on the evening news, we are told about new discoveries in cell biology, such as cancer research, cloning, and embryology. (https://highered.mheducation.com/sites/0073031216/student_view0/exercise3/the_importance_of_cell_biology.html) This report provides an insight into the differences in the structure of cells and the way that they carry out their internal mechanisms. Cells form the basis of all living things and they are the smallest single unit of life.