1a.3 Integumentary System.pdf

[00:00:06] >> This lecture will briefly cover the integumentary system with an overview of the entire system but primary attention to the skin. As an overview, the entire integumentary system includes quite a list of structures, including the skin, the hair and nails, the sweat glands and sebaceous...

[00:00:06] >> This lecture will briefly cover the integumentary system with an overview of the entire system but primary attention to the skin. As an overview, the entire integumentary system includes quite a list of structures, including the skin, the hair and nails, the sweat glands and sebaceous glands, the subcutaneous fat, the deep fascia and our mucous membranes. [00:00:33] The functions of this system are, number one, to provide protection and this happens in many ways, actually. As a physical barrier, our skin especially allows multiple layers to protect us from abrasions. It also protects us from chemical substances. The melanocytes in the skin help to protect from UV and there's also immune functions within the skin. [00:00:59] The integumentary system also functions for regulation. So this can include thermoregulation such as sweating for cooling or blood flow constriction for heating as well as the heating aspects of the adipose tissue. The integumentary system also allows communication between the body and the outside environment through different sensory receptors. [00:01:26] The integumentary system also allows for synthesis and secretion of different chemicals, including our vitamin D synthesis and certain growth factors. And finally, the integumentary system is also a system for excretion our sweat glands, not only release water but also can release waste products. The skin consists of many layers of tissue that helps to protect the body, as well as carrying out other functions. [00:01:57] The most superficial layer of the skin is the epidermis? So this is the layer of the skin that is actually exposed to the outside environment and this is composed of stratified squamous epithelium that also has keratinized cells which help to prevent water loss. Deep to the epidermis is the dermis and the dermis consists of two layers, a papillary layer and a denser layer. [00:02:24] The papillary layer is a loose connective tissue that allows the epidermis some room for movement on top of the dermis, and the deeper layer of the dermis is a dense irregular connective tissue that helps to protect the body from tension in multiple directions. And finally, we look at the hypodermis which is the deepest layer and this consists of a loose connective tissue. [00:02:52] Oftentimes there's adipose tissue for cushioning and insulation. This also includes the superficial fascia and it helps to mediate the mobility of the skin from the other tissues. These different layers, the epidermis, dermis and hypodermis, including the fascia are going to become important as you learn about wound care because we assess the severity or the depth of a wound based on how many layers are compromised. [00:03:23] We conclude with one example of the thick skin in the body. This is the type of skin that is found on the soles of the feet and the palms of the hand. As you will notice, compared to the other slides, the stratum corneum or the most superficial layer of the epidermis is incredibly thick here. [00:03:42] This makes sense as the soles of our feet have to protect the muscles and all of the other tissues in the foot from friction with the ground, sharp items on the ground, even heat or cold coming from the ground. So this is a great demonstration of how that stratified squamous epithelium really plays out in the epidermis.