All the bones in a human body form the skeletal system. When a baby is born, he is made up of 270 bones. However, as he grows up, most of these bones are joined to form a single bone. As a result, an adult person has 206 bones in total. Now we explain the skeletal system for kids.
Skeletal System For Kids
Functions of the Skeletal System
- Bones are arranged in such a manner that they form a protective covering for other soft organs of human body.
- They keep the body structure straight while standing; a body would tumble if there had been no skeletal system.
- With the help of muscles, different bones assist in movement of the body. They are attached to the muscles at joints and together they perform any work.
- Bones act like a warehouse in which essential minerals such as calcium and phosphate are deposited. In times of need when the food intake becomes insufficient in providing them, bones supply these minerals to the blood. Hormones (present inside the bones) deliver these minerals to the blood.
- They prepare new blood cells for the body.
Types Of Skeleton
All bones are divided into two groups of skeletons namely axial skeleton and appendicular skeleton.
1. Axial Skeleton
- There are 80 bones in the axial skeleton.
- Breastbone, vertebral column bones, skull bones and ribs form axial skeleton.
2. Appendicular Skeleton
- There are 126 bones in the appendicular skeleton.
- It consists of the bones of legs, arms, pelvic as well as pectoral girdles.
Parts of the Skeletal System
The different parts of the skeletal system include:
- Cranium or skull bone
- Sternum or ribs
- Radius and ulna bones
- Carpals or bones of the wrist
- Phalanges or fingers or toes
- Femur or thigh bone
- Patella or kneecap
- Metatarsals or ankle bones
- Tarsal or foot bones
- Spinal column
- Maxilla bones or upper jaw
- Mandible bones or lower jaw
- Scapulae or shoulder blades
Bones of the Skull
- There are 22 bones in the skull of human body.
- Bones of the skull are flat bones.
- The brain is enclosed within a helmet-shaped part of the skull called cranium. It is very hard and protects the spongy brain inside it.
- Cranium is made up of 8 bones.
Bones Of The Face
- Facial bones comprise of 14 bones including lower jaw bone (mandible).
- Among all the facial bones, mandible is certainly the biggest as well as the strongest bone.
- There are 7 bones of different sizes in eye sockets.
Bones Of The Ear
- An ear consists of 3 very small bones.
- These three tiny bones are called ossicles.
- The names of these bones are malleus (hammer), incus (anvil) and stapes (stirrups).
Bones Of The Neck
- A neck consists of 7 bones called cervical vertebrae.
- A throat consists of only one bone called hyoid bone.
Bones Of The Shoulder
- Shoulder girdle is also called pectoral girdle.
- A shoulder girdle consists of 4 bones.
- Four bones are divided into two scapulae and two clavicles.
- There are two pairs of shoulder blades on each side (known as scapulae) and are attached to the arms’ bones.
- The word ‘scapula’ is a Greek term that means ‘to dig’.
- Scapula is shaped like a spade and it is a horizontal bone.
- It consists of 3 angles, 3 borders and 2 surfaces.
- There are two collarbones right in front of shoulder girdle, above the ribs and below the neck.
- These two bones are called clavicles.
- The word ‘clavicle’ is a Latin term meaning ‘little key’.
- Compared to women, men’s clavicles are bigger, thicker and more curved.
Bones in Chest
- Chest is made up of 12 pairs of bones called rib cage because they form a kind of cage to protect the heart. These are flat bones.
- A person can also have 13 or at times 11 pairs of ribs though it is very rare.
Types Of Ribs
- There are three types of ribs namely true ribs (also called typical ribs), false ribs and floating ribs.
- Rib cage consists of 7 pairs of true ribs.
- It consists of 8 to 10 pairs of false ribs.
- It consists of 11 to 12 pairs of floating ribs.
Function of the Ribs
- They shield various organs of human body such as the lungs and the heart.
- Lower Back Bones
- There are 5 lumber bones (lower back) in a body. They withstand most of the body’s weight.
Bones of the Hip
- Bones of the hip are known as coxals.
- The term ossa coxae or coxals used for bones of the hip is derived from the Latin word that means ‘hip bone’.
- Another name infrequently used is innominata, which derives its name from the Latin term that means ‘no name’.
- There are 3 pairs of bones in every hip bone. These are the ilium, the ischium and the pubis. All these pairs of bones collectively form a hip’s skeleton.
- The word ‘pubis’ is derived from the Greek term that means ‘adult’.
- Hip bone is located at the upper part of thighbone and is enveloped within densely packed coatings of muscles over it.
- Hipbone is a disproportionate large bone.
- It is squeezed in the middle while gets bigger from the top and bottom.
- Just as shoulder girdle supports arms, pelvic girdle or hip girdle joins legs.
- ‘Pelvis’ is derived from the Latin word meaning ‘basin’.
- There are 2 big hipbones anchored together in the pelvic girdle.
Bones of the Arm
- Each arm is broken up into three parts: upper arm, lower arm and the hand.
- There are three primary bones on every arm.
- The names of these bones are humerus, ulna and radius.
- These are connected to each other at joints and perform function in a group.
- The radius and ulna bones make up your entire forearm.
- The radius is shorter than the ulna.
- Compared to the radius, the ulna is more strongly linked to the humerus.
- While moving your hand, radius plays a relatively more important role than the ulna.
- When your arm is fractured, it is normally the radius bone that is ruptured.
- The word ‘humerus’ is derived from the Greek term that means ‘shoulder’.
- Humerus is a bone of upper arm and stretches from the shoulder to the elbow.
- It is the biggest bone of upper arm.
- Humerus is also known as brachium.
- The term ‘ulna’ is derived from the Latin word meaning ‘elbow’.
- It is the bigger bone of the forearm and lying at the back of it.
- At the elbow lies the edge of this bone.
- The head of this bone hooks up with the radius.
- Ulna is located on the medial side of human body.
- The word ‘radius’ is derived from the Latin term which means ‘ray’.
- Radius passes through ulna while spinning around its bigger axis.
- Radius is located on the lateral side of human body.
Bones of the Wrist
- There are 8 bones in each wrist.
- These bones are called carpals.
- The word ‘carpus’ is a Latin term that means ‘wrist’.
- Carpal bones are firmly held together by means ligaments.
- Bones of the wrist are shaped like a box.
- Carpal bones are divided into two rows for the wrist’s movement.
- The first row of carpal bones is also called proximal row.
- Bones in the first row are Scaphoid, Lunate, Triquetrum and Pisiform.
- The second row of carpal bones is also called distal row.
- Bones in the second row are Trapezium, Capitate and Hamate.
Bones in Thumb
- A thumb consists of 2 bones (or phalanges).
- Thumb is the most flexible finger so much so that it can even cross your palm which is why it is known as opposable thumb.
- Fingers consist of 14 bones.
- These bones are called phalanges.
- Out of these 14 phalanges, one bone is called phalanx.
- All fingers consist of three phalanges (bones) except the thumb, which contains only two phalanges.
- Toe bones are also known as phalanges.
Names of Fingers
- Thumb is known as pollex.
- The word ‘pollex’ is derived from the Latin word that means ‘strong’.
- The second finger is known as index finger.
- The word ‘index’ is derived from the Latin word that means ‘pointer’.
- The middle finger is known as medius.
- The word ‘medius’ is derived from the Latin word that means ‘middle’.
- The fourth finger is known as annularis (or ring finger).
- The word ‘annularis’ is derived from the Latin word that means ‘ring’.
- The fifth finger is known as minimus.
- The word ‘minimus’ is derived from the Latin word that means ‘least’.
Bones of the Hand
- Both hands consist of 54 bones in total.
- Each hand has 27 bones.
- Bones of the hand are known as metacarpals.
- The word ‘metacarpal’ comes from the Latin term meaning ‘after the wrist’.
- The palm of your hand consists of 5 metacarpal bones located between fingers and the wrist.
- One end of the metacarpal bones is linked up to the finger bones while the other end stretches out from the wrist.
- You can see your metacarpal bones from the backside of your hand.
- Metacarpals are numbered from one to five beginning from the thumb.
- Metacarpal One | comparatively shorter bone
- Metacarpal Two | biggest of all metacarpal bones
- Metacarpal Three | compared to metacarpal two, it is a smaller bone
- Metacarpal Four | compared to metacarpal two, it is smaller and also a shorter bone
- Metacarpal Five | it contains one facet only
Parts of Hand
- Each hand consists of 3 parts.
- The names of these parts are fingers, palm and wrist.
Bones of the Leg
- A leg consists of 2 bones.
- Bones of the leg are not equal in length.
- Bones of the leg are femur, tibia and fibula.
- Bones of the lower leg are tibia and fibula.
- Thigh bone is called femur.
- Femur is located between kneecap and hip.
- The word ‘femur’ is derived from the Latin term that means ‘thigh’.
- Femur is the largest bone in human skeleton.
- Femur is the strongest of all bones in human body.
- It comprises of 2/7th of your height.
- The parts of femur involve patellar surface, body, trochanter, the neck and the head of femur.
- Fibula is a second bone of leg going parallel to shin bone and located below kneecap.
- A cartilage called meniscus minimizes shock which your body experiences while strolling or going for a run.
- Meniscus is shaped like a curved substance and is located in the middle of two leg bones: shin bone and thigh bone.
- Tibia is also called shin bone.
- It is located below kneecap.
- The term ‘tibia’ is a Latin word that means ‘flute’. It looks a lot like a flute.
- It is the second biggest bone of human skeleton.
- It is a slim and bigger of the two bones.
- Tibia supports the weight of the leg.
- The term ‘fibula’ is derived from the Latin word that means ‘pin’.
- Fibula is located on one side of tibia (calfbone) between ankle and kneecap.
- Fibula is also known as calfbone.
- At times, fibula is also known as splinter bone.
- Fibula is smaller and slimmer of the two parallel bones of the lower leg.
- It is connected to those muscles that are essential in the movement of foot.
- Since fibula is densely packed with muscles, you cannot actually feel it.
- Bone of kneecap is known as patella.
- There are thirteen muscles and four ligaments that give protection to the knee still knee joint is at great risk because external forces can relocate it quite easily.
- The word ‘patella’ is derived from the Latin term that means ‘small pan’.
- It is a small and horizontal bone that is triangular in shape.
- There is a knee joint formed by the connection of tibia bone and the bigger of two bones at lower portion of the leg. The patella is responsible to guard this joint.
Bones of the Ankle
- An ankle consists of 7 bones in total (four relatively smaller bones and three bigger ones).
- These bones are called tarsals.
Bones of the Feet
- Both feet consist of 52 bones in total. That means each foot has 26 bones.
- Each foot consists of 5 metatarsal bones located between toes and the ankle.
- Bones of sole are called metatarsals.
Bones of the Spinal Column
- There are 33 bones in a spinal column called vertebrae.
- 7 neck bones or cervical vertebrae form the upper portion of spine.
- These neck bones are joined by 12 bones called thoracic vertebrae.
- Thoracic vertebrae are then joined by 5 lumbar bones.
- Below lumbar bones, there are 5 vertebrae called sacrum that are merged into one another.
- Finally, coccyx bone is present at the end of spine and comprises of 4 vertebrae that are also merged.
- Tailbone is a bone that lies at the bottom most part of spinal column.
- There are pads of cartilage fixed in the middle of two vertebrae of spinal cord. They prevent these bones from chafing over each other and from wearing away.