Anatomy Overview and Body Systems

Definition: Study of the structure of the body and its parts.
Types:
- Gross Anatomy: Study of structures visible to the naked eye.
- Microscopic Anatomy: Study of structures at the cellular and tissue levels.
Levels of Organization:
- Chemical Level: Atoms and molecules.
- Cellular Level: Cells, the basic unit of life.
- Tissue Level: Groups of similar cells performing a common function.
- Organ Level: Two or more types of tissues working together.
- Organ System Level: Groups of organs that function together.
- Organism Level: The complete living entity.

Skeletal System: Provides structure, support, and protection; facilitates movement.
Muscular System: Enables movement, maintains posture, and produces heat.
Nervous System: Controls body functions through electrical signals; includes brain, spinal cord, and nerves.
Endocrine System: Regulates bodily functions through hormones; includes glands like thyroid and adrenal.
Cardiovascular System: Transports blood, nutrients, gases, and waste; includes heart and blood vessels.
Respiratory System: Facilitates breathing and gas exchange; includes lungs and airways.
Digestive System: Breaks down food for nutrient absorption; includes stomach and intestines.
Urinary System: Eliminates waste and regulates fluid balance; includes kidneys and bladder.
Reproductive System: Facilitates reproduction; includes organs like ovaries and testes.
Lymphatic System: Supports immune function and fluid homeostasis; includes lymph nodes and vessels.

Definition: Study of the functions of body parts and systems.
Homeostasis: The body's ability to maintain a stable internal environment despite external changes.
Feedback Mechanisms:
- Negative Feedback: Reduces the output or activity to maintain balance (e.g., temperature regulation).
- Positive Feedback: Amplifies responses or processes until a specific outcome is achieved (e.g., childbirth).

Cell Membrane: Semi-permeable barrier; regulates what enters and exits the cell.
Organelles:
- Nucleus: Contains genetic material and controls cell activities.
- Mitochondria: Powerhouse of the cell; site of ATP production.
- Ribosomes: Sites of protein synthesis.
- Endoplasmic Reticulum: Synthesizes proteins (rough ER) and lipids (smooth ER).
- Golgi Apparatus: Modifies, sorts, and packages proteins and lipids for secretion or use.

Epithelial Tissue: Covers surfaces, lines cavities, and forms glands; functions in protection, absorption, and secretion.
Connective Tissue: Supports, binds, and protects other tissues; includes bone, blood, and adipose tissue.
Muscle Tissue:
- Skeletal Muscle: Voluntary movement.
- Cardiac Muscle: Involuntary, found in the heart.
- Smooth Muscle: Involuntary, found in walls of hollow organs.
Nervous Tissue: Transmits impulses; comprises neurons and glial cells.

Anatomical Position: Standard body position used as a reference; body standing upright, facing forward, arms at sides, palms facing forward.
Directional Terms:
- Superior/Inferior: Above/below.
- Anterior/Posterior: Front/back.
- Medial/Lateral: Closer to the midline/farther from the midline.
- Proximal/Distal: Closer to/farther from the trunk.

Understanding the structure and function of the body is essential for diagnosing and treating medical conditions, as well as for fields like healthcare, sports science, and biology.

Study of the body's structure and its components.
Types of Anatomy:
- Gross Anatomy: Involves the examination of structures visible to the naked eye.
- Microscopic Anatomy: Focuses on cellular and tissue-level structures.
Levels of Organization:
- Chemical Level: Consists of atoms and molecules.
- Cellular Level: Basic unit of life, comprised of various types of cells.
- Tissue Level: Collection of similar cells that perform a common function.
- Organ Level: Combination of two or more tissue types.
- Organ System Level: Groups of organs working synergistically.
- Organism Level: Represents the complete living entity.

Skeletal System: Provides framework, support, protection, and aids in movement.
Muscular System: Responsible for movement, posture maintenance, and heat production.
Nervous System: Governs body functions through electrical impulses; includes brain, spinal cord, and nerves.
Endocrine System: Manages bodily functions via hormones; includes glands like thyroid and adrenal.
Cardiovascular System: Ensures transportation of blood, nutrients, gases, and waste; comprises heart and blood vessels.
Respiratory System: Facilitates gas exchange and breathing; entails lungs and airways.
Digestive System: Responsible for food breakdown and nutrient absorption; includes stomach and intestines.
Urinary System: Excretes waste and regulates fluid balance; includes kidneys and bladder.
Reproductive System: Essential for reproduction; includes organs such as ovaries and testes.
Lymphatic System: Aids immune response and fluid balance; encompasses lymph nodes and vessels.

Study of the functions of body parts and systems.
Homeostasis: Maintenance of a stable internal environment regardless of external changes.
Feedback Mechanisms:
- Negative Feedback: Inhibits output to maintain equilibrium, such as in temperature regulation.
- Positive Feedback: Enhances responses until a desired outcome occurs, exemplified by childbirth.

Cell Membrane: Acts as a semi-permeable barrier, controlling entry and exit of substances.
Organelles:
- Nucleus: Houses genetic material, orchestrating cell activities.
- Mitochondria: Main site for ATP generation, often referred to as the cell's powerhouse.
- Ribosomes: Key sites for protein synthesis.
- Endoplasmic Reticulum:
  - Rough ER: Synthesizes proteins.
  - Smooth ER: Synthesizes lipids.
- Golgi Apparatus: Modifies, sorts, and packages biomolecules for distribution.

Epithelial Tissue: Covers surfaces, lines cavities, and forms various glands; functions in protection, absorption, and secretion.
Connective Tissue: Provides structure, support, and protection; examples include bone, blood, and adipose tissue.
Muscle Tissue:
- Skeletal Muscle: Involved in voluntary movements.
- Cardiac Muscle: Involuntary tissue found in the heart.
- Smooth Muscle: Involuntary tissue located in hollow organ walls.
Nervous Tissue: Responsible for impulse transmission, made up of neurons and glial cells.

Anatomical Position: A standardized reference position; the body stands upright, facing forward, arms at sides with palms up.
Directional Terms:
- Superior/Inferior: Indicates vertical positioning (above/below).
- Anterior/Posterior: Refers to the front and back of the body.
- Medial/Lateral: Indicates closeness to the midline or distance from it.
- Proximal/Distal: Relates to positioning closer to or farther from the trunk.

Knowledge of body structure and function is crucial for diagnosing and treating medical conditions, and is foundational in healthcare, sports science, and biology.