Lecture 2 definitions

Question 1

Frontal lobe

Answer 1

Responsible for voluntary movement, expressive language, self-control, memory storage, managing thinking and more

Question 2

Parietal lobe

Answer 2

Sensory perception and integration, including the management of taste, hearing, sight, touch and smell

Question 3

Occipital lobe

Answer 3

Responsible for visual perception, including colour, form and motion

Question 4

Temporal lobe

Answer 4

The formation of visual memories, interpreting the meaning of visual stimuli, production of speech, recognition of language and controlling unconscious and automatic reactions (e.g., appetite, thirst)

Question 5

Midbrain

Answer 5

Considered part of the brainstem: contains important brain regions (nuclei) for motor planning and execution. Dysfunction is implicated in Parkinson’s disease

Question 6

Hindbrain

Answer 6

Composed of the cerebellum, pons, medulla and reticular formation

Question 7

Medulla

Answer 7

Part of the hindbrain: regulates heart rate, blood pressure and respiration

Question 8

Reticular formation

Answer 8

Begins at the level of the medulla and runs up through the midbrain to the forebrain. It is related to consciousness and deals with gating of incoming sensory information

Question 9

Cerebellum

Answer 9

Important for fine motor coordination, learning and memory. It regulates movements requiring precise timing. Its function is disrupted by alcohol consumption.

Question 10

Forebrain

Answer 10

Also called the cerebral cortex. It is composed of the thalamus and hypothalamus, cerebrum, limbic system (hippocampus, amygdala) and corpus callosum

Question 11

Thalamus

Answer 11

Part of the forebrain. It relays incoming signals from sensory neurons to corresponding areas of the brain (mostly in cerebrum)

Question 12

Hypothalamus

Answer 12

Part of the forebrain. It has a role in motivation and emotion and controls the secretion of hormones into the bloodstream via the pituitary gland. The pituitary gland releases hormones that regulate other glands. These glands are responsible for regulating sexual behaviour, metabolism, stress response, pleasure and pain

Question 13

Limbic system

Answer 13

Part of the forebrain. It is composed of the hippocampus and amygdala. The hippocampus is critical for memory encoding and retrieval, spatial orientation and contextual mapping. The amygdala is critical for motivational and emotional responses to environmental stressors. It plays a major role with aggression and fear

Question 14

Corpus callosum

Answer 14

Part of the forebrain. It represents a region containing white matter fibres (axons-wiring of the brain). It connects the two cerebral hemispheres. If this area is dissected, it may lead to split brain syndrome

Question 15

Somatic sensory cortex, primary auditory cortex and the primary visual cortex

Answer 15

Part of the cerebrum, responsible for processing brain sensory input

Question 16

Grey matter

Answer 16

Contains the somata (cell bodies) of neurons

Question 17

White matter

Answer 17

Contains the axonal projections (axons) of neurons

Question 18

Soma

Answer 18

The neuronal cell body, containing its nucleus and essential organelles

Question 19

Dendrites

Answer 19

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

Question 20

Axon

Answer 20

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

Question 21

Myelin sheath

Answer 21

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

Question 22

Axon terminals

Answer 22

Represent the end points of the axon, where electrical impulses typically release chemical signals

Question 23

Depolarization

Answer 23

When neurons are stimulated (typically by other neurons, the membrane potential becomes more positive (from -70 mV towards 0 mv)

Question 24

When does a strong depolarisation occur?

Answer 24

When the membrane potential reaches a particular value (called a threshold, usually around -50 mV), the membrane potential is rapidly driven to around 30 mV. This rapid depolarisation event is called an action potential.

Question 25

Where is an action potential generated?

Answer 25

At the junction between soma and axon (axon hillock)

Question 26

What does synaptic transmission look like?

Answer 26

Action potentials arriving at axon terminals stimulate the release of chemicals (neurotransmitters) into the extracellular fluid. This gap is called the synapse and separates the sending (presynaptic) and receiving (postsynaptic) neurons. Neurotransmitters bind with special receptor molecules embedded in the membrane of the postsynaptic neuron. This can change the membrane potential of the postsynaptic dendrite, causing it to either depolarise (excitatory) or hyperpolarize (inhibitory)

Question 27

Which 3 types of neurotransmitters do you have?

Answer 27

Neurotransmitters that depolarise a postsynaptic neuron are called excitatory. Those that hyperpolarise it are called inhibitory. Lastly, there are neuromodulatory neurotransmitters, that modify the behaviour of a neuron in various ways.

Question 28

Dendritic intregration

Answer 28

Excitatory inputs depolarise the dendrite: this is called excitatory post-synaptic potential (EPSP). Inhibitory input hyperpolarises it: this is called inhibitory post-synaptic potential (IPSP). These passively diffuse along the dendrites and integrate at the axon hillock. If EPSP + IPSP exceed the threshold, an action potential is generated.