Human Body Systems Lecture Notes

Introduction

• Encouragement to follow Amoeba Sisters on social media
• Importance of understanding the human body and its systems

Overview

• The human body is made up of millions of cells
• Cells make up tissues, tissues make up organs, and organs form organ systems
• Organ systems do not work in isolation; they interact and function as a team
• Introduction to the 11 major organ systems in alphabetical order

Circulatory System

• Blood carries oxygen and removes CO2
• Blood transports nutrients
• The heart pumps blood
• Arteries: carry blood away from the heart
• Veins: carry blood back to the heart
• Capillaries: tiny blood vessels throughout the body
• Myth debunked: Blood is always red, not blue

Digestive System

• Breaks down and absorbs food for nutrients
• Starts in the mouth with enzymes in saliva
• Stomach acid further aids digestion
• Small intestine: main site for nutrient absorption
• Large intestine: reabsorbs water
• Accessory organs also play a role

Endocrine System

• Glands secrete hormones
• Growth hormone: impacts body growth
• Adrenaline: increases heart rate in stress situations

Excretory System

• Excretes waste products like urine
• Kidneys remove waste from the blood
• Dialysis: machine used for impaired kidneys
• Also involves sweating to remove waste

Integumentary System

• Comprised of skin, the largest organ
• Protects organs, helps with temperature regulation, and prevents water loss

Lymphatic/Immune System

• Lymph nodes swell during illness
• Lymph: clear fluid that surrounds cells
• Collects, filters, and returns lymph to the blood
• Structures involved: lymph nodes, thymus, spleen, tonsils, bone marrow
• Key in defending against pathogens

Muscular System

• Three major types of muscle tissue: skeletal, smooth, and cardiac
• Muscles work with bones for movement

Nervous System

• Brain and spinal cord
• Controls voluntary and involuntary actions
• Neurons: key cells in the nervous system

Reproductive System

• Allows for reproduction and the creation of offspring

Respiratory System

• Involves lungs, oxygen intake, and CO2 exhalation
• Essential for oxygen delivery and CO2 removal

Skeletal System

• Adults have 206 bones, which support and protect organs
• Bone marrow produces blood cells

Conclusion

• Understanding body systems helps in addressing health issues
• Importance of how systems work together for daily activities
• Encouragement to stay curious and keep learning about the human body