Science Quiz Body Systems

Heart and Circulatory System

• The heart consists of 4 chambers: right atrium, right ventricle, left atrium, left ventricle.
• Blood is prevented from flowing backward by valves located within the heart.
• Arteries carry oxygen-rich blood away from the heart; veins carry oxygen-poor blood back to the heart.
• Capillaries are the smallest blood vessels where oxygen and nutrients are exchanged with body cells.
• Red blood cells are responsible for transporting oxygen; white blood cells help fight infections; platelets play a key role in blood clotting.
• The circulatory system's primary functions include delivering oxygen and nutrients, removing carbon dioxide and waste, and maintaining overall body health.

Blood Sugar Regulation

• Sugar enters the bloodstream through the intestines; its levels increase during this process.
• Sugar is removed from the blood in capillaries, causing a decrease in sugar levels.

Levels of Organization in the Body

• The body is organized into four levels from smallest to largest: cell, tissue, organ, organ system.
• Organs are formed from different types of tissues working together for specific functions.
• Organ systems consist of multiple organs that collaborate to perform larger functions, such as digestion.

Muscular System

• The muscular system enables movement, supports bodily functions, and generates heat.
• There are three types of muscles: skeletal (voluntary), smooth (involuntary), and cardiac (involuntary).
• Skeletal muscles are responsible for voluntary movements and have distinct striations; smooth muscles operate in organs and lack striations; cardiac muscles form the heart and ensure its continuous function.

Nervous System

• The nervous system is divided into the central nervous system (CNS) and peripheral nervous system (PNS).
• The CNS includes the brain and spinal cord, acting as the control center for body functions.
• Neurons, the body’s nerve cells, have three main parts: soma (body), dendrites (receive signals), and axons (send signals).
• Nerve impulses travel electrochemically through neurons, allowing communication between the brain and body.

Receptors and Sensory Responses

• Five types of receptors are present in the body: mechanoreceptors (detect pressure), photoreceptors (respond to light), thermoreceptors (sensitive to temperature), chemoreceptors (measure chemical concentration), nociceptors (respond to pain).
• Receptor cells convey information to the brain, which responds with instructions, typically in seconds.
• The nervous system integrates all five senses: sight, hearing, smell, taste, and touch.

Homeostasis and Responses

• Homeostasis refers to the maintenance of stable internal conditions across various body systems.
• Responses to stimuli can be classified as learned (acquired through experience) or innate (natural instincts).

Blood Components and Functions

• Blood consists of red blood cells, white blood cells, platelets, and plasma, which largely consists of water.
• Plasma functions as the liquid medium for transporting nutrients, hormones, and waste products throughout the body.