Structure and functions of the skeleton
chemical and physical structure of the bones is the reason for their properties;
the shape of the bone depends on its functions;
bones of a human can be connected in a mobile or immobile form.
to show the connection between the structure of the elements of the skeleton and their functions;
to recognise the elements of the skeleton on a schematic drawing;
to describe the positioning of selected bones in your body;
to describe the functions of a human skeleton.
Axial skeleton
The skeletonskeleton is composed of axial skeleton and appendicular skeleton. The axial skeletonaxial skeleton consists of the skull, the spine and the chest.
Bones of the skull, with the exception of the mandible, are connected with each other in an immobile form, using sutures in the form of a connecting line. The skeleton of a skull consists of:
flat bones, attached by sutures, forming a box where the brain is enclosed (cranium);
bones of different shapes – the scaffolding of the face (facial skeleton), which are the support for the teeth and allow us to chew food.
The spinespine is connected with the upper body, supports the skull and gives support for the bones of the limbs. It is situated in the dorsal part of the body. It consists of 33‑34 vertebrae and is divided into sections: cervical (7 vertebrae), thoracic (12), lumbar (5), sacrum (5), coccyx (3‑4). The biggest vertebrae are in the lumbar section, which can sustain a significant weight. Each vertebra is composed of a vertebral body, vertebral arches and processes. The vertebrae are positioned one on top of the other along the vertical axis of the body.
Vertebral bodies of the vertebraevertebrae are connected with each other by cartilage disks – intervertebral discs. The discs work as shock absorbers eliminating shocks that could be transferred to the skull, e.g. when we jump. When viewed from the side, the spine is curved in the form of a double S, which allows us to keep the vertical position. The curvature of the spine is shaped when we are one year old.
The arches of the vertebrae are connected with each other behind the vertebral bodies, creating a spinal canalspinal canal, which protects the spinal cord that runs inside it.
The chest is composed of thoracic vertebrae, the ribs and the sternum. Ribs are connected with the sternum by means of cartilages, which allows us to change the volume of our chest when we breathe in and breathe out. The chest protects the lungs and the heart.
For one month, every morning and evening the height of 20 women at the age of 35 was measured. The measurements suggested that at evening, the women were shorter by 2 cm on average. Explain these changes. OR Describe the positioning of selected bones in your body.
What type of axial skeleton is going to work the best in a large vertebrate?
The spine should have the form of a rigid rod.
long, thick straw,
scissors,
pipe cleaner (creative wire).
Run the pipe cleaner through the straw.
Gently try to bend the straw with the pipe cleaner and observe, whether the straw bends.
Take the pipe cleaner from out of the straw.
Cut the straw into small pieces, about 2 cm long, put them on the pipe cleaner.
Gently try to bend the straws on the pipe cleaner. Observe, whether such construction bends easily.
Assess the influence of a rigid spine on the physical activity of the body.
The comparison of the model of axial skeleton that consists of one long bone (entire straw) with the model that consists of multiple short bones (fragments of the straw) does not confirm the hypothesis.
Based on an experiment form a conclusion.
The build of the appendicular skeleton and the skeleton of the limbs
The bones of the limbs are connected with the spine using groups of bones that are arranged into horizontal sections called girdles. Shoulder girdleShoulder girdle is composed of shoulder blades and clavicles – it attaches the skeleton of the upper limb. The place where it is connected is the sternoclavicular joint. It has a shallow joint socket, which allows great mobility of the shoulder. The bones of the upper limb are the humerus, 2 bones of the forearm - radius and ulna, and bones of the wrist, the hand and the fingers (phalanges).
The lower limbs are connected with the axis of the body via pelvic girdlepelvic girdle that consists of two pelvic bones, which, together with the sacrum, create the pelvis - stable and massive pelvic girdle that supports the upper body. The limbs are connected with the pelvis on its outer sides, forming two massive support pillars. Long and wide feet on the ground provide a solid base for a vertical body.
The hip joint is a connection between the pelvic bone and the lower limb. The skeleton of the lower limb consists of a femur, 2 bones of the crus - tibia and fibula, and the bones of the foot - tarsal, metatarsal and of the toes (phalanges). Bones of the foot are arranged in such a way so that there is a characteristic arch on its internal part. It allows the gait to be flexible as well as it absorbs shocks.
Based on the shape of the pelvis, you can identify the gender of a person. Try to figure out whose pelvis is wider: that of a woman or that of a man? Why are the pelvises different? OR Whose pelvis is wider: that of a woman or that of a man?
Mutual examination of the bones of the forearm.
uncovered upper limb.
Extend your right arm with your palm facing downwards.
Put your left hand on the forearm, in the middle.
Touch the bones and explain their placement.
Put your right arm with your palm facing upwards. Touch the arm and decide, whether the bones of the forearm changed their position.
Repeat the actions.
Draw an outline of the arm with both bones of the forearm and hand in both positions that you investigated.
Check other movements of the forearm in relation to the arm.
If the bones of the forearm are crossed when turning, this means the elbow joint is a pivot joint. If the bones can be bend in the elbow joint, this means the joint is a hinge joint. The elbow joint connects 3 bones that share one joint capsule.
Summary
The skeleton is a scaffolding for the body and gives the body its shape.
The axial skeleton consists of the skull, the spine and the chest.
The spine that runs along the upper body gives it support, allows for bending the body, absorbs shocks that could reach the skull, protects the spinal cord which is situated in the spinal canal.
Skull creates a protection for the brain and the senses.
Chest is composed of many bones that are connected with each other mainly in a mobile way; together with the muscles, it is responsible for respiratory movements.
Limbs are connected with the axial skeleton via girdles.
Using a selected bone as an example explain, how its build depends on the functions it has in the skeleton.
Keywords
skeleton, axial skeleton, girdles
Match the pairs: English words with Polish definition.
kość różnokształtna stanowiąca jednostkę budulcową kręgosłupa; składa się z trzonu, łuków kręgowych i wyrostków, obręcz kończyny dolnej; kostny element szkieletu łączący kończynę dolną wolną (nogę) ze szkieletem osiowym; składa się z 2 kości miednicznych, obręcz kończyny górnej; kostny element szkieletu łączący kończynę górną wolną ze szkieletem osiowym; składa się z obojczyka i łopatki, część centralnego układu nerwowego położona w kanale kręgowym; odpowiada za przekazywanie informacji do mózgu i z mózgu oraz kontrolę czynności wykonywanych odruchowo, kanał utworzony przez łączące się za trzonem kręgu łuki kręgowe; przebiega w nim element układu nerwowego --- rdzeń kręgowy, twarda struktura zbudowana z substancji organicznych i nieorganicznych, stanowiąca rusztowanie ciała i podporę dla mięśni, część szkieletu osiowego zbudowana z kręgów ułożonych jeden nad drugim; u człowieka wyznacza pionową oś ciała, część szkieletu tworząca oś ciała, zbudowana z czaszki, kręgosłupa, żeber i mostka
| spinal canal | |
| vertebra | |
| spine | |
| shoulder girdle | |
| pelvic girdle | |
| spinal cord | |
| skeleton | |
| axial skeleton |
Glossary
kanał kręgowy – kanał utworzony przez łączące się za trzonem kręgu łuki kręgowe; przebiega w nim element układu nerwowego – rdzeń kręgowy
kręg – kość różnokształtna stanowiąca jednostkę budulcową kręgosłupa; składa się z trzonu, łuków kręgowych i wyrostków
kręgosłup – część szkieletu osiowego zbudowana z kręgów ułożonych jeden nad drugim; u człowieka wyznacza pionową oś ciała
obręcz barkowa – obręcz kończyny górnej; kostny element szkieletu łączący kończynę górną wolną ze szkieletem osiowym; składa się z obojczyka i łopatki
obręcz miednicowa – obręcz kończyny dolnej; kostny element szkieletu łączący kończynę dolną wolną (nogę) ze szkieletem osiowym; składa się z 2 kości miednicznych
rdzeń kręgowy – część centralnego układu nerwowego położona w kanale kręgowym; odpowiada za przekazywanie informacji do mózgu i z mózgu oraz kontrolę czynności wykonywanych odruchowo
szkielet – twarda struktura zbudowana z substancji organicznych i nieorganicznych, stanowiąca rusztowanie ciała i podporę dla mięśni
szkielet osiowy – część szkieletu tworząca oś ciała, zbudowana z czaszki, kręgosłupa, żeber i mostka