Understanding Human Body Systems: Circulatory, Nervous, Locomotor, and Digestive

The Circulatory System

The circulatory system is the anatomical structure that includes both the cardiovascular system (which carries and circulates blood) and the lymphatic system (which carries lymph).

Its main function is to transport nutrients, gases, hormones, and blood cells to the body's cells. It also helps fight disease, stabilize body temperature and pH, and maintain homeostasis.

Basic Structures of the Circulatory System

• Arteries
• Veins
• Blood
• Heart
• Capillaries

The Nervous System

The nervous system is a network of ectodermal tissues found in animals. Its basic unit is the neuron. Its main function is to quickly capture and process signals, exerting control and coordination over other body systems to achieve timely and effective interaction with the changing environment.

Basic Structures of the Nervous System

Histological Structures

• Neuron
• Neuroglia

Reflex Function

• Afferent system
• Partnership scheme
• Efferent system

Anatomical Structures

• Central Nervous System (CNS)
• Peripheral Nervous System (PNS)

By Function

• Autonomous Nervous System
• Somatic Nervous System

The Locomotor System

The locomotor system consists of the osteoarticular system (bones, joints, and ligaments) and the muscular system (muscles and tendons that attach to bones). It allows humans and animals to interact with their environment through movement and provides support and protection to other organs.

It is based on three elements:

• Bones
• Joints
• Muscles

The musculoskeletal system is not independent; it is integrated with various systems, such as the nervous system, for the generation and modulation of motor commands. This system consists of the structures that support and facilitate body movements and comprises two systems:

• Skeletal System: The passive component, formed by bones, cartilage, and ligaments.
• Muscular System: Formed by the muscles which attach to the bone and therefore the contract cause movement of the body.

In addition to these, the nervous system is crucial, as it is responsible for the coordination and stimulation of muscles to produce movement.

The Digestive System

The digestive system is the set of organs (mouth, pharynx, esophagus, stomach, small intestine, and large intestine) responsible for the process of digestion, i.e., the transformation of food into substances that can be absorbed and utilized by the body's cells.

The functions performed include transport (of food), secretion (of digestive juices), absorption (of nutrients), and excretion (through defecation).

The process of digestion is the same in all monogastric animals: transforming carbohydrates, lipids, and proteins into simpler units, thanks to digestive enzymes, so they can be absorbed and transported by the blood.