Unit 5 5 1 Skin The Bodys Largest

Unit 5 5. 1 Skin The Body’s Largest Organ

Fingerprints �

Functions of the Skin �Physical barrier -1 st line of defense. Protects against injury, infection by microorganisms, and damage by harmful rays of the sun. �protects the internal tissues and organs, helps regulate internal conditions �protects the body from dehydration �protect the body against changes in temperature �chemicals on the skin kill certain surface bacteria � acidic p. H of sweat slows the growth of some microbes �helps dispose of wastes and helps stores water and fat �receptor for touch, pressure, pain and temperature

Skin Tissues � 2 main layers �Epidermis- the outermost layer of skin, waterproof barrier and creates our skin tone �Dermis- beneath the epidermis, contains tough connective tissue, and accessory organs. �accessory organs � sweat glands � hair follicles.

Epidermis �made up of epithelial tissue �makes up the “coverings and linings” in the human body. �cells are packed closely together �avascular, (lacking a blood supply) �the reasons we shed dry skin cells.

Dermis �composed of connective tissue �blood supply located in the lower levels of connective tissue �consists of cells embedded in a matrix, or framework. �contain elastin or collagen fibers provide flexibility, �durability �stretch to the tissue as in skin. �

Keratin �a very strong protein that can be found in outer layers of the skin, hair, nails, hooves, feathers. �Fingernails and Horse hoof is an example of keratin.

Collagen � gives the skin its strength and durability and is responsible for the smooth, plump appearance �providing the structural scaffolding for shape of cells, tissues, and organs. �if it weren't for collagen the body would fall apart

Elastin �In connective tissue that is elastic and allows tissues in the body to resume their shape after stretching or contracting. �Elastin helps skin to return to its original position when it is poked or pinched.

sweat glands and sebaceous glands �sweat glands situated in almost all of the human skin �sebaceous glands are tiny glands in the skin which secrete a lubricating oily matter (sebum) into the hair follicles to lubricate the skin and hair

Essential Questions � 1. What are the functions of skin? � 2. What types of tissue make up the layers of the skin? � 3. What role do accessory organs such as sweat glands and sebaceous glands play in the skin?

Activity 5. 1. 1 Under Your Skin �add a piece of skin to their maniken. �Roll out a thin sheet of yellow or orange clay. This layer will represent the dermis. �Roll out an even thinner sheet of white clay and place this sheet over the dermis. This will serve as the epidermis. �Carefully drape the newly formed “skin” over the chest or upper arm, Place the skin over existing blood vessels and muscles �This strong tissue will cover and protect structures found beneath. �Note how these structures that lie beneath contribute to physical appearance and identity. �Leave an open edge to appreciate layering of skin tissue. �(NOTE) blood vessels do traverse the dermis.

Protection �In what ways can we protect our skin from stress and injury? �even with protection our skin, is going to have natural wear and tear. �since the skin is the body’s first line of defense, it is subject to major damage.

Activity 5. 1. 2 Burn Unit

st 1 nd 2 rd 3 and th 4 degree burns

Essential Questions � 4. What happens to skin as it is exposed to sunlight and as a person ages? � 5. Which layers of the skin are damaged in different types of burns? � 6. How does burn damage in the skin affect other functions in the body? � 7. How do medical professionals in different fields assist with burn care and rehabilitation?

Activity 5. 1. 3 Hurts so Good �Raise their hands if they would be happy never to feel pain again. �watch a video clip presented in the Discovery Channel special, Human Body: Pushing the Limits. �Video 3 �Examine the role pain plays in protection,

Essential Questions � 8. What role does pain play in the human body? � 9. How does the body interpret and process pain? � 10. Why would the inability to feel pain actually put the human body in danger

5. 1 Key Terms � Collagen- An insoluble fibrous protein of vertebrates that is the chief constituent of the fibrils of connective tissue (as in skin and tendons) and of the organic substance of bones. � Connective Tissue- Animal tissue that functions mainly to bind and support other tissues, having a sparse population of cells scattered through an extracellular matrix. � Dermis- The sensitive vascular inner mesodermic layer of the skin. � Elastin- A protein that is similar to collagen and is the chief constituent of elastic fibers. � Endorphin- A hormone produced in the brain and anterior pituitary that inhibits pain perception. � Epidermis- The outer nonsensitive and nonvascular layer of the skin of a vertebrate that overlies the dermis. � Epithelium- A membranous cellular tissue that covers a free surface or lines a tube or cavity of an animal body and serves especially to enclose and protect the other parts of the body, to produce secretions and excretions, and to function in assimilation. � Exocrine gland- A gland (as a sweat gland, a salivary gland, or a kidney) that releases a secretion external to or at the surface of an organ by means of a canal or duct.

5. 1 Key Terms � First-degree burn- A mild burn characterized by heat, pain, and reddening of the burned surface but not exhibiting blistering or charring of tissues. � Keratin- Any of various sulfur-containing fibrous proteins that form the chemical basis of epidermal tissues (as hair and nails) and are typically not digested by enzymes of the gastrointestinal tract. � Melanin- Any of various black, dark brown, reddish brown, or yellow pigments of animal or plant structures (as in skin and hair). � Pain- Basic bodily sensation that is induced by a noxious stimulus, is received by naked nerve endings, is characterized by physical discomfort (as pricking, throbbing, or aching), and typically leads to evasive action. � Sebaceous gland- Any of the small sacculated glands lodged in the substance of the derma, usually opening into the hair follicles, and secreting an oily or greasy material composed in great part of fat which softens and lubricates the hair and skin. � Second-degree burn- A burn marked by pain, blistering, and superficial destruction of dermis with edema and hyperemia of the tissues beneath the burn. � Third-degree burn- Severe burn characterized by destruction of the skin through the depth of the dermis and possibly into underlying tissues, loss of fluid, and sometimes shock.

Activity 5. 2. 1 �Bones - Remarkable example of engineering combining light weight, flexibility and incredible strength. � lb per lb stronger then concrete �Every 7 years a healthy body completely replaces every bone cell in the entire body keeping them strong. �Constantly remodeling �osteoblast �osteoclast �Who in the class has ever broken a bone. �How does human skeletal system protect us � Human Body: Pushing the Limits video on strength available at http: //dsc. discovery. com/tv/human-body/explorer. html. �Alternatively, view the clip on DVD. The clip is located on the Strength DVD – Chapter 2 – 1. 15.

Bone make up �Matrix of hollow cells �Walls thin as paper �Get flexibility �elastin �collagen �Gets it rigidity �calcium �Phosphorus �Almost ½ of bone mass is soft and alive allowing them to bend

Bones � 206 Tough but Flexible Bones in the human body. �Protein fibers wrapped in hard mineral salts � 4 types �Long bone �Short bone �flat bone �Irregular bone

�Spongy Bone �Irregular latticework of thin plates of bone �Found inside short, flat and irregular bones �In the epiphysis of long bone �Red bone marrow �Compact Bone�External portion of all bone �Contains few spaces between osteons �Bulk of the shaft of long bone �Yellow bone marrow

5. 2. 2 X-Ray Vision �Bones are strong but sometimes extreme stress will fracture of break a bone

Essential Questions � 1. How does the skeletal system assist with protection in the body? � 2. How does the structure of compact bone differ from the structure of spongy bone? � 3. How does the overall structure of bone provide great strength and flexibility, but keep bone from being too bulky and heavy? � 4. What is an X-ray? � 5. What are the different types of bone fractures and how are they identified on X-rays? � 6. How can damage to a bone affect other human body systems? � 7. What is bone remodeling?

Essential Questions � 8. How do osteoblasts and osteoclasts assist with bone remodeling and overall bone homeostasis? � 9. What is the relationship between bone remodeling and blood calcium levels? � 10. How do hormones assist in the maintenance of healthy bone and the release of calcium to be used in other body processes? � 11. What are the four main stages of healing that occur after a bone fracture? � 12. What lifestyle choices relate to the overall strength and protective properties of bone?

Key terms �Bone marrow -A soft highly vascular modified connective tissue that occupies the cavities and cancellous part of most bones and occurs in two forms – yellow and red. �Bone remodeling-The continuous turnover of bone matrix and mineral that involves first, an increase in resorption and osteoclast activity, and later, reactive bone formation by osteoblast activity. �Calcitonin -A polypeptide hormone especially from the thyroid gland that tends to lower the level of calcium in the blood plasma. �Callus -A growth of new bone tissue in and around a fractured area, ultimately replaced by mature bone. �Cartilage -A usually translucent somewhat elastic tissue that composes most of the skeleton of vertebrate embryos and except for a small number of structures (as some joints, respiratory passages, and the external ear) is replaced by bone during ossification in the higher vertebrates.

Key terms �Compact bone -Bone tissue that contains few spaces between osteons; forms the external portion of all bones and the bulk of the diaphysis (shaft) of long bones. �Diaphysis-The shaft of a long bone. �Epiphysis-The end of a long bone, usually larger in diameter than the shaft. �Fracture -The breaking of hard tissue (as bone). �Osteoblast-A bone-forming cell. �Osteoclast -Any of the large multinucleate cells closely associated with areas of bone resorption (as in a fracture that is healing). �Osteocyte -Cell that is characteristic of adult bone and is isolated in a lacuna of the bone substance. �Parathyroid hormone -A hormone of the parathyroid gland that regulates the metabolism of calcium and phosphorus in the body. �Spongy (cancellous) bone-Bone tissue that consists of an irregular latticework of thin plates of bone called trabeculae; found inside short, flat, and irregular bones and in the epiphyses of long bone.

5. 3 Lymph and Blood Cells

Essential Question � 1. What body systems function to protect the human body? �The immune system is the primary system that helps protect the body. The skeletal system supports the immune system by making immune cells within the bone marrow. The cardiovascular system supports the immune system by moving immune components through the body.

Blood Cells �How do specific components of the blood protect the body? �White blood cells fight disease and platelets prevent blood loss by facilitating clotting

White Blood Cells �Largest of the blood cells �Normally 5000 to 10, 000 WBC per m. L blood �Variable life span – from a few days to years �Produced in bone marrow �Part of the immune system �Increase in number when infection or inflammation is present

White Blood Cells ~ Leukocytes � 5 Types �Monocyte �Neutrophil �Lymphocyte �Basophil �Eosinophil

Monocytes �Monocytes share the "vacuum cleaner" (phagocytosis) � They present pieces of pathogens to T cells so that the pathogens may be recognized again and killed. �Signal other immune cells that foreign material is inside body

Neutrophils �Neutrophils defend against bacterial or fungal infection. �They are usually first responders to microbial infection; their activity and death in large numbers forms pus. �Neutrophils are the most common cell type seen in the early stages of acute inflammation. �They make up 60 -70% of total leukocyte count in human blood. �The life span of a circulating human neutrophil is about 5. 4 days. [

Lymphocytes �Destroy abnormal cells �Produce antibodies �Moderate immune response

Basophils �Can destroy foreign material �Involved in inflammation response �Involved in development of allergies

Eosinophils �Kill multicellular parasites (e. g. blood fluke)

Lymph and Lymphatic System �Activity 5. 3. 1 To Drain and Protect �Equipment Needed � Computer with Internet access � Anatomy in Clay® Maniken® � Green clay � Spaghetti gun and extruder � Body system graphic organizer handout � Colored pencils or markers � Laboratory journal

Essential Question � 2. How does the structure of the lymphatic system relate to its function? � The lymphatic (“water”) system is part of the cardiovascular system. � It’s made up lymphatic vessels that carry lymph fluid (recycled blood plasma with WBCs) toward the heart. � It overlaps with the immune system & contains organs like the lymph nodes & tonsils. � It makes and circulates lymphocytes (WBCs that are the main cells of the system). � The spleen, thymus and bone marrow are considered parts of the system. � There are rounded masses of lymph tissue called lymph nodes (“water knots”) that contain lots of lymphocytes and filter the lymph fluid. � The lymph vessels empty into ducts that drain into veins.

Blood Typing

Blood Typing Game �Type in �http: //www. nobelprize. org/educational/medicine/blo odtypinggame/ or type in Nobelprize Blood Typing Game �Watch the 3 min tutorial first- before you begin the game

Essential Question � 3. What is an antigen? Antigen (“against formation”) �Proteins found on the outside of pathogens (“disease starters” —viruses and disease-causing bacteria), unique to each pathogen. Lymphocytes recognize antigens as foreign and produce antibodies specific to each antigen � 4. What is an antibody? �Y-shaped structures produced by lymphocytes to fight against pathogens by attaching to their antigens. Antibodies destroy the antigen (and therefore the pathogen) and it is then consumed by macrophages (“big eaters”). Memory cells remember past pathogens and can quickly make the right antibodies if attacked again, giving immunity in the future.

Essential Question 5. How do circulating antibodies protect a person from receiving incompatible blood during a transfusion? �Antigens are found on the surface of blood cells and platelets and if the antigens trigger an immune response (happens if blood types don’t match), the body produces antibodies to attack the antigens. �This results in agglutination, which is a clumping of blood cells caused by the antigen-antibody interaction. �Agglutination can be deadly, which is why it is critically important to know a person’s blood type before performing a transfusion. �Type O blood does not contain antigens, which is why people with type O blood are considered “universal donors”—it won’t trigger agglutination in others.

Immunity �Has anyone in here had chicken pox? �If so, could you be able to catch them again? �Why or Why Not? �Antigens and Antibodies �Circulating antibodies can protect the body from foreign invaders.

Activity 5. 3. 3 Fighting the Common Cold �Equipment Needed �Computer with Internet access and Inspiration® software �Red and blue colored pencil or marker �Graph paper �Laboratory journal

Essential Question � 6. What is specific immunity? �Specific immunity is immunity against a particular antigen (or pathogen).

Essential Question � 7. What role do lymphocytes play in specific immunity? �T lymphocytes (T cells) and B lymphocytes (B cells) are the two kinds of lymphocytes. All lymphocytes begin in the bone marrow and then mature into one of these types, with T cells maturing in the bone marrow and B cells maturing in the thymus gland. B cells are like military intelligence, seeking out pathogens and sending T cells to attack. B cells make the antibodies that match to each antigen. T cells are like solders, binging to antigens and then releasing a protein that punctures the pathogenic cells, destroying them.

Essential Question � 8. How does your body react the second time it is exposed to a particular antigen? �Once produces, antibodies stay in a person’s body, so if the same pathogen shows up again, the antibodies to attack it are already present and the person doesn’t usually get sick (hence the beauty of a vaccine!)

Key Terms Agglutination Alleles Antibody Antigen B lymphocyte (B cell) Blood type (group) Immunity Lymph node Lymphocyte Macrophage Memory cell Pathogen Pedigree T lymphocyte (T cells) Clumping of microorganisms or blood cells, typically due to an antigen-antibody interaction. Alternate forms of a single gene that control the same inherited trait (such as type A blood) and are located at the same position on homologous chromosomes. An antigen-binding immunoglobulin, produced by B cells, that functions as the effector in an immune response. A foreign macromolecule that does not belong to the host organism and elicits and immune response. A type of lymphocyte that develops in the bone marrow and later produces antibodies, which mediate humoral immunity. One of the classes (as A, B, AB, or O) into which individual vertebrates and especially human beings or their blood can be separated on the basis of the presence or absence of specific antigens in the blood. A condition of being able to resist a particular disease especially through preventing development of a pathogenic microorganism or by counteracting the effects of its products. A usually clear fluid that passes from intercellular spaces of body tissue into the lymphatic vessels, is discharged into the blood by way of the thoracic duct and right lymphatic duct, and resembles blood plasma in containing white blood cells and especially lymphocytes but normally few red blood cells and no platelets. Any of the rounded masses of lymphoid tissue that are surrounded by a capsule of connective tissue, are distributed along the lymphatic vessels, and contain numerous lymphocytes which filter the flow of lymph passing through the node. Any of the colorless weakly motile cells that originate from stem cells and differentiate in lymphoid tissue (as of the thymus or bone marrow), that are the typical cellular elements of lymph, that include the cellular mediators of immunity, and that constitute 20 to 30 percent of the white blood cells of normal human blood. An amoeboid cell that moves through tissue fibers, engulfing bacteria and dead cells by phagocytosis. A long-lived lymphocyte that carries the antibody or receptor for a specific antigen after a first exposure to the antigen and that remains in a less than mature state until stimulated by a second exposure to the antigen at which time it mounts a more effective immune response than a cell which has not been exposed previously. A specific causative agent (as a bacterium or virus) of disease. A diagram of a family tree showing the heritable characters in parents and offspring over multiple generations. A type of lymphocyte responsible for cell-mediated immunity that differentiates under the influence of the thymus.