Body Cavity and Early Embryo Development in humans Flashcards
(28 cards)
Body cavities develop in…
Early embryo
Body cavity starts as…
Coelom
Coelom is…
Single ventral cavity
Body cavity provides…
Space for the visceral organs to grow
In adults, the ventral body cavity is divided into…
The thoracic cavity and the abdominopelvic cavity
The body cavity is in all animal groups, except…
Porifera (sponges), Radiata (jellyfish) and Platyhelminths (flatworm)
The animals with body cavity have… (3)
1- more organs
2- longer digestive tract
3- can store egg and sperm
In humans, the digestive tract consists of… (6)
1- Mouth 2- Pharynx 3- Esophagus 4- Stomach 5- Small intestine 6- Large intestine
What makes the organs of the digestive tract mix and move food? (In humans)
Their smooth muscles
The basic functions of the digestive tracts are… (4)
1- Ingest
2- Digest
3- Absorb
4- Defecate
In Radiata and platyminths, how many opening does the digestive system have?
One
In Nematoda and in Rotifera, how does the food in their digestive system move?
It moves only when they are moving (two openings, but no muscles)
What is the advantage of having a longer digestive tract?
It allows food to be exposed longer to digestive enzymes
What are the functions of jointed appendages? (2)
1- Increase flexibility
2- Increase the efficiency of movement
What is the main difference between verterbrates and anthropods? (appendage wise)
Vertebrates have endoskeletons (muscles attached to bones) anthropods, exoskeletons
A type of neuronal system is present in all animals except in…
Porifera, which have a neural net
What are the steps of the early embryo development in humans? (4)
1- Fertilization
2- Cleavage (from fertilization to formation of Blastocysts)
3- Gastrulation
4- Organogenesis
What is an oocyte?
A cell that divides to create an ova
How does a zygote form?
The nuclei of an oocyte and a sperm fuse
What happens to the oocyte in fertilization stage?
It engulfs the sperm, completes meiosis 2 and a zygote forms.
What is the cleavage?
Repeated cell division with little or no overall growth
What is a blastocyst? (in mammals, blastula in other animals)
A hollow ball of cells
What is a blastomere?
A cell in blastocyst
What is a blastocoel?
A fluid-filled cavity
