BIO204L Week 10-12 Module PDF

College of Arts and Sciences Education General Education - Science 2nd Floor, DPT Building, Matina Campus, Davao City...

College of Arts and Sciences Education General Education - Science 2nd Floor, DPT Building, Matina Campus, Davao City Phone No.: (082)300-5456/305-0647 Local 134 Week 10-11: Unit Learning Outcomes (ULO): At the end of the unit, you are expected to a. discuss the important parts and functions of the Excretory System and Integumentary System. Big Picture in Focus ULO-a. discuss the important parts and functions of the Excretory System and Integumentary System. In this segment, the important terminologies related to the essential parts and functions of the Excretory System and Integumentary System, which were denoted in the ULO-a, will be operationally and theoretically defined to establish a collective understanding needed for the discussion of the topics. You will encounter these vocabularies as we go through the details of the Excretory System and Integumentary System. Please refer to these definitions when you have difficulty in understanding some concepts. 1. Control Systems in the Body Internal control systems require sensors, a control center, communication systems, and targets. Sensors or the receptors gather information about conditions inside and outside of the body. 2. Homeostasis One of the living organisms' necessary attributes is the regulation and maintenance of the internal environment like temperature, fluids, salts, pH, nutrients, and gases within the narrow ranges that support human life. 3. Osmoconformers or Stenohalines These are organisms such as marine invertebrates that have body surfaces w/c are permeable to water salts. These animals are restricted to a narrow range of salinity because they have limited capacities to withstand sharp fluctuations. 4. Feedback Loops The sensors, control centers, communication systems, and targets working together make up a Feedback Loop. Feedback is information from sensors that allows a control center to compare current conditions to a set of ideal values. In a feedback loop, information moves continuously among sensors, a control center, and a target. 117 | P a g e  College of Arts and Sciences Education General Education - Science 2nd Floor, DPT Building, Matina Campus, Davao City Phone No.: (082)300-5456/305-0647 Local 134 5. Excretion It is a biological process of the animal’s body for the disposal of particular metabolic wastes, and excess substances are removed. It also removes excess heat from the body, thus keeping the temperature of the body constant. 6. Basal Cell Carcinoma The most common type of skin cancer. This resulted from prolonged UV exposure that damages cells at the base of the epidermis. It forms a mound of slow- growing cancerous cells. 7. Integumentary System It is an organ system that functions to resist water, protect the tissues, eliminate wastes, and regulate the body’s temperature. It also serves as an attachment site for the sensory organs to perceive pain, feeling, pressure, and changes in the environmental temperature. 8. Stratum Basale The stratum basale is the only layer capable of mitotic activity, pushing up cells to replenish the outer layer in a process called terminal differentiation. 9. Epidermis This is the outermost layer of skin made up of tightly packed epithelial cells. It does not contain nerve and blood vessels, so it does not bleed if it breaks. Its principal function is protection, absorption of nutrients, and homeostasis. 10. Sweat Glands Sweat glands are found in nearly all parts of the skin but are most abundant in the palms and soles. The sweat gland consists of a tiny tube from a ball-shaped coil in the dermis or subcutaneous layer of the skin. The looped part of the gland is fastened at its deep end and is lined with sweat-producing cells. In this portion, you will accomplish the Unit Learning Outcomes, which was stipulated in the Big Picture. This will be done for the tenth and eleventh weeks of this course. Your understanding of the following concepts is essential to proceed with successive topics. You may refer to other available references to explore more on the subjects. Thus, you are expected to utilize other books, research articles, and other resources that are available in the university’s library, e.g., ebrary, search.proquest.com, etc. 118 | P a g e  College of Arts and Sciences Education General Education - Science 2nd Floor, DPT Building, Matina Campus, Davao City Phone No.: (082)300-5456/305-0647 Local 134 LECTURE INTERNAL CONSTANCY AND EXCRETION Homeostasis One of the primary attributes of the living organism is the regulation and maintenance of the internal environment like temperature, fluids, salts, pH, nutrients, and gases within the narrow ranges that support human life. Life depends on five (5) environmental factors as requirements of the organisms: 1. Water is the most abundant substance in the body that makes up about 60-70% of the body. It is required for metabolic processes and the transport of materials. It also regulates body temperature. 2. Food - It provides necessary nutrients to supply energy and raw materials 3. Oxygen - Air molecules used to release energy from nutrients. 4. Heat – It is a form of energy that partly controls the rate of metabolic reactions. 5. Pressure – It is an application of force on an object. The atmospheric pressure is vital for breathing and movement of air. Hydrostatic pressure keeps blood flowing. Control Systems in the Body Internal control systems require sensors, a control center, communication system and targets. Sensors or the receptors gather information about conditions inside and outside of the body. - Control Center/SetPoint The brain receives info from the sensors. Then, the brain compares that info to the ideal values. When conditions move above or below a set point, the control center responds by sending messages through a communication system. - Communication Systems The nervous system and the endocrine system carry messages to all parts of the body. Messages are in the form of nerve impulses or hormones. The communication system tell targets in the body how to respond to internal or external changes. - Effectors/Targets A target is any organ, tissue, or cell that changes its activity level in response to a message. Example: In a cold environment, a message might cause the muscles to start shivering to generate more body heat. Feedback Loops The sensors, control centers, communication systems, and targets working together make up a Feedback Loop. Feedback is information from sensors that allows a control center 119 | P a g e  College of Arts and Sciences Education General Education - Science 2nd Floor, DPT Building, Matina Campus, Davao City Phone No.: (082)300-5456/305-0647 Local 134 to compare current conditions to a set of ideal values. In a feedback loop, information moves continuously among sensors, a control center, and a target. - Negative feedback loops Negative feedback loops regulate almost all functions in the body. Negative feedback sends instructions to a target to counteract changes. The target responds to bring conditions back to normal. Example: - Thermostat's response causes temperature decrease to reverse and become a temperature increase - Shivering in response to cold weather The thermostat in our classroom is like a negative feedback loop. A sensor in the thermostat continuously measures air temperature in a room. A control mechanism then compares the current room temperature to a set point, say 69.8˚F. When the temperature falls below 69.8˚F, the thermostat sends an electronic message that turns on the furnace. When the sensor indicates the air temperature is at or just above 69.8˚F, the thermostat sends another signal that turns off the heater. As a result, the room always stays within a few degrees of the desired temperature. Examples of Negative Feedbacks: 1. What does the body do if you get too cold? Blood flow decreases. Tiny muscles contract the pores and skin around body hairs to conserve heat. 120 | P a g e  College of Arts and Sciences Education General Education - Science 2nd Floor, DPT Building, Matina Campus, Davao City Phone No.: (082)300-5456/305-0647 Local 134 2. What does the body do if you get too hot? Blood flow to the skin increases. Tiny muscles expand the pores. Sweat glands release water to cool the body.. 3. What does the body do if your blood pressure is too high? The brain tells heart chambers to contract more slowly and with less force, decreasing heart action, blood flow, and the pressure inside the blood vessels. 4. What does the body do if your blood pressure is too low? Brains tell the heart to contract more rapidly and with greater force to increase blood vessels' pressure. Positive Feedback In some cases, the body needs change to accomplish a specific task. How is positive feedback involved in clotting our blood when we cut our finger? Positive feedback mechanisms increase the clotting factors in your blood until the wound has healed. The body is moving further away from its ideal conditions for a short time. Example of Positive Feedbacks: When a pregnant woman goes into labor, the contractions usually get closer and closer together as time goes on, and more intense. Is this negative or positive feedback? Positive Feedback. Fetus's head moves into the birth canal at the start of labor, which causes the birth canal to stretch beyond its set point amount of stretch, which is detected by sensors in the vaginal wall and fed back to the hypothalamus of the brain, which releases the hormone, oxytocin, which stimulates stronger and more frequent uterine contractions, which 121 | P a g e  College of Arts and Sciences Education General Education - Science 2nd Floor, DPT Building, Matina Campus, Davao City Phone No.: (082)300-5456/305-0647 Local 134 pushes the fetus, which causes more vaginal stretch, which produces more OT, and so on that greatly amplifying and speeding up labor contractions. Sample conditions of Negative and Positive Feedbacks: 1. When you ride a bike and make adjustments to balance the bike, is this positive or negative? Negative Feedback. You are trying to help your bike maintain homeostasis (balance). 2. Why are most functions of your body regulated by negative feedback, not positive feedback? Negative feedback loops help your body to maintain homeostasis. They work to bring the body back to its normal conditions. On the other hand, positive feedback loops move the body's conditions further away from the ideal conditions. 3. Suppose you are caught out in the rain and get drenched and cold. Which type of feedback loop would cause your body to start shivering to keep warm? Negative Feedback. Your brain sends instructions to your muscles, causing them to shiver and generate heat that will help raise your body temperature and bring conditions back to normal. THE HUMAN EXCRETORY SYSTEM Excretion is a biological process of the animal's body for the disposal of particular metabolic wastes, and excess substances are removed. It also removes excess heat from the body, thus keeping the temperature of the body constant. The waste materials that are eliminated during excretion are the urea for mammals, insoluble uric acid for land reptile, Trimethylamine oxide for marine fish, and Ammonia invertebrates/aquatic vertebrates, and Guanine for spiders. Metabolic wastes are poisonous if they are in high concentration. Nitrogen is the most troublesome wastes. It is removed from proteins and nucleic acid when they are broken down for energy or converted to carbohydrates. Other metabolic wastes are Carbon dioxide, excess water, and mineral salts. The human excretory system eliminates nonsolid wastes through the lungs, skin, and kidneys. The lungs exhale carbon dioxide and water vapor. Sweat glands in skin release excess water and salts. Organs of Excretion and their functions: - Lungs- eliminates carbon dioxide and water - Kidney- eliminates urine. - Liver- eliminates toxic materials from large intestines that are bile pigments. - Skin- removes water, salts, acids, and nitrogenous wastes. 122 | P a g e  College of Arts and Sciences Education General Education - Science 2nd Floor, DPT Building, Matina Campus, Davao City Phone No.: (082)300-5456/305-0647 Local 134 Structure and Function of the Urinary System One of the central organ systems of the Excretory System is the Urinary System. The urinary system is also named as the Renal System. This system filters excess water, salt, and metabolic wastes in the body. It stores and excretes urine, the unsolidified waste excreted by the kidneys. The kidneys produce urine by filtering wastes and extra water from the blood. Urine moves from the kidneys through two narrow tubes called ureters and fills the urinary bladder. The ureters are tubes that conduct urine from the pelvis of the kidneys to the urinary bladder. The urinary bladder temporarily stores urine until it is released from the body. The urethra is the tube that carries urine from the urinary bladder to the outside of the body. A circular muscle controls the outer end of the urethra called a sphincter. Nephrons clean the blood and produce urine. They are the filtering units in the kidneys. They clean and rebalance the blood to produce urine. There approximately 1 million nephrons in each kidney. The Function of the Kidney The principal purpose of the Kidney is to filter blood to remove cellular waste products from the body. At any given time, 20 % of blood is in the kidneys. Humans can function with one Kidney. If one ceases to work, the other increases in size to handle the workload. The kidneys help to maintain homeostasis by filtering the blood. The kidneys are fist-sized, bean- shaped structures. The two layers of kidneys are the medulla and cortex. The filtering units called nephrons. The Kidney can also excrete other waste products, such as the urea, a nitrogenous waste produced in the liver from the breakdown of protein. It is the main component of urine. Uric acid is usually produced from the breakdown of DNA or RNA. Another filtered substance is the creatinine, which is a waste product of muscle action. 123 | P a g e  College of Arts and Sciences Education General Education - Science 2nd Floor, DPT Building, Matina Campus, Davao City Phone No.: (082)300-5456/305-0647 Local 134 Kidneys have three essential functions in maintaining homeostasis. - remove waste from the blood - help to maintain electrolyte, pH, and fluid balances - release key hormones Urine Formation Nephrons clean the blood in a three-step process: 1. The first step is the FILTRATION of the blood. The Glomerulus is the network of capillaries. The Bowman’s Capsule encases the glomerulus. The body’s entire volume of blood is filtered every 45 min. 124 | P a g e  College of Arts and Sciences Education General Education - Science 2nd Floor, DPT Building, Matina Campus, Davao City Phone No.: (082)300-5456/305-0647 Local 134 2. The second step is REABSORPTION of materials. 3. The third step is EXCRETION of materials. Overloading the kidney with harmful substances: Alcohol can lead to a disease called cirrhosis. It is where the liver becomes overgrow with excess tissues. Excess tissues clots down the blood flow through the liver. It limits its performance in detoxifying and removing harmful substances. If the liver ceases to function altogether, it results in death. Jaundice is the condition of when the bile is not appropriately excreted. These metabolic wastes are reabsorbed into the blood, resulting in a condition called Jaundice, reabsorbed hemoglobin fragments in the bloodstream cause the skin to look yellow. 125 | P a g e  College of Arts and Sciences Education General Education - Science 2nd Floor, DPT Building, Matina Campus, Davao City Phone No.: (082)300-5456/305-0647 Local 134 Excretion of Bile Bile is made up of the cells of the liver. It contains bile salts, cholesterol, lecithin, and part of the ingredients of bile are metabolic wastes so that the bile is considered as an excretory product. Bile is produced in the liver and stored in the gall bladder and passes through the bile duct to the small intestines. It helps in digestion and absorption of fats. At the end of the small intestines, most of the bile salts are reabsorbed into the blood and returned to the liver. From the liver, it is passed again to the small intestines. Bile salts are reused. The rest of the bile passes into the large intestines and leaves the body in the feces. Role of the Liver in Excretion The liver supports the kidney's excretory role by detoxifying many chemical poisons and synthesizing ammonia, urea, and uric acid from using nitrogen from the amino acid. The liver removes harmful substances drugs hormones from the blood. It also purifies or detoxifies the blood. It neutralizes the substances and returns to the bloodstream that will be excreted from the body by the kidney. Formation of Urea As the ammonia produced from the amino group, it is very poisonous when not excreted from the body. Ammonia is changed into the less harmful substances, the urea, by a series of enzyme-catalyzed reactions. The urea diffuses from the liver to the bloodstream. Then the bloodstream carries the urea to the kidney. The kidney filters the urea from the blood and is finally excreted from the body in the urine. Injury and disease can damage kidney functions. 1. UTI (Urinary Tract Infection)It is a pervasive disorder. If the bladder has become infected, it is known as cystitis. If the urethra is infected., it is called urethritis. Symptoms include painful urination burning sensation and frequent urination even if no urine present. The color of the urine is bloody or brown urine. The infection can lead to chills, fever, nausea, vomiting, and upper abdomen tenderness. If left untreated, all UTI’s can lead to permanent kidney damage and possible kidney failure. The general treatment is by antibiotics. A person needs to maintain good personal hygiene when eliminating wastes (liquid and solid forms) from the body. Also, a person should drink lots of water. Dialysis can be used to filter and clean the blood. 126 | P a g e  College of Arts and Sciences Education General Education - Science 2nd Floor, DPT Building, Matina Campus, Davao City Phone No.: (082)300-5456/305-0647 Local 134 2. Kidney Infections These infections result when an infection reaches the kidneys known as pyelonephritis. Common causes can be an infection from elsewhere in the body or the prostate gland (usually in older men). For children, the disease can be caused by the tube that drains urine from the kidneys and the bladder. 3. Kidney Stones These are the crystals formed from minerals in the urine. They can be found in the kidney, ureter, or bladder. 80% of those stricken are males. The most common crystals are Calcium Oxalates and Uric acid. Symptoms include severe back or abdomen pain, blood in the urine, nausea, and vomiting. Diagnosis involves a complete medical examination, including X- rays. Treatment may vary from letting the stones pass through the urinary tract to ultrasound shock (or lithotripsy) to disintegrate the stones to a small size that can be passed through the urinary tract. Real large stones require surgery for removal.. Ways to avoid kidney stones: - Increase liquid intake (more than 2L / day) - Limit sodium intake - Limit animal protein (link shown in men) - Limit foods high in oxalate (spinach, strawberries, nuts, dark chocolate, brewed tea). 127 | P a g e  College of Arts and Sciences Education General Education - Science 2nd Floor, DPT Building, Matina Campus, Davao City Phone No.: (082)300-5456/305-0647 Local 134 INTEGUMENTARY SYSTEM The integumentary system has many essential physiologies. It functions to resist water, protect the tissues, eliminate wastes, and regulate the body’s temperature. It also serves as an attachment site for the sensory organs to perceive pain, feeling, pressure, and changes in the environmental temperature. It is the primary organ system that serves as the front liner from the infections and damage. It composes the skin and its accessories like nails, hairs, glands, scales, and feathers. In humans, the skin is the site for Vitamin D synthesis when exposed to the sunlight. It is the largest organ of the body by weight, which accounts for about 16% of total body weight. The skin of an average adult weighs 8-10 pounds and averages an area of about 22 square feet. Layers of Skin - Epidermis - Dermis - Subcutaneous layer or Hypodermis 1. Epidermis This is the outermost layer of skin made up of tightly packed epithelial cells. It does not contain nerve and blood vessels, so it does not bleed if it breaks. Its principal function is protection, absorption of nutrients, and homeostasis. It comprises a keratinized stratified squamous epithelium containing four types of cells: the Keratinocytes, Merkel Cells, Melanocytes,, and Langerhans’s cells. The keratinocyte, the cell that produces keratin, is the primary key player of the integumentary system. The majority of our skin is made up of keratin, 128 | P a g e  College of Arts and Sciences Education General Education - Science 2nd Floor, DPT Building, Matina Campus, Davao City Phone No.: (082)300-5456/305-0647 Local 134 a fibrous protein that helps in protection. Numerous of these said cells sloughed off and replaced daily. Almost all of our skin on the body is keratinized that makes the water- impermeable. The epidermis is always regenerating. As dead outer cells flake off, living cells below replace them. The epidermis comprises various kinds of cells. The greatest in numbers are squamous cells that are plane and dry, scaly skin. Another type is the round basal cells. The cells that give skin color are the melanocytes that protect the body from the UV rays. It also comprises Langerhan’s cells produced in the bone marrow and then transferred to the epidermis. These cells coordinate with other cells to combat foreign materials. They are part of the immune defense of the body. There are five (5) layers of the epidermis: - Stratum corneum - Stratum lucidum - Stratum granulosum - Stratum spinosum - Stratum basale The stratum basale is the only layer capable of mitotic activity, pushing up cells to replenish the outer layer in a process called terminal differentiation. The stratum corneum is the most superficial layer and is made up of dead cells, proteins, and glycolipids. The protein keratin thickens and hardens epidermal tissue to form fingernails. The nails develop from a thin area called the nail matrix. The growth of nails is 1 mm per week on average. The lunula is the crescent-shape area at the base of the nail. This is a lighter color as it mixes with the matrix cells. Nails Main Parts Nail plate Cuticle (embedded root under fold of skin) Nail bed Capillaries in underlying nail bed give nail body its pinkish color 129 | P a g e  College of Arts and Sciences Education General Education - Science 2nd Floor, DPT Building, Matina Campus, Davao City Phone No.: (082)300-5456/305-0647 Local 134 Skin color Heredity and environment determine skin color. Genetic Factors - Varying amounts of melanin - Varying size of melanin granules - Albinos lack melanin Physiological Factors - Dilation of dermal blood vessels - Constriction of dermal blood vessels - Accumulation of carotene - Jaundice Environmental Factors - Sunlight - UV light from sunlamps - Darkens melanin 2. Dermis The dermis is the mid-layer of the skin. This layer comprises thick asymmetrical connective tissues like the collagen with elastin that are arranged in a dispersed group and knitted patterns. The dermis gives elasticity to the skin that permits stretching and suppleness, which also repelling distortions, wrinkling, and sagging. This dermal layer is a venue for the endings of blood vessels and nerves. Many chromatophores are contained in the mid-layer that serve as the foundation of the integument structures such as glands, hairs, and feathers. It has two layers: the papillary layer and the reticular layer. It contains blood vessels, nerve endings, hair follicles, sebaceous glands, sweat glands, and lymphatic vessels. Sensory Receptors Sense organs are sensory receptors that contain the sensory nerve endings that perceive the stimuli from the internal and external sources. In response to stimuli, the sensory receptor initiates sensory transduction by creating action potentials within the cell or neighboring cells. The Sensory receptors involved in taste and smell contain receptor molecules that bind to specific chemicals. The odor receptor in an olfactory receptor neuron. Meanwhile, the taste receptor or the gustatory receptors in the taste buds interact with chemicals in food to produce an action potential. Melanin Melanocytes produce the brown-black pigment melanin, a substance that gives the skin color. All humans have roughly the same number of melanocytes. It is the genetic differences that determine how melanocytes are distributed and how much melanin they produce. 130 | P a g e  College of Arts and Sciences Education General Education - Science 2nd Floor, DPT Building, Matina Campus, Davao City Phone No.: (082)300-5456/305-0647 Local 134 Melanocytes in darker skin produce more melanin than in fairer skin—pinkish color of fair skin due to hemoglobin in vessels near the skin’s surface. Hair Hairs are filamentous keratins that grow from hair follicles in the mid-layer of the skin. Hair often refers to two distinct structures. The first structure is called the hair follicle or when pulled from the skin, called the bulb. This maintains stem cells that re-grow the hair after it falls out and are recruited to regrow skin after a wound. Second, the shaft, the hard filamentous part that extends above the skin surface. A cross-section of the hair shaft may be divided roughly into three zones: the cuticle which consists of several layers of flat, thin cells laid out overlapping one another as roof shingles; the cortex which contains the keratin bundles in cell structures that remain roughly rod-like and in some cases; the medulla, a disorganized and open area at the fiber's center. There are all different shades of blonde, brunette, black, and red hair. The hair follicles have three parts: Hair root, Hair shaft, and Hair papilla—Arrector pili muscle has the bundle of smooth muscle cells attached to each hair follicle. Nerve impulses stimulate arrector pili to contract, causing goosebumps.. 131 | P a g e  College of Arts and Sciences Education General Education - Science 2nd Floor, DPT Building, Matina Campus, Davao City Phone No.: (082)300-5456/305-0647 Local 134 Sebaceous Glands or the Oil Gland It is usually associated with hair follicles. Holocrine glands secrete oily matter that keeps hair and skin soft and somewhat waterproof. The sebaceous glands are microscopic glands that produce a fatty or waxy matter, called sebum, to lubricate the skin and hair. They are commonly located in high numbers on the face and scalp, though distributed to the entire body except in the palm and sole. In the eyelids, Meibomian sebaceous glands secrete a particular type of sebum into tears. Sweat Glands Sweat glands are found in nearly all parts of the skin but are most abundant in the palms and soles. The sweat gland consists of a tiny tube from a ball-shaped coil in the dermis or subcutaneous layer of the skin. The looped part of the gland is fastened at its deep end and is lined with sweat-producing cells. The Apocrine glands respond to emotional stress. Apocrine secretions typically have odors, and the glands are considered to be scent glands. They started to function at puberty and are responsible for moist skin regions when a person is emotionally upset, frightened, or experiencing pain. They are also active when a person is sexually stimulated. The apocrine glands are most numerous in the armpits, groin, and the regions around the nipples. They are usually associated with hair follicles. 132 | P a g e  College of Arts and Sciences Education General Education - Science 2nd Floor, DPT Building, Matina Campus, Davao City Phone No.: (082)300-5456/305-0647 Local 134 The Eccrine Glands are not connected to hair follicles. This sweat gland's task is to respond to elevated body temperature due to environmental heat or physical exercise. These glands are common on the forehead, neck, and back, where they produce profuse sweating on hot days and when a person is physically active. They are also responsible for the moisture that may appear on the palms and soles when they are emotionally stressed. Sweat Glands Apocrine sweat glands - armpits & groin - secretions triggered by sexual arousal and anxiety (“cold sweat”) - body odor is produced by micro-organisms that grow in particularly moist areas of the skin (armpit). They produce body odor by digesting sebum, but they can only work efficiently if the water is present. Eccrine sweat glands – populate much of human skin – Found in palms & soles of feet – Secrete sweat which helps dissipate body heat Subcutaneous Layer/ Hypodermis Although technically not part of the integumentary system, the hypodermis is the layer of tissue directly underneath the dermis. It is composed mainly of connective and adipose tissues or fatty tissue. Its physiological functions include insulation, the storage of energy, and aiding in the skin's anchoring. It is the innermost and thickest layer of the skin. It is primarily composed of a type of cell specialized in accumulating and storing fats, known as adipocytes. These cells are grouped in lobules separated by connective tissue. Skin Cancers 1. Basal Cell Carcinoma.- The most common type of skin cancer. This resulted from prolonged UV exposure that damages cells at the base of the epidermis. It forms a mound of slow-growing cancerous cells. 133 | P a g e  College of Arts and Sciences Education General Education - Science 2nd Floor, DPT Building, Matina Campus, Davao City Phone No.: (082)300-5456/305-0647 Local 134 2. Squamous Cell Carcinoma – more dangerous because cells proliferate and may spread to nearby lymph nodes. The second most common skin cancer. Most impacts the elderly. It has a rough, dark region. 3. Malignant Melanoma - radiation damage to melanocytes that forms a dark, irregular mass. It is highly metastatic. Injury to Dermis or Subcutaneous Layer – Blood vessels break. – Blood forms clot. – Clotted and dried fluids form scab to protect underlying tissues. – Fibroblasts migrate to the injured site and form a new fibers to close the wound (stitching up the wound) – Healing continues. Phagocytic cells remove the dead cells. – Damaged tissues replaced – Scab falls off. – If the wound is extensive, new connective tissue may appear on the surface as a scar. 134 | P a g e  College of Arts and Sciences Education General Education - Science 2nd Floor, DPT Building, Matina Campus, Davao City Phone No.: (082)300-5456/305-0647 Local 134 Granulations – Granulation tissue is collagen-rich tissue that forms at the site of an injury. – As the body heals, this tissue fills in the injury, and may eventually scar over. – The scar may fade over time, especially if the wound is small. Types of Burns First degree – superficial, partial-thickness Epidermal layer only. Second degree – deep, partial- thickness. Epidermis and dermis damaged Forms blisters Third degree – full-thickness Autograft Homograft Various skin substitutes Performance Task/ Laboratory Activities (Instructions and procedures will be provided by the subject teacher.) Laboratory Activity # 13 Laboratory Activity # 14 135 | P a g e  College of Arts and Sciences Education General Education - Science 2nd Floor, DPT Building, Matina Campus, Davao City Phone No.: (082)300-5456/305-0647 Local 134 You can also refer to the sources below to help you further understand the lesson: Mason, Kenneth A. (2017). Biology (11th edition). New York, NY McGraw-Hill Educ. Johnson, George B. (2017). Essentials to the living world. New York, NY McGraw- Hill Educ. https://ebookcentral.proquest.com Starr, Cecie (2015). Biology: A Human Emphasis (9th edition). Australia Cengage. Learning. https://ebookcentral.proquest.com Excretory System : How it works? https://www.youtube.com/watch?v=zAczdDFyglA How the kidney work? https://youtu.be/FN3MFhYPWWo Integumentary System https://www.youtube.com/watch?v=OxPlCkTKhzY Since you already know the basic concepts of the Excretory System and Integumentary Systems. Let us determine your understanding of the ideas presented in the unit content by answering the following: Activity 1 – Four Pic-One-Word. In this activity, you will be given a group of 4 pictures that share a common word. Figure out the common name based on the term length that will be provided to you. 1. 2. 136 | P a g e College of Arts and Sciences Education General Education - Science 2nd Floor, DPT Building, Matina Campus, Davao City Phone No.: (082)300-5456/305-0647 Local 134 3. 4. 5. 6. 7. 8. 137 | P a g e  College of Arts and Sciences Education General Education - Science 2nd Floor, DPT Building, Matina Campus, Davao City Phone No.: (082)300-5456/305-0647 Local 134 9. 10. Activity 1. In this activity, you are expected to give a detailed explanation of your answer to the following questions. 1. How does the dialysis help a person with renal failure? _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ 2. Explain the effects of hair dyes to the hair follicles and the functions of the oil glands. _____________________________________________________________________ _____________________________________________________________________ __________________________________________________________________ 3. What is the cause of underarm or body odor? Suggest ways how to prevent it. _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ 4. Why does the skin get wrinkly or saggy as the person ages? _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ 5. Compare and contrast the Bowman’s capsule and the Malphigian capsule in terms of structure and functions. _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ 138 | P a g e  College of Arts and Sciences Education General Education - Science 2nd Floor, DPT Building, Matina Campus, Davao City Phone No.: (082)300-5456/305-0647 Local 134 Activity 1. Based on the discussion of the essential concepts in the Excretory System and the Integumentary System and the laboratory activities you have done, what do you think are the three most significant lessons you have learned. Write your answers below. 1. _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ 2. _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ 3. _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ Do you have any questions for clarification? Questions/Issues Answers 1. 2. 3. 4. 5. 139 | P a g e  College of Arts and Sciences Education General Education - Science 2nd Floor, DPT Building, Matina Campus, Davao City Phone No.: (082)300-5456/305-0647 Local 134 Excretory System Urinary System Urinary bladder Integumentary System Epidermis Filtration Dialysis Dermis Skin Cancer Nephrons Hypodermis Feedback Loop 140 | P a g e