Human Anatomy Skeletal System Flashcards

Functions of the Skeletal System

• Provides structural support to the body.
• Protects vital soft organs from injury.
• Facilitates movement through attachment to skeletal muscles.
• Produces blood cells within bone marrow.

Number of Bones

• An adult human body contains 206 bones.

Osseous Tissue Types

• Osseous tissue consists of two types: compact and spongy.

Compact vs. Spongy Bone

• Compact bone is dense, smooth, and homogeneous.
• Spongy bone has a porous structure with needle-like pieces.

Bone Classifications

• Bones can be classified into four categories: long, short, flat, and irregular.

Bone Markings Functions

• Serve as pathways for blood vessels and nerves.
• Provide attachment points for ligaments and muscles.
• Help in the formation of joints.

Skeleton Parts

• Skeleton is divided into two main parts: axial and appendicular.

Axial Skeleton

• Comprises the body's longitudinal structure.

Components of Axial Skeleton

• Axial skeleton consists of three parts: skull, vertebral column, and bony thorax.

Appendicular Skeleton

• Includes the limbs (arms and legs) and structures that support them.

Components of Appendicular Skeleton

• Divided into pectoral girdle, pelvic girdle, and limbs.

Pectoral Girdle

• Consists of two bones: clavicle (collarbone) and scapula (shoulder blade).

Pelvic Girdle

• Made up of the hip bones: ilium, ischium, and pubic bone.
• Major functions include bearing the upper body's weight and protecting reproductive organs.

Upper Limbs

• The humerus is the single bone in the upper arm.

Forearm Bones

• Radius is located on the thumb side of the forearm.
• Ulna lies on the pinky side of the forearm.

Wrist and Hand Structures

• The wrist consists of 8 carpal bones.
• The palm includes 5 metacarpal bones.
• The fingers are made up of 14 phalanges.

Ankle and Foot Structures

• The ankle comprises 7 tarsal bones, including the calcaneus (heel bone) and talus.
• The foot consists of tarsals, metatarsals, and phalanges.

Ligaments and Tendons

• Ligaments bind bones together.
• Tendons connect muscles to bones.

Vertebral Column Functions

• Supports the head and trunk.
• Protects the spinal cord.

Intervertebral Discs

• Cushioned fibrocartilage structures between vertebrae.

Cervical Vertebrae

• The first 7 vertebrae form the neck and support the head.
• C1 is called the atlas; C2 is called the axis.

Thoracic and Lumbar Vertebrae

• Thoracic vertebrae consist of 12 vertebrae supporting the ribcage.
• Lumbar vertebrae include 5 vertebrae that support the body's lower back.

Sacrum and Coccyx

• Sacrum consists of 5 fused vertebrae at the base of the vertebral column.
• Coccyx, also known as the tailbone, is made up of 4 fused vertebrae.

Vertebral Anatomy

• Spinous processes project from the vertebrae's middle.
• Transverse processes are located on either side of the vertebra.
• The vertebral foramen is the opening where the spinal cord travels.

Bony Thorax Composition

• Protects major internal organs.
• Made up of three bones: sternum, ribs, and thoracic vertebrae.

Rib Classifications

• True ribs (1-7) directly connect to the sternum.
• False ribs (8-12) do not connect to the sternum.
• Floating ribs (last 2) do not connect to the vertebrae.

Skull Composition

• Comprised of two types of bones: cranium and facial bones.
• There are 8 cranial bones and 14 facial bones.

Sutures

• Immovable joints that connect skull bones.

Mandible

• The only bone in the skull connected by a freely movable joint.

Paranasal Sinuses Functions

• Lighten the skull's weight.
• Enhance vocal resonance and amplification.