Exam 2 Study Guide: Lectures 9-17

Comprehensive vocabulary flashcards covering the core concepts, mechanisms, and physiological terminology from the Exam 2 Study Guide (Lectures 9–17).

Negative feedback

A regulatory feedback loop (such as the pituitary-to-thyroid axis) in which an increase in the output signal acts to inhibit or switch off the initial stimulating signal.

Insulin

A pancreatic hormone that facilitates glucose uptake into cells; lack of production or cellular insensitivity causes glucose to build up in the bloodstream.

Type 1 diabetes

An autoimmune condition in which the immune system attacks insulin-producing cells, leaving the body unable to produce insulin and causing glucose accumulation in the blood.

Type 2 diabetes

A metabolic disorder where body cells become resistant to insulin, preventing proper cellular uptake and causing glucose to accumulate in the blood.

Prediabetes

A clinical stage characterized by elevated blood glucose levels below the diagnostic threshold for diabetes, viewed as an actionable window of opportunity for intervention.

GLP-1 drugs

A class of newer medications used to manage metabolism, diabetes, and weight regulation.

Low-Density Lipoprotein (LDL)

A lipoprotein that transports cholesterol through the bloodstream and contributes to arterial plaque formation when present in high amounts.

High-Density Lipoprotein (HDL)

A protective lipoprotein that scavenges excess cholesterol from the bloodstream and arterial walls and carries it to the liver for disposal.

Emphysema

A form of chronic obstructive pulmonary disease (COPD) characterized by the destruction of lung tissue and loss of alveoli surface area, impairing oxygen exchange and causing shortness of breath.

Chronic bronchitis

A form of COPD involving persistent inflammation, airway irritation, and excessive mucus production that obstructs airflow in the respiratory tract.

Cilia

Microscopic, hair-like projections lining the respiratory tract that sweep mucus and inhaled debris outward; tested via clearance rates in the 1970s iron-particle experiment.

Epidemiology studies

Observational population studies used to evaluate health patterns and outcomes when controlled, two-group experimental trials are ethically unfeasible (such as with alcohol harm).

J curve hypothesis

The proposition that light-to-moderate alcohol consumption offers a minor reduction in mortality or cardiovascular risk compared to non-drinking, while heavier drinking steeply escalates harm.

Blood Alcohol Concentration (BAC)

A measurement of the percentage of alcohol circulating in a person's bloodstream, illustrating how even modest alcohol quantities can place an individual over the legal limit.

Nephron

The structural and functional filtration unit of the kidney that processes blood to form urine; its filtration capacity is directly reliant on proper blood pressure.

Antidiuretic Hormone (ADH)

A hormone regulating systemic water balance by prompting the kidneys to reabsorb water; suppression of ADH increases fluid loss and contributes to dehydration during hangovers.

Dopamine

A neurotransmitter mediating reward, motivation, and survival behaviors; prolonged drug abuse causes down-regulation of its receptors and decreases natural production.

Narcan

An emergency opioid receptor antagonist that interrupts fatal respiratory arrest during an opioid overdose by displacing the drug from opioid receptors.

Plague

A severe bacterial disease historically responsible for widespread fatalities in Europe, transmitted via fleas from rodent hosts and treatable with modern antibiotics.

Malaria

A parasitic disease transmitted to humans via mosquito vectors, controlled primarily through mosquito netting, vector eradication, and standing-water removal.

West Nile disease

A viral disease maintained in an avian reservoir and transmitted to humans via infected mosquito bites.

Lyme disease

A tick-borne bacterial infection transmitted through the bite of infected ticks, preventable by tick checks and avoidance of tick habitat.

Escherichia coli O157

A pathogenic bacterial strain producing potent toxins capable of migrating from the digestive system to cause damage to secondary organs such as the kidneys.

Innate immunity

The rapid, non-specific arm of the immune system that provides immediate defense against broad categories of pathogens.

Adaptive immunity

The slower, highly specific branch of the immune system that mounts targeted responses against unique pathogens and forms immunological memory.

Macrophage

A large immune cell of the innate immune system responsible for identifying, engulfing, and destroying pathogens and cellular debris.

Helper T cell

An adaptive immune lymphocyte that recognizes foreign antigens presented by other cells and coordinates the overall response by activating B cells and killer T cells.

B cell

An adaptive immune lymphocyte responsible for synthesizing and secreting specific antibodies against targeted foreign antigens.

Killer T cell

A cytotoxic lymphocyte of the adaptive immune system that directly detects and destroys infected, damaged, or foreign host cells.

Memory cell

A long-surviving lymphocyte generated during an initial adaptive immune response that rapidly activates upon secondary exposure to the same pathogen.

Antigen

A distinctive molecular structure or foreign marker on a pathogen that is recognized by and triggers an adaptive immune response.

Antibody

A specialized protein produced by B cells that binds precisely to a complementary foreign antigen, neutralizing it or tagging it for destruction.

Autoimmune disorder

A condition resulting from immune system dysregulation where immune cells mistakenly attack the body's own healthy tissues.

Microbiome

The vast ecosystem of predominantly beneficial bacteria residing on the skin and within the digestive tract that play key roles in health and digestion rather than causing disease.