Evolutionary history of the brain

Question 1

What are the functions of the brain?

Answer 1

• using sensory input to guide movement

- using sensory input to regulate internal organs

Question 2

What are the 3 parts that the brain is divided into?

Answer 2

• forebrain: uses current sensory input and past experience to make and communicate decisions
• midbrain: uses current sensory input to direct movement
• hindbrain: maintains the current state, controls the mouth and is found coming up from top of the spinal cord

Question 3

Definition of gyrus and sulcus?

Answer 3

• gyrus: little ridges seen in the cortex
• sulcus: little folds/valleys
• the cortex covers most of the surface of the brain, beneath it there’s many brain regions that have variety of functions

Question 4

What are the 2 ways that the brain sends messages to the body?

Answer 4

• through the nervous system using electrical signals (are sent rapidly but costly due to amount of energy required and there’s structural/maintenance of having the system) (network structure determines which cells receive the messages)
• through the vascular system using chemical signals (are sent slower buy communication is cheap since system exists for other purposes) (membrane receptors determine which cells receive the messages)

Question 5

What is the timeline of the evolution of life?

Answer 5

• prokaryotic cells
• eukaryotic cells
• metazoa (first animals)
• bilateria
• chordates
• vertebrates
• jawed fishes
• mammals
• primates
• homo

Question 6

What are the comparisons in neuroanatomy?

Answer 6

• great variation in sizes of different brain regions, the size of different brain regions gives insight to abilities
• can divide up cerebral cortex by types of information it processes, size of cortical area is related to importance of information it processes
• brain tissue has high running costs: 2% of body weight but responsible for 20% of energy
• natural selection will favour enlargement of brain region only if it enhances survival/reproduction thus brain evolution depends on an animal’s anatomy and ecology

Question 7

What insight can be gained from other species?

Answer 7

-shared ancestry means that studying other animals helps us understand how our brains work