Medical Entomology Exam 1

Front 1

What are the 5 types of problems caused by arthropods?

Back 1

-annoyance

-contamination

-phobias

-direct injury

-disease transmission

Front 2

What is Delusional Parasitosis?

Back 2

The mistaken belief of being infested. Can lead to self-mutilation.

Front 3

Myiasis?

Back 3

The infestation/parasitism of fly larvae somewhere in the body. Ex: bot flies

Front 4

Viruses transmitted by arthropods are known as what?

Back 4

Arboviruses

Front 5

What's Biological Transmission?

Back 5

When the disease has an obligatory life cycle stage inside the vector species.

Front 6

What is Mechanical Transmission?

Back 6

Incidental transfer of disease organism during contact between vector and host. Parasite does not reproduce/develop within the vector. Can be external or internal.

ex: when cockroaches come into contact with food.

Front 7

What are the 3 subphyla of phylum Arthropoda?

Back 7

1) Trilobitomorpha=trilobites

2) Chelicerata

3) Mandibulata

Front 8

What kinds of species are in subphylum Chelicerata?

Back 8

mites, ticks, spiders, scorpions, horseshoe crabs

Front 9

What kinds of species are in subphylum Mandibulata?

Back 9

Crustaceans, centipedes, insects

Front 10

What is the name of the main body cavity (containing a circulatory fluid) found in arthropods?

Back 10

hemocoel

Front 11

What is a tagmata?

Back 11

A body region type. For example, Arachnids have 2 tagmata: head and trunk. Insects have 3 tagmata: head, thorax and abdomen.

Front 12

The epidermis of arthropods secretes a noncellular __________.

Back 12

cuticle

Front 13

What are the 2 sections of the cuticle in arthropods?

Back 13

1) procuticle: proteins and chitin-hardened layer.

2) epicuticle: the varnish-like waterproof layer.

Front 14

Developmental stages are separated by molts of the exoskeleton. What are the 2 possible kinds of developmental stages in insects?

Back 14

1) gradual development=found in primitive species (ex: cockroach); larvae look, move and feed like adults.

2) Complete development=found in advanced species (flies, fleas, etc.); larvae are very physically different than adults

Front 15

What is the name of the opening tubes lining the body of arthropods that lead to the tracheal tubes on the inside of the body?

Back 15

spiracles

Front 16

Which mosquito species vectors malaria?

Back 16

Anopheles gambiae

Front 17

What is Morgellon's Disease?

Back 17

A fake disease characterized by unexplained infestation symptoms (crawling skin, etc)

Front 18

What are the 3 sections of the digestive system in arthropods?

Back 18

1) foregut

2) midgut

3) hindgut

Front 19

What is the structure of the foregut? What is its function?

Back 19

An infolding of the exoskeleton (so, it's lined with impermeable cuticle). Stores food.

Front 20

What is the structure and funtion of the midgut?

What is the peritrophic membrane?

Back 20

Not lined with cuticle; involved in nutrient absorption. The peritrophic membrane surrounds food to enhance digestion and isolate microbes in food. Infective microbes can invade hemocoel here by lysing the peritrophic membrane with enzymes.

Front 21

What is the structure and function of the hindgut?

Back 21

An infolding of the exoskeleton; expels waste

Front 22

What are the 6 main characteristics of arthropods?

Back 22

1) segmented body

2) exoskeleton

3) Jointed exoskeleton with paired appendages

4) hemocoel body cavity

5) Specialized respiratory system = trachea

6) Unique sensory structures: ocelli, setae; compound eyes

Front 23

What is the difference between ocelli and ommatidia?

Back 23

ocelli=simple eyes/eyespots. Detect simple changes in light.

Ommatidia=individual eye units that make up compound eyes.

Front 24

What are setae?

Back 24

stiff, bristle/hair-like structures found on arthropods. Found on antennae

Front 25

From outside to inside, what are the 3 layers of the insect exoskeleton?

Back 25

1) epicuticle (outside)

2) procuticle

3) epidermis (inside, living cells)

Front 26

What is epidemiology?

Back 26

The study of maintenance, outbreak, ecology and prevention of diseases.

Front 27

What are the 4 routes of infection in epidemiology?

Back 27

1) aerosols (inhalation of infectious particle)

2) physical contact (predation, sexual, etc)

3) Fomites= infection thru contact w/ infected object.

4) Vectors

Front 28

What percentage of diseases are vector-borne?

Back 28

20%

Front 29

What are the symptoms of Zika virus? How is it transmitted?

Back 29

Symptoms: fever, rash (2-7 days); can cause microcephaly in infants born to infected women.

Transmitted by Aedes mosquitoes

Front 30

From 1918 to 1919, how many people/what percentage of the population did the Spanish Flu kill?

Back 30

3% (about 50 million people worldwide)

Front 31

The modern swine flu is a mutated version of what disease?

Back 31

the Spanish Flu

Front 32

What's the difference between and Anthropozootic Disease and an Enzootic Disease?

Back 32

Anthropozootic Disease=parasite resides primarily in humans (ex: malaria)

Enzootic disease=parasite primarily in animals, but can infect humans (ex: West Nile Virus)

Front 33

What are the 2 kinds of disease transmission cycles?

Back 33

-Simple=disease vectored by mosquitoes among humans

-complex=disease vectored by mosquitoes between humans and multiple different animals

Front 34

What's the difference between an obligate and facultative parasite?

Back 34

obligate=only in host/vector

facultative=in host/vector and in free living stages (ex: nematodes)

Front 35

What is Vector competence and what is it affected by?

Back 35

Vector competence=the probability that a pathogen will be transmitted by a particular vector. The competence of a vector at spreading disease.

Affected by

-host selection (vector must feed on correct host)

-vector susceptibility to pathogen

-how often a vector feeds

Front 36

What is the difference between horizontal transmission and vertical transmission?

Back 36

Horizontal transmission=from vector to host

Vertical transmission=between vector generations

Front 37

What are the 3 types of vertical transmission in vector species?

Back 37

1) Trans-stadial=within an organism's lifespan

2) Trans-ovarial=from mother to offspring

3) Venereal=from males to females

Front 38

Regarding biological transmission, what is the difference between the extrinsic incubation time and intrinsic incubation time?

Back 38

extrinsic=the time a pathogen must develop/reproduce before the vector is infective. Competent vectors feed after the extrinsic period.

intrinsic=the time for host to develop symptoms

Front 39

Difference between endemics, epidemics and pandemics?

Back 39

Endemics=sustained, low levels of infection in an area.

Epidemic=outbreak of disease

Pandemic=epidemic across wide geographic area

Front 40

What are sentinel animals?

Back 40

Animals that are often reservoirs for diseases and can be monitored to track disease prevalence.

Front 41

What is the labrum in some insect species?

Back 41

the "upper lip"--the food tube

Front 42

What are the maxillae and labium used for in some insects?

Back 42

to manipulate food (they're parts of the mouth)

Front 43

What is the name for the "tongue" in some insect species?

Back 43

the hypopharynx

Front 44

Having a flattened body is a necessary adaptation for some parasitic vector species. What are the 2 ways the body can be flattened?

Back 44

Dorsoventral=in ticks, lice, bedbugs

Lateral compression=fleas

Front 45

What are the 3 Classes (and their corresponding orders) of venomous arthropods?

Back 45

1) Insecta: order Hymenoptera

2) Arachnida: Order Scorpiones

3) Arachnida: Order Araneae (spiders)

Front 46

Within the order Hymenoptera, what are the 3 families?

Back 46

1) Vespidae=wasps (predatory)

2) Formicidae= ants

3) Apoidea= bees (honey bees; pollinators)

Front 47

How many of the 115,000 species of Hymenoptera are stingless?

Back 47

half

Front 48

In hymenoptera, the thorax is joined by 2 segments via a flexible structure called ___________.

Back 48

Petiolate gaste (The "wasp waist")

Front 49

In hymenoptera, what is the stinger made of?

Back 49

A Hollow stylet (sheath) plus 2 barbed, moveable lancets

Front 50

What is the Schmidt scale?

Back 50

A scale of pain intensity of insect stings from 0-4

Front 51

What are the 2 different subspecies of honeybees?

Back 51

1) Apis m. mellifera=European honeybees

2) Apis m. scutellata=African honeybees (darker, less honey, more aggressive)

Front 52

Hymenoptera venom has multiple components. What are they and what do they do?

Back 52

-histamines=increase capillary permeability, vasodilation, pain, itching.

-mastoparans=induce release of histamines from target's own mast cells

-hemolysins=rupture red blood cells

-neurotoxins=cause pain, cardiac/respiratory arrest.

-enzymes=phospholipidase, etc. Spread venom by degrading cell membranes

Front 53

Bee venom contains ________, unique to honeybees. What does it do?

Back 53

Melittin (a peptide): enhances action of phospholipidases, pain, ruptures RBCs, vasodilation.

Front 54

What is an LD50?

Back 54

The amount of toxin per kg of body weight required to kill 50% of the population

Front 55

The death-stalker scorpion's venom is comparable to what? Is the emperor scorpion as deadly?

Back 55

cobra venom; no, emperor scorpion is a popular pet.

Front 56

What is the most dangerous species of scorpion in the US?

Back 56

the bark scorpion (Centruroides exilicauda)

Front 57

In Scorpions, how many segments are found in the cephalothorax?

Back 57

6 segments: chelicera, pedipalps and 4 pairs of walking legs

Front 58

In scorpions, how many segments are found in the abdomen?

Back 58

12 segments with 2 regions:

front region and hind region

Front 59

What are pectines?

Back 59

modified abdominal appendages unique to scorpions that look like combs. Found of the belly and can detect vibrations, moisture, taste, etc.

Front 60

In scorpions, food is transferred from ________ to ____________.

Back 60

chelicera; gnathobases=region where pedipalps join body to grind prey; mouth is located here.

Front 61

How do scorpions reproduce?

Back 61

Males signal females and wait for signal back to approach. Mating "dance"--> male drops spermatophore on ground and guides female over it.

Front 62

How many species of spiders are there? How many in the US?

Back 62

40k species; 4k in US

Front 63

How many segments are in the cephalothorax in spiders?

Back 63

6: chelicera, pedipalps, 4 pairs walking legs

Front 64

Chelicera appear in what form in spiders?

Back 64

modified as venomous fangs

Front 65

What species of spider can kill a person with a bite within 15 minutes?

Back 65

Australian Funnel-web spider

Front 66

What are the 3 medically important spider species in the US? What kinds of venom do the 2 most dangerous possess?

Back 66

1) Black Widow (neurotoxin venom)

2) Brown Recluse (cytolytic venom)

3) Hobo spider

Front 67

What subphyla, class and order are ticks found in?

Back 67

Subphyla Chelicerata

--> Class Arachnida

--->Order Acari

Front 68

Ticks are found in the suborder Parasitiformes. What are the 2 families of ticks in this suborder?

Back 68

-Family Ixodidae (hard ticks)

Family Argasidae (soft ticks)

Front 69

How many species of ticks are there?

Back 69

1000

Front 70

What are the 2 differences in morphology between hard and soft ticks?

Back 70

1) hard ticks have a visible capitulum (mouth)

2) Hard ticks have a scutum

Front 71

What are the 3 parts of the capitulum in ticks?

Back 71

1) chelicera: serrated for cutting

2) Pedipalps: for holding onto host

3) hypostome: a barbed, harpoon-like holdfast

Front 72

There are 2 major regions on a tick: the "head" region and the idiosoma. What is the idiosoma made up of?

Back 72

posterior cephalothorax + abdomen

Front 73

On the idiosoma of female ticks, where do you find the ventral gonopore?

Back 73

On the underside/belly

Front 74

Where is the Haller's organ found on ticks and what does it do?

Back 74

Found on forelegs; detects taste, odors, touch.

Front 75

How can you tell a female hard tick from a male hard tick?

Back 75

Female Ixodidae have smaller scutum on the idiosoma

Front 76

What is "questing"?

Back 76

The practice of ambush ticks of sticking out forelegs and jumping/dropping/latching onto host as it passes by.

Front 77

What is the stylostome?

Back 77

The feeding tube that forms on ticks during feeding by injecting saliva into the wound that then cements to the capitulum.

Front 78

What is the difference of feeding between hard ticks and soft ticks?

Back 78

Hard ticks: add new cuticle; feed from 2 days-2 weeks.

Soft ticks: stretch cuticle; take small meal; detach w/in hours.

Front 79

What are the 2 strategies for getting onto a host for ticks?

Back 79

1) Hunting--tick runs up and seizes host

2) Ambush--tick waits and "quests"

Front 80

Describe the mating and egg-laying process of ticks

Back 80

Female secretes hormones while feeding and males come up to her and attach to underside to insert spermatophore into the ventral gonopore. Female continues to feed until completely full then drops off. She lays eggs basically until she dies.

Front 81

What is diapause?

Back 81

The state of dormancy a tick goes into between feeding. Reduces moisture/energy requirements. Induced by day length, humidity, temperature, etc.

Front 82

How can ticks take in atmospheric moisture?

Back 82

By using a Hydrophilic Secretion: they secrete a salty substance around the mouth that that will attract atmospheric moisture if the humidity is greater than 40%.

Front 83

What are 4 important diseases vectored by ticks?

Back 83

1) Lyme disease

2) Rocky mountain spotted fever

3) Babesiosis

4) tick-borne encephalitis

Front 84

Besides vectoring diseases, what other medically-important consequence can occur from a tick biting you?

Back 84

TIck paralysis--caused by toxic protein in saliva. Causes respiratory failure within 48 hours but recovery happens within days after removal.