Ch04_Types of Tissues – Organ Systems Part II.pdf

Types of Tissues- Organ systems- Part II Nermin Eissa, Ph.D. College of Health Sciences Abu Dhabi University Fall-2023 Learning Outcomes: Explain the function of human skin. Describe the structure of the epidermis and dermi...

Types of Tissues- Organ systems- Part II Nermin Eissa, Ph.D. College of Health Sciences Abu Dhabi University Fall-2023 Learning Outcomes: Explain the function of human skin. Describe the structure of the epidermis and dermis. Summarize the function of each organ system in the human body. Identify the major cavities of the human body. Name the body membranes and provide a function for each. Define homeostasis and provide an example. Distinguish between positive and negative feedback mechanisms. 2 ©2020 McGraw-Hill Education  The Integumentary System 1 Integumentary system. Includes the skin and accessory organs such as hair, nails, and glands. Functions: Protects underlying tissues from trauma, pathogen invasion, and water loss. Helps regulate body temperature. Contains sensory receptors, such as touch and temperature receptors. 3 ©2020 McGraw-Hill Education  The Integumentary System 2 Skin Skin has 2 main regions: the epidermis and the dermis. Under the skin there is a subcutaneous layer (hypodermis). 4 ©2020 McGraw-Hill Education  The Epidermis 1 Epidermis Thin, outermost layer of the skin. Made of stratified squamous epithelium. Stem cells that produce new epidermal cells are in the deepest layer. If an injury destroys the stem cells, skin needs to be replaced. Autograft—from another area of the body. Allograft—from another person. Can also grow skin in the lab. 5 ©2020 McGraw-Hill Education  The Epidermis 2 Cells of the epidermis. Keratinocytes—in the upper layers of epidermis. Dead and filled with keratin. Forms a waterproof barrier. Langerhans cells—a type of white blood cell. Melanocytes—produce melanin. Produces skin color and protects from UV light. People have the same number of melanocytes but the amount of melanin produced varies. 6 ©2020 McGraw-Hill Education  The Epidermis 3 Epidermal cells produce vitamin D when exposed to UV rays. Vitamin D is important in the regulation of calcium and phosphorus levels in the body. 7 ©2020 McGraw-Hill Education  Skin Cancer Skin cancer. Caused by ultraviolet rays from the sun. Basal cell carcinoma—cancer of the epidermal stem cells. Most common type of skin cancer; easily curable. Melanoma—cancer of melanocytes. Extremely serious. 8 ©2020 McGraw-Hill Education  The Dermis The dermis. Thick, inner layer of the skin. Made of dense fibrous connective tissue. Contains collagen and elastic fibers for strength and elasticity. Contains blood vessels, sensory receptors, and glands. Sensory receptors are specialized for touch, pressure, pain, hot, and cold. 9 ©2020 McGraw-Hill Education  The Subcutaneous Layer The subcutaneous layer. Technically not part of the skin. Composed of loose connective tissue and adipose tissue. Stores energy, insulates and protects. 10 ©2020 McGraw-Hill Education  Organ Systems, Body Cavities, and Body Membranes 2 Organ—a group of tissues performing a common function. Groups of organs with a similar function form an organ system. Some of these organ systems (for example, the respiratory system) occupy specific cavities; others, (for example, the muscular system) are found throughout the body. Organs and cavities are lined with membranes, many of which secrete fluid. 11 ©2020 McGraw-Hill Education  Organ Systems of the Body Access the text alternative for these images 12 ©2020 McGraw-Hill Education  Organ Systems of the Body Access the text alternative for these images 13 ©2020 McGraw-Hill Education  Body Cavities Body cavities. Two main cavities: ventral and dorsal. Ventral cavity. Contains the thoracic, abdominal, and pelvic cavities. Thoracic and abdominal cavities are separated by the diaphragm. Dorsal cavity. Contains the cranial cavity and vertebral canal. 14 ©2020 McGraw-Hill Education  Body Membranes Body membranes line cavities and the internal spaces of organs and tubes that open to the outside. Four types: mucous, serous, and synovial membranes and the meninges. 15 ©2020 McGraw-Hill Education  Mucous Membranes Mucous membranes Line the tubes of the digestive, respiratory, urinary, and reproductive systems. Composed of epithelium overlying loose fibrous connective tissue. Contains goblet cells that secrete mucus. 16 ©2020 McGraw-Hill Education  Serous Membranes Serous membranes. Line closed cavities (not open to the environment) and cover the surface of the organs contained within. That is, pleurae line the thoracic cavity and cover the lungs. That is, pericardium forms the pericardial sac and covers the heart. That is, peritoneum lines the abdominal cavity and covers its organs. ©2020 McGraw-Hill Education 17  Synovial Membranes and Meninges Synovial membranes. Composed only of loose connective tissue. Line freely moveable joints. Secrete synovial fluid for lubrication. Meninges. Composed only of connective tissue. In the dorsal cavity (around the brain and spinal cord). Meningitis—inflammation of the meninges. 18 ©2020 McGraw-Hill Education  Check Your Progress Describe the location of the major body cavities. List the four types of body membranes, and describe the structure and function of each. 19 ©2020 McGraw-Hill Education  Homeostasis 2 Homeostasis. A relatively constant internal environment. There are various conditions in the body that are maintained within a relatively narrow range of normal values. blood glucose, pH, body temperature. If conditions vary too much, illness results. 20 ©2020 McGraw-Hill Education  The Internal Environment The internal environment has two parts: blood and interstitial fluid. Blood delivers oxygen and nutrients to the tissues and carries away carbon dioxide and wastes. Interstitial fluid surrounds body cells; substances are exchanged through it. Body systems work together to keep these substances within the range of normalcy. 21 ©2020 McGraw-Hill Education  The Body Systems and Homeostasis The nervous and endocrine systems coordinate the other organ systems. The nervous system is faster, but the effects of the endocrine system last longer. The endocrine system secretes hormones— chemical messengers that travel in blood. 22 ©2020 McGraw-Hill Education  Mechanisms for Maintaining Homeostasis 1 Mechanisms for maintaining homeostasis: negative and positive feedback. Negative feedback. The primary mechanism used in the body. Has two components: a sensor and a control center. The output of the system turns down, or off, the production. That is, how a furnace works. That is, temperature regulation. 23 ©2020 McGraw-Hill Education  Negative Feedback Mechanisms 24 ©2020 McGraw-Hill Education  Action of a Complex Negative Feedback Mechanism Access the text alternative for these images 25 ©2020 McGraw-Hill Education  Body Temperature Homeostasis Access the text alternative for these images 26 ©2020 McGraw-Hill Education  Mechanisms for Maintaining Homeostasis 2 Positive feedback. Brings about a change in the same direction as the original stimulus. For example, childbirth: the fetus’ head pushes against the cervix, which stimulates signals that are sent to the brain. The brain then secretes the hormone oxytocin, which causes stronger contractions. This causes more oxytocin to be released. Childbirth stops the positive feedback. 27 ©2020 McGraw-Hill Education  Check Your Progress Define homeostasis, and explain why it is important to body function. Summarize how the body systems contribute to homeostasis. 28 ©2020 McGraw-Hill Education