Parasites Intro

Question 1

obligate v facultative parasites

Answer 1

obligate can’t live outside (Ascaris Lumbricoides)

facultative- can grow free living as well as in host ( stronglyloides)

Question 2

endoparasite

Answer 2

parasite the lives inside host

leishmania

Question 3

ectoparasite

Answer 3

lives outside of host (phtrhus pubis)

Question 4

definitive hosts

Answer 4

hosts in which a parasite reaches sexual maturity and reproduces ( malaria mosquito– for schistosome mansoni)

Question 5

intermediate hosts

Answer 5

host in which some development of parasite occurs but doesn’t mature
(boar– trichinella spirals)

Question 6

reservoir host

Answer 6

animals that harbor a species of parasite that is infective for humans
(armadillo- trypanosome cruzi)

Question 7

vector host

Answer 7

arthropod or other carriers that transport pathogenic parasite from infected to non infected host
(Aedes Aegypti)

Question 8

dead end host

Answer 8

organisms that harbor intermediate life stage BUT do no transmit parasite to another host
(Dirofilaria minis, heart worm)

Question 9

I. protozoan size and movement

Answer 9

unicellular organisms, 1 micron– 100 microns
locomotion by:
- flagella-
-cilia- hair like that also serve as organelles
- pseudopodia: temporary projections of cytoplasm used for ingestion of food and locomotion
or undulating membranes

Question 10

protozoal GI and membranes

Answer 10

outer cell membrane controls fluid and food uptake

cytoplasm consists of a thin ectoplasm (where digested particles are extruded) and a thick endoplasm

Question 11

protozoan nucleus

Answer 11

has outer nuclear membrane inner reticulum
chromatin
karyosome (tight amount of dna)

Question 12

function of endoplasm in protozoa

Answer 12

nutrition

contains food vacuoles, reserves and foreign bodies

Question 13

function of contractile vacuoles in protozoa

Answer 13

regulate osmotic pressure and eliminate waste materials

Question 14

protozoan Sex

Answer 14

• asexual- binary fission
• asexual- multiple fission (schizogony)
• asexual - internal budding (endodyogeny)
• sexual- fertilization (syngamy)

Question 15

II. Flat worms (class Trematodes)
size and morphology

Answer 15

flattened elongated leaf like
schistozosomes - ovoid and cylindrical

1-5 cm
they have a non cellular integument that has spines and tubercles

Question 16

body of trematodes

Answer 16

• they have suckers or spines that used for attachment of host
  don’t have a body cavity

Question 17

trematode life cycle always includes?

Answer 17

SNAILS as an intermediate host

Question 18

trematode sex

schistosome sex?

Answer 18

Hermaphroditic!- Ovaries and testes present in each individual

eggs are released into body cavity of host

schistosomes– dioecious- either ovaries or sperm

Question 19

III, Cestodes – tapeworms

body

Answer 19

ribbon like segmented and inhabit intestinal tract

microvillus like structures make it continuous from one segment to another - body wall is an active tegument

Question 20

cestodes

• • scolex
• • proglotid
• • strobilus

Answer 20

scolex- anterior attachment organ
proglotid- segments
strobila- chain of segments

Question 21

sex of cestodes

Answer 21

HERMAPHRODITIC

each proglottid has reproductive organs that allow self fertilization- each one is considered a reproductive unit

Question 22

larva of cestodes

Answer 22

mature- inhabit GI tract

larva- tissues and organs (brain)

Question 23

Nematodes (round worms) body

Answer 23

1- 30 cm
stiff clear non cellular cuticle
has teeth hook and lips used for tissue abrasion or attachment

Question 24

nematode digestive sistem

Answer 24

well developed

- feed by sucking host blood or ingesting lysed tissues or GI contents - has midgut handout and anus

Question 25

how do nematodes grow

Answer 25

molting to increase body size

- these skins cause an immune response

Question 26

nematode sex

Answer 26

BOTH MALE AND FEMALE* dioecious

Question 27

5. Arhtropods body

Answer 27

exoskeleton- external rigid tegument with chitinized membranes
3 legs0 insect
4 legs arachnids

Question 28

arthropod GI

Answer 28

forgot midgut handout rectum anus

Question 29

arthropod growth

Answer 29

molting - complete/ incomplete metamorphosis

Question 30

sex arthropods

Answer 30

dioecious
oviparious
viviparous
oviviparous- larvated eggs

Question 31

GI tract trematodes

Answer 31

• they just have a digestive tract rather than a body cavity
  starts with a pharynx and bifurcates into two posterior tubes

Question 32

GI tract cestodes

Answer 32

absent GI tract

but their integument is enzymatically active = so they absorb their host food

Question 33

non specific host resistance to parasites

Answer 33

chemical barriers
physical barriers
microbial antagonism– anti parasitic factors in serum and competition of nutrients by normal flora

Question 34

pathological changes caused by parasites

Answer 34

• parenchymatous degeneration
• fatty degeneration
• necrosis
• hyperplasia
• hypertrophy
• metaplasia
• neoplasia

Question 35

parenchymatous degeneration

Answer 35

damage to cells- characterized by swollen cells packed with fatty granules, indistinct nuclei and pale cytoplasm (washed out)

liver heart kidney

Question 36

fatty degeneration

Answer 36

deposition of large amounts of fat in cells- yellowish color

Question 37

necrosis

Answer 37

death- gives an opaque appearance

Question 38

hyperplasia v hypertrophy

Answer 38

hyperplasia increase in cell number due to accelerated cell division (due to an increase in body repair activity due to inflammation)
hypertrophy increase in cell size

Question 39

metaplasia

Answer 39

conversion of one tissue into another without intervention of embryonic tissue

Question 40

neoplasia

Answer 40

abnormal cell growth- producing an entirely new cell structure

Question 41

lab diagnosis of parasites

Answer 41

• fecal concentration
• trichrome stain
• acid fast stain
• KOH
• Giemsa
• wrights

Question 42

fecal concentration test

Answer 42

use of flotation (bc parasite eggs float in zinc sulfate solutions of high osmolarity)

so they are picked up and observed

Question 43

trichrome stain

Answer 43

stain parasites in fecal matter- stain protozoans cells pink with blue green organelles

Question 44

acid fast stain

Answer 44

stance cells pink with a blue background

Question 45

KOH preparatun

Answer 45

for presence of arthropods and parasites

tissues dissolve away leaving the clinical specimens

Question 46

giemsa stain

Answer 46

looking for intracellular structures

blue colored intracellular parasites

Question 47

wright stain

Answer 47

for identification of cell types in blood smears