Tissues, Organs, and Systems

Organization of Your Body There are four levels of organization, it is called a HIERARCHY. 1. Cells; 2. Tissues; 3. Organs; 4. Organ Systems. Bodies of vertebrates (animals with spines) are composed of different cell types -Humans have 210 2

Organization of Your Body Smallest Level Largest Level 5

Organization of Your Body Tissues: are groups of cells that are similar in structure and function In adult vertebrates, there are four primary tissues: -Epithelial, -Connective, -Muscle, -Nerve Tissue. All preform different bodily functions, thus are different cells. 3

Epithelial Tissue Epithelial Tissue: Separates, protects, and keeps organs in place. Covers the body surface and forms the lining of most organs. Ex: Skin Layer of skins 6

Connective Tissue Connective Tissue- Provides support and structure to the body, also fills spaces. The most abundant tissue in the human body.  Ex: Blood, bones, cartilage, and fat.

Muscle Tissue Muscle Tissue -Contracts and relaxes to support movement. Three types: Skeletal, smooth, and cardiac. Ex: Cardiac muscle contracts to pump blood through the body; Skeletal muscle moves the bones when directed by brain. Smooth muscle contracts in digesting;

Nerve Tissue Nerve Tissue - responds to stimuli in the environment; - controls movement, reflexes, and receives sensory information; Ex: Brain tissue, Spinal Cord Tissue, Peripheral nerve cells.

Organization of Your Body Organs: are combinations of different tissues that form a structural and functional UNIT. Any organ that is essential to life is called a vital organ. Examples: Heart - Pumps blood throughout the body. Liver - Removes toxins from the blood, produces chemicals that help in digestion. Lungs - Supplies oxygen to the blood and removes CO2 from blood. Brain - The control center of the body. 4

Organization of Your Body 4. Organ systems: are groups of organs that cooperate to perform the major activities of the body. -The vertebrate body contains 11 principal organ systems.

The 11 human body systems are as follows: -- nervous system -- integumentary system -- respiratory system -- digestive system -- excretory system -- skeletal system -- muscular system -- circulatory system -- endocrine system -- reproductive system -- lymphatic (immune) system All are extremely important because each system is responsible for a specific cellular function, just on a much larger scale.

Organ Systems 1. Circulatory System: The main function of this system is to transport nutrients and gasses to cells and tissues throughout body. This is accomplished by the circulation of blood. Cardiovascular: The beating of the heart drives the cardiac cycle which pumps blood throughout body. Cardiovascular organs: heart, blood vessels, blood Lymphatic: As a component of the immune system, the lymphatic system produces and circulates immune cells called lymphocytes. Lymphatic organs: lymph vessels, lymph nodes, thymus, spleen, tonsils

From the wikimedia free licensed media file repository 2. Digestive System: This system breaks down food into smaller molecules to provide energy for the body. Primary organs: mouth, stomach, intestines, rectum Accessory organs: teeth, tongue, liver, pancreas 3. Endocrine System: This system regulates growth, homeostasis, and metabolism. Endocrine organs secrete hormones to regulate body processes. Endocrine structures: pituitary gland, pineal gland, thymus, thyroid gland From the wikimedia free licensed media file repository

Integumentary structures: 4. Integumentary System: This system protects the internal structures of the body from damage, prevents dehydration, stores fat and produces vitamins and hormones. Integumentary structures: skin, nails, hair, sweat glands 5. Muscular System: This system enables movement through the contraction of muscles. Structures: muscles

brain, spinal cord, nerves 6. Nervous System: This system monitors and coordinates internal organ function and responds to changes in the external environment Structures: brain, spinal cord, nerves 7. Reproductive System: This system enables the production of offspring through sexual reproduction. It is comprised of male and female reproductive organs and structures which produce sex cells and ensure the growth and development of offspring. Male organs: testes, scrotum, penis, vas deferens, prostate Female organs: ovaries, uterus, vagina, mammary glands

8. Respiratory System: This system provides the body with oxygen via gas exchange between air from the outside environment and gases in the blood. Respiratory organs: lungs, nose, trachea, bronchi 9. Skeletal System: This system supports and protects the body while giving it shape and form. Structures: bones, joints, ligaments, tendons, cartilage

10. Urinary/Excretory Systems: The kidneys filter the blood to remove wastes and produce urine. The ureters, urinary bladder, and urethra together form the urinary tract, which acts as a plumbing system to drain urine from the kidneys, store it, and then release it during urination. Besides filtering and eliminating wastes from the body, the urinary system also maintains the homeostasis of water, ions, pH, blood pressure, calcium and red blood cells Structures: kidneys, urinary bladder, urethra, ureters

Homeostasis For your body to function efficiently, internal conditions must be relatively constant -This constancy of your internal environment is called homeostasis -It is essential for life Humans have set points for body temperature, blood glucose concentrations, electrolyte concentration, tendon tension, etc. 55