Human Body Systems (Skeletal, Integumentary, Digestive) PDF

SCI6-Q2-W1 **THE HUMAN BODY SYSTEMS** **(SKELETAL, INTEGUMENTARY AND** **DIGESTIVE SYSTEM)** **[Lesson 1: The Skeletal System]** The human body is made up of different kinds of bones. These bones are called skeleton. The human skeleton is the internal framework of the body. The adult human skel...

SCI6-Q2-W1 **THE HUMAN BODY SYSTEMS** **(SKELETAL, INTEGUMENTARY AND** **DIGESTIVE SYSTEM)** **[Lesson 1: The Skeletal System]** The human body is made up of different kinds of bones. These bones are called skeleton. The human skeleton is the internal framework of the body. The adult human skeleton consists of 206 bones that are connected to one another by ligaments. At birth, infants have around 300 bones fused together when they become adults. These bones work together as a system called a skeletal system. The skeletal system serves as the framework of the body. Its major functions are body support, facilitation of movement, protection of internal organs, storage of minerals and fats, and blood cell formation. The skeletal system is mainly composed of bones which are classified into two divisions, the **axial** and the **appendicular** skeleton. The axial skeleton includes the skull, vertebral column, ribs, and sternum. These bones form the axes or framework of the trunk and head. The appendicular skeleton includes the bones of the shoulder, arms, hands, hips, legs, and feet. All other bones of skeletal system are classified into 4 as shown in the table below:  One of the axial skeletons is the skull which consists of cranium and facial bones. The cranium is made up of eight bones joined together to form a rigid case that protects the brain. The face is made up of 14 facial bones. The eye socket protects the eyeball while mandible or jawbone is movable bone that holds the teeth. The **spinal column** or vertebrae (neck and backbone) are irregular bones that protect the spinal cord while the **ribcage** protects the lungs and the heart. Vertebrae are arranged on top of the other and move over each other slightly. There are 33 vertebrae in the spinal column of a child and 26 in an adult. This is so because as the child grows, the last seven bones join together to form just two bones. Ribs are the bones at the side of the chest. There are 12 pairs of ribs. The upper 7 pairs are the true ribs because they are connected to the breastbone and the last two pairs are not connected. These ribs are called floating ribs. The shoulder has the collarbone found in front of it. Scapula is the shoulder bone found at the back of your shoulder. The appendages found in the lower extremities are composed of pelvic bones. **Pelvic bones** support the lower parts of the body and aid the movement of the legs. The upper arms have one long bone called the **humerus** and two bones in the lower arm are known as the **radius and ulna**. Radius or radial bone is one of the two large bones of the forearm. The other bone is the ulna. The ulna is usually slightly longer than the radius while the latter is usually thicker. The **wrist** connects the hand to the forearm. Each wrist or carpal consists of 8 bones. The palm or metacarpal has 5 bones. Inside the bones are bone marrows that are very important for the body to manufacture blood cells. Bone marrows are of two types, the **red bone marrow** and the **yellow bone marrow**. The red bone marrow is found in the humerus, femur, pelvis and vertebrae while the yellow bone marrow is found in many other bones. **The human skeletal system has several important functions.** 1\. **Support** -The skeletal system provides the framework which supports and maintains shape of the body. It gives the body much needed support. 2\. **Protection** -The skeletal system protects the internal organ of the body. 3\. **Movement**- The skeletal system provides an attachment for the muscle which makes body movements possible. 4\. **Storage and Supply**- The skeletal system stores important minerals like calcium and phosphorus and produces both red and white blood cells. **[Lesson 2: The Integumentary System]** The **integumentary system** is composed of organs that form the external covering of the body and protect it from many threats such as infection, desiccation, abrasion, chemical assault and radiation damage. In humans the integumentary system comprises the skin and its appendages acting to protect the body from various kinds of damage such as loss of water and damages from the outside. It is also made of specialized cells that secrete melanin to protect the body from the carcinogenic effects of UV rays and cells that have an immune function. Sweat glands that excrete wastes and regulate body temperature are also part of the integumentary system.  **Answer this!** 1\. The outer layer of the skin is \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_. 2\. It is known as the layer directly below the epidermis \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_. 3\. Beneath the dermis is the \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_, a layer of connective tissue that stores fat and helps the body in retaining heat. 4\. The \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ is a tabular structure located in the skin whose function is to and produces sweat. 5\. The \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ is the opening upon the skin of the hair follicle, which extends downward through several layers of skin. The integumentary system consists of the skin, hair, nails, glands, and nerves. Its main function is to act as a barrier to protect the body from the outside environment. It also helps to retain body fluids, protects against disease, eliminates waste products, and regulates body temperature. In order to do these things, the integumentary system works with all the other systems of our body, each of them has a role to play in maintaining the internal conditions that a human body needs to function properly. The integumentary system serves as one of the first lines of defense of our body against pathogens. Hair-helps keep you warm Nails- give structure to the ends of our fingers Glands- release oils for moisture and protection Nerves- send and receive messages to the brain **FUNCTIONS OF THE INTEGUMENTARY SYSTEM** The integumentary system has many functions, most of them are involved in protecting you and regulating your body's internal functions in a variety of ways: 1\. Protects the body\'s internal living tissues and organs 2\. Protects against invasion by infectious organisms 3\. Protects the body from dehydration 4\. Protects the body against abrupt changes in temperature 5\. Helps in disposing waste materials 6\. Acts as a receptor for touch, pressure, pain, heat, and cold 7\. Stores water and fat The human skin is composed of different essential parts such as the epidermis and the dermis. The epidermis is composed of epithelial cells that serve as the outer layer of the skin. The outer layer of the epidermal cells secrete protein which is referred to as the keratin. The **dermis** is the layer directly below the epidermis. This layer is 15 to 40 times thicker than the **epidermis**. It is composed of connective tissues to prevent the skin from tearing and enable the skin to return to its normal state after being stretched. The **hypo dermis** is the layer beneath the dermis composed of connective tissue that stores fats and helps the body in retaining heat. **Sweat glands**, also known as **sudoriferous** or **sudoriparous glands**, are small tubular structures of the skin that produces sweat. The **hair root** is the part of the hair below the surface of the skin. It is the part that includes and/or interacts with many other associated structures within the dermis and hypodermis layers of skin. The **hair shaft** is the visible part of the hair that protrudes through the skin. The skin's color is created by special cells called melanocytes which produce the pigment, melanin. Melanocytes are located in the epidermis. **ANSWER THIS!** **A.** **B. Directions:** Read the following statements carefully. Write **TRUE** if the statement is correct and **FALSE** if the statement is wrong. Write your answer on the space provided. \_\_\_\_\_\_\_1. Too much exposure to the ultraviolet rays of the sun is good for the skin. \_\_\_\_\_\_\_ 2. The fingernails must be properly trimmed to prevent the accumulation of dirt and other unwanted substances. \_\_\_\_\_\_\_ 3. In keeping our skin, nails and hair healthy, we must avoid using products with strong chemicals. \_\_\_\_\_\_\_ 4. Consulting the dermatologist regularly is highly encouraged to maintain good health of your integumentary system. \_\_\_\_\_\_\_ 5. Integumentary system is considered as one of the first lines of defense of our body against pathogens. **[Lesson 3: The Digestive System]** Whatever you do, you need energy. To have energy, you have to eat. You have learned that you get energy from the food you eat. Before food can be distributed and absorbed by the cells of the body, it must be changed first to soluble materials. The process of breaking down and dissolving the food so that it can be taken into the blood to be used by the body is called digestion. The organs that do work for digestion make up the Digestive System. It includes the mouth, esophagus, stomach, and small and large intestines. The digestive system is composed of the mouth, esophagus, stomach, small intestine and large intestine. The process of breaking down the food into a form that can be absorbed for use by the body is called digestion. Digestion starts in the **mouth**. The **teeth** cut and grind the food. The saliva, a liquid in the mouth moistens the food and changes starch to sugar. The ptyalin as an enzyme in saliva helps in the digestion of starch. When the food is swallowed, it enters the esophagus, a long muscular tube that starts from the back of the throat and ends in the stomach. The food is pushed down the esophagus into the stomach by rhythmic, wave-like muscle movements known as peristalsis. The food then travels to the stomach, a muscular pouch that secretes gastric juice. In the **stomach**, the food is broken down into smaller pieces. The gastric juices in the starch act on the food and split proteins and fats. The food goes to the **small intestine,** a 7-meter coiled long tube in the lower abdomen where food is finally digested and absorbed. Undigested food goes to the large intestine. The **large intestine** is also, a temporary storage of water. The feces which are the waste product of digestion are stored in the lower part of the large intestine called rectum. The **rectum** stores this waste until it is eliminated through the anus. **TRY THIS!**