Neuroanatomy (L2)

Question 1

Central nervous system (two main features)

Answer 1

Brain and spinal cord
- Spinal cord is the primary means for transmitting messages between the brain and the rest of the body.

Question 2

CNS - three main brain sections

Answer 2

Forebrain, midbrain, hindbrain

Question 3

CNS forebrain (5)

Answer 3

Thalamus, hypothalamus, cerebrum, limbic system, corpus callosum.

Question 4

CNS hindbrain (5)

Answer 4

Cerebellum, pons, medulla, brain stem, spinal cord.

Question 5

PNS systems

Answer 5

Somatic system, automatic system

Question 6

Somatic system (+ neuron activity)

Answer 6

Voluntary muscle activation.
- Sensory neurons carry messages from sensory organs (ears, eyes, skin) to CNS.
- Motor neurons carry messages from motor cortex to voluntary muscle fibres.

Question 7

Automatic system (+ 2 key components)

Answer 7

Controls smooth muscles, cardiac muscles, and glands; basically involuntary.
1. Sympathetic: generally activates
2. Parasympathetic: generally inhibits.

Question 8

Cross sections of the brain (3)

Answer 8

1. Coronal (vertically ear to ear)
2. Horizontal (through the jaw direction)
3. Sagittal (mid) (spine to mouth)
   - Mid sagittal means it was cut directly in the middle of the brain

Question 9

Medulla functions (3)

Answer 9

• Heart rate
• Blood pressure
• Respiration

Question 10

Pons functions (3)

Answer 10

• Sleeping and dreaming
• Breathing
• Arousal

Question 11

Reticular formation functions (2)

Answer 11

• Consciousness
• Gating of incoming sensory information

Question 12

Reticular formation + location

Answer 12

Begins at the level of the medulla and runs up through the midbrain to the forebrain.
- Located at the formation of the brainstem.

Question 13

What is the cerebellum good for/what does it do?

Answer 13

• Important for fine motor coordination, learning and memory.
• Regulates movements requiring precise timing.
• Function is disrupted by alcohol consumption

Question 14

Thalamus information

Answer 14

• ‘Switchboard’ of the CNS
• Relays incoming signals from sensory neurons to corresponding areas of the brain (mostly in the cerebrum).

Question 15

What does the hypothalamus do?

Answer 15

• Role in motivation and emotion
• Controls the secretion of hormones into the bloodstream via the pituitary gland.

Question 16

Pituitary gland information

Answer 16

• Brains portal to the neuroendocrine system.
• Releases hormones that regulate other glands.
• Hormones regulate sexual behaviour, metabolism, stress response, pleasure, pain.

Question 17

Hippocampus information (2)

Answer 17

• Part of the limbic system
• Critical for: memory encoding and retrieval, spatial orientation, contextual mapping.

Question 18

Amygdala information (3)

Answer 18

• Part of the limbic system
• Motivational and emotional response to environmental stressors.
• Aggression and fear.

Question 19

Corpus callosum information (2)

Answer 19

• A region containing ‘white matter’ fibres (axons) connecting the two cerebral hemispheres.
• Dissection/agenesis leads to ‘split brain syndrome’.

Question 20

Gyrus

Answer 20

The gyri are the ridges that appear on the wrinkled surface of the brain.

Question 21

Sulcus

Answer 21

The sulci are the grooves that appear on the wrinkled surface of the brain.

Question 22

What are the four lobes?

Answer 22

1. Frontal lobe
2. Parietal lobe
3. Temporal lobe
4. Occipital lobe

Question 23

Association cortex

Answer 23

• Areas that, when stimulated, do not cause sensory or motor reactions.
• These regions process associations
  (relationships) between one (unimodal) or multiple (multimodal) sensory and/or motor representations.

Question 24

Grey matter

Answer 24

Contains the somata (cell bodies) or neurons.

Question 25

White matter

Answer 25

Contains the axonal projections (axons) of neurons.

Question 26

Cellular organisation (8)

Answer 26

1. Cell membrane
2. Dendrites
3. Nucleus
4. Myelin sheath
5. Node of Ranvier
6. Soma (cell body)
7. Axon
8. Axon terminals

Question 27

Soma

Answer 27

The neuronal cell body, containing its nucleus and essential organelles.

Question 28

Dendrites

Answer 28

Specialised receiving units that collect messages from neighbouring neurons and send them to the cell body.

Question 29

Axon

Answer 29

Conducts electrical impulses from the soma to distal target regions, such as other neuron or muscle cells.

Question 30

Myelin sheath

Answer 30

A layer of fatty tissue that surrounds and insulates the axon, improving its transmission efficiency.

Question 31

Axon terminals

Answer 31

End points of the axon, where electrical impulses typically release chemical signals.

Question 32

Resting membrane potential (2)

Answer 32

• Neuronal membranes regulate the flow of charged ionic particles or molecules into and out of a neuron.
• At rest, neurons use this mechanism to maintain a net negative interal charge of around -70 mV.

Question 33

Action potential

Answer 33

When neurons are stimulated (typically by other neurons), the membrane potential becomes more positive (moves from -70 mV towards 0 mV).
- This is called depolarisation
- When the membrane potential reaches a particular value (called a threshold, typically -50 mV), a strong depolarisation occurs, driving the membrane potential rapidly to around +30mV.