Skeletal System Flashcards
What is the Skeletal System?
Supports and protects the body, provides a framework for movement, stores minerals, and manufactures blood.
What is the Role of the Skeletal System?
The skeletal system provides support for the entire body, enables movement, protects vital organs and plays an important role in blood cell production, endocrine regulation and calcium storage.
What are the 6 main functions of the skeleton?
- Support
- Attachment
- Movement
- Protection
- Blood cell production
- Storage
Support (function of the skeleton):
The skeleton provides a framework that supports the body, allowing humans to maintain their shape.
Attachment (function of the skeleton):
The bones of the skeleton provide an attachment surface for muscles, tendons and ligaments.
Movement (function of the skeleton):
Muscles attach to the bones via. tendon. This tendon is attached to a joint to provide movement when the muscle is contracted.
Protection (function of the skeleton):
The skeleton protects many vital organs.
Blood Cell Production (function of the skeleton):
The skeleton is the site of haematopoiesis, the generation of blood cells, which happens in the red bone marrow.
Storage (function of the skeleton):
Bone serves as a mineral storage deposit in which nutrients can be stored and retrieved. The most notable is calcium.
What are the 5 types of bones?
- Long bone
- Short bone
- Flat bone
- Sesamoid bone
- Irregular
What is a long bone?
Long bones are longer than they are wide. They are comprised mostly of compact bone but are generally thick enough to contain considerable spongy bone and marrow in the hollow centre. Most bones of the limbs are long bones. The classification refers to the shape rather than the size.
Examples of long bones:
Femur, tibia, ulna, radius, phalanges, humerus, fibula
What is a short bone?
Short bones are roughly cube-shaped and have only a thin layer of compact bone surrounding a spongy interior. They’re approximately as wide as they are long.
Examples of short bones:
Trapezoid, carpus, tarsals, scaphoid bone
What is a flat bone?
Flat bones are strong, bones that enable muscular attachment and protection of vital organs.
Examples of flat bones:
Occipital, nasal, hip bone, sternum, ribs
What is an irregular bone?
Irregular bones do not fit into the above categories. They consist of thin layers of compact bone surrounding a spongy interior. As implied by the name, their shapes are irregular and complicated.
Examples of irregular bones:
Vertebrae (sacrum, coccyx, mandible)
What is a sesamoid bone?
Sesamoid bones are usually small, irregular-shaped bones that are embedded in tendons. The patella is an example of a sesamoid bone that sits within the quadriceps tendon.
Examples of sesamoid bones:
Patella
How many bones are in the human skeleton?
206
What are joints?
Joints are where 2 or more bones meet. It is also known as an articulation. Joints can allow movement, but they can provide stability.
What are the 3 types of joints?
- Fibrous
- Cartilaginous
- Synovial
How many types of joints are there?
3
What are fibrous or immovable joints?
Bones are connected by fibrous tissue and don’t allow movement, such as the joints found between the bones of the skull. These provide protection for the brain.
What are cartilaginous or slightly moveable joints?
Bones are connected by cartilage and allow a little bit of movement, such as in the vertebral column. The vertebral column consists of many bones positioned one on top of the other, with a pad of cartilage, known as a disc, between the bones. The vertebral column is S-shaped. Movement is possible because the discs can compress slightly, allowing one bone to move in relation to the other. The actual movement that takes place at each joint is minimal, but the combined movement allows considerable flexibility of the spine.
Examples of fibrous joints:
- Cranial sutures between bones of the skull.
- Gomphoses between teeth and alveolar bone.
- Syndesmoses between the radius and ulna, and between the tibia and fibula.
What are synovial or freely moveable joints?
These are the most common types of joints in the human body and allow for maximum movement.
What are some common features of synovial or freely moveable joints?
- Synovial membrane that lines the outside of the joint and encloses the synovial fluid.
- Synovial fluid, which is found in the joint capsule, absorbs shock and reduces friction
- Cartilage, which is a hard, rubbery substance that prevents the bones from rubbing together
- Ligaments, which are fibrous straps that attach bones to bones at joints. Their function is to hold bones together and prevent dislocation
What are some types of synovial joints?
Ball and socket, hinge, pivot, saddle, gliding and condyloid.
What are some characteristics and functions of the synovial membrane?
The lining around the outside. It encloses the synovial fluid.
What are some characteristics and functions of synovial fluid?
Fluid in the joint capsule. Its function is to absorb shock and reduce friction.
What are some characteristics and functions of tendons?
Straps that surround a joint. They attach muscles to bones.
What are some characteristics and functions of ligaments?
Straps that surround a joint. They hold bone to bone, prevent dislocation and add stability to the joint.
What are some characteristics and functions of cartilage?
A slightly hard, rubbery substance that prevents the bones from rubbing together.
What are some characteristics and functions of the bursa?
A fluid-filled sac that functions as a gliding surface to reduce friction between tissues of the body.
What movements are possible with the ball-and-socket joint?
Backward, forward, sideways, rotating.
Examples of ball-and-socket joints:
Shoulder, hip.
What movements are possible with hinge joints?
Bending & straightening, flexion, extension.
Examples of hinge joints:
Fingers & toes, knees, elbows.
What movements are possible with condyloid joints?
Flexion, extension, adduction, abduction, circumduction.
Examples of condyloid joints:
Wrist.
What movements are possible with pivot joints?
Rotation.
Examples of pivot joints:
Neck, forearm (radius & ulna).
What movements are possible with gliding joints?
Slight sliding movements.
Examples of gliding joints:
Bones of the wrist, vertebrae.
What movements are possible with saddle joints?
Flexion, extension, adduction, abduction, circumduction.
Examples of saddle joints:
Thumb.
