Human Body Systems: Structure and Function

Understanding Human Body Systems

The Locomotor System

The locomotor system allows humans and animals to move and interact with their environment. It consists of the bony system and the muscular system.

The Skeletal System

Components and Functions

The skeletal system includes the human skeleton and its components:

• Bones: Provide internal support. Muscles are attached to bones via tendons.
• Articular Cartilage: Cartilage linking different pieces of bone.

Joints

Structure and Movement

Joints are the junction of skeletal bones and allow a wide range of body movements.

Joint Conditions

Common conditions affecting joints include:

• Dislocation: When a bone is out of the joint.
• Sprain: Injury to the ligaments when joints are stressed.
• Arthritis: An inflammation of the joints.
• Osteoarthritis (OA): A degenerative joint disease characterized by wear and tear, later producing mild inflammatory episodes.

The Immune System

The immune system consists of a set of cells and organs that protect the body against infection.

The Nervous System

Structure and Function

The nervous system allows the relationship between our body and the outside environment. It includes the central nervous system and the peripheral nervous system.

The Brain

The brain is the control center of the body, protected by the bones of the skull.

Key Regions and Roles

Key parts include the cerebrum (often referred to as the brain itself), cerebellum, and medulla oblongata.

The cerebrum governs intelligence, regulates sensation and movements, and controls the operations of organs.

Brain Hemispheres

The right hemisphere controls the left half of the body.

The left hemisphere controls the right half of the body.

Cerebellum

The cerebellum is located at the back and bottom of the skull. Its function is responsible for maintaining balance and muscle coordination.

Medulla Oblongata

The medulla oblongata is the continuation of the spinal cord, becoming thicker as it enters the skull.

The Spinal Cord

The spinal cord is a white nerve cord enclosed within the cylindrical backbone. Its most important function is to transmit nerve signals, forming the nerve current.

Nervous System Conditions

Meningitis: A disease affecting the nervous system, producing inflammation of the meninges that protect the brain and spinal cord.

Sensory Systems

The Sense of Touch

The sense of touch helps us determine whether something is smooth or rough. It provides much feeling and allows us to relate to our environment.

The Eye

Anatomy of the Eye

Key parts of the eye include:

• Lens: Formed by elongated cells, it serves to focus the image entering through the pupil.
• Iris: The circular colored area of the eye. It has small muscles that regulate the diameter of the pupil.
• Pupil: The opening in the center of the iris that allows light to enter.
• Retina: A membrane lining the eyeball containing cells sensitive to light.
• Sclera: The tough, thick white outer layer of the eyeball.
• Choroid: Contains abundant blood vessels.

Common Eye Conditions

Common eye conditions include:

• Myopia
• Hyperopia
• Astigmatism
• Presbyopia
• Cataract
• Strabismus
• Glaucoma
• Blindness

Other Conditions Mentioned

Herpes: Can be latent in the root zone of the medulla, potentially reactivating in states of stress or immune system deficiency.

Flu Symptoms: High fever, headache, painful eyes (especially behind them), mucosal redness and tearing, nasal catarrh with shortness of breath, loss of appetite, nausea, and sometimes vomiting.