MED TERM CH. 2
Quadrants and Body Cavities
Quadrants are a simpler but less precise way to divide the abdomen.
Formed by drawing two imaginary lines through the umbilicus: one horizontal and one vertical.
RUQ = right upper quadrant; LUQ = left upper quadrant; RLQ = right lower quadrant; LLQ = left lower quadrant.
Organs by quadrant:
RUQ: right lobe of the liver, gallbladder, part of the pancreas, part of the small and large intestines.
LUQ: left lobe of the liver, spleen, stomach, part of the pancreas, part of the small and large intestines.
RLQ: part of the small and large intestines, right ovary, right fallopian tube, appendix, right ureter.
LLQ: parts of the small and large intestines, left ovary, left fallopian tube, left ureter.
Cavities
A body cavity is a space within the body that contains and protects internal organs.
The body has five cavities in total.
Two main body cavities: the dorsal cavity and the ventral cavity.
Dorsal cavity overview (back of the body)
Composed of two subcavities: the cranial cavity and the spinal cavity.
Dorsal cavities are located at the back of the body.
Define dorsal using the slash technique:
Suffix in dorsal: -al (meaning pertaining to).
Prefix/combining form: dorso- or dorsal- (meaning back).
The combining vowel o is dropped because the suffix starts with a vowel.
Dorsal = pertaining to the back.
Cranial cavity contains the brain.
Spinal cavity contains the spinal cord.
Defining cranial and spinal (word parts)
Cranial:
Suffix: -al (pertaining to).
Prefix/combining form: cranio- (relating to the skull).
Combining vowel dropped when suffix begins with a vowel.
Cranial means pertaining to the skull.
Spinal:
Suffix: -al (pertaining to).
Combining form: spino- (spine or backbone).
Spinal means pertaining to the backbone or spine.
Ventral cavity overview (front of the body)
Ventral = anterior (front).
Ventral/anterior cavity is divided into three parts: thoracic, abdominal, and pelvic cavities.
Thoracic cavity (chest):
Suffix: -ic (pertaining to).
Prefix/combining form: thoraco- (chest).
Thoracic means pertaining to the chest.
Organs in the thoracic cavity: heart, esophagus, trachea, aorta, and lungs.
The diaphragm separates the thoracic cavity from the abdominal cavity.
Abdominal cavity (often referred to as the abdominal part of the abdominopelvic cavity):
Abdomin is the combining form meaning abdomen.
Abdominal = pertaining to the abdomen (suffix -al).
Organs: liver, stomach, and intestines.
The abdominopelvic cavity is used because there isn’t a clear anatomical division between the abdomen and the pelvic area.
Pelvic cavity:
Contains the urinary bladder and reproductive organs (uterus in women, prostate gland in men).
Pelvic words: suffix -ic (pertaining to); combining form pelvo- (hip or pelvis); pelvic means pertaining to the hip or pelvis.
Body organization: from small to large
The body is made of progressively larger and more complex units: cells, tissues, organs, and body systems.
Working together, these structures form the complete body and enable proper function.
Cells, Tissues, and Basic Cell Biology
Cells: basic structural and functional units of the body.
Cells are specialized and grouped to form tissues and organs.
Cytology: the study of the anatomy, physiology, pathology, and chemistry of the cell.
A cytologist is a specialist in the study and analysis of cells.
Cell components
Cell membrane: a tissue that surrounds and protects the contents of a cell from the external environment.
Cytoplasm: material within the cell membrane that is not part of the nucleus.
Nucleus: surrounded by a nuclear membrane; a structure within the cell with two important functions:
Controls activities of the cell.
Helps the cell divide.
Stem cells
Two key characteristics:
1) Unspecialized cells that can renew themselves for long periods via cell division.
2) Under certain conditions, stem cells can transform into cells with specialized functions (e.g., heart cells that make the heartbeat, pancreatic cells that produce insulin).Adult stem cells (somatic stem cells): undifferentiated cells found in tissues; primarily maintain and repair tissue.
Embryonic stem cells: undifferentiated and can form any adult cell.
Embryonic stem cells sources:
Cord blood from the umbilical cord and placenta of a newborn (obtained at birth without danger to mother or child).
Surplus embryos from in vitro fertilization (IVF) with informed consent of the donor couple.
Informed consent: individuals are given information about what is involved before giving permission.
Stem cell therapy (regenerative medicine): potential uses to heal injuries and treat diseases.
Common source of stem cells for therapy: bone marrow (hemopoietic tissue).
Rejection risk: graft-versus-host disease occurs if donor and recipient are not well matched.
Genetics, Genome, and Chromosomes
Gene and genetics basics
Gene: fundamental physical and functional unit of heredity; genes influence health, disease, and physical traits (e.g., hair, skin, eye color).
Genetics: study of how genes are transferred from parents to offspring and the role of genes in health and disease.
The word root for gene-related terms: e.g., gene; suffix -ics in genetics (study of).
Geneticist: a specialist in genetics.
Inheritance basics
Each new individual receives two genes for each trait, one from each parent.
Dominant gene: inherited from either parent, offspring will express that trait or condition (e.g., freckles, Huntington disease).
Recessive gene: requires inheritance from both parents for the condition to manifest (e.g., sickle cell anemia).
If one recessive gene is inherited with a normal gene from the other parent, the child will be a carrier and typically not show disease.
The Human Genome and genome concept
Genome: complete set of genetic information of an organism.
Human Genome Project: studied the human genetic code and found it is >99% identical among humans worldwide.
First complete mapping published in 2003; goal is to understand proteins encoded by ~25,000 genes.
Chromosomes and somatic vs gamete cells
Chromosome: genetic structure in the nucleus made of DNA; carries genes.
Somatic (body) cells: 46 chromosomes arranged in 23 pairs.
Pairs include 22 autosomes and 1 sex chromosome pair.
Typical female: XX; typical male: XY.
Gametes (sperm/egg): 23 single chromosomes each (no paired chromosomes).
Fertilization: sperm and ovum each contribute 23 chromosomes; offspring have 46.
Sex determination: the father's X or Y chromosome determines the child’s sex.
Down syndrome example: individuals have 47 chromosomes due to trisomy 21.
DNA structure and identification
DNA is the main component of chromosomes, carrying genetic information.
DNA in humans: thousands of genes; determines heredity, disease risk, physical traits.
Location: DNA is located in the nucleus of almost all cells (erythrocytes lack a nucleus).
DNA structure: two spiraling strands form a double helix.
Identical twins: share the same DNA pattern, but phenotypic differences (e.g., fingerprints) can still exist.
Small DNA samples (hair, tissue) can be used for identification in forensics, paternity testing, and genealogical research.
Genetic testing is discussed later in the material.
Genetic mutations and genetic engineering
Genetic mutation: a change in the DNA sequence.
Potential causes: exposure to radiation or environmental pollution.
Somatic cell mutation: changes in body cells; not transmitted to offspring.
Gamete cell mutation: changes in sperm or egg DNA; can be transmitted to offspring.
Genetic engineering: manipulation or splicing of genes for specific purposes (e.g., producing human insulin in bacteria).
Genetic disorders
A genetic disorder is a hereditary disease caused by absent or deficient genes.
Examples:
Cystic fibrosis: present at birth; affects respiratory and digestive systems.
Down syndrome (trisomy 21): facial features, learning disabilities, heart valve disease.
Fragile X syndrome: changes in the MR1 gene; developmental delays, learning disabilities, and social/behavioral problems.
Hemophilia: bleeding disorder due to missing clotting factor; mostly affects males.
Huntington's disease: inherited; 50% risk to offspring; nerve degeneration with midlife onset; movement and cognitive/psychiatric symptoms.
Marfan syndrome: connective tissue disorder; tall, slender build; long limbs.
Muscular dystrophy: progressive weakness and degeneration of skeletal muscle.
Phenylketonuria (PKU): missing enzyme phenylalanine hydroxylase; detectable by newborn screening; requires dietary control to limit phenylalanine.
Tissues and histology
Tissue: group or layer of similarly specialized cells performing specific functions.
Histology: microscopic study of tissue structure, composition, and function.
Histologist: specialist in microscopic tissue structures.
Four main tissue types:
Epithelial tissue: protective covering; forms glands; includes epithelium (skin surface) and endothelium (lining blood/lymph vessels and glands).
Connective tissue: supports and connects tissues; subtypes include dense connective (bone, cartilage), adipose (fat), loose connective, and fluid connective (blood and lymph).
Muscle tissue: contracts and relaxes for movement.
Nerve tissue: reacts to stimuli and conducts electrical impulses.
Pathology of tissue formation
Aplasia: deficient development or absence of an organ or tissue.
Hypoplasia: underdevelopment of an organ or tissue (cellular deficiency).
Anaplasia: abnormal transformation of cells and their orientation; often seen in cancer.
Dysplasia: abnormal development or presence of abnormal cells within a tissue type (e.g., cervical dysplasia).
Hyperplasia: increase in number of cells in a tissue or organ; some hyperplasias are normal (e.g., breast tissue during pregnancy) while others may be precancerous.
Hypertrophy: enlargement of tissue or organ due to increased size of cells, not cell number (e.g., muscle hypertrophy from weight lifting).
Exocrine vs endocrine glands
Gland: organ that produces a secretion.
Aden- as a combining form meaning gland.
Exocrine glands: secrete into ducts that lead to organs or out of the body (e.g., salivary, mammary, sweat glands).
Endocrine glands: secrete hormones directly into the bloodstream; no ducts.
Endocrine system consists of seven types of glands, each secreting hormones that regulate activity of specific cells, organs, or both.
Additional gland terms:
Aden/o- (root: gland).
Adenoids: lymphoid tissue mass at the back of the upper pharynx (not a true gland).
Adenitis: inflammation of a gland.
Mesenteric adenitis: inflammation of abdominal lymph nodes with symptoms similar to appendicitis.
Adenocarcinoma: malignant tumor originating in glands; spreads elsewhere.
Adenoma: benign tumor arising in glandular tissue.
Adenosis: any disease or condition of a gland.
Body systems and related organs (conceptual)
An organ is a distinct structure that performs a specific function.
Organs and tissues are organized into body systems with specialized functions.
Pathology and disease terminology (overview)
Pathology: study of disease; etiology (causes) of disease; conditions produced by disease.
Pathologist: physician specializing in lab analysis of diseased tissue to confirm or establish a diagnosis.
Etiology: study of causes of diseases or abnormal conditions.
Patho- root and -pathy suffix both relate to disease and suffering.
Disease transmission and infection control
Pathogen: disease-causing microorganism (e.g., virus).
Transmission: spread of disease.
Contamination: pathogen possibly present due to poor hygiene or infection control.
Communicable (contagious) disease: transmitted from person to person.
Direct transmission: direct human-to-human contact or exchange of bodily fluids.
Bloodborne transmission: spread through infected blood or body fluids; must enter bloodstream (e.g., HIV, hepatitis B, many STDs).
Droplet transmission: respiratory droplets from coughing/sneezing; diseases include measles, common cold, COVID-19, flu; masks help limit.
Nosocomial (hospital-acquired) infections.
Indirect contact: susceptible person affected via contaminated surfaces.
Airborne transmission: pathogens carried by air; particles can remain airborne and travel; significant for TB, measles, COVID-19, chickenpox.
Aerosol: fine liquid particles suspended in air.
Aerosol-generating procedures (in healthcare) increase airborne risk (e.g., endotracheal intubation, suctioning).
Foodborne and waterborne transmission: contaminated foods or water.
Vector-borne transmission: disease spread via insects (vectors) like mosquitoes (malaria, West Nile).
Epidemiology terms:
Epidemiologist: studies disease outbreaks in populations.
CDC: Centers for Disease Control and Prevention; national health protection agency in the U.S.; tracks outbreaks and prevention.
Endemic: disease remains present within a population or area.
Epidemic: sudden, widespread outbreak within a population or area.
Pandemic: outbreak across a large geographic area, possibly worldwide (e.g., HIV, COVID-19).
Types of diseases and related concepts
Organic disease: produces detectable physical changes (e.g., varicella/chickenpox).
Functional (non-organic) disorder: symptoms without identifiable organic cause (e.g., chronic fatigue syndrome).
Iatrogenic illness: adverse effect caused by medical treatment.
Idiopathic disease: unknown cause.
Infectious disease: illness caused by living pathogens (bacteria, viruses).
Nosocomial infection: hospital-acquired infection.
Syndromes: signs and symptoms that occur together as part of a disease process (e.g., Down syndrome, fetal alcohol syndrome).
Metabolic syndrome: risk factors for heart disease, stroke, type 2 diabetes (elevated blood pressure, central adiposity, high insulin, high cholesterol/triglycerides).
Congenital and prenatal factors
Congenital disorder: abnormal condition existing at birth; may be caused by developmental disorders, prenatal risk factors, premature birth, or birth injuries.
Prenatal risk factors: maternal health, behavior, and prenatal care influence birth outcomes (e.g., rubella infection, fetal alcohol syndrome).
Premature birth: birth before 37 weeks; can cause breathing problems and heart issues due to incomplete organ development.
Birth injuries: injuries during labor or delivery (e.g., clavicle fractures) that heal relatively quickly.
Anomalies, anomalies, and atresias: congenital abnormalities; anal atresia = absence of opening; pulmonary atresia = absence of opening in pulmonary system.
Aging and death; geriatrics
Aging: normal progression toward end of life; increased risk of chronic or fatal diseases with age.
Geriatrics/gerontology: study and care of older adults.
Postmortem: after death; autopsy used to determine cause of death, evaluate disease presence, and treatment efficacy.
Advance directives and healthcare decision-making
Advance directives provide guidance about treatment choices in emergencies.
Healthcare proxy (durable power of attorney for healthcare): appoints someone to make decisions if patient cannot.
Living will (physician’s order for life-sustaining treatment): states wishes for end-of-life care.
Do Not Resuscitate (DNR/No Code/Allow Natural Death): directs that CPR is not performed if the heart or breathing stops.
Healthcare professionals and settings
Primary care providers (PCP): general practitioners, family practice physicians.
Internist: diagnosis and treatment of internal organ diseases.
Pediatrician: children’s health.
Geriatrician/gerontologist: care of older adults.
Nurse practitioner (NP): advanced practice nurse; often a primary care provider.
Physician assistant (PA): licensed professional working under physician supervision.
Medical office staff roles:
Medical receptionist: schedules and registers patients; may assist as a medical assistant.
Medical assistant (clinical): performs administrative and clinical tasks (vital signs, injections, phlebotomy) and may work in long-term care.
Certified medical assistant (CMA): credential through the American Association of Medical Assistants.
Medical coder: assigns diagnosis, procedure, and equipment codes for insurance purposes (alphanumeric).
Hospital and emergency settings:
Emergency department (ED/ER): triage and treatment of life-threatening conditions.
Emergency physician: specializes in high-acuity medicine.
Emergency medical technician (EMT): pre-hospital care on ambulance.
Registered nurse (RN): licensed clinician; supports patient care.
Licensed practical/vocation nurse (LPN/LVN): under supervision of physician or RN; basic patient care.
Certified nursing assistant (CNA): provides basic patient care under supervision.
Pharmacist: dispenses prescribed medications.
Intensive care unit (ICU): continuous monitoring for critically ill patients.
Anesthesiologist: specializes in care of critically ill patients in ICU/settings.
Hospitalist: focuses on medical care of hospitalized patients.
Telemetry unit: continuous cardiac monitoring.
Med-surgical unit: care for lower-acuity patients recovering from surgery or ongoing therapy.
Common abbreviations and terms
AMP: Anatomy and Physiology (a field/discipline abbreviation).
DNA: Deoxyribonucleic acid.
GP: General Practitioner.
HD: Huntington’s disease.
LLQ: Left lower quadrant.
LUQ: Left upper quadrant.
RLQ: Right lower quadrant.
RUQ: Right upper quadrant.
PA: Physician assistant.
Miscellaneous concepts touched in the lecture
The slash technique for defining word parts is illustrated with dorsal, cranial, and spinal examples, showing how suffixes and prefixes combine with combining forms to convey meaning.
The diaphragm’s role as a separator between thoracic and abdominal cavities is highlighted.
The abdominopelvic cavity is a practical term used when a clear anatomical boundary between abdomen and pelvis is not present.
The hematopoietic (bone marrow) stem cell source is mentioned as a common source for transplantation.
Graft-versus-host disease is noted as a potential complication of stem cell transplants when there isn't a good donor match.
PKU management highlights newborn screening and dietary limitations to prevent neurological damage.
The role of vaccines, masks, and infection control measures are implied in the discussion of transmission and nosocomial infections.
The distinction between organic vs functional disorders, congenital vs developmental conditions, and the concept of syndromes is emphasized for clinical classification.
Notable numerical references (reformatted in LaTeX)
Five body cavities in total: 5
Dorsal cavities: two (cranial and spinal): 2
Ventral cavity subdivided into three parts: thoracic, abdominal, pelvic: 3
Thoracic cavity organs: heart, esophagus, trachea, aorta, lungs (list only)
Abdominal organs: liver, stomach, intestines (list only)
Pelvic organs: urinary bladder, uterus, prostate (list only)
Chromosome count in somatic cells: 46 chromosomes, arranged into 23 pairs
Sex chromosome pairs: XX in typical females, XY in typical males
Gametes: each carries 23 single chromosomes
Post-fertilization chromosome count: 46 chromosomes
Down syndrome chromosome count: 47 (trisomy 21)
Embryonic stem cells can proliferate indefinitely in a laboratory: (conceptual, no numerical value)
Human genome gene count: about 25{,}000 genes
Identical twins have identical DNA patterns (subject to individualization by phenotypic traits)
Endemic/epidemic/pandemic concepts examples: measles (epidemic in a community; could become endemic); HIV/COVID-19 as pandemics (no numerical value assigned here)