Cardiovascular System And Sensory Organs

Question 1

what is an advantage of the mammalian heart having pulmonary and sysemic segregation?

Answer 1

differences in blood pressure
systemic bp nearly 10x more

Question 2

what is the anatomy of the fish cardiac structure?

Answer 2

• sinus venosus (pre-pump)
• atrium
• ventricle
• bulbus arteriosus (extra ‘push’)
• simple linear circulation

Question 3

what is the anatomy of the amphibian cardiac structure?

Answer 3

• single outflow
• 2 atria, 1 ventricle = slight mixed but segregated blood flow
• spiral valve = blood input + output frim different directions
• superior vena cava -> sinus venosus -> right atrium

Question 4

what is the anatomy of the three-chambered (non-crocodillian) reptillian cardiac structure?

Answer 4

• 2 atria, 1 ventricle BUT partial septum
• 2 aorta, 1 pulmonary trunk
• into heart from right side (no left outflow), exit pulmonary artery
• septum positioning differs with reptile class

Question 5

what do all vertebrate embryo’s hearts display during development?

Answer 5

branchial arch arterial arches (maintained in fish)

Question 6

which vessel does amphibian blood flow through from the systemic arches?

Answer 6

dorsal aorta

Question 7

what is seen in amphibia but not reptiles in terms of cardiac vessels?

Answer 7

cutaneous arteries

Question 8

what big difference is there in anatomical layout of mammalian cardiovascular system compared to lower vertebrates?

Answer 8

breaking of left/right symmetry: mammals have only one aorta on the left

Question 9

what are branchial arch arteries?

Answer 9

arteries supplying blood around the body of fish
only found embryonically of non-fish vertebrates + fish

Question 10

hippocampal pathway

Answer 10

• enterial cortex signal from parahippocampal gyrus to dendrate gyrus (along perforant axons)
• mossy fiber axon -> schaffer collateral axon

Question 11

hippocampal lesion experiment

Answer 11

• lesion on entorhial cortex, fornix, fimbria and hippocampus
• radial arm maze
• repetition of sequence of choice even when wrong
• = important for spatial learning, not queued learning

Question 12

correlations between food-cathing bird and hippocampal size?

Answer 12

• larger hippocampus
• more neurogenesis (especially in autumn)

Question 13

where in the hippocampus are place cells located?

Answer 13

CA1 + CA3

Question 14

what do CA1 neurons do?

Answer 14

• predict direction
• specific firing in stem when preparing left/right turn

Question 15

where are head direction cells found?

Answer 15

post-subiculum

Question 16

ensemble code

Answer 16

groups of neurons firing together when in same location in space

Question 17

where are grid cells located?

Answer 17

entorhinal cortex

Question 18

what is the foramen of panizza?

Answer 18

• hole which connects the left + right aorta
• operates when crocodile holds its breath = shunting vessel

Question 19

Path integration

Answer 19

Using a range of internal movement cues to determine position relative to starting point

Question 20

Edward Tolman radial maze experiment method

Answer 20

-Put a rat in a round thing with a tunnel leading via a circuitous route to some food until rat learns there’s food there
-Block that tunnel, add a bunch of straight tunnels projecting out in a semicircle and put food in the same place as before

Question 21

Edward Tolman radial maze experiment results

Answer 21

-Rat realises original tunnel is blocked and finds alternative route to the same spot where the food was.
-Rats are capable of dead reckoning by path integration

Question 22

Reference memory example

Answer 22

Remembering where something was last time

Question 23

Working memory example

Answer 23

Remembering where you’ve already looked for something

Question 24

Morris water maze

Answer 24

-Put a rat in water with some visual clues to act as landmarks and a platform submerged somewhere in the water
-Rat will get quicker over time at finding the platform using the landmarks
-Other mazes demonstrating the same principle include elevated platform maze and elevated honeycomb

Question 25

Hippocampal circuit

Answer 25

Entorhinal cortex–> dentate gyrus–> CA3–> CA1–> subiculum

Question 26

Components of tri-synaptic circuit

Answer 26

-Perforant
-Mossy fiber
-Schaffer collaterals

Question 27

What effect did injuring the entorhinal complex, fornix, fimbria and hippocampus of rats have?

Answer 27

Rats repeated the same choices even when incorrect, demonstrating deficit in spatial learning but not cued learning

Question 28

Three key conclusions of maze experiments

Answer 28

-Hippocampal lesion/injury affects spatial learning more than cued learning
-Timing of lesion (before or after learning) is significant
-In animals with hippocampal lesions, performance was worse in working memory tasks than reference memory tasks

Question 29

Three examples of hippocampal size variation

Answer 29

-Hippocampus of black capped chickadee gets bigger and has more neurogenesis occurring in Autumn
-Homing pigeons have larger hippocampus than non-homing relatives
-Taxi drivers have larger posterior hippocampus than other humans

Question 30

Place cells key characteristics

Answer 30

-Located in CA1 and CA3 of hippocampus
-Firing rate of each cell increases when in a particular place
-Different cells fire in different places, forming a spatial map

Question 31

Head direction cells key characteristics

Answer 31

-Located in post-subiculum
-Each cell is active when facing a particular direction
-Different cells fire when head facing different directions

Question 32

Grid cells key characteristics

Answer 32

-Located in entorhinal cortex
-Fire at regular intervals according to distance traveled in any direction
-Provides most entorhinal spatial input to CA1 and CA3

Question 33

Key characteristics of social place cells in bats

Answer 33

-Hippocampal CA1 neurons
-Track position of another bat