Monocytes and Immune System Functions

Monocytes are a type of white blood cell (WBC) that differentiate into macrophages.
Macrophages play a vital role in removing dead cells and damaged tissues.
They combat infections by engulfing (phagocytizing) and destroying pathogens and foreign particles.

This blood test measures the varieties of WBCs present in a blood sample.
Essential for diagnosing and monitoring medical conditions such as infections, inflammatory responses, and leukemias.

Calcium is critical for blood coagulation processes.
It is essential in activating multiple clotting factors, notably factor IX and factor X, contributing to the clotting cascade.

Neutrophils, another type of WBC, are primary responders to bacterial infections.
They engulf and destroy bacteria through a process called phagocytosis.
Neutrophils release chemicals that recruit additional immune cells to infection sites, amplifying the immune response.

Study of the structure and organization of the human body
Organized into levels, starting from cells to systems
Cells: The fundamental unit of life
Tissues: Groups of similar cells that perform specific functions like:
- Epithelial: Covers surfaces
- Connective: Supports and binds other tissues
- Muscle: Responsible for movement
- Nervous: Transmits impulses for communication
Organs: Composed of two or more tissue types, such as the heart and lungs
Systems: Collections of organs working together, including:
- Circulatory System: Transports blood, nutrients, and waste; includes the heart and blood vessels
- Respiratory System: Facilitates breathing and gas exchange; includes the lungs and trachea
- Digestive System: Breaks down food and absorbs nutrients; includes the stomach and intestines
- Nervous System: Controls body functions through electrical signals; encompasses the brain and spinal cord
- Musculoskeletal System: Provides structure and movement; consists of muscles and bones

Framework of bones and cartilage that supports and protects the body
Functions:
- Support: Provides stability and shape to the body
- Protection: Safeguards vital organs, for example, the skull protects the brain
- Movement: Facilitates joint movement with muscle attachment
- Mineral Storage: Reservoir for minerals like calcium and phosphorus
- Blood Cell Production: Occurs in the bone marrow through hematopoiesis
Components:
- Bones: Adult human body contains 206 bones, divided into two categories:
  - Axial Skeleton: Comprises the skull, vertebral column, and rib cage
  - Appendicular Skeleton: Contains limbs and the pelvic girdle
- Cartilage: Flexible tissue present in joints, ears, and nose
- Ligaments: Connective tissue linking bones to other bones
Types of Bones:
- Long Bones: Longer than they are wide (e.g., femur, humerus)
- Short Bones: Cube-shaped (e.g., carpals, tarsals)
- Flat Bones: Thin and flat structures (e.g., skull, sternum)
- Irregular Bones: Complex shapes (e.g., vertebrae)
Joints:
- Locations where two or more bones meet
- Types:
  - Synovial Joints: Freely movable, allow extensive movement (e.g., knees, elbows)
  - Cartilaginous Joints: Allow limited movement (e.g., intervertebral discs)
  - Fibrous Joints: Do not allow movement (e.g., sutures in the skull)