3.6 - Senses and the Brain

Question 1

What do the cranial nerves detect?

Answer 1

5 senses:
- Olfactory stimuli (smell)
- Gustatory stimuli (taste)
- Auditory stimuli (sound)
- Visual stimuli (sight)
- Somatosensory stimuli (touch)

• Spinal nerves detect somatosensory stimuli

Question 2

What are the 3 main sections of the brain?

Answer 2

• Hindbrain
• Midbrain
• Forebrain

Question 3

What is the hindbrain?

Answer 3

The hindbrain is the most primitive and manages vital functions (breathing, heartbeat, and coordination of movement)

Question 4

Where is the hindbrain located?

Answer 4

The hindbrain is located at the back of the head

Question 5

What are the components of the hindbrain?

Answer 5

The hindbrain includes the cerebellum, pons, and medulla oblongata

Question 6

What is the midbrain?

Answer 6

The midbrain manages incoming information as well as coordinating sound and vision with muscle movement

• Also called the mesencephalon

Question 7

Where is the midbrain located?

Answer 7

The midbrain is positioned between the hindbrain and the forebrain

Question 8

What are the components of the midbrain?

Answer 8

The midbrain consists of structures like the tectum and tegmentum

Question 9

What is the forebrain?

Answer 9

The forebrain includes the “diencephalon” which manages incoming information and the endocrine system, and the “cerebral cortex”, which is the largest and most complex brain region, where decisions are made

• It is associated with complex cognitive processes, emotions, sensory processing, and the regulation of various physiological functions

Question 10

Where is the forebrain located?

Answer 10

It is located at the front of the brain

Question 11

What are the components of the forebrain?

Answer 11

The forebrain includes the cerebral cortex, thalamus, and hypothalamus

Question 12

What are the components of the diencephalon?

Answer 12

The diancephalon is another word for the thalamus and the hypothalamus

Question 13

What are the layers of protection for the brain?

Answer 13

The brain is protected by:
- Skull
- Floating in a bath of CSF
- Blood-brain barrier
- Meninges: 3 layers of protective material around the CNS: dura, arachnoid, pia (these layers also exists around the spinal cord. In fact, the entire CNS is protected with meninges, CSF and bone)

Question 14

What do the medulla oblongata and pons do?

Answer 14

Medulla oblongata and pons send information received from the spinal cord up to the midbrain (and then the thalamus)

They also send information from the brain back down to the spine

Question 15

What autonomic functions does the medulla oblongata do?

Answer 15

Medulla oblongata manages breathing rate, heart rate and blood vessel diameters (blood pressure) along with reflexes like gagging, sneezing, etc.

Question 16

What autonomic functions does the pons do?

Answer 16

Pons coordinates respiration (through the MO) and links the cerebellum to the rest of the brain

Question 17

What does the cerebllum do?

Answer 17

• Manages “learned” movements and coordinates motor functions
• When the brain determines that we should move, the cerebellum ensures that it is a smooth and accurate movement
• It is involved in coordinating things like balance, posture, and fine-movement
• As muscular behaviours are repeated (ex: learning to walk, ride a bike) the “memory” is moved to the cerebellum

Question 18

What are the three components of the brain stem?

Answer 18

• The medulla oblongata
• The pons
• The midbrain

Question 19

What is the cerebrum?

Answer 19

The cerebrum is the entire brain (two hemispheres) minus the cerebellum and the brain stem

Question 20

What is the bridge connecting the two hemispheres of the brain called?

Answer 20

The corpus callosum

Question 21

What is the outer layer of the cerebrum called?

Answer 21

The cerebral cortex

• Large surface area of grey-matter
  ** Contains sensory areas (one for each sense) and association areas (that relate those sensations to past experiences to interpret the information)
  *** Also contains motor areas to manage responses and a decision-making centre (prefrontal cortex)

Question 22

What does the thalamus do?

Answer 22

• Thalamus sends sensory information to the correct region of the cerebrum
• Also regulates sleep, alertness, consciousness

Question 23

What does the hypothalamus do?

Answer 23

Hypothalamus and pituitary gland control the endocrine system

Question 24

What are the 4 components of the limbic system?

Answer 24

• Hypothalamus (homeostasis)
• Thalamus (relays information)
• Amygdala (behaviour)
• Hippocampus (memory)

Question 25

What are the 4 lobes of the brain?

Answer 25

• Frontal lobe (decision-making centre; taste)
• Parietal lobe (touch)
• Occipital lobe (visual)
• Temporal lobe (auditory; smell)