Introduction to the brain Flashcards
What are the functions of the brain?
1) use sensory input to guide movement
2) use sensory input to regulate internal organs
What are the bumps and rigids in the cortex?
Gyrus
What are the folds and calleys in the cortex?
Sulcus
What are the 3 main parts of the brain?
Forebrain, midbrain, hindbrain
What does the forebrain use?
current sensory input and past experience to make (and communicate) decisions
What does the midbrain use?
current sensory input to direct movement
what does the hindbrain use?
maintains the current state; controls mouth
how are messages sent through the nervous system?
uses electrical signals. Messages are sent rapidly but the communication is costly.
Network structure determines which cells receive the messages
How are messages sense through the vascular system?
Through chemical signals (hormones).
Messages are sent more slowly but the communication is cheap.
Membrane receptors determine which cells receive the messages
Why are both the vascular system and nervous system used for communicating
We have two ways of communicating because sometimes the vascular system is not quick enough (e.g. someone about to hit you wouldn’t be responded to fast enough). We can’t just have the nervous system as it is much costlier. This is a cost-benefit trade off.
Order of animals existing?
Prokaryotic cells, eukaryotic cells, metazoa, bilateria, chordates, vertebrates, jawed fishes, mammals, primates, homo
PEMBCVJWPH
Characteristics of prokaryotic cells
Membrane produces energy
DNA regulates protein
Characteristics of eukaryotic cells
Energy production is no longer in the cell membrane but now the mitochondria.
Cell membrane performs phagocytosis
Phagocytosis
white blood cell engulfs bacterium
Characteristics of metazoa
After divisions, cells are now able to stick together to form a multicellularity. Cell division. Different cells can focus on different functions.
Get a digestive chamber within the cell for more efficient use of energy.
What is multicellular
of an organism or part) having or consisting of many cells.
What is bilateria
The appearance of the bilateria are the first to have bilateral symmetry. They have a proper front, back, left and right. Bilateria are our direct ancestors. Prior to this there was radial symmetry (like we see now in jelly fish). Now we have bilateral symmetry which means the mouth and anus are completely separate (as shown in the right picture). The right end of the body shows the start of the brain. This has the first appearance of muscle
What characteristcs are there of chordates
After cambrian explosion.
Chordates had a stiffened rod and a recognisable tail. This is the beginning of a spinal cord
Characteristics of a jawed fish
First organisms to have teeth meaning they can catch and eat food more easily. This makes them more efficient and become bigger and put more energy into the brain. They can also move their eyes separate to the rest of their body. They can maintain a gaze on a prey item. The cerebellum appears here
characteristics of mammals
The key innovations here are differentiated teeth (e.g. a horse vs cat have different teeth such as enlarged canines in cats).
Mammals here tended to be insectivorous.
Primates emerged from this.
characteristics of homo
Changes of hands and teeth changed before the volume of cerebral cortex increased.
Why do teleost fish have a large optic tectum?
have a good sense of sight
Why do mammals have a large olfactory bulb?
good sense of smell
Why do platypus have a large bill
to sense through electrical perception where its prey is. A huge part of its cortex is dedicated to this perception. The bill is full of sensitive regions.
Key points
- The brain sends messages to body via nervous system (electrical signals; quick/costly) and vascular system (hormones; slow/cheap)
- The brain can be subdivided into regions that are (loosely) associated with particular functions
- The brains of humans and other vertebrates share a similar gross structure
- The relative size of different brain areas indicates the functional specialisations of the animal, reflecting its ecology
- Several of the major evolutionary changes in the brain were linked to changes in motor control and digestive efficiency
