Chapters 18–19: Nervous and Digestive Infections Vocabulary

A comprehensive set of vocabulary flashcards summarizing key nervous-system and digestive-system infection terms from Chapters 18 and 19.

Meninges

Three protective tissue layers—dura mater, arachnoid mater, and pia mater—that encase the CNS, supplying nutrients, removing waste, and guarding against physical shock.

Cerebrospinal fluid (CSF)

Colorless, watery fluid produced in the brain that cushions and nourishes the CNS.

Concussion

Brain or spinal-cord injury from jarring force; causes temporary CNS dysfunction with or without brief unconsciousness.

Coma

Prolonged state of unconsciousness in which a person cannot be awakened.

Meningitis

Inflammation of the meninges; increases pressure on brain and spinal cord and may quickly become life-threatening if bacterial.

Encephalitis

Inflammation of the brain itself.

Meningoencephalitis

Concurrent inflammation of the brain and meninges.

Lumbar puncture

Diagnostic procedure in which CSF is removed via a needle between lower-back vertebrae for analysis.

Immunocompromised

Having an incompletely functioning immune system, as in transplant recipients, cancer patients, or individuals with HIV/AIDS.

Peripheral nervous system (PNS)

Part of the nervous system that gathers sensory input and conveys motor output via nerves.

Central nervous system (CNS)

Brain and spinal cord; integrates information and issues action plans.

Neurons

Nerve cells that transmit signals within the CNS and PNS.

Sensory neurons

Afferent neurons specialized for incoming signals.

Motor neurons

Efferent neurons specialized for outgoing signals.

Interneurons

Neurons that facilitate communication between the CNS and PNS.

Neurotransmitters

Chemical messengers released by neurons in response to internal or external stimuli.

Blood-brain barrier

Selective CNS capillaries that let in only certain small or lipophilic molecules; most microbes are blocked except many viruses.

Cytolytic agent

Substance that causes cell lysis or rupture.

Zoonosis

Disease transmitted from animals to humans.

Systemic infection

Infection that spreads throughout the body via the bloodstream, usually sparing the CNS due to the blood-brain barrier.

Paranesthesia

Prickling or “pins and needles” neurological sensation.

Flaccid paralysis

Paralysis marked by inability to contract muscles.

Symmetric paralysis

Paralysis affecting both sides of the body equally.

Asymmetric paralysis

Paralysis affecting one side of the body more than the other.

Polio

Non-enveloped RNA virus transmitted oral-fecally; usually flulike but can damage motor neurons and cause paralysis.

Rabies

Viral disease with fever, nausea, wound paranesthesia, coma, cardiac arrest, and respiratory failure; fatal without prompt vaccination.

Spastic paralysis

Paralysis characterized by inability to relax muscles.

Toxemia

Presence of bioactive bacterial toxins in the bloodstream.

Serotype

Group of related microbes sharing common antigens used for identification.

Protozoans

Single-celled eukaryotic parasites, many flagellated or amoeboid, often facultative anaerobes with complex life cycles.

Digestive system

Includes GI tract plus accessory organs involved in food processing.

Gastrointestinal (GI) tract

Tube from mouth to anus; site of digestion and absorption.

Upper GI tract

Mouth, pharynx, esophagus, and stomach.

Lower GI tract

Small intestine, large intestine, rectum, and anus.

Accessory digestive organs

Salivary glands, liver, gallbladder, and pancreas.

Diarrhea

Passing loose or watery stool; ≥5 watery stools qualifies for diagnosis.

Enteritis

Inflammation of the intestines.

Gastritis

Inflammation of the stomach lining.

Gastroenteritis

Inflammation of both stomach and intestines.

Dysentery

Diarrhea accompanied by pain, blood, and/or mucus.

Dehydration

Excessive fluid loss, often from severe diarrhea or vomiting.

Hypovolemic shock

Dangerously low blood volume from blood or fluid loss, risking organ failure.

Upper endoscopy

Fiber-optic examination of esophagus, stomach, and small intestine via the mouth.

Lower endoscopy (colonoscopy)

Fiber-optic examination of the large intestine via the anus.

Mumps

Viral illness with dry mouth, fever, headache, fatigue, and swollen parotid glands (parotitis).

Hepatitis

Liver inflammation from infectious or noninfectious sources.

Hepatitis A

Usually mild liver infection with possible jaundice and pale stools.

Hepatitis B

Liver infection similar to hepatitis A but often more severe, with jaundice and pale stools.

Periodontal disease

Tender, swollen, often discolored gums that may recede from teeth, potentially progressing to bone-eroding periodontitis.

Dental plaque

Biofilm of bacteria such as Streptococcus, Actinomyces, Veillonella, and Haemophilus that promotes tooth decay.

Foodborne bacterial infection

Illness from ingesting live bacteria that colonize and infect the GI tract.

Food poisoning

GI illness caused by ingestion of preformed bacterial toxins; bacteria need not grow in host.

Bacteremia

Presence of bacteria in the bloodstream.

Sepsis

Body-wide immune response to persistent or high levels of microbes in blood; may escalate to septic shock.

Septic shock

Advanced sepsis causing organ failure; 20–30 % mortality.

Hematuria

Blood in the urine.

Purpura

Purple skin spots/bruises from RBC lysis or capillary damage without external trauma.

Edema

Generalized swelling from fluid accumulation in tissues, often extremities.

Colitis

Inflammation of the colon or large intestine.

Helminths

Multicellular parasitic worms transmitted as microscopic eggs or larvae.

Tapeworms

Flat, segmented helminths possessing hooks for attachment to host tissue.