Chapter 1 – The Human Body: An Orientation

Definitions and Principles

• Anatomy is the study of the structure of body parts and their relationships to one another. Physiology is the study of the function of the body and its parts.

• The principle of complementarity states that function always reflects structure; what a structure can do depends on its specific form.

Levels of Structural Organization

• The human body is organized into several levels: chemical, cellular, tissue, organ, organ system, and organismal.

• There are 11 major organ systems: integumentary, skeletal, muscular, nervous, endocrine, cardiovascular, lymphatic, respiratory, digestive, urinary, and reproductive. Each system has specific components and functions.

Requirements for Life and Homeostasis

• Life requires maintaining boundaries, movement, responsiveness, digestion, metabolism, excretion, reproduction, and growth.

• Homeostasis is the maintenance of a stable internal environment despite external changes. It is primarily controlled by negative feedback mechanisms.

• Positive feedback mechanisms amplify changes and are less common (e.g., blood clotting, childbirth).

Anatomical Terminology

• Standard anatomical terms are used to describe body directions, regions, and planes (e.g., superior/inferior, anterior/posterior, sagittal/coronal/transverse planes).

Body Cavities and Membranes

• The major body cavities are the dorsal (cranial and vertebral) and ventral (thoracic and abdominopelvic) cavities.

• Each cavity contains specific organs and is lined by membranes (e.g., serous membranes).

Chapter 4 – Tissue: The Living Fabric

Microscopy and Tissue Preparation

• Tissue samples are fixed, sectioned, and stained for microscopic examination.

Epithelial Tissue

• Epithelial tissue covers body surfaces, lines cavities, and forms glands.

• It is classified by cell shape (squamous, cuboidal, columnar) and layers (simple, stratified).

• Functions include protection, absorption, filtration, excretion, secretion, and sensory reception.

• Glands are classified as endocrine (ductless, secrete hormones) or exocrine (secrete via ducts).

Connective Tissue

• Common characteristics: cells separated by extracellular matrix, varying degrees of vascularity.

• Main types: connective tissue proper, cartilage, bone, and blood.

Muscle and Nervous Tissue

• Muscle tissue is responsible for movement and is classified as skeletal, cardiac, or smooth.

• Nervous tissue consists of neurons and supporting cells; it transmits electrical impulses.

Membranes and Tissue Repair

• Cutaneous, mucous, and serous membranes line body surfaces and cavities.

• Tissue repair involves inflammation, organization, and regeneration/fibrosis.

Developmental Aspects

• Primary germ layers (ectoderm, mesoderm, endoderm) give rise to all tissues.

Chapter 6 – Bones and Skeletal Tissues

Skeletal Cartilages

• Three types: hyaline (most abundant, flexible support), elastic (flexible, external ear), fibrocartilage (strong, intervertebral discs).

• Cartilage grows by appositional and interstitial growth.

Bone Functions and Classification

• Functions: support, protection, movement, mineral storage, blood cell formation, triglyceride storage, hormone production.

• Bones are classified by shape: long, short, flat, irregular.

Bone Structure

• Typical long bone anatomy: diaphysis, epiphyses, medullary cavity, periosteum, endosteum.

• Bone markings serve as attachment sites for muscles, ligaments, and tendons.

• Two types of bone tissue: compact (dense, outer layer) and spongy (trabecular, inner layer).

• Organic components: cells and osteoid; inorganic: hydroxyapatite (mineral salts).

Chapter 7 – The Skeleton

The Axial Skeleton

• Includes the skull, vertebral column, and thoracic cage.

• The skull is composed of cranial and facial bones, protecting the brain and supporting facial structures.

• The vertebral column consists of cervical, thoracic, lumbar, sacral, and coccygeal regions. It supports the body and protects the spinal cord.

• Thoracic cage: ribs and sternum, protects thoracic organs.

The Appendicular Skeleton

• Pectoral girdle: clavicle and scapula, attaches upper limbs to trunk.

• Upper limb: humerus, radius, ulna, carpals, metacarpals, phalanges.

• Pelvic girdle: hip bones (os coxae), supports lower limbs.

• Lower limb: femur, tibia, fibula, tarsals, metatarsals, phalanges.

Developmental Aspects of the Skeleton

• Membrane bones form via intramembranous ossification; others by endochondral ossification.

• Fontanelles in infant skulls allow for growth and flexibility during birth.

• Body proportions change with age; cranium grows rapidly in early childhood, limbs lengthen later.

• With aging, bones lose mass and become more brittle.

Chapter 5 – The Integumentary System

Structure and Function of Skin

• The skin consists of two main layers: epidermis (superficial, epithelial tissue) and dermis (deeper, connective tissue).

• Subcutaneous tissue (hypodermis) lies below the dermis and anchors skin to underlying structures.

Epidermis

• Composed of keratinized stratified squamous epithelium.

• Main layers: stratum basale, spinosum, granulosum, lucidum (in thick skin), corneum.

• Functions: protection, water resistance, vitamin D synthesis.

Dermis

• Composed of connective tissue; two layers: papillary (areolar) and reticular (dense irregular).

• Contains blood vessels, nerves, hair follicles, and glands.

Skin Color and Hair

• Skin color is determined by melanin, carotene, and hemoglobin.

• Hair consists of dead keratinized cells; functions include protection and sensation.

• Arrector pili muscles cause hair to stand (goosebumps).

Nails, Sweat, and Sebaceous Glands

• Nails are protective coverings of the distal fingers and toes.

• Sweat glands: eccrine (thermoregulation) and apocrine (odor, puberty).

• Sebaceous glands secrete sebum (oil) for lubrication.

Clinical Aspects

• Skin cancers: basal cell carcinoma, squamous cell carcinoma, melanoma.

• Burns are classified by depth and extent; severe burns can be life-threatening due to fluid loss and infection.

Additional info:

• For equations related to homeostasis, the concept can be represented as:

• Bone growth and remodeling are regulated by hormones (e.g., growth hormone, sex hormones, parathyroid hormone).