Levels of Organization, Characteristics of Life, Survival Needs, Intro to Body Systems, Survival Functions

Levels of Organization

Organelle → Cell → Tissue → Organ → Organ System → Organism

Cell

The smallest unit of function and structure

Tissue

a layer or mass of specialized cells

Organ

groups of different tissues

organ systems

groups of organs that function closely together

organism

interacting organ systems

Skeletal System Function

provides support and protection, gives body shape

Major Organs of Skeletal System

bones, ligaments, cartilage, joints

Nervous System Function

detects impulses from the senses, control center

Nervous System Major Organs

brain, spinal cord, senses, nerves

Circulatory System Function

transports nutrients and gases around the body

Circulatory System Major Organs

heart, blood vessels, blood

Respiratory System Function

exchanges gases (CO2 and oxygen)

Respiratory System Major Organs

lungs, sinuses, diaphragm

Digestive System Function

breaks down and absorbs nutrients

Digestive System Major Organs

mouth, esophagus, stomach, intestines, liver, gallbladder

Muscular System Function

provides movement for all parts of the body

Muscular System Major Organs

skeletal and smooth muscles

Integumentary System Function

protect the body, regulate temperature, and prevent water loss

Integumentary System Major Organs

skin, hair, nails

Lymphatic System Function

fights infection and provides fluid for cells

Lymphatic System Major Organs

spleen, thymus gland, lymphatic vessels, lymph nodes

Excretory System Function

removes waste from the blood

Excretory System Major Organs

kidneys, bladder, urethra, ureters

Endocrine System Function

secretes hormones

Endocrine System Major Organs

hypothalamus gland, pineal gland, pituitary gland, thyroid gland, parathyroid glands, thymus gland, adrenal glands, pancreas, ovaries/testes (depending on gender)

Reproductive System Function

produces cells used in sexual reproduction

Reproductive System Major Organs

female: ovaries, vagina, uterus, mammary glands

male: testes, penis, prostate gland

Function for Life - maintaining boundaries

lets some substances in and keeps others out

Example: skin protects, absorbs, and keeps water in, which prevents entry of pathogens

Function for Life - Movement

internal movement - example: digestive contrations

ability to move through surroundings

Function for Life - Responsiveness

sensing and reacting to changes in the environment

can be inside or outside of the body

Function for Life - Digestion

breaking down and absorbing nutrients (function of life)

Function for Life - Metabolism

building large molecules from smaller ones (anabolism)

breaking down larger molecules into smaller ones (catabolism)

Function for Life - Excretion

removal of wastes (function of life)

Function for Life - Reproducrtion

production of offspring

Function for Life - Growth

increase in cell size and overall body size

Survival Needs - Nutrients

through digestion and metabolism

Survival Needs - Oxygen

heart and lungs

Survival Needs - Normal Body Temp

skin, blood, muscles

Survival Needs - Water

allows molecules to move throughout the body

Survival Needs - Normal Atmospheric Pressure

provides appropriate gas exchange between lungs and environment