The Human Body

Levels of Organization in Humans

Human Organ Systems  Skeletal System  Muscular System  Circulatory System  Respiratory System  Digestive System  Nervous System  Reproductive System  Endocrine System  Integumentary System  Excretory System  Lymphatic/Immune System

Skeletal System  Structures: Bones, Cartilage, Ligaments, tendons  Functions: Supports the body, protects internal organs, allows movement, stores mineral reserves, provides a site for blood cell formation

Makes up the general framework of the body. Composed of 206 named bones of various shapes and sizes. Ligaments hold bones together. Cartilage can be found between many of the bones. This smooth, slightly elastic connective tissue works to cushion the ends of the bones where they bump together at a joint. Bones are alive and continue to grow until about age 25. They are hard due to the high concentration of certain minerals such as calcium and phosphorus.

Human Joints  The joint is the place where two bones meet.  There are two types of joints: Immovable joints do not permit any movement of the bones.  The suture joints of the skull and the fused bones of the sacrum and coccyx are examples of this type of joint.  Movable joints allow the body to move depending on the type of joint will determine how the joint will move.

Movable Joints  Hinge joints found in knee and elbow permit back and forth motion in only one direction.  Ball-and-socket joints The hip and shoulder joints They permit nearly a full range of motion.  Pivot joint The joint at the base of the skull It allows movement of the head in a circular motion.  Gliding joints The joints of the wrist and ankle. The many small bones found in the wrist and ankle move slightly over one another permitting movement to occur.

ASIMO = Advanced Steps In Mobility

Muscular System  Structures: Skeletal Muscle, smooth muscle, cardiac muscle  Function: Works with skeletal system to produce voluntary movement, helps to circulate blood and move food through the digestive system

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Circulatory System  Structures: heart, blood vessels, blood  Function: Brings oxygen, nutrients, and hormones to cells, fights infections, removes cell wastes, helps to regulate body temperature

Blood Flow through the Heart 1.Oxygen-poor blood flows from the body into the right atrium. 2.Blood flows through the right atrium into the right ventricle. 3.The right ventricle pumps the blood to the lungs, where the blood releases waste gases and picks up oxygen. 4.The newly oxygen-rich blood (shown in red) returns to the heart and enters the left atrium. 5.Blood flows through the left atrium into the left ventricle. 6.The left ventricle pumps the oxygen- rich blood to all parts of the body.

Respiratory System  Structures: Nose, pharynx, larynx, trachea, bronchi, bronchioles, lungs  Function: Provides oxygen needed for cellular respiration and removes excess carbon dioxide from the body

 One of the main jobs of the cardiovascular system is to deliver oxygen (O 2 ) to the body.  As our bodies work, it uses up oxygen, replacing it with carbon dioxide (CO 2 ).

 Air enters our lungs through pressure changes.  Inhalation – Diaphragm and related muscles contract, chest expands, air gets pulled in  Exhalation – Muscles relax, elastic cartilage pulls ribs in, chest contracts, air is pushed out of lungs

Digestive System  Structures: Mouth, pharynx, esophagus, stomach, small and large intestines, rectum  Functions: Converts food into simpler molecules that can be used by the cells of the body, absorbs food, eliminates wastes

Nervous System  Structures: Brain, spinal cord. Peripheral nerves  Functions: Recognizes and coordinates the body’s responses to changes in its internal and external environments

Reproductive Systems  Structures: Males-Testes, epididymis, vas deferens, urethra, and penis Females-Ovaries, Fallopian tubes uterus, vagina  Functions: Produces reproductive cells Males-sperm Females- eggs, also nurtures and protects developing embryo ○ Stages development Sperm & egg unite during fertilization to create a zygote- blastocyst – embryo- fetus- Infant

Endocrine System  Structures: Glands- Hypothalamus, pituitary, pineal, thyroid, parathyroid, adrenals, pancreas, ovaries (females), testes (males)  Function: Controls growth, development, and metabolism, maintains homeostasis

1. Pineal gland, 2. Pituitary gland, 3. Thyroid gland, 4. Thymus, 5. Adrenal gland, 6. Pancreas, 7. Ovary, female only 8. Testis, male only MaleFemale

Integumentary System  Structures: Skin, hair, nails, sweat and oil glands  Functions: Serves as a barrier to regulate body temperatures, provides protection against ultraviolet radiation from the sun

Excretory System  Structures: Skin, Lungs, kidneys, ureters, urinary, bladder, urethra  Functions: Eliminates waste products from the body in ways that maintain homeostasis

Lymphatic/immune System  Structures: White blood cells, thymus, spleen lymph nodes, lymph vessels  Functions: Helps protect the body from disease. Collects fluid lost from blood vessels and returns the fluid to the circulatory system

ʘ Part of the immune system, which defends the body against infection. ʘ A network of small lymph nodes connected by very thin lymph vessels, which branch into every part of the body except the brain and spinal cord. Lymphatic System

 The major nodes can be found in the neck, armpits, chest, abdomen, pelvis and groin. Other parts of the lymphatic system include the spleen, thymus and bone marrow.  A clear fluid called lymph flows through the lymph vessels. It contains white blood cells called lymphocytes, special proteins called antibodies, and some waste products.  The lymph fluid passes through the lymph nodes, which filter out bacteria and other harmful things