lab 11 Flashcards
How does a hydra eat?
By shooting a nematocyst from its tentacles that stings the prey and paralyzes it. The tentacle bring the food to its mouth located at the top of the hydra. As the food is eaten it enters the gastrovascular cavity which is located in the body column
Two disadvantages of having a single opening to the digestive cavity?
- It is not efficient because they have to wait to eat again
- Food and wastes are mixed together
Mouth
Anterior opening for food intake
Pharynx
Muscular tube that produces suction to bring in dirt
Esophagus
Propels food from the pharynx to the crop
Crop
Storage sac for food and softens it
Gizzard
Used for mechanical digestion, grinding food into smaller pieces
Intestine
Secretes enzymes for chemical digestion, also necessary for absorption of nutrients into blood
Anus
Releases digestive system wastes
How does an earthworm eliminate its nitrogenous wastes?
The nephridia are organs that filter out the nitrogenous waste from the blood and then gets rid of it in the the form of urine to “tiny” pores in the skin
What type of urine do earthworms produce?
Dilute and hypotonic
Why is it necessary for earthworms that live in a moist environment to excrete dilute urine
They tend to make alot of ammonia which is toxic to the body so it results in the rapid removal of highly toxic ammonia
What tube-like structures produce urine in the mammalian kidney?
Nephrons
What is the function of the Interstitial Cells?
To produce testosterone
Zygote
Name for a fertilized egg
Morula
Solid ball of cells
Blastula
Hollow ball of cells
Gastrulation
Stage in which primary germ layers develop
Gastrula
Stage characterized by an inward folding to form a digestive cavity
Difference between an unfertilized egg and a fertilized egg
The fertilized egg has a membrane around it created by the sperm
How does the position of the rats eyes on its head compare to the position of your eyes?
The rat has eyes the bulge from the head, whereas we do not
How does the position of the rats eyes on its head compare to the position of your eyes?
The rat has eyes the bulge from the head, whereas we do not
What is the advantage to the rat of having eyes that bulge from the head and large pupils?
They can see in the dark and can also see more of its surroundings
Example of a digitigrade animal
Dog
Are humans digitigrade or plantigrade animals?
Plantigrade
Incisor
Cut/bite food
Molars
Grind food
The Pharynx is a component of which two body systems?
The respiratory and digestive system
Function of the diaphragm
The main muscle used for breathing
What tissue makes up the bulk of the heart
Cardiac tissue
Why does the trachea have rings around it?
To prevent it from collapsing, keeping it open for air to flow in and out
What is the function of the esophagus?
Carries food, liquids and saliva from the mouth to the stomach
Function of the stomach
Stores the food and adds gastric juices such as hydrochloric acid and pepsin enzymes
Function of the small intestine
Where most of digestion and absorption takes place. It is 20 feet long but small in diameter. Structures called the villi absorb nutrients and minerals from the food
Function of the large intestine
Absorbs water and makes feces
Why is the small intestine so long
It is where most of digestion happens and it increases the surface area for absorption
What substance secreted by the liver and what is its function
Bile is secreted and it breaks fat down into small pieces and aids in fat absorption
Is the pancreas an endocrine or exocrine gland
It is both
What is the endocrine function of the pancreas?
It’s secretes hormones, insulin and glycogen, to control blood sugar levels throughout the day
What is that exocrine function of the pancreas?
It excretes enzymes to break down macromolecules into food
Exocrine glands
Secretes enzymes which is poured directly at the site of action and controls short-term activity
Endocrine gland
It pours secretion directly into the blood, secretes hormones, and controls long term activity
