Invertebrates Flashcards
1
Q
Multicellular invertebrates are divided into (how many?) groups based upon the number of germ layers formed during embryogenesis.
A
Two groups
2
Q
(????????) are groups of cells that behave as a unit during early embryonic development and give rise to distinctly different tissue systems in the adult.
A
Germ Layers
3
Q
What are the two germ layers Diploblastic animals have?
A
Ectoderm (outermost layer)
Endoderm (innermost layer)
4
Q
What are the three germ layers Triploblastic animals have?
A
Ectoderm
Mesoderm
Endoderm
5
Q
Triploblastic animals are further classified by their internal body cavity
Acoelomate:
A
No internal body cavity
6
Q
Triploblastic animals are further classified by their internal body cavity
Pseudocoelomate:
A
fluid-filled cavity between endoderm and mesoderm
7
Q
Triploblastic animals are further classified by their internal body cavity
Coelomate:
A
internal, fluid-filled cavity between endoderm and mesoderm, lined with mesoderm
8
Q
What phylum does flatworms belong to?
A
Phylum Platyhelminths
9
Q
What are 3 kinds of flatworms?
A
Tapeworms, flukes, and non-parasitic flatworms
10
Q
What class does tapeworms belong to?
A
Class Cestoda
11
Q
What class does flukes belong to?
A
Class Trematoda
12
Q
What class does free-living, non-parasitic worms belong to?
A
Class Turbellaria
13
Q
What is the cat (or dog) tapeworm called?
A
Taenia pisiformis
14
Q
What system do tapeworms lack?
A
Digestive system
15
Q
What is the best place in the body for a tapeworm to live?
A
Intestines
16
Q
What is a scolex?
A
The head of the tapeworm
17
Q
What 2 structures does the scolex have that helps it grab onto the mucosa of the intestines?
A
Suckers and Hooks
18
Q
Tapeworms belong to what Class?
A
Class Cestoda
19
Q
What is the term for a dog or cat tapeworm?
A
Taenia-pisiformis
20
Q
The head of a tapeworm is called what?
A
Scolex
21
Q
What does the Scolex contain?
A
Suckers and hooks
22
Q
What are the segments of a tapeworm called?
A
Proglottids
23
Q
What do the Proglottids contain?
A
Testes and ovaries
24
Q
What are the 3 tapeworm diseases?
A
- TAENIASIS (Pork and Beef)
- CYSTICERCOSIS (Pork only)
- TAENIA-PISIFORMIS (Dog and Cat tapeworms)
25
What is Taeniasis caused by?
Pork or beef intestinal infections
26
What are the symptoms of Taeniasis?
It is usually asymptomatic, mild GI pain, but you may see the proglottids wiggling in the stool
27
What is Cysticercosis caused by?
Pork tapeworms
28
What are the characteristics of Cysticercosis?
- It is much more serious, even life-threatening
- The Tania egg is ingested by the fecal-oral route
- Larvae embed in any tissue (esp. muscle, brain, eye)
- Once ingested, the eggs hatch and invade.
29
What are the symptoms of the Dog and Cat tapeworms (Taenia-Pisiformis)?
Mild symptom of diarrhea and gas
30
How do flukes differ from tapeworms?
Flukes are non-segmented.
31
Where do flukes live?
Venuoles in humans
32
What characteristic of flukes causes damage in the human brain?
Their large number of eggs
33
What disease do they cause?
Granulomas, which are inflammatory lesions
34
Where can granulomas occur?
Many organs including the brain, spinal cord and liver.
35
Clonorchic sinensis (liver fluke) and the Fasciolopsis buski (giant intestinal fluke) belongs to what class?
Class Trematoda
36
What are the main parts of the clonorchic sinesis (liver fluke)?
```
Oral sucker
Pharynx
Intestines (cecum)
Uterus
Testes
```
37
What are the main parts of the Fasciolopsis buski (giant intestinal fluke)?
Mouth (for feeding)
Ventral sucker (for attachment)
Intestines (cecum)
Testes
38
Define Schistosoma mansoni
Female blood fluke:
- Ventral sucker (for attachment)
- Ovary
- Mouth (for feeding)
39
Define Schistosomiasis
- The blood fluke is called Schistostoma. “Schisto” means “split” and “soma” means opening.
- The male’s body is split into a gynecohoric canal; this is where the females live. The female is smaller and lives within the male her whole life.
- She lays thousands of eggs a day
40
What are the blood fluke diseases?
- Schistosomiasis
| - Swimmer’s Itch
41
Characteristics of Schistosomiasis?
- Schistosomiasis kills 1-2 million people per year; it’s almost as bad as malaria. It is a tropical disease. It is also known as “Male menstruation” because there is a bladder fluke which causes hematuria (blood in the urine). When Napoleon invaded Egypt, his men got this disease and called it the Curse of the Pharaoh.
- Many people are asymptomatic, but the acute form (Katayama’s Fever) can occur weeks later, manifesting with fever, coughing, nausea, vomiting, diarrhea, hepatosplenomegaly, and eosinophilia (excess eosinophils, a type of white blood cell that responds to parasitic infections).
42
Where do the schistosomulae migrate to?
The veins
43
The females are smaller and live where?
inside the male
44
The Schistosomiasis deposit eggs inside where?
small venules
45
Where do the Schistosomiasis eggs move toward?
moved progressively toward the lumen of the intestine and are eliminated with feces or urine.
46
How is Schistosomiasis infection transmitted?
Human contact with water is necessary for infection by schistosomes. Skin penetration in required.
47
What are the symptoms of Schistosomiasis?
Katayama fever, granulomas (occasionally in brain or spinal cord)
48
Swimmer’s itch is the only schistosome disease found where?
USA
49
Swimmer’s itch is caused by?
A schistosome that should have a bird as a host, but humans can become an accidental host. An infected duck passes the eggs in the water. Humans who are swimming in late July and August are more likely to get this.
50
What happens to the organism since it cannot live in humans?
It dies under the skin after it penetrates it.
51
What does this cause?
An itchy reaction.
52
What is the treatment?
oral trimeprazine and topical cortisone (anti-inflammatory) creams.
53
What is the prevention?
rub your skin hard with a towel as soon as you get out of the water to prevent the worms from penetrating.
54
What are Class Turbellaria Invertebrates?
Free living flatworms (not parasitic)
55
What are characteristics of class Turbellaria invertebrates?
Planaria spp.
Pharynx
Eye spots (light sensitive)
Gastrovascular cavity
56
What is Phylum Platyhelminthes?
Flatworms: Tapeworms, flukes and non-parasitic flatworms
57
What is Phylum Nematoda?
Roundworms, hookworms and threadworms
58
What is Phylum Annelida?
Segmented worms
59
What is Arthropoda?
Ticks, mites and lice
60
What classification is Enterobius vermicularis?
Nematode
61
What is Enterobius vermicularis?
Pinworm
62
How is enterobius vermicularis transmitted?
Mouth and pharynx
63
What is pinworm disease called?
Enterobiasis
64
Who/what are hosts of enterobiasis?
Humans are the only host
65
What are differences between the male and female pinworms?
Males: smaller than the female, curl-shaped tail which allows clasping to the female during copulation and spicules to allow attachment
Females: Migrates to the rectum, crawls out onto skin and deposits eggs on the perianal folds
66
What is one effective way to decrease infection and spread of the disease?
Proper hand washing
67
A female Ascariasis may produce
Approximately 200,000 eggs per day, which are passed with the feces and are ingested from soil contamination.
68
Ascariasis
- It is the largest worm pathogen.
| - It causes the most infections of all the Helminthes world-wide.
69
What cause a disease in humans called Visceral Larva Migrans (VLM)?
Dog and cat roundworms (Toxocara canis and Toxocara cati).
70
Why are preschool children most often affected by dog and cat roundworms?
Because it is spread by ingestion of contaminated dirt.
71
What are the symptoms for Visceral Larva Migrans (VLM)?
Brain damage, respiratory failure, cardiac arrhythmias, or eye lesions that resemble cancer or retinal detachment.
72
The Necator americanus or American hookworm is from what phylum?
Phylum Nemotoda- roundworms
73
The male Necator americanus or American hookworm has what physical characteristics?
Teeth, muscular pharynx, posterior bursa and rays
74
What is the function of the posterior bursa and rays of the male hookworm?
Copulation
75
What is the difference between a male and female hookworm?
The male has a feathered copulatory bursae,on the tail and the female’s tail is just pointy.
76
What is the pathway of infection from hookworms to humans?
The larvae travel to the heart, then to the lungs, where they penetrate the alveoli, make their way up the trachea, up to the epiglottis, and then they are swallowed. They live in the small intestine lumen.
77
What symptoms do hookworm diseases cause?
The hookworms causes bleeding in the small intestine lumen and persistent anemia. The patient may also have cardiac symptoms from penetration of the alveoli.
78
What is the condition "pica"?
A desire to eat soil. This is caused from an iron deficiency in the diet, sometimes because of a hookworm infection.
79
What is Ancylostoma braziliense?
Dog and Cat Hookworms (Humans are accidental hosts)
80
When dog and cat hookworms migrate to the lungs it is called what syndrome?
Loeffler's syndrome
81
Very red (erythemic) and itchy (pruitic) lesions are a sign of what infection?
Ancylostoma braziliense- Dog and Cat Hookworms
82
What is cutaneous larva migrans?
This is when a dog or cat hookworm gets into a human by accident. Since we are not the right kind of host, the worm dies under the skin and causes an allergic reaction.
83
Phylum Nematoda is considered to be what?
Roundworms
84
Threadworm encysted in muscle
Trichinella spiralis
85
How are humans infected with Trichinellosis?
When they eat improperly processed meat. The larvae migrate to the skeletal muscles where they encyst.
86
Within the U.S. where is this disease most common?
In Alaska, where wild bear meat might be undercooked. The bears can be infected.
87
Why are there few cases of this in the U.S.?
By law, pigs are not allowed to free-graze. If they eat an infected rodent, they can get the disease and pass it on to humans. Pigs are fed grains to deter them from a desire to eat meat.
88
Wuchereria bancrofti are:
parasitic worms that cause Elephantitis, which are transmitted by mosquitos ,most common in tropical regions, like Africa (mosquitos:anopheles or Culex)
89
What are characteristics of Elephantitis?
Blocks lymph drainage
90
How is Elephantitis contracted?
During a blood meal, an infected mosquito introduces filarial larvae onto the skin of the human host, where they penetrate into the bite wound.
91
How does the mosquito get infected?
Another mosquito ingests the microfilariae during a blood meal and work their way to the mosquitos midgut and develop into infective larvae. The infected larvae migrate through to the mosquito’s probocis and can infect another human when the mosquito takes a blood meal.
92
Where is this condition usually found in humans?
They develop in adults that commonly reside in the lymphatics
93
How does the Loa Loa “eye worm” infect humans?
Vector=flies from the genus Chrysops
During a blood meal → an infected fly introduces filarial larvae onto the skin of the human host → where they penetrate into the bite wound.
The larvae develop into adults→ commonly reside in subcutaneous tissue → can migrate into spinal fluids, urine, and sputum
-----During the day they are found in peripheral blood
-----During the non-circulation phase, they are found in the lungs.
The fly ingests microfilariae during a blood meal→ migrate to the thoracic muscles → develop into infective larvae → migrate to the fly's proboscis and can infect another human when the fly takes a blood meal.
94
Kingdom Animalia
| -----Sub-kingdom Invertebrata
III. Phylum Annelida- segmented worms
95
Phylum Annelida-segmented worms
```
Class- Hirudinea
Leech (Hirudo medicinalis)
Anterior sucker (for cutting skin)
Mouth (for feeding)
Intestine
Posterior sucker (for attachment)
```
96
Leech
- Used as a medicinal agent for centuries
- First used in ancient Egypt to bleed people of “bad blood”
- Medieval times-used in conjunction with blood-letting by incisions.
- Today- used for patients with finger amputations- keep the veins open until the finger can be reattached-saliva has anesthesia and prevents clotting.
97
Leech
The leech has two suckers
-----The posterior sucker attaches to the host
------The anterior sucker makes a slit in the host’s skin so it can suck the blood.
The leech can take in up to 5 times its weight in blood.
Leeches are only used for one person for medicinal purposes-they are destroyed to prevent disease transmission.
98
What is included in Phylum Arthropoda?
- Ticks
- Mites
- Fleas
- Lice
99
What is under Phylum Arthropoda, Class Arachnia?
- Ticks
| - Mites
100
Phylum Arthropoda, Class Insecta
- Fleas
| - Lice
101
What is a Dermacentor Spp?
Tick - Class Arachnia
- Head
- Thorax
- Abdomen
- Legs
102
Hard Ticks
- Have a hard body
- Mouth parts are visible from the top surface
- Feed for days
103
Soft Ticks
- Have a soft, leathery body
- Mouth parts are on the bottom surface
- Feed from minutes to hours
104
What are three types of hard ticks and what diseases do they transmit?
1. Dermacenter
- --Ehrlichiosis (Ehrlichia spp)
- --Rocky Mountain Spotted Fever (Rickettsia rickettsii)
2. Ixodes
- --Lyme Disease (Borrelia burgdorferi)
- --Babbesiosis (Babesia microti; USA protozoa)
3. Amblyomma
- --Ehrlickiosis
105
What are some symptoms of Ehrlichiosis?
Fever, headache, fatigue, and muscle aches
106
What are some symptoms of Rocky Mountain Spotted Fever?
- Fever, headache, abdominal pain, vomiting, and muscle pain.
- A rash may also develop, but is often absent in the first few days, and in some patients, never develops.
- Rocky Mountain spotted fever can be a severe or even fatal illness if not treated in the first few days of symptoms
107
What are the symptoms of lyme disease?
Fever, headache, fatigue, and a characteristic rash called erythema migrans
108
If left untreated where can lyme disease spread?
The joints, the heart, and the nervous system
109
What are the signs and symptoms of babesiosis?
Fevers, chills, sweating, myalgias, fatigue, hepatosplenomegaly, and hemolytic anemia
110
When do symptoms typically occur?
After an incubation period of 1 to 4 weeks and can last several weeks
111
In whom is the disease more severe?
The immunosuppressed, splenectomized, or the elderly. It may cause death.
112
What is the genus name of the soft bodied tick?
Ornithidoros
113
What disease is transmitted by the soft tick?
Endemic relapsing fever
114
What are the signs and symptoms of endemic relapsing fever?
High fever, rigors, severe headache, muscle pains, weakness, anorexia, weight loss, and cough
115
What systemic complications can occur?
Nausea, vomiting, upper abdominal pain due to liver and spleen involvement, and a dry cough
116
How else may the disease manifest?
splenomegaly, hepatomegaly, jaundice, rash, respiratory symptoms, and central nervous system involvement.
117
What is another disease caused by the soft tick?
Tick paralysis
118
Is it more common in children or adults?
Children
119
How does the disease present?
As an ascending flaccid paralysis, accompanied by fever and toxemia (toxins in their saliva) that can lead to respiratory compromise and death
120
What is Sarcoptes scabiei (Scabies)?
Itch mite
121
Describe distinguishing parts of Sarcoptes scabiei.
Mouth
Legs
*Bristles on rear legs
*Bristles on abdomen
122
Describe the characteristics of Sarcoptes scabiei (Scabies).
* Scabies is an itchy, highly contagious skin disease.
* Mites are small eight-legged parasites (in contrast to insects, which have six legs).
* They are tiny, just 1/3 millimeter long. The mite is harmless, but causes an allergic reaction when it burrows into the skin to produce intense itching (pruritus), which tends to be worse at night.
* They can move one inch a minute.
123
What part of the human body do they prefer to burrow into?
They prefer thin skin like the areas between the fingers, and the bends of the elbows, wrists, and knees.
124
How is scabies transmitted?
They are sometimes transmitted by contact with contaminated gym equipment.
125
What is Dermatophagoides spp.?
Dust mite
126
What do dust mites feed on?
Organic detritus such as flakes of human skin
127
What symptoms may a person have that is allergic to dust mites?
Occasional runny nose, sneezing, and watery eyes
128
What makes up the class insecta?
Fleas and lice
129
What does the flea consist of?
Head, Thorax, Abdomen, and Legs
130
What is the common cause of asthma and allergic symptoms?
Dust mites
131
Name the parts of the flea.
Head, thorax, abdomen, legs
132
Fleas:
Vectors for disease
do not live on their hosts
They take their blood meal and return to their nest (carpet, etc).
133
Fleas cause the following diseases
```
Bubonic plague (Yersinia pestis)
Endemic typhus (Rickettsia typhi)
Tapeworms in pets
```
134
Bubonic plague (Yersinia pestis)
Caused by fleas
Wiped out almost 1/3 of Europe
Still have outbreaks from rodent population on West Coast (Squirrels in San Bernardino)
135
Endemic typhus (Rickettsia typhi)
from Rodents in Texas
136
Tapeworms in pets
When the dog or cat ingests the flea, it ingests the eggs and larvae inside the flea.
137
Fleas use
A rodent for a host
138
Where can you find Human Body Louse on clothing?
Nests in the seams of clothing, and lays eggs there.
139
What do Human Body Louse come out for?
It comes out for a blood meal.
140
What are Human Body Louses associated with?
They are associated with crowded, unsanitary conditions, such as during war, famines, and natural disasters.
141
What are diseases transmitted by body lice?
```
Epidemic Typhus (Rickettsia prowasekii) and
Relapsing Fever (Borrelia recurrentis and B. hermsii)
```
142
What is the treatment for body lice?
Clothing must be treated with insecticide or dry cleaning.
In the old days, they would boil the clothes.
The host also is also treated with Lindane solution and washed off 4-24 hours later.
143
Where is Pthirus pubis- crab louse found?
```
Thorax
Abdominal segments
Eyes
Legs
Antennae
```
144
What do crab lice infest? And where else are they found?
Crab lice tend to infest human pubic hair. The species may also live on other areas with hair, including the eyelashes.
145
What do crab lice feed on?
They feed exclusively on blood.
146
What are the only Host of crab lice?
Humans are the only known hosts
147
What are the symptoms of having crab lice?
The main symptom is itching, usually in the pubic-hair area, resulting from hypersensitivity to louse saliva, which can become stronger over two or more weeks following initial infestation.
148
How do you get crab lice?
Pubic lice usually infect a new host only by close contact between individuals, usually through sexual intercourse because they primarily spread through sweat, body fluids. Parent-to-child infestations are more likely to occur through routes of shared towels, clothing, beds or closets. Adults are more frequently infested than children.
