Unit 1 Lesson 4 Human Body PDF

Unit 1 Prepare to Respond to a Medical Emergency Lesson 4 Human Body Lesson Goal At the end of this lesson, you will be able to describe basic human anatomy with a focus on the respiratory and circulatory systems. Eleven systems interact and work together to make up the body. This lesson w...

Unit 1 Prepare to Respond to a Medical Emergency Lesson 4 Human Body Lesson Goal At the end of this lesson, you will be able to describe basic human anatomy with a focus on the respiratory and circulatory systems. Eleven systems interact and work together to make up the body. This lesson will focus on the systems and organs that are most relevant to providing life-saving first aid. By learning about the different systems inside the body, you can better determine the proper care for each individual patient and their specific symptoms. Respiratory System ✅ HL214.1. Describe the function of the respiratory system and its main parts The respiratory system delivers oxygen to and removes carbon dioxide from the blood. The body can go without oxygen only for a few minutes. The nose, mouth, and throat make up the upper airway that brings oxygen to the lungs (lower airway). The passage that connects the upper airway with the lower airway includes the voice box (larynx) and the windpipe (trachea). At the upper end of this passageway is a small leaf-shaped flap (epiglottis) that keeps food and other foreign objects from entering the windpipe. A large muscle, the diaphragm, below the lungs at the bottom of the chest cavity, helps move air in and out of the lungs. The respiratory systems of infants and chil- dren differ from an adult. Their tongues take up proportionally more space in their mouths. Their windpipes are narrower, softer, and Figure 2-1 Respiratory system more flexible. Very young infants breathe mostly through their noses and at a faster rate than adults. 48 / Florida Basic Recruit Training Program (HL): Volume 2 Circulatory System ✅ HL214.2. Describe the function of the circulatory system and the four major arteries The circulatory system, or cardiovascular system, pumps blood throughout the body. It delivers oxygen and nutrients to and removes waste from the body’s tissues. Basic parts of the circulatory system are the heart, veins, capillaries, arteries, and blood. Positioned behind the breastbone (sternum), slightly to the left in the chest cavity, is the heart, a hollow, muscular organ about the size of your fist. The circulatory system is a closed system, and the blood is under constant pres- sure and circulation from the heart’s pumping action. Blood vessels are a system of tubes through which blood flows. Vessels called arteries carry blood away from the heart to the rest of the body. Vessels called veins carry blood back to the heart. Throughout the body, small vessels called capillaries connect arteries to veins. The following major arteries determine blood flow and are used to feel for a patient’s pulse: carotid—supplies blood to the head and neck, felt on either side of the neck brachial—supplies blood to the upper arm, felt on the inside of the upper arm femoral—supplies blood to the upper thigh and leg, felt in the groin area radial—supplies blood to the lower arm and hand, felt at the thumb side of the wrist Figure 2-2 Taking a pulse Skeletal System ✅ HL214.3. Describe the function of the skeletal system and its main parts The skeletal system is the supporting framework for the body, giving it shape and protecting vital organs; it attains mobility from the attached muscles and manufactures red blood cells. The main components of the skeletal system are: the skull, spinal column, shoulder girdle, rib cage, pelvis, lower extremities, and upper extremities. Chapter 2 First Aid for Criminal Justice Officers / 49  The skull—houses and protects the brain. It also gives shape and function to the face. The spinal column—protects the spinal cord and is the primary support for the entire body. It consists of separate bones called vertebrae that stack one on top of each other and are held together by muscles. The shoulder girdle—consists of the collarbone and shoulder blades. The rib cage—contains the sternum and ribs. It protects the heart, lungs, liver, and spleen. The pelvis—protects the reproductive organs and supports the organs in the lower abdomi- nal cavity. The lower extremities—consist of the upper leg, lower leg, ankle, and foot. The upper extremities—consist of the upper arm, lower arm (forearm), wrist, hand, and finger bones that comprise the arm. Muscular System ✅ HL214.4. Describe the function of the muscular system and types of muscle The muscular system gives the body shape, protects internal organs, and allows for body move- ment. The body contains three types of muscles. Muscles used for deliberate acts, such as chewing, bending, lifting, and running, are voluntary muscles. These are muscles attached to the skeleton and under the control of the nervous system and brain. A person can contract and relax these muscles. Involuntary muscles, or smooth muscles, carry out many automatic body functions. They are in the walls of the tube-like organs, such as ducts, blood vessels, and the intestinal wall. A person does not consciously control these muscles. Involuntary muscles called cardiac muscles, found only in the heart, work constantly to expand and contract the heart. Nervous System ✅ HL214.5. Describe the function of the nervous system and its two main parts The nervous system controls voluntary and involuntary body activity. It also supports higher mental functions, such as thought and emotion. It lets a person be aware of and react to the environment and keeps the rest of the body’s systems working together. The nervous system has two main parts: The central nervous system—consists of the brain and the spinal cord. Its components are the body’s “mainframe computer” and processing center. This is where all communi- cation and control originate. The peripheral nervous system—includes nerves that connect to the spinal cord and branch out to every other part of the body. These nerves serve as a two-way communica- tion system. Some carry information from the brain and spinal cord to the body. Others carry information from the body back to the brain. 50 / Florida Basic Recruit Training Program (HL): Volume 2 Skin ✅ HL214.6. Describe the function of the skin The skin is the largest organ of the body. It protects everything inside the body, provides a barrier against bacteria and other harmful substances and organisms, and regulates body tempera- ture. Acting as a communication organ, the skin also receives and relays information about heat, cold, touch, pressure, and pain. It transmits this information to the brain and spinal cord through nerve endings. Chapter 2 First Aid for Criminal Justice Officers / 51