Human Body Systems

Levels of Organization Cells Tissues Organs Organ Systems

Levels of Organization Level of Organization Examples CellsNerve cell, red blood cell TissuesEpithelial, connective, nervous, and muscle tissue OrgansStomach, eye, liver, heart Organ SystemDigestive, cardiovascular

Nervous System Structures: brain, spinal cord, peripheral nerves, neurons Functions: Sensory/Motor Controls and regulates body’s functions Communication system (relays info) Integumentary SystemSkeletal System Muscular System Circulatory System Nervous System

FUN FACT! How many neurons in the brain? Human brain= 86 billion Elephant = 23 billion Chimpanzee = 7 billion Cat = 1 billion Mouse = 75 million Cockroach = 1 million

Integumentary System Structures: skin, hair, nails, sweat & oil glands Functions: Barrier from injury and infection Largest organ Sensory neurons: Integumentary SystemSkeletal System Muscular System Circulatory System Nervous System

FUN FACT! The skin on your mouth is 200 times more sensitive than your fingertips.

Skeletal System Structures: bones, cartilage, ligaments, tendons Functions: Support Protection Movement Integumentary SystemSkeletal System Muscular System Circulatory System Nervous System

FUN FACT! The area of our body with the most bones is the hand, fingers and wrist where there are 54 bones.

Structures: Skeletal muscle, smooth muscle, cardiac muscle Integumentary SystemSkeletal System Muscular System Circulatory System Nervous System Functions: Voluntary movement >Skeletal system Involuntary movement >Circulates blood >Moves food Muscular System

FUN FACT! There are about 60 muscles in the face. Smiling is easier than frowning! It takes 20 muscles to smile and over 40 muscles to frown.

Circulatory System Structures: heart, blood vessels, blood Functions: Oxygen and nutrients Fights infection Removes cell waste Integumentary SystemSkeletal System Muscular System Circulatory System Nervous System

FUN FACT! “Broken heart syndrome” (stress cardiomyopathy) Feels like heart attack: –chest pain –shortness of breath –arm aches. Emotionally stressful event

Respiratory System Structures: nose, pharynx, larynx, trachea, bronchi, bronchioles, lungs Functions: Provides O 2 Remove CO 2 Works with circulatory system Digestive SystemEndocrine SystemExcretory SystemReproductive SystemRespiratory System

Digestive System Structures: Mouth, pharynx, esophagus, stomach, small and large intestines, rectum Functions: Take in, break down, absorb food Food  simpler molecules Eliminates wastes Digestive SystemEndocrine SystemExcretory SystemReproductive SystemRespiratory System

FUN FACT! The stomach secretes: a) hydrochloric acid 2 liters/day b) mucus new coat/2 weeks

Excretory System Structures: Skin, lungs, kidneys, ureters, urinary bladder, urethra Functions: Eliminate waste Homeostasis Digestive SystemEndocrine SystemExcretory SystemReproductive SystemRespiratory System

FUN FACT! Kidney Stones Painful crystals 0.12in = block Largest= 2.48 lbs (coconut)

Endocrine System Structures: Hypothalamus, pituitary, thyroid, parathyroids, adrenals, pancreas, ovaries, testes Functions: Uses chemicals (hormones) Growth and development Metabolism Homeostasis Internal & external stimuli Digestive SystemEndocrine SystemExcretory SystemReproductive SystemRespiratory System

Reproductive System Structures: -Ovaries, Fallopian tubes, uterus, vagina -Testes, epididymis, vas deferens, urethra, penis Functions: Reproductive/sex cells (sperm and egg) Male/female sex characteristics Nurtures and protects embryo Digestive SystemEndocrine SystemExcretory SystemReproductive SystemRespiratory System

Lymphatic/Immune System Structures: white blood cells, thymus, spleen, lymph nodes, lymph vessels Functions: Protects from disease Fluid collection B cells and T cells Immune/Inflammatory response Antibody production Lymphatic / Immune System B cells – Bone marrow, make antibodies T cells – Thymus, killer or helper T cells

Homeostasis “Keeping things in balance” Internal conditions = constant external conditions = changing

Room temperature increases Thermostat senses temperature change and switches on heating system Thermostat senses temperature change and switches off heating system Room temperature decreases Examples of Feedback Inhibition

Can Olaf maintain homeostasis using feedback inhibition?

Reference A