The epidermis is the relatively thin, tough, outer layer of the skin. The condition is especially noticeable on darker skin. It is composed mainly of loosely arranged collagen fibers. In older people, these proteins start to decrease, making their skin more delicate. Sensory receptors in the dermis are mainly responsible for the bodys tactile senses. Recall that melanin helps protect the skin from the harmful effects of UV radiation. View the University of Michigan WebScope to explore the tissue sample in greater detail. Last reviewed by a Cleveland Clinic medical professional on 10/19/2021. The dermis acts as a supporting structure for the epidermis and contains proteins such as collagen and elastin. In humans the process of digestion begins in the 5.______ where food is 6._______into small pieces by the teeth. This layer is made of flat, hard, tightly packed dead keratinocytes that form a waterproof keratin barrier to protect the underlying layers of the epidermis. Keratinocytes have granules within them, and in this layer theyre visible under a microscope. If you zoom on the cells at the outermost layer of this section of skin, what do you notice about the cells? Which layer of the epidermis contains keratinocytes that have begun to die? Avoid scrubbing, which can make acne worse. By the end of this section, you will be able to: Although you may not typically think of the skin as an organ, it is in fact made of tissues that work together as a single structure to perform unique and critical functions. The keratinocytes in this layer have begun to accumulate keratin, and they have become tougher and flatter. For unlimited access to Homework Help, a Homework+ subscription is required. It does not have any blood vessels within it (i.e., it is avascular). b: merocrine sweat duct How many layers of keratinocytes comprise the stratum granulosum? Once the food is mixed with 13.______and crushed some more. Which layer of the dermis provides cushioning for subcutaneous tissues and why does this layer provide most of the cushioning instead of the other layer? Stratum Basale. Acne is the most common skin disorder in the United States. Just above the stratum basale is the stratum spinosum. In thick skin, the layers of epidermis that contain dead keratinocytes are the stratum lucidum and stratum ______. Fingerprints are unique to each individual and are used for forensic analyses because the patterns do not change with the growth and aging processes. A Pros and Cons Checklist, Embracing Gender Identity: Want to Be a Girl, Breaking Boundaries in Kpop: Foreign Idols, Living Smarter: Top Tips for Smart Ways to Live. When compressed, tactile cells release chemicals that stimulate ____ _____ endings in the dermis. DERMIS tissue type. LM 10. Ruffini corpuscles sense stretching and sustained pressure. Examples include the heavy metal lead and many pesticides. Sharp objects and rough surfaces have difficulty penetrating or removing the tough, dead, keratin-filled cells of the stratum corneum. The epidermis is the outermost layer of skin composed entirely of epithelial cells whose primary function is to protect against injury or any other harm from entering into sensitive structures underneath it such as nerve endings. A nevus is commonly referred to as a _______. View this animation to learn more about layers of the skin. It is the thickest layer of the skin, and is made up of fibrous and elastic tissue. How does the dermis excrete wastes, and what waste products does it excrete? While the epidermis is the thinnest layer of skin, the dermis is the thickest layer of skin. They originate from cells in the deepest layer of the epidermis called the basal layer. What is the purpose of describing the demographic data? And so, all animals have a group of connected organs called the digestive 4.______. Among the stimuli detected by the sensory receptors of the skin are _____. The stratum basale is primarily made up of a single layer of basal cells. There are usually 15 to 30 layers of cells in the stratum corneum. This results in more air being trapped under the hairs to insulate the surface of the skin. Inflammation, in turn, causes swelling and redness and may be associated with the formation of pus. Use a mild soap for your bath or shower, and pat your skin dry instead of rubbing it. are licensed under a, Structural Organization of the Human Body, Elements and Atoms: The Building Blocks of Matter, Inorganic Compounds Essential to Human Functioning, Organic Compounds Essential to Human Functioning, Nervous Tissue Mediates Perception and Response, Diseases, Disorders, and Injuries of the Integumentary System, Exercise, Nutrition, Hormones, and Bone Tissue, Calcium Homeostasis: Interactions of the Skeletal System and Other Organ Systems, Embryonic Development of the Axial Skeleton, Development and Regeneration of Muscle Tissue, Interactions of Skeletal Muscles, Their Fascicle Arrangement, and Their Lever Systems, Axial Muscles of the Head, Neck, and Back, Axial Muscles of the Abdominal Wall, and Thorax, Muscles of the Pectoral Girdle and Upper Limbs, Appendicular Muscles of the Pelvic Girdle and Lower Limbs, Basic Structure and Function of the Nervous System, Circulation and the Central Nervous System, Divisions of the Autonomic Nervous System, Organs with Secondary Endocrine Functions, Development and Aging of the Endocrine System, The Cardiovascular System: Blood Vessels and Circulation, Blood Flow, Blood Pressure, and Resistance, Homeostatic Regulation of the Vascular System, Development of Blood Vessels and Fetal Circulation, Anatomy of the Lymphatic and Immune Systems, Barrier Defenses and the Innate Immune Response, The Adaptive Immune Response: T lymphocytes and Their Functional Types, The Adaptive Immune Response: B-lymphocytes and Antibodies, Diseases Associated with Depressed or Overactive Immune Responses, Energy, Maintenance, and Environmental Exchange, Organs and Structures of the Respiratory System, Embryonic Development of the Respiratory System, Digestive System Processes and Regulation, Accessory Organs in Digestion: The Liver, Pancreas, and Gallbladder, Chemical Digestion and Absorption: A Closer Look, Regulation of Fluid Volume and Composition, Fluid, Electrolyte, and Acid-Base Balance, Human Development and the Continuity of Life, Anatomy and Physiology of the Testicular Reproductive System, Anatomy and Physiology of the Ovarian Reproductive System, Development of the Male and Female Reproductive Systems, Changes During Pregnancy, Labor, and Birth, Adjustments of the Infant at Birth and Postnatal Stages.