The Skeletal, Muscular, and Circulatory Systems: A Comprehensive Guide

What are the Two Types of Skeletons?

Axial Skeleton

Protects organs (skull, vertebrae, ribs)

Appendicular Skeleton

Allows movement (shoulders, arms, legs)

Types of Joints

  1. Joints can be classified by structure and function.
  2. The classification regarding texture is fibrous, cartilaginous, and synovial.
  3. The classification regarding movement is movable, slightly movable, and immovable.

Disorders of the Skeletal System

  • Greenstick: Incomplete break of the bone
  • Spiral: Caused by excessive twisting
  • Comminuted: Bone is crushed into pieces
  • Transverse: Fracture in a straight line
  • Compound: Exposure of the bone through the skin

Types of Muscles

Smooth Muscle

Contracts slowly. It is found in blood vessels and the intestine. Control is involuntary.

Skeletal Muscle

Contracts rapidly. It is found in the trunk, limbs, head, and neck. Control is voluntary.

Cardiac Muscle

Contracts rapidly. It is found in the heart. Control is involuntary.

Muscular System Disorders

  1. Tendinitis: Inflammation of the tendon that connects muscles to bones.
  2. Muscular Dystrophy: Hereditary disease in which the muscle becomes weaker over time.
  3. Muscle Strain: Caused by overstretching the muscle.

What is Found in Blood?

It is a fluid that carries gases, nutrients, and wastes through the body.

Functions of the Skeletal System

ProtectionIt provides protection to organs such as the brain.
StorageIt stores important minerals such as calcium.
Blood Cell ProductionRed marrow is in charge of producing red & white blood cells.
SupportWithout bones and muscles, we couldn’t move.
MovementIt makes it possible for us to sit and stand.

Labeling the Parts of the Skeletal System

  • Bones: They have blood vessels and nerves.
  • Ligaments: They hold bones together.
  • Cartilage: They allow movement without rubbing of bones.
  • Minerals: They make bones strong and hard. Calcium is the most plentiful.
  • Connective Tissue: They are made of collagen and withstand hits or bumps.
  • Marrow: There are two types found in the center of bones.

Venn Diagram: Cardiovascular and Lymphatic Systems

  • Cardiovascular: Blood flows in a closed, continuous loop throughout the body via the arteries, capillaries, and veins.
  • Both: Carry fluids through the body.
  • Lymphatic: Lymph is responsible for collecting and removing waste products left behind in the tissues.

What is the Job of Lymph Capillaries?

They absorb fluids around the body.


  • Bone Marrow: Where blood cells are produced.
  • Thymus: Where bone marrow finishes developing.
  • Lymph Nodes: Small organs that remove pathogens and dead cells.
  • Tonsils: Defend the body against infections.
  • Spleen: Stores white blood cells and allows them to mature.

Circulatory System Definition

  • Heart: It contracts to pump blood to the body.
  • Blood: Carries chemical messages and removes waste.
  • Arteries: Carry oxygen-rich blood away from the heart.
  • Veins: Carry oxygen-poor blood back to the heart.
  • Capillaries: Deliver oxygen-rich blood and take oxygen-poor blood away.

What Four Types of Cells is Blood Made Of?

The types of cells are plasma, platelets, white blood cells, and red blood cells.