Arthropod Characteristics and Medical Importance
Key Features of Arthropods
Which of the following features are not characteristic of arthropods?
- Four pairs of legs and a hexoesqueleto
- Correct answer: Three pairs of legs and a hemocoel, have articulated appendages.
Incorrect Associations of Arthropods
Which of the following associations is incorrect?
Correct answer: Dipterous / Rodnius prolixus
Definition of Halteres
Define Halteres:
Correct answer: A pair of atrophied wings unfit for flight.
Stages of Holometabolous Cycle
A holometabolous cycle has the following evolutionary stages:
Correct answer: Adult, egg, larva, pupa.
Characteristics of a Hemimetabolous Cycle
What characterizes a hemimetabolous cycle?
Correct answer: The nymphs have the same eating habits as the imagos.
Arthropods with an Incomplete Cycle
Which of the following arthropods have an incomplete cycle?
Correct answer: Periplaneta americana (American Cockroach)
Respiratory Structures Used by Mosquito Larvae
What structures do mosquito larvae use to breathe?
Correct answer: Respiratory siphon.
Conditions that are Vector Mosquitoes
Which of the following conditions is/are vector mosquitoes?
Correct answer: Leishmaniasis
Medical Importance of Musca domestica
Why is Musca domestica of medical importance?
Correct answer: It is a mechanical vector of many microorganisms, an agent is annoying, and their larvae are producing diseases.
False Statement About Anoplura
Which of the following statements about Anoplura is FALSE?
Correct answer: Only females have sucking habits.
Anoplura Species as Biological Vectors
Are all species of Anoplura biological vectors?
Correct answer: No, only the Pediculus humanus variety corporis.
Characteristics NOT Belonging to Siphonaptera
Which of the following characteristics does NOT belong to Siphonaptera?
- Simple eyes
- Three pairs of legs adapted for jumping, born in the chest as in all insects
- Sexual dimorphism
- Males and females feed on blood
- Are temporary or transitory ectoparasites.
Pulex irritans as an Ectoparasite
Pulex irritans is an ectoparasite of man; this sentence is?
Correct answer: True.
Importance of Triatomines in Medical Parasitology
The study of triatomines in medical parasitology is due to:
Correct answer: They are biological vectors of Trypanosoma cruzi.
Common Names of Triatoma Species
What are common names of species of Triatoma?
Correct answer: Quechua “those who drop”, Portuguese “Barber”, English “kissing bugs”.
Statements that do NOT Belong to Cockroaches
Which of the following statements does NOT belong to cockroaches of medical importance?
Correct answer: They have a holometabolous type life cycle.
Pathology Produced by Sarcoptes scabiei
Pathology produced by the spider Sarcoptes scabiei?
Correct answer: Scabies mite.
Secondary Infections from Tick Bites
In ectoparasitosis produced by ticks, secondary infection may occur at the site of the bite, a product of a flawed method of removing the tick. Which of the following organs is related to this affection?
Correct answer: Hypostome.
Differences that do NOT Belong to Spiders
Which of these differences does NOT belong to the spiders?
Correct answer: All are poisonous to humans.
Pathology of Cutaneous and Visceral Loxoscelism
Cutaneous and visceral pathology during loxoscelism is due to:
Correct answer: A potent neurotoxin, a neurotransmitter, an enzyme that degrades phospholipids.
Incorrect Preventive Measure Against Loxoscelism
Which of the following preventive measures against loxoscelism is WRONG?
Correct answer: Remove sites that favor their development, such as stagnant water.
Common Name of Latrodectus mactans
Latrodectus mactans is commonly called a black widow because:
Correct answer: It kills the male after copulation to feed their young.
False Association
Which of the following associations is false:
Correct answer: Loxosceles laeta / affects primarily males.
Examples
Malaria / Anopheles spp: Body segmented into head, thorax, and abdomen; hematophagous (female); 3 pairs of legs emerge from the thorax; piercing mouthparts (proboscis).
Scale / Pediculus humanus: Square head, simple eyes, three pairs of legs in the form of tweezers, dorsoventrally flattened, short antennae; eggs have an operculum with swellings where the nymph exits, is transparent, and has a sticky substance to hold on to hair.
Fly / Musca domestica: It has three pairs of legs, compound eyes, two pairs of wings, head, thorax, and abdomen; the adults feed on liquids degraded by enzymes and then vomit; the larvae feed on solids, this stage produces myiasis.
Cockroaches / Blattella germanica: Hemimetabolous cycle, segmented body, three pairs of legs emerge from the thorax, adapted to move quickly, simple eyes, a pair of atrophied wings, a pair of long antennae.
Scabies / Sarcoptes scabiei: Hemimetabolous cycle, has two pairs of front and two rear legs, chewing mouthparts by the chelicerae (teeth) and pedipalps (sensory organs).
Flea / Pulex irritans (Siphonaptera): Three pairs of legs, short antennae, complete cycle, dorsoventrally flattened, simple eyes, head attached to the thorax.