Exam 1

Chapter 1: Introduction to Anatomy & Physiology

Characteristics of Living Things

Understanding the fundamental traits of living organisms is essential in anatomy and physiology. These characteristics distinguish living things from non-living matter.

• Organization: Living things exhibit complex organization, from cells to tissues to organs.

• Metabolism: The sum of all chemical reactions in the body, including anabolism and catabolism.

• Responsiveness: Ability to sense and respond to stimuli.

• Growth: Increase in size and number of cells.

• Reproduction: Production of new organisms and cells.

• Homeostasis: Maintenance of a stable internal environment.

• Evolution: Adaptation over generations.

Hypertrophy refers to the increase in cell size, while atrophy is the decrease in cell size or wasting away of tissue.

Levels of Organization

The human body is organized into several hierarchical levels:

• Atoms & Molecules

• Cells

• Tissues

• Organs

• Organ Systems

• Organism

Example: The heart is an organ composed of muscle tissue, connective tissue, and nervous tissue, working together to pump blood.

Body Cavities & Membranes

Body cavities house and protect internal organs. Membranes line these cavities and organs.

• Thoracic cavity: Contains lungs and heart, separated from the abdominal cavity by the diaphragm.

• Abdominal cavity: Contains digestive organs.

• Pelvic cavity: Contains reproductive and urinary organs.

• Serous membranes: Include pleura (lungs), pericardium (heart), and peritoneum (abdominal organs).

Example: The pericardium surrounds the heart and contains serous fluid to reduce friction.

Medical Imaging

Various imaging techniques are used to visualize internal structures:

• X-ray: Best for bones.

• MRI: Best for soft tissues.

• CT scan: Combines X-rays for detailed images.

• PET scan: Shows metabolic activity.

• Barium contrast: Used to show the GI tract.

Chapter 2: Tissues

Overview of Tissues

Tissues are groups of similar cells performing a common function. There are four main types:

• Epithelial tissue: Covers surfaces and lines cavities.

• Connective tissue: Supports, binds, and protects organs.

• Muscular tissue: Responsible for movement.

• Nervous tissue: Conducts electrical impulses.

Epithelial Tissue

Epithelial tissue forms protective barriers and is involved in absorption, secretion, and sensation.

• Cell junctions: Tight junctions, desmosomes, gap junctions.

• Protein fibers: Collagen, elastin, reticular fibers.

• Examples: Skin epidermis, lining of the GI tract.

Connective Tissue

Connective tissue is the most abundant and diverse tissue type, providing support and structure.

• Cells: Fibroblasts, macrophages, mast cells, adipocytes, mesenchymal cells, neutrophils, eosinophils.

• Matrix: Ground substance and protein fibers.

• Types: Loose (areolar), dense regular, dense irregular, reticular, elastic, adipose, cartilage, bone, blood.

Example: Adipose tissue stores fat; bone tissue provides structural support.

Bone and Cartilage

Bone and cartilage are specialized connective tissues.

• Bone cells: Osteoblasts (build bone), osteocytes (maintain bone), osteoclasts (break down bone).

• Matrix: Collagen fibers and mineral salts (hydroxyapatite).

• Cartilage types: Hyaline, elastic, fibrocartilage.

Example: Hyaline cartilage is found in the nose and trachea; fibrocartilage in intervertebral discs.

Muscular Tissue

Muscular tissue is specialized for contraction and movement.

• Skeletal muscle: Voluntary, striated, attached to bones.

• Cardiac muscle: Involuntary, striated, found in the heart.

• Smooth muscle: Involuntary, non-striated, found in walls of hollow organs.

Example: Skeletal muscle enables locomotion; cardiac muscle pumps blood.

Nervous Tissue

Nervous tissue is responsible for transmitting electrical signals throughout the body.

• Neurons: Conduct impulses.

• Neuroglia: Support and protect neurons.

Example: The brain and spinal cord are composed of nervous tissue.

Chapter 3: Homeostasis

Homeostasis and Feedback Loops

Homeostasis is the maintenance of a stable internal environment. Feedback loops regulate physiological processes.

• Negative feedback: Reduces the effect of a stimulus (e.g., body temperature regulation).

• Positive feedback: Enhances the effect of a stimulus (e.g., blood clotting).

Example: When blood glucose rises, insulin is released to lower it (negative feedback).

Chapter 4: Integumentary System

Structure and Function

The integumentary system includes the skin, hair, nails, and associated glands. It protects the body and regulates temperature.

• Layers of skin: Epidermis (outer), dermis (middle), hypodermis (inner/subcutaneous).

• Functions: Protection, sensation, thermoregulation, vitamin D synthesis.

Epidermis

The epidermis is the outermost layer of skin, composed mainly of keratinocytes.

• Strata: Stratum basale, stratum spinosum, stratum granulosum, stratum lucidum (in thick skin), stratum corneum.

• Cells: Keratinocytes, melanocytes, Langerhans cells, Merkel cells.

Example: Melanocytes produce melanin, which gives skin its color and protects against UV radiation.

Dermis

The dermis provides strength and elasticity to the skin.

• Layers: Papillary (superficial), reticular (deep).

• Structures: Blood vessels, nerves, hair follicles, sweat glands.

Hypodermis

The hypodermis (subcutaneous layer) anchors the skin to underlying tissues and stores fat.

• Composition: Adipose tissue, connective tissue.

Skin Color and Clinical Aspects

Skin color is determined by melanin, hemoglobin, and carotene. Clinical conditions include cyanosis, jaundice, albinism, and vitiligo.

• Cyanosis: Bluish skin due to lack of oxygen.

• Jaundice: Yellow skin due to bilirubin accumulation.

• Albinism: Lack of melanin production.

• Vitiligo: Loss of pigment in patches.

Hair and Nails

Hair and nails are accessory structures of the skin.

• Hair: Protects, insulates, and senses.

• Nails: Protect fingertips, aid in grasping.

• Hair growth: Influenced by genetics, hormones, and nutrition.

Example: The arrector pili muscle causes hair to stand up (goosebumps).

Skin Repair and Clinical Procedures

The skin repairs itself through a series of steps:

• Hemostasis

• Inflammation

• Proliferation

• Remodeling

Types of skin grafts: Autograft (self), allograft (other human), xenograft (other species).

Key Terms and Definitions

• Diffusion: Movement of molecules from high to low concentration.

• Osmosis: Diffusion of water across a semipermeable membrane.

• Endocytosis/Exocytosis: Active transport mechanisms for large molecules.

• Glycogenesis/Glycogenolysis: Formation and breakdown of glycogen.

• Phospholipid bilayer: Structure of the cell membrane.

• Enzymes: Biological catalysts that speed up reactions.

Sample Table: Comparison of Tissue Types

Tissue Type	Main Function	Location Example
Epithelial	Protection, absorption, secretion	Skin, lining of GI tract
Connective	Support, binding, storage	Bone, blood, adipose tissue
Muscular	Movement	Skeletal muscles, heart
Nervous	Communication, control	Brain, spinal cord

Sample Equations

• Osmosis: $J = -D \frac{dC}{dx}$

• Rate of diffusion: $\text{Rate} = k[A][B]$

Additional info: Some content was inferred and expanded for clarity and completeness, including definitions, examples, and table structure.