This is a guide by Online PhD Programs
The Body’s Muscles
The primary framework of the body, the human skeleton, is covered by muscles which maintain posture and permit body movement. Within the muscles, sensory receptors monitor the amount of tension and strain the muscles endure and transmit vital data to the nervous system for proper muscle function. As we grow older or undergo injuries or illnesses, muscles can weaken or waste away. Certain muscle disorders, called myopathy, can also be caused by overuse, genetics (such as muscular dystrophy), certain cancers, inflammation (such as myositis), diseases of the nerves, infections, and certain medications.
- Virtual Tour of the Body’s Muscles
- Kids Health – Your Muscles
- Complete Muscle Tables for the Human Body
- Muscular System Information
- Structures of the Muscular System
- Human Anatomy – Muscular System Overview
- Muscle Cell Types and How We Move
The Digestive System
The digestive system is a large system of continuous tubes that extends over thirty feet, beginning at the mouth and ending at the anus. There are dozens of processes that the digestive system performs in the process of digestion. The digestive system has the responsibility of breaking down the food we eat into a minuscule size in order for our body to absorb the nutrients and release energy. As we age, the digestive system begins to slow down and nutrients may not be absorbed as efficiently as before. There are several common digestive problems that many people encounter. Some of these conditions include irritable bowel syndrome, diverticular disease, inflammatory bowel disease, leaky gut syndrome, and candidiasis.
- Virtual Tour of the Digestive System
- Your Digestive System and How it Works
- Structure and Function of the Digestive System
- Digestive System Fun Facts
- The Digestive System – Parts and Functions
- Voyage Through the Digestive Tract
- Kids Information Guide – Digestive System
The Circulatory System
The circulatory system is used for the transportation of hormones, nutrients, blood cells, and gases through a network of vessels throughout the body. This organ system is essential for stabilizing body temperature, homeostasis, and pH levels. The two types of fluid that move through the circulatory system include blood and lymph. The cardiovascular system consists of the heart, blood, and blood vessels. The lymph includes lymph vessels and lymph nodes to form the lymphatic system. As we age, the cardiovascular system becomes increasingly susceptible to various conditions, such as atherosclerosis and high blood pressure. Poor lifestyle choices, such as lack of exercise and smoking, can increase these risks.
- Virtual Tour of the Circulatory System
- Global Classroom – The Circulatory System
- Circulatory System – Functions and Parts
- How Your Heart Works
- Map of the Human Heart
- Amazing Facts About the Circulatory System
- Parts of the Circulatory System
The Respiratory System
The exchange of gases, including carbon dioxide and oxygen, in the lungs is conduced by the respiratory system. Oxygen enters the body when we breathe in air and carbon dioxide is expelled from the body after completing the respiratory process. Oxygen is a vital resource to our survival and serves many bodily functions. Carbon dioxide is merely a waste product of the inner workings of the body and is not essential to cell health. As the respiratory system ages, certain changes begin to take place. The elasticity of the lung starts to reduce, as well as the amount of carbon dioxide that is expelled. As our vital body organs receive less oxygen, they must work harder to function. The most common problems that occur in the respiratory system include asthma and bronchiolitis. More serious conditions can occur such as the lung diseases, emphysema and chronic bronchitis.
- Virtual Tour of the Respiratory System
- The Human Respiratory System
- Functions of the Respiratory System
- The Respiratory System Anatomy
- Respiratory Diseases
- Biology – The Respiratory System
- Respiratory System – Inside the Human Body
The Urinary System
The urinary system, or excretory system, is the removal of waste products from the body in the form of urine. The primary components of this system include the urinary bladder, two kidneys, two sphincter muscles, two ureters, and the urethra. Each of these vital organs is essential to the elimination process of wastes from our body. Around the age of forty, many individuals experience a decline in kidney function, commonly due to changes in renal function. The aging bladder leads to an increase in urinary flow and urgency, as well as an increase risk of urinary tract infections. Kidney mass also decreases with age by twenty-five to thirty percent, making the ability to filter and concentrate urine more difficult.
- Virtual Tour of the Urinary System
- Your Urinary System and How it Works
- Anatomy of the Urinary System
- Urinary System - Anatomy and Function
- Urinary System Diseases
- Interesting Facts – The Urinary System
- Parts of the Urinary System
The Nervous System
The nervous system acts a highway of information by sending vital information to and from various parts of the body. The nervous system is made up of two main divisions, the central nervous system and the peripheral nervous system. The central nervous system consists of the spinal cord and brain while the peripheral nervous system is made up of the neural tissues that surrounds the outside of the central nervous system. The functioning of the nervous system continues to change from childhood to adulthood, reaching full development around the age of thirty. Certain processes, such as the use of words and vocabulary, begin to decline around seventy years of age. There are numerous problems that can affect the nervous systems, both temporary and permanent. The more serious problems that can affect the nervous systems include conditions, such as Multiple Sclerosis and Parkinson’s.
- Virtual Tour of the Nervous System
- Explore the Nervous System
- The Nervous System – Virtual Anatomy
- Nervous Systems and Senses
- Overview of the Nervous System Disorders
- The Central Nervous System
- Module – Introduction to the Nervous System
The Body’s Skeleton
The body’s skeleton system functions much like the frame of a house, providing the support your body requires to shelter organs and maintain posture. Ligaments, muscles, and joints provide the power the body needs for movement. The bone marrow is also used to produce certain red and white blood cells needed by the body. After the age of thirty, our bones begin to lose mass and become porous. This process begins to speed up after the age of fifty, especially in women during and post menopause. Vertebrae become thinner, padding between vertebrae begins to waste away, and the spine compresses. These changes can lead to certain bone conditions, including osteoporosis and arthritis.