Ap exam I

Levels of structural organization of the human body

Chemical (atoms, molecules) → Cellular (cells) → Tissue (groups of similar cells) → Organ (two or more tissue types) → Organ system (organs working together) → Organism (entire body).

Main characteristics of life

Organization, metabolism (catabolism + anabolism), growth & development, responsiveness to stimuli, regulation (homeostasis), reproduction.

Homeostasis

Homeostasis is the maintenance of stable internal conditions despite changes in the environment. It is vital to survival because it keeps body functions within normal limits (e.g., temperature, pH, fluid balance).

Negative feedback

Negative feedback reverses a deviation to maintain homeostasis (example: blood glucose regulation, body temp).

Positive feedback

Positive feedback amplifies a response until an endpoint is reached (example: uterine contractions in childbirth, blood clotting).

Anatomical planes of the body

Sagittal (left/right), Midsagittal (equal halves), Frontal/Coronal (anterior/posterior), Transverse (superior/inferior), Oblique (angled).

Major body cavities and membranes

Dorsal cavity (cranial and vertebral). Ventral cavity (thoracic, abdominopelvic). Thoracic contains pleural (lungs), pericardial (heart), mediastinum. Abdominopelvic contains abdominal and pelvic cavities. Lined by serous membranes (parietal and visceral).

11 organ systems and their representative organs

Integumentary (skin, hair, nails), Skeletal (bones, joints), Muscular (skeletal muscles), Nervous (brain, spinal cord, nerves), Endocrine (glands, hormones), Cardiovascular (heart, blood vessels), Lymphatic (lymph nodes, spleen), Respiratory (lungs, trachea), Digestive (stomach, intestines), Urinary (kidneys, bladder), Reproductive (testes/ovaries).

Main anatomical directional terms

Superior/inferior, anterior/posterior, medial/lateral, proximal/distal, superficial/deep, ipsilateral/contralateral.

4 main tissue types and their general functions

Epithelial (covering/lining, secretion, absorption), Connective (support, protection, binding, storage, transport), Muscle (movement, posture, heat), Nervous (communication, control).

General characteristics of epithelial tissue

Tightly packed cells, polarity (apical/basal surfaces), supported by basement membrane, avascular, high regenerative capacity.

Classification of epithelial tissues

By layers (simple, stratified, pseudostratified) and cell shape (squamous, cuboidal, columnar). Example: simple squamous epithelium = single flat layer.

Specialized epithelial tissues

Transitional epithelium (bladder), Pseudostratified columnar epithelium (respiratory tract).

Structural components of connective tissue

Cells (fibroblasts, chondrocytes, osteocytes, adipocytes, etc.), fibers (collagen, elastic, reticular), and ground substance (fluid to semi-solid matrix).

Types of connective tissue

Loose connective tissue (areolar, adipose, reticular), Dense connective tissue (regular, irregular, elastic), Cartilage (hyaline, elastic, fibrocartilage), Bone (compact, spongy), Blood.

Loose connective tissue

Includes areolar, adipose, and reticular tissues.

Dense connective tissue

Includes regular, irregular, and elastic tissues.

Cartilage

Types include hyaline, elastic, and fibrocartilage.

Bone

Types include compact and spongy bone.

Blood

A connective tissue that transports nutrients and oxygen.

Skeletal muscle

Striated, voluntary muscle that is multinucleated.

Cardiac muscle

Striated, involuntary muscle with intercalated discs.

Smooth muscle

Non-striated, involuntary muscle with spindle-shaped cells.

Nervous tissue

Made of neurons that send impulses and neuroglia that support cells.

Hypertrophy

Increase in cell size.

Hyperplasia

Increase in the number of cells.

Atrophy

Decrease in cell size.

Necrosis

Uncontrolled cell death due to injury.

Apoptosis

Programmed cell death.

Inflammation

The first step in tissue repair involving clotting and immune response.

Organization/proliferation

The second step in tissue repair where fibroblasts form new tissue and angiogenesis occurs.

Regeneration

Restoration of original tissue.

Fibrosis

Scar tissue formation.

Integumentary system functions

Includes protection, temperature regulation, sensation, metabolic functions (vitamin D synthesis), excretion, and immune defense.

Epidermis

The outer layer of skin made of keratinized stratified squamous epithelium.

Dermis

The layer of skin made of connective tissue, nerves, and vessels.

Hypodermis

Subcutaneous tissue that provides fat storage and insulation.

Stratum basale

The deepest layer of the epidermis.

Stratum spinosum

The layer of the epidermis above the stratum basale.

Stratum granulosum

The layer of the epidermis above the stratum spinosum.

Stratum lucidum

A layer of the epidermis only present in thick skin like palms and soles.

Stratum corneum

The outermost layer of the epidermis.

Keratinocytes

Cells that provide protection and produce keratin protein.

Melanocytes

Cells that produce melanin pigment for UV protection.

Tactile/Merkel cells

Cells responsible for touch sensation.

Dendritic/Langerhans cells

Cells involved in immune defense.

Melanin

Brown/black pigment contributing to skin color.

Hemoglobin

Red pigment contributing to skin color.

Carotene

Yellow/orange pigment contributing to skin color.

Papillary layer

The upper layer of the dermis made of areolar connective tissue.

Reticular layer

The deeper layer of the dermis made of dense irregular connective tissue.

Sebaceous glands

Glands that secrete sebum (oil).

Eccrine sweat glands

Glands that secrete watery sweat for thermoregulation.

Apocrine sweat glands

Glands that secrete thicker sweat in the axilla and groin, often with odor.

Ceruminous glands

Glands that produce earwax.

Mammary glands

Glands that produce milk.

Lanugo

Fetal hair.

Vellus hair

Fine body hair.

Terminal hair

Thick, pigmented hair found on the scalp, face, and pubic regions.

Nail plate

The visible part of the nail.

Nail bed

The skin under the nail.

Nail matrix

The growth area of the nail.

Cuticle

Also known as eponychium, it protects the nail matrix.

Basal cell carcinoma

The most common and least dangerous type of skin cancer.

Squamous cell carcinoma

A type of skin cancer that can metastasize.

Malignant melanoma

The most dangerous type of skin cancer that spreads quickly.

ABCDE rule

A method for melanoma detection: A = Asymmetry, B = Border irregularity, C = Color variation, D = Diameter >6mm, E = Evolving.

1st degree burn

Involves the epidermis only, characterized by redness and pain.

2nd degree burn

Involves the epidermis and dermis, characterized by blisters and pain.

3rd degree burn

Full thickness burn that destroys the epidermis and dermis, may damage nerves and is less painful initially.

Rule of 9s

A method that divides the body into regions each representing ~9% of total body surface area to estimate burn coverage.