General Biology Study Notes: Chemistry of Life, Cells, Organ Systems, Skeletal and Muscular Systems

Chapter 4: From Cells to Organ Systems

Body Position and Terminology

• Body planes: midsagittal, frontal, transverse.

• Terms: proximal, distal, anterior, posterior, superior, inferior.

Tissue Types in Humans

• Epithelial: Protection, secretion, absorption.

• Connective: Support, structure, transport.

• Muscle: Movement.

• Nervous: Communication.

Epithelial Tissue

• Simple (one layer) or stratified (multiple layers).

• Shapes: cuboidal, columnar, squamous.

• Glandular epithelium: exocrine (ducts), endocrine (hormones).

Connective Tissue

• Fibrous: strength, elasticity.

• Specialized: cartilage, bone, blood, adipose.

Muscle Tissue

• Skeletal: voluntary, multinucleated.

• Cardiac: involuntary, heart only.

• Smooth: involuntary, single nucleus.

Nervous Tissue

• Neurons: transmit impulses.

• Glial cells: support and protect neurons.

Organs and Organ Systems

• Organs: two or more tissue types performing specific functions.

• Organ systems: groups of organs with a common function.

Skin: Epidermis and Dermis

• Epidermis: outer layer, stratified squamous epithelial cells.

• Dermis: middle layer, supports tissues, contains fibroblasts, white blood cells, fat cells, hair follicles.

Hair and Nails

• Hair: grows from follicles, color from melanin.

• Nails: grow from keratinocytes.

Vitamin D Formation

• Starts in skin, complex series of reactions.

Disease Overview

• Germ theory: microorganisms cause disease.

• Immune deficiencies: cancer, allergies, genetics.

• Environmental toxins: chemicals, poisons, gases.

• Skin disorders: acne, cancer, hemangioma, melanoma, vitiligo, psoriasis, necrotizing fasciitis, shingles.

Chapter 5: The Skeletal System

Functions of the Skeleton

• Support, protection, movement, blood cell formation, mineral storage.

Skeletal System Structure

• Connective tissue: bone, ligaments, cartilage.

• Bone: hard matrix of calcium salts, living cells (osteocytes).

• Ligaments: attach bone to bone.

• Cartilage: support under pressure.

Bone Development and Repair

• Ossification: formation of bone tissue.

• Repair: hematoma, fibrocartilage, bony callus, remodeling.

Skeleton Organization

• Axial skeleton: skull, sternum, ribs, vertebral column.

• Appendicular skeleton: limbs, pelvic and pectoral girdles.

Diseases and Disorders

• Sprains, bursitis, tendinitis, arthritis, osteoporosis, bone cancer.

Chapter 6: The Muscular System

Functions of the Muscular System

• Mobility, protection, circulation, temperature regulation, transport of nutrients and fluids.

Muscle Types and Features

• Skeletal: voluntary, multinucleated.

• Cardiac: involuntary, heart only.

• Smooth: involuntary, digestive tract, blood vessels, uterus, ureters.

Muscle Structure

• Muscle fibers: long cylindrical cells, contain actin and myosin.

• Sarcomere: contractile unit.

  • Actin: thin filaments

  • Myosin: thick filaments

Muscle Contraction

• Initiated by nerve impulses (acetylcholine).

• Calcium ions trigger sliding filament mechanism.

• ATP required for contraction and relaxation.

Muscle Disorders

• Muscular dystrophy, tetanus, cramps, fascitis, tendinitis.

Major Muscles to Know

• Pectoralis major, biceps brachii, rectus abdominis, external oblique, sartorius, quadriceps, tibialis anterior, trapezius, deltoid, triceps brachii, latissimus dorsi, gluteus maximus, gastrocnemius, Achilles tendon.

Additional info:

• Tables and diagrams referenced in the notes have been described in text for clarity.

• All major concepts have been expanded with definitions, examples, and academic context for self-contained study.