Intro to Body Systems Mrs. Rich, RN, BSN

Bell Work Define Anatomy and Physiology List the systems of the body What is homeostasis? What is a cell? What is an organ? What is a blood vessel?

Definitions Anatomy – branch of science that deals with the structure of body parts, their forms, and how they are formed Physiology – the functions of body parts – what they do and how they do it A body part’s function(s) depends on it’s construction

Human Body in Nutshell The human body contains trillions of cells, 78 different organs and more than 60,000 miles of blood vessels if you stretched them end-to-end. Incredibly, all of these cells, vessels and organs work together to keep you alive. What is a cell? What is an Organ? What is a blood vessel?

Vocabulary Cells are the basic building blocks of all living things. The human body is composed of trillions of cells. They provide structure for the body, take in nutrients from food, convert those nutrients into energy, and carry out specialized functions. An organ is a collection of millions of cells which group together to perform single functions in a our body. Blood vessels are intricate networks of hollow tubes that transport blood throughout the entire body; a vein, artery, or capillary.

More on Organs Skin is the largest organ with respect to its size and weight. The major organ in the body of human beings is the brain which is primarily responsible for performing all the functions and actions of the body. 

It must all work together! Each organ belongs to one of ten body systems. These body systems are interconnected and dependent upon one another to function. Your heart does not beat unless your brain and nervous system tell it to do so. Your skeletal system relies on the nutrients it gains from your digestive system to build strong, healthy bones.

Homeostasis Regulation of internal conditions Maintains a stable internal environment The body has internal, self-regulating control systems (homeostatic mechanisms)

Maintenance of Life Requirements of Organisms Water Foods Oxygen Heat Pressure The quantities and qualities are important!!

Levels of Organization

Systems of the Body https://www.youtube.com/watch?v=0yjLJfz6saU

Systems of the Body Circulatory System Digestive System Endocrine System Lymphatic/Immune system Muscular System Nervous System Reproductive System Respiratory System Skeletal System Excretory/Urinary System Integumentary System file:///C:/Users/richm/Desktop/School/Human%20body%20mini%20boo k.pdf

THE NERVOUS SYSTEM The nervous system controls & coordinates everything in the body. This includes all movement and all of the activities of the organs & organ systems.

MAJOR PARTS OF THE NERVOUS SYSTEM Brain: The controls center of the nervous system, and the whole body Spinal cord: Carries messages to and from the brain. Neurons (nerves) are the special cells that carry the messages through the body.

The Circulatory System The circulatory system carries blood around the body. It is composed of the heart, lungs, and blood vessels. Responsible for transporting oxygen, nutrients, hormones, and cellular waste products throughout the body Powered by the body’s hardest-working organ — the heart, which is only about the size of a closed fist. Even at rest, the average heart easily pumps over 5 liters of blood throughout the body every minute

Major Parts of the Circulatory System 1.Heart: strong muscle tissue and is protected by your rib cage.  2. Blood Vessels: The blood vessels are one of the most important circulatory system organs. Your blood vessels allow blood to flow quickly from one region to another and then allow it to come back to your heart.  Arteries take oxygen-rich blood away from your heart. Veins take blood back toward your heart. Capillaries are very tiny blood vessels that form a connection between arteries and veins. The capillary walls facilitate the transfer of oxygen, nutrients and wastes in and out of your body. 3. Blood: Your blood is an amazing substance that carries water, nutrients, waste products and oxygen to and from your body cells. 

Circulatory and Respiratory Systems The circulatory system & Respiratory systems work together to supply cells with the oxygen and nutrients they need to stay alive. The lungs send oxygen-rich blood to the left side of your heart and your heart then uses blood vessels and arteries to transfer it to the rest of your body.

The Respiratory System The basic function of the human respiratory system is the exchange of oxygen & carbon dioxide between the blood, air and tissues. In addition, air entering the respiratory system is warmed, moistened & cleaned before it enters the lungs. Main Parts: Nose (& mouth): air enters here Pharynx: serves as a passageway for both AIR & food Epiglottis covers the entrance to the trachea when you swallow (so food does not go into lungs)

THE MUSCULAR SYSTEM FUNCTIONS Muscle allow organs & bones of the body to move. The fibers that make up muscle, “contract”. The contraction makes the whole muscle shorter which allows them to move organs and bones.

3 TYPES OF MUSCLE 1. Skeletal: Attaches to bone & allows for movement 2. Smooth: Found in the walls of the stomach, intestines & blood vessels. Helps materials move through these structures 3. Cardiac: Makes the heart beat to send blood to the body.

The Skeletal System The framework of the body, consisting of bones and other connective tissues, which protects and supports the body tissues and internal organs. Parts of the skeletal system - bones - ligaments - tendons - cartilage

Bone TRIVIA There are 206 bones in the human body. Bones are living tissue that grow and need blood. Bones have blood vessels inside of them and are made of cells

The Digestive System Mouth – food is chewed & mashed into paste and The digestive system converts food into simpler molecules that can be used by the cells of the body. The Parts of the Digestive System: Mouth – food is chewed & mashed into paste and salivary glands secrete saliva which contains enzymes

Major Parts of the Digestive System Esophagus Muscular tube that contracts, pushing food into the stomach Stomach Muscular sac that churns, continuing the breakdown of food mechanically & chemically with enzymes Small Intestine long tube where most of the nutrient molecules are absorbed into cells Large Intestine Removes water from undigested food material. Also called the colon

The Excretory / Urinary System The basic function of the human excretory system is the removal of waste from the cells and body. The skin excretes excess water and salts in the form of sweat. The lungs excrete carbon dioxide. The kidneys play a major role in excretion and remove waste products from the blood, maintain blood pH and regulate the water content of the blood and, therefore homeostasis.

Main Parts of the Urinary System Kidneys = located on either side of the backbone and partially protected by the ribcage Blood enters the kidney and is cleaned and filtered. Urea (a toxic substance), excess salts, and water are removed from the blood and form urine. Once filtered, clean blood leaves the kidney and returns to circulation.

The Reproductive Systems The main function of the reproductive systems is to make egg and sperm cells which will combine to make a zygote (offspring) Functions in creating offspring (penis and testes in males, ovaries, uterus, and vagina in females)

Integumentary System Organ system that includes hair, skin, and nails and protects the body from pathogens and maintains homeostasis

Lymphatic or Immune System Secondary circulatory system that helps the body fight pathogens and maintain its fluid balance parts: lymph nodes, tonsils, thymus, spleen

Endocrine System Collection of glands that secrete hormones into the blood which regulate growth, development, and homeostasis. Organs: hypothalamus, pituitary gland, thyroid, adrenal glands.