UNIFYING-THEMES 3
Introduction
Prepared by Coleen Casanova: An overview of how animals and plants survive.
Organ Systems Overview
Focus on various organ systems:
Excretory System
Immune System
Endocrine System
Nervous System
Skeletal and Muscular System
Excretory System
Responsible for removing nitrogenous wastes from the body,
Key organs include:
Skin
Kidneys
Ureter
Urinary Bladder
Urethra
Integumentary System
Composed of hair, skin, nails, and exocrine glands.
Skin
Epidermis: Outer covering, prevents fluid evaporation.
Dermis: Beneath the epidermis, contains sweat glands.
Subcutaneous Layer: Deepest layer, insulates, stores fat, protects against injuries.
Hair: Formed from epidermal cells; keratinized.
Nails: Protect distal parts of fingers and toes, composed of hardened skin tissue.
Waste Removal
Wastes originate from body cells or diet.
Urinary system manages liquid waste removal and blood cleansing.
Urinary System
Comprises organs that dispose of liquid waste to purify blood.
Urea: By-product of protein digestion, toxic if not expelled.
Kidneys
Vital organs of the urinary system.
Structures involved:
Renal Vein: Carries blood away from kidneys.
Renal Artery: Supplies blood to kidneys.
Ureter: Transports waste to bladder.
Nephrons
Microscopic units within kidneys for filtering blood and forming urine.
Excretion through Different Organs
Lungs: Excrete CO2, maintain oxygen levels.
Large Intestine: Absorbs water from unabsorbed food to form feces for excretion.
Excretion and Homeostasis
Integumentary system maintains temperature.
Excretory system regulates body fluid levels.
Immune System
Composed of specialized cells, proteins, and organs that protect against pathogens.
Immune Components
Key elements include:
Adenoids
Tonsils
Lymph nodes
Thymus
Lymphatic vessels
Spleen
Bone marrow
Lymph Nodes
Filter lymphatic fluid, trap cancer cells or bacteria.
Spleen
Largest lymphatic organ, fights infections, regulates blood control.
Bone Marrow
Center of bones, produces white blood cells.
Generates leukocytes.
Types of Leukocytes
Phagocytes: Engulf pathogens.
Lymphocytes: Memory cells for pathogen recognition.
B cells: Produce antibodies.
T cells: Attack infected or cancerous cells.
Endocrine System
Communicates through hormones, does not use nerve cells.
Hormones act as chemical messengers.
Endocrine Glands
Major glands include:
Hypothalamus
Pituitary
Thyroid
Adrenal glands
Pancreas
Hormone Functions
Regulate metabolism, bodily functions, and homeostasis.
Control bodily responses to stimuli.
Nervous System
Comprised of billions of neurons (nerve cells).
Divided into:
Central Nervous System (CNS)
Peripheral Nervous System (PNS)
Brain Structure
Main control center:
Cerebrum: Controls higher brain functions.
Cerebellum: Regulates muscle coordination and balance.
Medulla: Governs automatic functions like heartbeat and breathing.
Spinal Cord
Connects the brain to the body, facilitates nerve impulse transport.
Skeletal and Muscular Systems
Skeletal System: Provides framework and protects vital organs.
Bones have living cells, enabling growth and repair (ossification).
Composed of bones, cartilage, ligaments, and tendons.
Cartilage
Tough yet flexible tissue, found on bone ends.
Muscular System
Enables movement necessary for daily functions.
Types of muscles:
Skeletal Muscles: Voluntary, enable locomotion.
Smooth Muscles: Involuntary, control internal workings.
Cardiac Muscles: Found only in the heart.
Conclusion
Study Session Questions:
What is the role of calcium in the skeleton?
What are the functions of the nervous system?
How does adrenaline affect the body?
Where is urine stored in the body?
Thank You!