Anatomical Terminology and Body Organization

Body Cavities and Membranes

• Parietal Pleura: The parietal pleura is the serous membrane lining the thoracic cavity, providing a protective layer around the lungs.

• Serous Membrane: An epithelial membrane that lines closed ventral body cavities, such as the thoracic and abdominal cavities.

• Mucous Membrane: An epithelial membrane that lines open body cavities exposed to the exterior, such as the digestive and respiratory tracts.

• Cutaneous Membrane: The skin; consists of keratinized stratified squamous epithelium, providing a tough, protective outer layer.

Body Quadrants and Divisions

• Left Upper Quadrant: The stomach is located in the left upper quadrant of the abdomen.

• Appendicular Division: If someone breaks their leg, they have damaged the appendicular division of the body, which includes limbs and girdles.

Body Planes

• Frontal (Coronal) Plane: Separates the body into anterior (front) and posterior (back) sections.

Cell Structure and Function

Basic Cell Concepts

• Cells: Considered the smallest units of life because they carry out all vital functions, including metabolism, growth, and reproduction.

• Plasma Membrane: The phospholipid bilayer surrounding the cell, controlling the movement of substances in and out.

• Main Component of Cytosol: Water is the primary component, providing a medium for cellular processes.

Cellular Connections

• Desmosomes: Specialized cell junctions that provide strong adhesion between cells, especially in tissues subject to mechanical stress, such as the lining of the intestines.

Cell Organelles and Functions

• Ribosomes: Organelles that facilitate peptide bond formation between amino acids during protein synthesis.

• Smooth Endoplasmic Reticulum (Smooth ER): Synthesizes steroid-based hormones and lipids; also involved in detoxification.

• Nucleus: Houses the vast majority of the cell's genetic material (DNA).

Genetic Material and Protein Synthesis

• Gene: A segment of DNA that carries instructions for making one polypeptide chain.

• mRNA (Messenger RNA): The type of RNA that serves as the template for protein synthesis.

Cell Cycle and Mitosis

• Phases of Mitosis: The order of phases is: Prophase, Metaphase, Anaphase, Telophase.

• Drug Arresting Mitosis: Colchicine is a drug that arrests mitosis by stopping spindle microtubule formation.

Tissues and Membranes

Epithelial Tissue

• Simple Squamous Epithelium: Found in air sacs (alveoli) of the lungs; allows for rapid diffusion of gases.

• Stratum Corneum: The outermost, protective, non-viable layer of the epidermis, composed of dead keratinized cells.

• Stratum Basale: The deepest layer of the epidermis; contains mitotically active, viable cells responsible for regeneration.

Connective Tissue

• Collagen Fibers: Provide great tensile strength to connective tissues.

• Fibroblasts: The primary blast cells for connective tissue proper; responsible for producing fibers and ground substance.

Glands

• Endocrine Glands: Secrete their products (hormones) directly into the blood, rather than through ducts.

• Apocrine Glands: Found in the anogenital and axillary (armpit) regions; secrete a thicker, milky sweat.

• Sebaceous Glands: Release sebum (oil) to lubricate skin and hair; the arrector pili muscle assists in releasing sebum.

Integumentary System

Layers of the Dermis

• Reticular Layer: Makes up about 80% of the dermis; composed of dense irregular connective tissue, providing strength and elasticity.

Hair Types

• Vellus Hair: Fine, soft "peach fuzz" hair covering most of the body.

Skin Color and Associated Diseases

• Bronze Appearance: Associated with diseases such as Addison's disease, which affects adrenal gland function.

• Melanocytes: All humans, regardless of race, have the same number of melanocytes; differences in skin color are due to the activity and type of melanin produced.

Burns

• Third-Degree Burns: The first threat to life is catastrophic fluid loss, which can lead to shock and organ failure.

Skin Cancer

• Melanoma: Although rare, melanoma must be removed quickly if found due to its aggressive nature.

Hair Loss

• Alopecia: True; alopecia is caused by hair not being replaced as often, leading to thinning or baldness.

Body Systems Overview

• Muscular System: Responsible for movement by contracting muscles attached to bones.

• Nervous System: Responds to environmental changes by transmitting electrical signals throughout the body.

Summary Table: Key Tissue Types and Functions

Key Definitions and Concepts

• Gene: Segment of DNA carrying instructions for one polypeptide chain.

• mRNA: Messenger RNA; template for protein synthesis.

• Desmosomes: Cell junctions providing mechanical strength.

• Colchicine: Drug that arrests mitosis by inhibiting spindle formation.

Important Equations and Processes

• Peptide Bond Formation: Ribosomes catalyze the reaction:

• Phases of Mitosis (in order):

Additional info: Addison's disease is a classic example of a disorder causing bronze skin pigmentation due to increased ACTH stimulating melanocytes.