The Structure Of The Integumentary System

The skin is divided into three different parts including the epidermis, dermis, and hypodermis. The epidermis is the outermost layer of the skin. This region of the skin has no blood cells or blood vessels running through it. All of the nutrients that the epidermis needs are received through diffusion from the dermis. The epidermis is made up of stratified squamous epithelial cells. The epidermis is made of five separate layers: the stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, and the stratum corneum. Starting at the innermost layer, the stratum basale is where mitosis of keratinocytes takes place. This layer of the epidermis also contains melanocytes which give the skin it’s pigment. As mitosis takes place in the stratum

The stratum spinosum is also known as the prickly layer. It is superficial to the stratum basale. This is many

The Integumentary System, also known as the skin, is the largest organ of the body. Its complete structure is composed of many different tissues. The skin protects the cow’s body from any bacterial invasions and physical damage. When a cow becomes sick, the skin is the first system that is affected. The integumentary system is composed of three layers: (i) Epidermis, (ii) Dermis, and (iii) Hypodermis or Subcutis. To start with the inner most layer you have the Hypodermis (Subcutis). The Hypodermis consists of connective tissues, elastic fibers and fat. When fat forms a layer of thickness it is called Peniculus Adiposus. Any reserved energy is also stored within the Hypodermis. Then you have the layer, Dermis. The Dermis supports the outer most layer, Epidermis. Dermis consist of collagen, reticular and elastic fibers which plays a large role in the strength and elasticity in the skin; as well as the maintenance and repair of the skin. Lastly, you have the Epidermis. The Epidermis alone consist of four sublayers, (i) Stratum Corneum – outermost horny layer, (ii) Stratum Lucidum – clear layer, (iii) Stratum Granulosum – granular layer, and (iv) Stratum Spinosum – prickly cell layer. The Epidermis is derived from basal membrane Stratum Basale, which presents the openings for the hair follicles. Some of the functions of the skin include: preservation of the cow’s shape, protection from water loss, protection from any physical, chemical and microbial injury imposed by an external agent. An important role of the skin is it balances its Thermoregulation, which is its ability of an organism to regulate its body

Fact 1: Biology - The skin The skin is the outer most layer of most animals and is seen as the largest organ of the body consisting of 3 layers, namely the epidermis, dermis and sub-dermis or hypodermis. These layers contain different specialized structures, as can be seen on the diagram on the cover page, which perform functions that are essential for our survival. The skin separates the internal body from the surrounding environment and thus it protects the body against water loss, radiation, toxic chemicals and infections in the surrounding environment. One of the structures that is further discussed are melanocytes in the epidermis and melanin production.

Carville (2012, p 8) defined epidermis as ‘the outer layer of the skin and is comprised of stratified, squamous epithelial cells or keratinocytes’. Epidermis have also various layers that are divided into 4 or 5 layers, stratum germinativum, stratum spinosum, stratum granulosum, stratum lucidum and stratum corneum, respectively. The first layer of epidermis is the stratum corneum, which is also known as a horny layer. The other layer is stratum lucidum, however this is mostly found in a thicker part of epidermis, such as soles of the feet and palms. The middles layer is the stratum granulosum, which is also known as the granular layer. According to Carville (2012, p 9), it is comprised of one to five cells thick of granular cells that contain keratin and shrivelled nuclei’. The next layer after the stratum granulosum is the stratum spinosum, otherwise known as the prickly layer. ‘The stratum spinosum is made up of several layers of polyhedral shaped cells, which have large oval nuclei’ (Carville 2012, p 9). The last layer of epidermis is the stratum germinativum or commonly known as basal layer. This is a layer where basal cells or keratinocytes develop. In comparison to epidermis, dermis have also layers, these are papillary layer, which is composed of loose connective tissue, and reticular layer, which is mostly composed of dense connective

Stratum Granulosum is another shallow layer; it is made up 3 to 5 layers of flat packed grainy cells called kertaohylain cells which act similar to a water filter, to absorb any foreign bodies. This eases water loss and keeps up hydration in the skin.

The epidermis is the relatively thin, outer layer of the skin. It provides a waterproof barrier and creates our skin tone. Its also an avascular region of the body, meaning that it does not contain any blood or blood vessels. The epidermis along with other layers of the skin protect internal organs, muscles, nerves, and blood vessels again trauma. The epidermis is divided into five layers. The first layer is called the stratum corneum which is the outmost layer made of dead keratinocytes with a layer of protein around them. The second layer is Stratum lucidum it constitutes the outer epidermal layer and comprises of dead skin cells. The third layer is Stratum granulosum also known as the granular layer, Keratinocytes migrating from the underlying

3. Name and discuss the four cell types found in the epidermis. (Give the structure and function of each)

Epidermis : this is the layer of skin that we can see, it has the thickest layer which can be found on the soles of the feet and palms of the hands, thinnest layer on the eyelids and nipples. The cells on surface are constantly shedding (the dead cells) this is called Desquamation.

The skin is the largest organ in the body and is composed of three main layers; the epidermis, the dermis and the subcutaneous layer. (Hse.gov.uk, 2015) The top layer of the skin is the epidermis and is largely made of keratinocytes, or epidermal cells. Under the epidermis is the dermis, which is composed mainly of collagen but also contains hair follicles, apocrine glands and eccrine glands. Many blood vessels, lymphatics and nerves also pass through the dermis. Below the dermis is where the subcutaneous layer is situated. (Fitzpatrick and Morelli, 2011) The skin is adapted to carry out many functions such as protection, regulation and sensation. However, the skins ability to perform these functions are

Stratified squamous keratinizing epithelium makes up the epidermis of the skin(Scalnon & Sanders, 2011). Even though this is a good barrier, this tissue would not be suitable for the lining of the trachea or small intestine. Stratified squamous epithelium consists of many layers. Columnar cells are tall and narrow and stratified means many cells (Scalnon & Sanders,2011). This type of epithelium makes the epidermis of the skin, protein keratin is produced.

The dermis is the deep layer of the skin found under the outer skin. The dermis is mostly made of dense irregular connective tissue along with nervous tissue, blood, and blood vessels. The dermis is much thicker than the outer skin and gives the skin its strength and ability to stretch. Within the dermis there are two clear/separate areas: the papillary layer and the reticular layer.

The main functions of the skin, explain the basis for dividing the epidermis into strata. List and describe each stratum

Skin, the largest organ in the human body covers the whole body. It has many function such as protecting as barrier against radiations, pathogens etc. Skin mainly consists of 3 layers, epidermis, dermis and hypodermis. Epidermis is the outer layer of the skin which is comparatively thin and tough. Epidermis does not have blood vessels and comprised of epithelial cells. Most of the cells in the epidermis are keratinocytes. Epidermis is originated from the deepest layer of the epidermis called basal layer. New keratinocytes slowly migrate up toward the surface of the epidermis. Upon reaching the skin surface, keratinocytes will gradually shed and will be replaced by new cells. Stratum comeum is the topmost layer of the epidermis. It is

layer is called stratum lucidum; these cells are clear and have a flattened shape and do not possess