flatworms roundworms notes
DESCRIPTION
TRANSCRIPT
Warm up
1. What are some characteristics that flatworms and cnidarians share?
2. What are some characteristics that are different?
Platyhelminthes
The flatworms
Bilateral Symmetry
3 tissue layers
No body cavity
Mouth but no anus
Branched intestines
Feed on small animals; scavengers
Parasites; tapeworms
No skeleton; Body cavity is fluid filled to move and keep shape
Sexual reproduction, but hermaphroditic
Live in all environments
Primitive muscles!
Many parasitic for humans
Definite nerve organs including eyespots for sensing light
Most primitive of the bilateral animals!!!
CEPHALIZATION: definite head end
Collection of nerves in the head; ganglia
Hymenolepis dimunataThis is how tapeworm attach to a host.They are found in uncooked meat and fecal material.The host can become VERY SICK!!!
Bilharzia burrows through you skin and moves to your gut. The host becomes very sick. It comes from fouled water. ~250,000,000 people are infected
Sparganosis is from infected water.
Humans can get it from reptiles, birds, & other mammals that have it.
They can grow up to 14 inches.
This flatworm can infect the brain or eyes.
Most common in eastern Asia!
Nematoda
The roundworms
Bilateral
Digestive cavity
Mouth and anus
Feed on just about anything
Many harmful parasites to humans!
No skeletonSexual reproductionFound everywhereName means thread-like
No circulatory system
Look like worms, but are NOT!
Coelom (body cavity type body plan)
Two nerve cords that transmit impulses
These parasites have teeth-like plates to attach them to the intestinal tract.
Hookworms can each drink 1.0 ml (1/2 cup) of blood per day.
You can get them by walking barefoot then they burrow into your skin and move to your blood.
Trichinella roundworms in human muscle
Whipworm found in 50% of puppies;Transmitted to human owners
Most common childhood intestinal parasite