Skin Anatomy Quiz

Introduction to Anatomy and Physiology

• Human anatomy is the study of the shape and structure of the body and its parts.
• Gross anatomy examines large-scale structures visible to the naked eye.
• Microscopic anatomy studies structures using a microscope.
• Electron microscopy provides detailed views of minute cellular components.
• Human physiology is the study of the functions of the body and its parts.
• Cellular physiology focuses on the activities of individual cells.
• Cytology examines the structure and function of cells.
• Histology explores the structure and function of tissues.
• Pathology investigates abnormal or diseased states.
• Embryology studies the development of a fertilized egg into a mature organism.

Body Fluids

• Body fluids are found inside (intracellular) and outside (extracellular) cells.
• Extracellular fluids are subdivided into vascular (plasma) and interstitial components.
• In adults, plasma comprises approximately 5% of body weight, interstitial fluid 15%, and intracellular fluid 45%.
• Water constitutes about 65% of adult body weight.
• The remaining 35% of body weight is composed of 15% protein, 5% mineral matter, and 15% fat.

Homeostasis

• Cells require a constant internal environment (interstitial fluid) for proper function.
• Homeostatic control mechanisms maintain internal conditions within normal ranges.
• These mechanisms typically involve negative feedback loops.
• These mechanisms include maintaining normal concentrations of blood constituents, body temperature, and fluid volumes.

Coordination of the Body

• Several organs, like the heart, lungs, kidneys, liver, and gastrointestinal tract, are crucial for homeostasis.
• Internal regulatory mechanisms (nervous and hormonal) coordinate organ function.
• The central nervous system acts as an integrator, receiving sensory input and initiating motor responses.
• The hormonal system involves endocrine glands that secrete hormones, regulating function in various body parts.

Positive Feedback

• Positive feedback loops amplify deviations from normal values.
• They are not homeostatic and are less common in healthy individuals.
• Sometimes, positive feedback mechanisms can lead to death.

Organization of the Body: Directional Terms

• Superior (upper/above), inferior (lower/below), anterior (front/ventral), and posterior (back/dorsal) describe body positions and locations.
• Medial (toward the midline), lateral (away from the midline), proximal (closer to the point of attachment), and distal (farther from the point of attachment) are additional directional terms used to precisely define locations.

Organization of the Body: Planes

• Midsagittal plane vertically divides the body into equal left and right halves.
• Sagittal planes are parallel to the midsagittal plane, dividing the body into unequal left and right portions.
• Horizontal (transverse) planes divide the body into superior and inferior portions.
• Frontal (coronal) planes divide the body into anterior and posterior portions.

Organization of the Body: Cavities

• Cavities are enclosed spaces within the body that contain and protect internal organs.
• The ventral cavity includes the thoracic (containing pleural and pericardial cavities) and abdominopelvic cavities.
• The dorsal cavity includes the cranial and spinal cavities.

Structural Units

• Cells are the fundamental structural and functional units of life.
• Protoplasm is a complex mixture of substances within the cell.
• All life depends on the cell's functions, including metabolism, respiration, digestion, assimilation, excretion, and reproduction.

Cell Structure

• Cells are highly organized units with organelles (specialized structures) performing numerous tasks.
• The nucleus houses genetic material (DNA) and controls cell activities.
• The cytoplasm contains diverse organelles essential for cellular functions.
• The cell membrane acts as a boundary controlling substances entering and exiting the cell.

Cell Membrane Transport: Diffusion

• Diffusion is the passive movement of molecules from higher to lower concentration, aiming for equilibrium.
• Facilitated diffusion uses transport proteins for larger molecules.

Cell Membrane Transport: Osmosis

• Osmosis is the passive movement of water across a selectively permeable membrane from an area of high water concentration to an area of low water concentration.

Endocytosis and Exocytosis

• Endocytosis involves bringing substances into the cell via vesicular formation (e.g. phagocytosis, receptor mediated endocytosis).
• Exocytosis involves expelling substances from the cell via vesicular formation.

Organelles

• Nucleus: Contains genetic material (DNA) and regulates cellular activities.
• Nucleoli and Ribosomes: Sites of ribosome assembly and protein synthesis respectively.
• Rough and Smooth Endoplasmic Reticulum: Involved in protein and lipid synthesis respectively.
• Golgi Apparatus: Modifies, packages, and distributes proteins and lipids.
• Lysosomes and Peroxisomes: Sacs containing enzymes for breaking down material.
• Mitochondria: Site of ATP (energy) production through aerobic respiration.
• Cytoskeleton: Provides structure, support, and facilitates cell movement.
• Centrioles: Involved in cell division.
• Cilia: Hair-like structures that move substances across cell surface.
• Flagella: Long, tail-like structures that propel cells.
• Microvilli: Increase surface area in cells for absorption.

Cell Metabolism and Protein Synthesis

• Aerobic respiration produces energy (ATP) from glucose.
• Anaerobic respiration produces less ATP without oxygen.
• Protein synthesis involves DNA transcription (forming mRNA), ribosome translation (using mRNA to create amino acid chains), and tRNA in joining amino acids to form a protein.

Cell Division: Mitosis

(Detailed stages of mitosis are presented in the provided image, which is not suitable to be presented as a bulleted point summary but can be examined for diagrammatic learning)

Tissues and Membranes

• Tissues are groups of similar cells performing a specific function.

• Epithelial tissue covers surfaces and lines body cavities.

• Connective tissue supports, connects, and protects other tissues.

• Muscle tissue provides movement.

• Nervous tissue transmits nerve impulses.

• Membranes are thin layers covering or lining body structures.

• Mucous membranes line body cavities open to the exterior.

Overview of Connective Tissues

• Embryonic connective tissue is the precursor to various connective tissues.
• Loose connective tissue provides support and space between tissues and organs.
• Adipose tissue stores energy and serves as a thermal insulator.
• Dense connective tissue provides strength and support (e.g. tendons, ligaments).
• Cartilage serves as support structures and shock absorbers.
• Bone's mineralized matrix provides structural support.
• Blood is a fluid connective tissue transporting various materials.

Overview of the Integumentary System

• The integumentary system consists of the skin.
• Epidermis (outer layer) is a protective sheet of cells.
• Dermis (inner layer) contains supportive structures like blood vessels, nerves, and sensory receptors.
• Subcutaneous layer (under dermis) is largely fatty connective tissue joining the skin to underlying structures, and insulates.

Diseases

• Various skin diseases, like acne, burns, decubitus ulcers, and cancers, are examined in terms of causes, appearance, severity, and treatment.

Inflammation

• Inflammation is a local response to injury, designed to isolate, destroy, and repair damage.
• Acute inflammation (short duration) displays five signs (redness, heat, swelling, pain, and loss of function).
• Chronic inflammation arises from persistent agents or a compromised healing process.
• Tissue repair involves the substitution of viable cells for dead ones (regeneration or replacement). Labile, stable, and permanent cells exhibit different repair capabilities.

The Skeletal System

• The skeletal system provides support, protection, and enables movement.
• Bones are organs composed of connective tissues, supporting structures like cartilage, ligaments, tendons, and joints.