Lecture 5

Question 1

How come ground squirrels don’t suffer from ischemic stroke?

Answer 1

They have something that alters proteins in body and allows blood flow into the brain.

Question 2

What happens to ground squirrels during winter?

Answer 2

Brain temperature is just above freezing, body temperature is just below. Heart rate at 1BPM.

Question 3

What is the corpus callosum?

Answer 3

Major band of fibres that connects brain hemispheres. Has approximately 200 million nerves

Question 4

What are the cortical layers?

Answer 4

Grey matter: Cell bodies+ capiliary blood vessels. White matter: Myelinated axons (myelin and insulation).

Question 5

What are the 2 main types of cells in the brain?

Answer 5

1) Neurons-carry out brains major functions

2) Glial cells- aid and modulate the neurons activities. Research has shown that this is connected to addiction.

Question 6

How many layers does the neocortex have?

Answer 6

6

Question 7

What are the layers of the neocortex?

Answer 7

Sensory input (afferent) layer: Layer IV
Info Integration: Layer I-III
Output (efferent) info: Layer V-VI
You can see these layers when looking at a picture of them-the darker it gets, the more neurons there are.

Question 8

How are the layers of the neocortex organized?

Answer 8

In a column (columna approach)

Question 9

What part of the nervous system is necessary for surivial according to evolution?

Answer 9

The spinal cord.

Question 10

What is the function of the spinal cord?

Answer 10

Involved in movement production. Often in conjunction with brain, but not always. Receives and sends information to and from the entire body. The segments of our bodies (dermatomes) correspond with segments in the spinal cord.

Question 11

What is the patellar reflex and if there’s an issue with it what does this show?

Answer 11

When you hit the knee and your leg goes wild. If theres a problem with it then there’s probably an issue with the spinal cord.

Question 12

How many pairs of cranial nerves are there and what do they do?

Answer 12

12 pairs, control head and neck (sensory+motor).

Question 13

What is the Law of Bell and Megendie?

Answer 13

Sensory information is transmitted to the brain (afferent) via the dorsal portion of the spinal cord.
Motor information is transmitted (efferent) in the ventral portion of the spinal cord.

Question 14

What are the 3 divisions of the brainstem?

Answer 14

1) Hindbrain
2) Midbrain
3) Diencephalon

Question 15

What is the hindbrain composed of?

Answer 15

Cerebellum, medulla, pons, and reticular formation.

Question 16

What does the cerebellum do?

Answer 16

Controls complex movement-size varies as a function of the physical speed and dexterity of an animal

Question 17

What is the reticular formation responsible for?

Answer 17

Stimulating the forebrain, sleep/wake cycles, arousal.

Question 18

What is the Pons responsible for?

Answer 18

Receives input from the cerebellum and transmits it to the rest of the brain.

Question 19

What is the medulla responsible for?

Answer 19

Breathing and heart rate- a blow to the base of the skull can be incredibly dangerous cuz thats where the medulla is.

Question 20

What is the tectum and where is it located (midbrain)?

Answer 20

Tectum-contains superior and inferior colliculi which take input from the optic nerve and auditory pathways respectively. It is located dorsally (to the roof)

Question 21

What is the tegmentum and where is it located? (midbrain)

Answer 21

Nuclei responsible for movement, located ventrally (to the floor).

Question 22

What is the substantia nigra and what happens if it’s damaged?

Answer 22

responsible for initiating movement-damage results in Parkinson’s disease.

Question 23

What is the diencephalon (brain stem)?

Answer 23

Top of the brainstem responsible for integrating sensory and motor information on it’s way to the cortex-thalamus and hypothalamus.

Question 24

What is the function of the thalamus?

Answer 24

To relay information to the cortex.

Question 25

What is the lateral geniculate nucleus?

Answer 25

Part of the thalamus-receives info from the optic tract and relays it to visual regions in the cortex.

Question 26

What does the hypothalamus do?

Answer 26

Controls horomone function via interactions with the pituitary gland (master gland). Includes feeding, sleep, sex, temperature regulation, emotional regulation.

Question 27

What is the forebrain and what does it consist of?

Answer 27

The largest region of the mammalian brain. Consists of the cortex and the basal ganglia.

Question 28

What does the cortex consist of?

Answer 28

The neocortex- Stuff you can see from the outside of the brain, unique to mammals
The allocortex- (other cortex), Evident in birds and reptiles as well as mammals.

Question 29

How many layers does each cortex have?

Answer 29

Neo- more complex, 5-6 layers
Allo- Less complex, 3-4 layers.
The density and type of cells vary across these layers.

Question 30

What does the Basal Ganglia do and what does it consist of?

Answer 30

Controls voluntary movment, consists of:

1) The caudate nucleus
2) The putamen
3) The globus pallidus.

Question 31

What are the 3 main structures of the allocortex?

Answer 31

1) The amygdala-emotional memory
2) The hippocampus-spatial navigation, episodic memory
3) The cingulate cortex- formerly known as limbic cortex, helps with navigation.

Question 32

What happens if the hippocampus gets damaged?

Answer 32

Spatial behaviour problems, no episodic memory.

Question 33

What is toxoplasmosis?

Answer 33

Primarily found in cats-may be transmitted to humans through cat feces. Symptoms include headaches, aches, and chills, weakened immune systems: confusion, seizures, enchephalitis. Worse in pregnant women, can only reproduce in the gut of cats, inhibits fear in rats, permanently rewires brain, but not in cats!