A&P EXAM 1 (ch1,3)

Chapter One: Introduction to Anatomy

Definition of Anatomy and Physiology

• Anatomy: The study of structures of living organisms, for example, the anatomy of the heart includes its four chambers (two upper chambers and two lower chambers) and the four valves.

• Physiology: The study of the functions of body parts. For instance, physiology investigates how organs like the kidneys, heart, and liver operate.

• Pathology: Focuses on the study of diseases.

Levels of Organization

• Chemical Level: The simplest level composed of atoms and molecules. Both living and non-living entities consist of these.

• Cellular Level: Cells are the smallest units of living organisms; all living organisms are made of cells.

• Tissue Level: Groups of similar cells working together. Different types include epithelial tissue, connective tissue, and nervous tissue.

• Organ Level: Comprised of different types of tissues working together (e.g., the brain, heart, liver).

• Organ System Level: Composed of groups of organs that work together to perform complex functions, such as the cardiovascular, nervous, respiratory, and digestive systems.

Anatomical Position and Directional Terms

• Standard Anatomical Position: The model stands erect, facing forward, with arms at the sides and palms facing forward. Definitions of directional terms:

  • Superior: Toward the head.

  • Inferior: Toward the feet.

  • Anterior (Ventral): Toward the front.

  • Posterior (Dorsal): Toward the back.

  • Medial: Closer to the midline of the body.

  • Lateral: Farther from the midline.

  • Superficial: Closer to the body surface.

  • Deep: Farther from the body surface.

  • For limbs:

    • Proximal: Closer to the trunk.

    • Distal: Farther from the trunk.

Body Planes and Cavities

• Body Planes:

  • Frontal (Coronal) Plane: Divides the body into anterior and posterior parts.

  • Sagittal Plane: Divides the body into right and left parts; midsagittal plane divides it into equal halves.

  • Transverse (Horizontal) Plane: Divides the body into superior and inferior parts.

• Body Cavities:

  • Dorsal Cavities: Include cranial (housing the brain) and spinal (housing the spinal cord).

  • Ventral Cavities: Include thoracic cavity (with pleural cavities for lungs and mediastinum for heart and esophagus) and abdominopelvic cavity.

Chapter Three: Cells

Definition and Components of Cells

• Definition: Cells are the smallest units of living organisms.

• Eukaryotic Cells: Comprised of three main parts:

  • Plasma Membrane: Separates inside of the cell from the external environment.

  • Cytoplasm: Contains the organelles and cytosol (liquid part of cytoplasm).

  • Nucleus: Contains DNA and nucleolus.

Organelles and Their Functions

• Ribosomes: Site of protein synthesis; can float freely or be attached to rough endoplasmic reticulum (rER).

• Endoplasmic Reticulum (ER):

  • Rough ER: Has ribosomes; transports proteins.

  • Smooth ER: No ribosomes; involved in lipid metabolism and membrane synthesis.

• Golgi Apparatus: Modifies, packages, and ships proteins and materials both within and outside the cell.

• Mitochondria: Powerhouse of the cell; generates ATP for energy.

• Lysosomes: Contain digestive enzymes to break down waste and foreign substances.

Movement across Cell Membranes

• Passive Transport: Movement of substances from higher to lower concentration without energy, e.g., diffusion (general movement), osmosis (water only), and dialysis (solutes).

• Filtration: Movement caused by hydrostatic pressure, as seen in kidney function.

Cell Life Cycle and Mitosis

• Mitosis: Process of cell division which includes the following stages:

  • Prophase: Chromatin condenses into visible chromosomes.

  • Metaphase: Chromosomes align at the cell's equator.

  • Anaphase: Sister chromatids are pulled apart due to centromere division.

  • Telophase: Formation of two new nuclear envelopes around divided chromosomes.

  • Cytokinesis: Division of the cytoplasm leading to two distinct daughter cells.

Abnormalities in Cell Function

• Atrophy: Decrease in cell size due to lack of use or stress.

• Hypertrophy: Increase in cell size due to overuse (e.g., working out).

• Hyperplasia: Increase in the number of cells (e.g., benign prostate hyperplasia).

• Anaplasia: Failure of cell maturation, often associated with cancer risk.

The material covered for the first exam spans a foundational understanding of anatomy and physiology, levels of organization in the human body, anatomical terminology, cellular structures, and functions, as well as the mechanisms governing cellular division and abnormal cell growth. Good luck on your exam!