Circulatory and Digestive Systems Quiz

Circulatory System

• The circulatory system transports oxygen, carbon dioxide, nutrients, and blood throughout the body.
• The heart, the main organ, pumps blood.
• The heart has four chambers: right atrium, right ventricle, left atrium, and left ventricle.
• Valves prevent backflow of blood.
• Arteries carry blood away from the heart.
• Veins carry blood back to the heart.
• Capillaries connect arteries and veins.
• Blood's color varies slightly based on oxygen content.
• Blood is red, regardless of oxygen level.

Digestive System

• The digestive system breaks down food and absorbs nutrients.
• Digestion begins in the mouth with saliva enzymes.
• The stomach uses acid and enzymes for further digestion.
• Most nutrient absorption occurs in the small intestine via villi and microvilli.
• The large intestine reabsorbs water.
• Waste is expelled through the anus.
• The digestive system includes accessory structures.

Endocrine System

• The endocrine system consists of glands secreting hormones.
• Hormones act as messengers, triggering actions in target cells.
• Hormones regulate growth, metabolism, and other bodily functions.

Excretory System

• The excretory system maintains osmotic balance and removes metabolic wastes.
• Metabolic wastes include carbon dioxide and nitrogenous waste (urea).
• The excretory system includes liver, skin, lungs, and urinary system.
• The liver detoxifies blood and processes urea.
• The skin excretes through sweat.
• The lungs excrete carbon dioxide.
• The urinary system (kidneys, bladder, ureters, urethra) filters blood and eliminates urine.
• Kidney failure can require dialysis.
• Nephrons are the functional units within kidneys.

Integumentary System

• The integumentary system includes the skin, the body's largest organ.
• Skin protects, regulates temperature, and prevents water loss.
• The skin has three layers: epidermis, dermis, and hypodermis.
• The epidermis' outer layer has cornified cells that are constantly shed and replaced.
• The integumentary system has hair, nails, and sebaceous glands.

Lymphatic and Immune System

• The lymphatic system collects, filters, and returns lymph fluid to the blood.
• Lymph is a clear fluid derived from blood plasma, surrounding cells.
• The lymphatic system supports immune function, protecting against pathogens.
• The immune system includes lymph nodes, thymus, spleen, tonsils, and bone marrow.
• Specialized white blood cells combat pathogens.
• Antibodies bind to pathogens, marking them for macrophage ingestion.

Muscular System

• The muscular system enables movement.
• Skeletal muscle moves bones.
• Muscle tissues include skeletal, smooth, and cardiac.

Nervous System

• The nervous system controls bodily actions, voluntary and involuntary.
• It includes the central nervous system (CNS) and the peripheral nervous system (PNS).
• The CNS includes the brain and spinal cord.
• The PNS includes nerves throughout the body.
• The PNS transmits sensory information to the CNS.
• Neurons and glia transmit messages.

Reproductive System

• The reproductive system is responsible for reproduction.
• The reproductive system has internal and external structures.
• Gonads produce gametes: egg cells (female) and sperm cells (male).
• Ovaries produce egg cells.
• Testes produce sperm cells.

Respiratory System

• The respiratory system takes in oxygen and releases carbon dioxide.
• Structures include the trachea and lungs.
• Alveolar sacs contain alveoli, where gas exchange occurs.
• Alveoli have thin walls and a large surface area for efficient gas exchange with capillaries.

Skeletal System

• The skeletal system supports, protects organs, and produces blood cells.
• Humans have 206 bones, developed from fused fetal bones.
• The skeletal system includes axial (skull, vertebrae, ribcage) and appendicular (limbs, girdles) skeletons.
• Bone marrow produces blood cells.