The skeletal system and anatomy of the human bones, from head to toe

Human skeletal system

What is the human skeletal system?

At birth, the human body is formed by 270 bones. However, as the body develops, some of the bones fuse together. By the time they reach adulthood, the human skeleton will be formed by only 206 bones.

Then, what is the anatomy of the human bones? Check out the complete explanation of the anatomy of bones and joints in humans below.

Bone function in humans

Before studying the anatomy of the human skeleton, you need to understand the function of its presence in the body. From your head to your fingers, your bones protect and shape your body. The skull protects the brain while the ribs protect the vital organs in the chest.

Apart from that, there are five other main functions of human bones, which are:

• Formers of structures in the body.
• A place to store minerals and lipids needed by the body.
• A place to produce red blood cells, white blood cells, and other blood elements.
• Protect the organs in the body.
• Give the body the ability to move.

The forms of the human skeleton

It is better to understand the shapes of the bones before understanding the anatomy of the human skeleton.

Based on its shape, human bones are divided into five forms, namely:

source: Daydream Anatomy

1. Long bones

Long bones have cavities and are responsible for supporting the body's skeleton. For example, the long bones are the thighbone (femur), calf bone (fibula), shin bone (tibia), the sole of the foot (metatarsal), and the bones of the palms (metacarpals), fingers (phalanges), and the bones that make up the arms. namely the humerus, ulna, and radius.

2. Short bones

It is about the length of its width and is shaped like a dice or a circle. This bone allows you to move. For example, short bones include the bones that make up the ankle (tarsals) and the bones that make up the wrist (carpal).

3. Flat bones

Flat bones are very thin in size, but vary in size and shape. This bone has a surface area to protect the muscles contained in the bone. Examples of flat bones include the ribs, skull (cranial), sternum (sternum), and scapula (scapula).

4. Irregular bones

Irregular bones have a shape that is incompatible with long, short, or flat bones. For example, these bones are the spine (vertebrae), sacrum bone, coccygeal bone, and some bones that make up the face such as the wedge bone (sphenoid), cheekbone (zygomatic), and ethmoid bone.

5. Sesamoid bone

The sesamoid bone is a bone that is embedded in a tendon (the connective tissue that connects muscle tissue to bone). These small round bones are commonly found in the tendons of the hands, knees, and feet. The sesamoid bone protects the tendons from stressing the joints and increases the efficiency of the joints. One example of this bone is the kneecap (patella).

Anatomy of human bones

The anatomy of the human skeleton is divided into two groups, namely axial and appendicular.

Axial bone

Axial bones include all bones throughout the body, including the skull skeleton, which includes both the skull and the facial skeleton.

1. Skull bone

source: Healthiack

The skull protects the most important part of the whole brain. The skull is actually made up of different bones. Some of these bones protect your brain, while others make up the structure of your face.

The skull consists of the forehead (frontal) bone, the crown bone (parietal), the temporal bones, and the bones that form the face, namely the cheekbones, wedge bones, mandibular bones (mandible), maxillary bone (maxilla), bone tears (lacrimal), and nasal bones (nasal).

2. Spine (vertebral column)

The human spine skeleton has 33 vertebrae which are divided into five vertebrae, namely 7 cervical bones, 12 thoracic bones, 5 lower back bones (lumbar), 5 sacrum bones, and 4 coccygeal bones (coccygeal).

Each vertebra is named based on the first letter of the segment and its position along the upper to lower axis, except for the sacrum and coccyx. For example, the sternum or thoracic the very top is called T1 and the very bottom is called T12.

3. Ribs and sternum

The anatomy of the human skeleton also includes the sternum (sternum), which is a thin, knife-shaped bone that runs along the midline of your body. The sternum is connected to the ribs by cartilage called the costal cartilage.

The ribs are used to protect the heart, lungs, and liver and other organs in the chest cavity to keep it safe. Human ribs consist of 12 pairs, consisting of 7 pairs of true ribs, 3 pairs of false ribs, and 2 pairs of floating ribs.

Appendicular bone

Meanwhile, the anatomy of the appendicular human skeleton includes all the bones that make up the upper limbs, lower limbs, shoulders and pelvis and connects with the axial parts.

1. Hand bones

The anatomy of the bones in the hand, consisting of the bones of the upper arm (humerus), wrist (carpal), palm (metacarpal) and fingers. Each arm is attached to the scapula, which is the large triangular bone at the corner of the top of each side of the rib.

The humerus is located just above your elbow, then below the elbow there are two bones, namely the radius and ulna. Each one is wide at the tip and thin at the middle. This is to provide strength when it meets other bones.

At the tips of your fingers and ulna are eight small bones that make up your wrist. On the palms of the hands are five bones. Each finger consists of three vertebrae, except for the thumb which only consists of two vertebrae.

2. Pelvic bones

The anatomical leg bones are attached to a group of pelvic bones, which form the cup that supports the spine. The pelvis is made up of the right and left pelvic bones, each of which is a combination of three large, flattened and irregular bones: ilium, ischium, pubis.

3. Foot bones

The leg bones are also part of the anatomy of the human skeleton which functions to support body weight so that you can stand and walk upright. The leg bones starting from the hip to the knee are called the femur or thighbone. It is the longest bone in the human body. This femur is attached to the pelvis.

On the knee, there is a triangular shaped bone called the patella, or kneecap. This bone protects the knee joint.

Below the knee are two other leg bones, namely the tibia or known as the shinbone and fibula or calf bone. Just like the three bones in your arm, the three bones in your leg have ends that are wider than the middle to provide strength when they meet other bones.

While the ankle (metatarsal) bone is slightly different from the wrist. At the ankle there is the talus bone, which is attached to the calf bone and forms the ankle, then under the talus bone is the heel, which is connected to six other bones.

On the sole (tarsal) bones there are five long bones that connect to the toes. Each toe has three small bones, except the thumb has only two bones.

The relationship between the skeleton and the joints

After knowing the anatomy of the human skeleton, you need to understand the relationship between bones and joints in the human body. According to Standfort Children's Health, the joint is the place where two or more bones meet in the body.

Therefore, joints are closely related to the human skeleton. Most of the joints are mobileor can be moved, so that the bones are also easier to move. Joints consist of:

1. Cartilage (cartilage)

Although called cartilage, this part of the joint is the tissue that covers or lines the joint. This cartilage can help reduce the friction that occurs due to movement within the joints.

2.Synovial membrane (synovial membrane)

This part of the joint lines the joint capsule. In addition, this synovial membrane secretes a clear, slightly thick and sticky liquid called synovial fluid around the joints which functions as a joint lubricant.

3.Ligaments (ligaments)

Ligaments are fibrous but elastic in nature and function as connective tissue around joints to support and limit joint movement. Ligaments are responsible for connecting one bone to another.

4. Tendon (tendons)

Similar to ligaments, tendons sit on the sides of joints and attach to muscles that control the movement of the joint. Tendons function to connect muscles to bones.

5. Exchange

Meanwhile, part of this joint is a fluid-filled sac between the bones, ligaments, or other structures. The function of this fluid sac is to reduce friction in the joint.

6. Meniscus

In fact, the meniscus is a type of cartilage. However, this cartilage is shaped like the letter C which functions as a cushion found in the knee joint.

Health problems in bones and joints

Health problems that attack the bones

The following are types of diseases or disorders that affect the human skeleton. Among them:

1. Osteoporosis

Osteoporosis is bone loss which, in a severe degree, causes fractures. Osteoporosis most commonly occurs in the pelvis, wrists, and spine.

Osteoporosis can be experienced by both women and men. However, women who are elderly and have experienced menopause have a higher risk of experiencing it.

The use of drugs and lifestyle changes can prevent the progression of this disease, and strengthen bones that begin to become brittle.

2. Broken bones

Skeletal problems can also occur if a bone is broken. Usually, this condition occurs as a result of falls, vehicle accidents, or sports injuries. The severity also varies.

If it's not too bad, you may just have a fracture. However, at a more severe stage, for example in a car accident, your bones may break and require immediate medical care.

3. Spinal disorders

There is also an abnormality in the spine which is one of the human skeletal problems. Some types of spinal disorders include kyphosis (the spine curves excessively forward), lordosis (the lower vertebrae curves inwardly), and scoliosis (the spine curves sideways).

There is also spondylolisthesis, which is a spinal disorder that occurs as a result of shifting the bones downward so that they press on the nerves and cause pain or pain. Then, spondylosis is a problem in the spine that occurs as part of the aging process.

4. Osteopenia

Osteopenia is a problem of the human skeleton due to decreased bone loss. This makes the bones even more brittle. If not treated immediately, osteopenia can lead to osteoporosis.

5. Osteomalacia

Osteomalacia is a bone health problem that causes the bones to become unable to harden. This makes the bones more susceptible to bending, even breaking. This is usually caused by a deficiency in vitamin D.

6. Bone paget disease

Paget's disease of bones is characterized by bones in certain parts of the body becoming bigger and thicker. This disease can interfere with the process of recycling new bone tissue.

You will be more at risk of experiencing this one bone disorder as you get older. This disease can also be hereditary, so the risk increases if a family member has bone paget disease.

7. Osteopetrosis

Osteopetrosis leads to a collection of bone disorders that occur from generation to generation. It is characterized by increased bone mass and abnormal bone growth.

8. Achondroplasia

Achondroplasia is a bone growth disorder characterized by stunted body problems (dwarfism). This also causes the elbow movement to be limited, the head size is larger than normal, and the fingers are small.

9. Osteogenesis imperfecta

Osteogenesis imperfecta (OI) is a group of rare disorders that can affect connective tissue. This means that it can cause the bones to become brittle and break easily.

10. Osteomyelitis

Osteomyelitis is a bone infection. This infection can be felt to the bones due to spread from body tissues or bloodstream. However, the infection can originate from the bone itself if there is a wound that leaves the bone contaminated with germs.

Health problems affecting the joints

In addition to bone health problems that attack the human skeleton, some also attack the joints. Among them:

1. Arthritis

Arthritis is inflammation of the joints that are divided into several types. Osteoarthritis, rheumatoid arthritis, gout, psoriatic arthritis, ankylosing spondylitis, septic arthritis, and juveline idiopathic arthritis are the types of arthritis that you need to know.

2. Bursitis

Bursitis is inflammation of theBursae,which is one part of the joint in the form of a bag containing lubricant. These pockets can be found on the shoulders, elbows, hips, knees and feet.

3. Tendinitis

This tendinitis attacks the tendons, where the network of fibers that connect the muscles to the bones becomes inflamed, which results from injuries that often occur suddenly.

4. Tendon injury

Tendon injuries occur when tendon tissue is torn as a result of overuse or part of the aging process.

5. Tennis elbow

Tennis elbow occurs when the tendons in the elbow area are overused, particularly due to repetitive movements of the wrist and arm.

6. Carpal tunnel syndrome

This condition attacks the wrist to the palm area causing pain, numbness, and pain. Carpal tunnel syndrome can occur if you have arthritis around the wrist that attacks the median nerve.