The human body is a complex structure of vital organs and interconnected systems that work hard daily to fulfil the functions necessary for everyday living. Here are twenty-five amazing facts about some of those systems that will offer plenty of inspiration for our human anatomy and physiology course!

The respiratory system

1. Did you know that our lungs float on water? In fact, they are the only organs that do. This is because they contain millions of balloon-like structures called alveoli.
2. The human nose is a heater (it has small bone-like “shelves” called turbinates which contain blood vessels that can heat the air), a humidifier (it has “goblet” cells that help humidify the air), and a filter (the air we breathe is filtered before it goes to our lungs).
3. Sneezing and coughing is one of the body’s natural mechanisms to help keep away foreign substances.
4. Even with optimal health, our lungs are never sterile or germ-free.

The digestive system

5. Whenever we eat something, our esophagus acts like a giant wave, involuntarily relaxing and constricting. This is known as peristalsis.
6. The middle part of our intestine is called the jejunum. It is located between the duodenum (the first part of the small intestine) and the ileum (the last part of the small intestine).
7. There is a bond between our brains and digestive systems, known as the gut-brain axis. Any brain disorders or even stress can affect how our bodies digest food.
8. Hiccups often occur when the temperature changes.

The nervous system

9. The brain uses more energy than the rest of our organs, with only 20 per cent of energy reserved for the rest of the body.
10. Our brains keep working hard even when we are asleep.
11. Because new neuronal connections are constantly occurring and the brain’s structure is constantly changing, the density of our brains keeps increasing.
12. The sciatic nerve is the longest nerve in the body, and it runs from the spinal cord down to our toes.

The skeletal system

13. Bones may present as hard substances, but are filled with a spongy substance called bone marrow.
14. The smallest bones in the body are in our inner ear. They are called the incus (anvil), the malleus (hammer) and the stapes (stirrup). They are known collectively as the ossicles (Latin for “tiny bones”).
15. The longest and strongest bone in the body is in the leg and is called the femur (thighbone).
16. Bones can heal themselves by producing new cells — that’s why broken bones are often placed in a cast.
17. The biggest joint in the body is the knee.

The reproductive system

18. The human reproductive system contains the smallest and the largest human cells.
19. A man produces more than 500 billion sperm cells in his entire lifetime.
20. Some women are born with a rare congenital condition where they have two uteruses. It is known as uterus didelphys.

The muscular system

21. The human body contains more than 600 muscles.
22. The largest muscle in the body is the gluteus maximus, which is the primary extensor muscle of the hip.
23. The body’s smallest muscle is inside the inner ear, and connects the inner ear and the eardrum.
24. More than forty per cent of your body weight is made up of muscles.
25. The heart is the hardest working muscle in the body, typically pumping over 7000 litres of blood daily.

A brief history of anatomy

The history of human anatomy and physiology extends from the earliest examinations of sacrificial victims to the sophisticated analyses of the body that modern-day scientists and anatomists have performed. And we are still learning!

Written descriptions of parts of the human body can be traced back thousands of years to ancient Egyptian papyri, where highly elaborate burial practices required much attention to detail.

Theoretical considerations of the function and structure of the human body didn’t develop until far later. Ancient Greek doctors like Hippocrates and philosophers like Empedocles and Alcmaeon paid much more attention to the causes of disease and the body’s different functions.

Aristotle performed dissections on animals to understand the causes of biological forms. Dissection of human beings took place for the first time during the Hellenistic Age with the work of Erasistratus and Herophilos. Galen also made important anatomical discoveries through his dissections and medical practice.

The Renaissance brought a reconsideration of classical medical texts, and Jacques Dubois, Berengario da Carpi and Mondino de Luzzi carried out important anatomical work in this period. This culminated in the books by Andreas Vesalius (De Humani Corporis Fabrica), which is Latin for “on the fabric of the human body in seven books”. It was a significant advance in the history of anatomy and has been an integral part of medical practice ever since.

 

Gain a strong foundation in human anatomy with a course in human anatomy and physiology such as our Certificate of Human Anatomy.