Lecture 4

Question 1

What are the three chambers in the heart?

Answer 1

The atrium, ventricle and sinus venosus

Question 2

What is the hepatic portal vein?

Answer 2

Transports substances from the gut to the liver for processing, detoxification and storage

Question 3

What is the renal portal vein?

Answer 3

Returns from the tail and posterior trunk to the kidneys. Lost in mammals, not well developed in jawless vertebrates

Question 4

What is the job of the archinephric duct?

Answer 4

Drains urine from kidneys to cloaca. Also used by gnathostomes to transport sperm: vas deferens

Question 5

What do kidneys do?

Answer 5

Dispose of waste products and regulate water and minerals

Question 6

Name the three parts of the kidneys

Answer 6

Pronephros, opistonephros and metanephros

Question 7

Explain the pronephros, opistonephros and metanephros

Answer 7

Pronephros: Functional only in embryos, Opistonephros: forms kidneys in adult fish & amphibians, Metanephros: kidney in adult amniotes & drained by ureter

Question 8

Describe the general location of gonads

Answer 8

They usually lay on the posterior body wall behind the peritoneum, paired.

Question 9

Describe the path of the sperm and egg in jawed vertebrates

Answer 9

The sperm exit via the archinephric tubule and the egg is released into the coleom and drawn into an oviduct where its fertilized

Question 10

What are the vestibular apparatus and the cochlea?

Answer 10

A membranous labyrinth that has balance organs. In tetrapods its the cochlea, responsible for hearing

Question 11

What is the vestibular apparatus contained within?

Answer 11

The optic capsule

Question 12

What does the optic capsule contain

Answer 12

The endolymph, a fluid that transmits waves of pressure that stimulates sensory hair cells

Question 13

What parts of the optic capsules detect which way is up & linear acceleration?

Answer 13

The sacculus and utriculus. They house sensory crystals that contain CaCO3 crystals resting on hair cells, sensations are detected on these

Question 14

Which part of the optic capsule detect angular acceleration?

Answer 14

The semicircular canals. The ampullae at each end have hair cells embedded in jelly that monitor the displacement of the haemolymph

Question 15

Describe the evolution of feeding in non-vertebrates

Answer 15

A suspension feeder developed more of a muscular pharynx then cartilage replaced collagen in pharyngeal bars which created a suction to suck in water, squeeze to expell water

Question 16

Describe the evolution of feeding in agnathans

Answer 16

Exploited muscular pharyngeal pump, would draw sediment inwards. Cilia still transported particles to oesophagus

Question 17

Describe the evolution of feeding in gnathostomes

Answer 17

Plucking individual foods, increased effort, favoured sudden/forceful expansion of pharyngeal cavity. Elastic recoil system not strong enough for forceful cpature = jaw

Question 18

What are the primitive features of agnathans/cyclostomes (e.g. hagfish/lamprey)?

Answer 18

No jaws, lack paired fins, no specialized reproductive tracts: coelom - contractions - archinephric duct - external fertilization

Question 19

Name the features of the agnathans

Answer 19

Only notochord, single nostril linked to olfactory sac, heart has one atrium and one ventricle & pore-like external gill openings

Question 20

What is the balancing organ in a hagfish and what does it have?

Answer 20

The vestibular apparatus or ear that includes a single semicircular canal. Lampreys have two

Question 21

What is the osmotic flow like in hagfish and why?

Answer 21

There’s no osmotic flow in or out because the salt concentration in the body fluid is similar to the sea

Question 22

What are petromyzontiformes?

Answer 22

Lampreys

Question 23

What kind of fins do lampreys have and lack?

Answer 23

Dorsal fins and lack lateral fins

Question 24

What is one difference between the hagfish and the lamprey?

Answer 24

The lamprey’s tissues can experimentally produce a mineralised skeleton, the hagfish cannot

Question 25

How does a lamprey respire?

Answer 25

Using tidal ventilation through seven gill slits. The velum prevents water back-flow into the mouth

Question 26

What does anadromous mean?

Answer 26

Adults live in large lakes/the sea and swim upstream to spawn

Question 27

Describe the breeding of lampreys

Answer 27

Both sexes dig out a hole in gravel, female attaches to rock, male attaches to her, eggs are fertilized as they're produced.

Question 28

Name the larvae of lampreys and what they do

Answer 28

Ammoecoetes float downstream and burrow in the sediment, water filtering through pharynx & feeding on organic matter. 3-7 years later it emerges and the parasite moves downstream

Question 29

What is another name for the splanchnocranium and what is it the oldest part of?

Answer 29

The branchial basket, it is the oldest part of the contemporary skull in vertebrates

Question 30

What structure is crucial to the evolution of jaws in gnathostomes?

Answer 30

Branchial arches

Question 31

What are myomeres?

Answer 31

Metamerically arranged W-shaped muscles

Question 32

Describe the digestive system in cyclostomes

Answer 32

A simple, straight tube and no pancreas

Question 33

What could be considered as the stomach in lampreys?

Answer 33

The liver tissue that surrounds a region of the gut. lampreys have no bileduct.

Question 34

Describe the liver of a hagfish

Answer 34

Tthey have two lobes and a bile duct that connects them to the gut.

Question 35

Describe the circulatory system in cyclostomes

Answer 35

Blood is pumped from heart to the gills then caudally in the dorsal aorta to the body. Blood returns to the heart via a simple system of veins