Introduction to the Human Body

Study Notes

The human body is studied to understand how it functions, reacts to injury/illness, and responds to stress.
Knowledge of structure and function is crucial for healthcare professionals.
Understanding how parts work together is vital.

Anatomy is the study of structure and relationships among structures.
Dissection is the careful cutting apart of body structures.
Imaging techniques (e.g., microscopic and macroscopic images) contribute to anatomical knowledge.
Anatomy has different levels, ranging from microscopic to macroscopic structures.

The body has six levels of organization: chemical, cellular, tissue, organ, system, and organismal.
Chemical level: Atoms (smallest unit) and molecules (combinations of atoms)
Cellular level: Molecules combine to form cells, fundamental units of life.
Tissue level: Tissues are groups of cells working together. There are four basic types in the body: epithelial, connective, muscular, and nervous tissue.
Organ level: Tissues work together to form organs, with distinct structures and functions (e.g., stomach, heart, liver).
System level: Related organs work together to perform a shared function (e.g., digestive system, cardiovascular system).
Organismal level: All parts of the body working together to create an organism.

The human body has eleven systems, each with specialized organs and functions.
Examples of systems include: integumentary, skeletal, muscular, nervous, cardiovascular, endocrine, lymphatic, respiratory, digestive, urinary, and reproductive.

Anatomical position: The standard position for describing structures (e.g., standing erect, palms forward).
Directional terms: Words that precisely locate one body part relative to another (e.g., superior/inferior, anterior/posterior, medial/lateral).
Anatomical planes: Imaginary flat surfaces dividing the body (e.g., sagittal, frontal, transverse).
Anatomical sections: Cuts of the body along a plane (e.g., midsagittal section, transverse section).

Body cavities are spaces within the body that house internal organs, providing protection and allowing freedom of movement.
Thoracic cavity: Houses organs like the heart and lungs.
Abdominal cavity: Houses organs like the stomach and intestines.
Pelvic cavity: Houses organs like the bladder and reproductive organs.
The thoracic and abdominal cavities are also referred to as the "abdominopelvic cavity".
The diaphragm separates the thoracic cavity from the abdominopelvic cavity.

Disease, disorder or abnormality: any condition in which body structures and/or functions are altered characteristic ways.
Symptoms and Signs: Symptoms refer to subjective changes in body functions while signs describe objective changes observable and measurable.
Diagnosing a disorder includes medical history, clinical observation and potentially diagnostic testing.