🥇 SISTEMA ÓSEO. -Esquelético-. Tipos de Huesos, clasificacion, función.

General Overview of the Skeletal System

Introduction to the Skeletal System

• The skeletal system, also known as the bone system, provides structure to the human body and supports other bodily structures.

• It is essential for maintaining the body's shape and serves as a framework for organs and muscles.

Components of the Skeletal System

• The skeletal system consists of two main types of tissues: osseous (bone) tissue and cartilaginous tissue, which work closely together.

• It is interconnected with both muscular and articular systems, forming a comprehensive locomotor apparatus responsible for movement.

Functions of the Skeletal System

• Support: Provides structural support for the body, allowing it to maintain its shape. This function is fundamental to human morphology.

• Protection: Vital organs are safeguarded by bones; for instance, the skull protects the brain while ribs shield heart and lungs.

• Mineral Reservoir: Bones store essential minerals like calcium and phosphates, playing a crucial role in metabolic functions.

• Hematopoiesis: Bone marrow within long bones produces blood cells (red blood cells, white blood cells, platelets), an often overlooked function outside health fields.

• Mechanical Base: Serves as an anchor point for muscle attachment facilitating movement through joints between bones.

Division of the Skeleton

• The skeleton is divided into two primary groups:

• Axial Skeleton: Comprises bones along the central axis including those in the head, vertebral column, and thoracic region—excluding limbs.

Understanding the Axial and Appendicular Skeleton

Connection Between Axial and Appendicular Skeleton

• The skeleton is divided into axial and appendicular components, with anatomical junctions known as "cinturas" (girdles) connecting them.

• The scapular girdle (also called thoracic girdle) connects the upper limb to the axial skeleton via two bones: the scapula (shoulder blade) and clavicle.

• The lower limbs connect to the axial skeleton through coxal bones (iliac bones or pelvic bones), articulating directly with the vertebral column at the sacrum.

Classic Parts of a Bone

Structure of Long Bones

• Bones exhibit various shapes; however, most share common parts, particularly long bones which are typically described in anatomy.

• A long bone consists of a central region called diaphysis, flanked by two ends known as epiphyses. The area connecting these is termed metaphysis, which contains growth cartilage crucial for lengthening during development.

Growth and Development

• The growth plate located in the metaphysis is hormonally stimulated for bone elongation; once adulthood is reached, this cartilage ossifies, ceasing further growth despite hormonal influence.

Bone Composition

Layers of Bone Structure

• Externally, bones are covered by a dense layer called periosteum, while internally they have a lining known as endosteum surrounding the medullary cavity filled with bone marrow. This cavity can contain red marrow (for blood component formation) or yellow marrow (rich in fat).

• Bones consist of two main portions:

• Compact bone, characterized by its hard structure.

• Spongy bone, which has a porous appearance resembling a sponge.

Types of Bones

Classification Overview

• There are different types of bones based on their dimensions:

• Long bones: Predominantly longer than wide; examples include femur and tibia but also smaller ones like phalanges that fit this definition due to their proportions.

Overview of Bone Types

Classification of Bones

• The carpal bones include the scaphoid, lunate, triangular (pyramidal), pisiform, and tarsal bones such as calcaneus, talus, cuboid, and cuneiform. These are categorized as short bones with similar length and width.

• Flat bones are defined by their structure of two thin layers of bone with reduced thickness. Common examples include cranial bones, sternum, ribs, and scapula.

• Irregular bones do not fit into the previous categories; they possess unique shapes that cannot be classified as long, short, or flat. Examples include vertebrae and certain cranial bones like the ethmoid and sphenoid.

Pneumatic Bones

• Some irregular bones can be further classified as pneumatic bones which contain air-filled cavities. Notable examples are the sphenoid and ethmoid bones that have a mixed composition.

Sesamoid Bones