Comparative Anatomy Exam#3

Question 1

From what germ layer does the heart arise?

Answer 1

Mesoderm

Question 2

How are the hearts of vertebrate ancestors different than that of derived vertebrates?

Answer 2

Ancestral vertebrates had linear heart chambers while derived vertebrate hearts became folded.

Question 3

Describe the hearts/circulatory system of cyclostomes and modern chondrichthyes.

Answer 3

They contain a single atrium and ventricle, chambers are aligned in an s-shape.

Question 4

Describe the hearts/circulatory system of modern teleosts.

Answer 4

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

Question 5

Describe the hearts/circulatory system of lungfish.

Answer 5

Incomplete septa for both atria and ventricles allowing for some separation of oxygen rich and blood.

Question 6

Describe the hearts/circulatory system of amphibians.

Answer 6

Heart has divided atrium and undivided ventricle which separates blood streams.

Question 7

Describe the hearts/circulatory system of reptiles.

Answer 7

Sinus venosus has been lost, 2 atria and a partially divided ventricle.

Question 8

What does the urinary system do?

Answer 8

Excretes ammonia and other wastes from the blood.

Question 9

What is a glomerulus?

Answer 9

capillary tuft that produces ultrafiltrate.

Question 10

What does the loop of henle do?

Answer 10

increases urine concentration, reabsorbing glucose and water.

Question 11

What is a nephron?

Answer 11

functional unit of the kidney.

Question 12

Where does the nephric ridge arise during embryo development?

Answer 12

the intermediate mesoderm.

Question 13

What are the three distinct regions of the nephric ridge?

Answer 13

pronephros(anterior), mesonephros(middle), and metanephros(posterior).

Question 14

What is the outer layer of the kidney?

Answer 14

the cortex.

Question 15

What is the inner layer of the kidney?

Answer 15

the medulla.

Question 16

What is significant about bird and reptile kidneys?

Answer 16

kidneys are elongated and composed of many lobules. Birds convergently evolved loops of henle(not as concentrated); reptiles have no loops of henle.

Question 17

What are the main functions of the kidney?

Answer 17

excretion and osmoregulation.

Question 18

What waste product do mammals excrete from their urinary?

Answer 18

urea.

Question 19

What waste product do birds excrete from their urinary?

Answer 19

uric acid.

Question 20

What waste product do fishes excrete from their urinary?

Answer 20

ammonia.

Question 21

What waste product to turtles excrete from their urinary?

Answer 21

urea, uric acid, and ammonia(depending on the species).

Question 22

From what do gonads arise?

Answer 22

mesoderm.

Question 23

What forms the oviduct, uterus, and vagina?

Answer 23

the mullerian duct(regresses in males)

Question 24

What forms the vas deferens and the epididymis?

Answer 24

the mesonephric duct.

Question 25

What suspends the ovary?

Answer 25

mesovarium.

Question 26

What suspends the testis?

Answer 26

mesorchium.

Question 27

What is significant about cyclostome genital systems?

Answer 27

gonads are unpaired and lack reproductive ducts.

Question 28

What parts of the digestive system originate from the ectoderm?

Answer 28

tooth enamel and epithelial lining of the mouth and anus

Question 29

What parts of the digestive system originate from the mesoderm?

Answer 29

muscular layer of the stomach and intestines.

Question 30

What parts of the digestive system originate from the endoderm?

Answer 30

epithelial lining of the digestive tract, pancreas, liver, gallbladder.

Question 31

What are the four stages of food processing?

Answer 31

ingestion, digestion, absorption, and elimination.

Question 32

What is the palatoglossal arch?

Answer 32

the posterior border of the mouth.

Question 33

What is polyphyodont?

Answer 33

teeth are replaced continuously.

Question 34

What is oligophyodont?

Answer 34

teeth become permanent after several rounds of replacement.

Question 35

What is diphyodont?

Answer 35

teeth become permanent after one round of replacement.

Question 36

What is monophyodont

Answer 36

first round of teeth are permanent.

Question 37

What are thecodont teeth

Answer 37

teeth are embedded in bone.

Question 38

What are acrodont teeth?

Answer 38

teeth are attached to edge/top of jaw.

Question 39

What are pleurodont teeth?

Answer 39

teeth are attached to lingual edge of jaw.

Question 40

What is the pharynx

Answer 40

the passage way for food and air.

Question 41

What are the 4 common tissues of the alimentary canal from outer to inner?

Answer 41

adventitia(fibrous connective tissue), muscularis externa(smooth muscle), submucosa(loose connective tissue, nerve plexus), mucosa(epithelium, smooth muscle)

Question 42

What is the cardia of the stomach?

Answer 42

the first division found only in mammals. produces mucus.

Question 43

What is the fundus of the stomach?

Answer 43

the second division. majority of nutrient breakdown occurs here. glands produce HCl and enzymes.

Question 44

What is the pylorus of the stomach?

Answer 44

the third division. mucus secretions neutralize chyme.

Question 45

What is the role of the liver?

Answer 45

destroys old RBCs, detoxifies the blood, metabolizes carbs, proteins, and fats,

Question 46

What animals lack a gallbladder?

Answer 46

cyclostomes, some birds, some mammals. animals without a gallbladder may have to eat more frequently.

Question 47

What is the function of the pancreas?

Answer 47

neutralizes stomach acids, helps processing proteins, carbs, and fats. produces insulin and glucagon to regulate blood sugar levels.

Question 48

What is the cecum?

Answer 48

protrusion at the junction of the small and large intestine. site of microbial fermentation of cellulose. larger in herbivores.