Comparative Anatomy Exam#3 Flashcards
From what germ layer does the heart arise?
Mesoderm
How are the hearts of vertebrate ancestors different than that of derived vertebrates?
Ancestral vertebrates had linear heart chambers while derived vertebrate hearts became folded.
Describe the hearts/circulatory system of cyclostomes and modern chondrichthyes.
They contain a single atrium and ventricle, chambers are aligned in an s-shape.
Describe the hearts/circulatory system of modern teleosts.
They contain a single atrium and ventricle, conus arteriosus has been lost(replaced with bulbus arteriosus), air bladder and intestine are highly vascularized for O2 uptake
Describe the hearts/circulatory system of lungfish.
Incomplete septa for both atria and ventricles allowing for some separation of oxygen rich and blood.
Describe the hearts/circulatory system of amphibians.
Heart has divided atrium and undivided ventricle which separates blood streams.
Describe the hearts/circulatory system of reptiles.
Sinus venosus has been lost, 2 atria and a partially divided ventricle.
What does the urinary system do?
Excretes ammonia and other wastes from the blood.
What is a glomerulus?
capillary tuft that produces ultrafiltrate.
What does the loop of henle do?
increases urine concentration, reabsorbing glucose and water.
What is a nephron?
functional unit of the kidney.
Where does the nephric ridge arise during embryo development?
the intermediate mesoderm.
What are the three distinct regions of the nephric ridge?
pronephros(anterior), mesonephros(middle), and metanephros(posterior).
What is the outer layer of the kidney?
the cortex.
What is the inner layer of the kidney?
the medulla.
What is significant about bird and reptile kidneys?
kidneys are elongated and composed of many lobules. Birds convergently evolved loops of henle(not as concentrated); reptiles have no loops of henle.
What are the main functions of the kidney?
excretion and osmoregulation.
What waste product do mammals excrete from their urinary?
urea.
What waste product do birds excrete from their urinary?
uric acid.
What waste product do fishes excrete from their urinary?
ammonia.
What waste product to turtles excrete from their urinary?
urea, uric acid, and ammonia(depending on the species).
From what do gonads arise?
mesoderm.
What forms the oviduct, uterus, and vagina?
the mullerian duct(regresses in males)
What forms the vas deferens and the epididymis?
the mesonephric duct.
What suspends the ovary?
mesovarium.
What suspends the testis?
mesorchium.
What is significant about cyclostome genital systems?
gonads are unpaired and lack reproductive ducts.
What parts of the digestive system originate from the ectoderm?
tooth enamel and epithelial lining of the mouth and anus
What parts of the digestive system originate from the mesoderm?
muscular layer of the stomach and intestines.
What parts of the digestive system originate from the endoderm?
epithelial lining of the digestive tract, pancreas, liver, gallbladder.
What are the four stages of food processing?
ingestion, digestion, absorption, and elimination.
What is the palatoglossal arch?
the posterior border of the mouth.
What is polyphyodont?
teeth are replaced continuously.
What is oligophyodont?
teeth become permanent after several rounds of replacement.
What is diphyodont?
teeth become permanent after one round of replacement.
What is monophyodont
first round of teeth are permanent.
What are thecodont teeth
teeth are embedded in bone.
What are acrodont teeth?
teeth are attached to edge/top of jaw.
What are pleurodont teeth?
teeth are attached to lingual edge of jaw.
What is the pharynx
the passage way for food and air.
What are the 4 common tissues of the alimentary canal from outer to inner?
adventitia(fibrous connective tissue), muscularis externa(smooth muscle), submucosa(loose connective tissue, nerve plexus), mucosa(epithelium, smooth muscle)
What is the cardia of the stomach?
the first division found only in mammals. produces mucus.
What is the fundus of the stomach?
the second division. majority of nutrient breakdown occurs here. glands produce HCl and enzymes.
What is the pylorus of the stomach?
the third division. mucus secretions neutralize chyme.
What is the role of the liver?
destroys old RBCs, detoxifies the blood, metabolizes carbs, proteins, and fats,
What animals lack a gallbladder?
cyclostomes, some birds, some mammals. animals without a gallbladder may have to eat more frequently.
What is the function of the pancreas?
neutralizes stomach acids, helps processing proteins, carbs, and fats. produces insulin and glucagon to regulate blood sugar levels.
What is the cecum?
protrusion at the junction of the small and large intestine. site of microbial fermentation of cellulose. larger in herbivores.
