Structure and function of the human nervous system- Part 2

Question 1

Frontal lobe

Answer 1

includes all the cortex anterior to the central sulcus. This region is especially large in humans, relative to other animals and is responsible for our unique ability to plan, reason, and reflect on our own behaviours

Question 2

Parietal lobe

Answer 2

includes cortex located behind the central sulcus, caudal to the frontal lobe and dorsal to the temporal lobe. In the left hemisphere this region plays a special role in aspects of language comprehension and mental arithmetic; in the right it is involved in representing the locations of salient objects in space

Question 3

Temporal lobe

Answer 3

includes cortex located ventral to the frontal and parietal lobes. In the left hemisphere this region plays a role in understanding the spoken and written word; in the right it may be particularly involved in recognising complex objects and faces

Question 4

Occipital lobe

Answer 4

includes the cortex at the back of the brain, caudal to the parietal and temporal lobes. Cortex in this are processes various aspects of visual information, such as motion, colour, shape and so on

Question 5

The corpus callosum

Answer 5

nerve fibres that connect the two hemispheres of the brain
myelinated axons extend from one hemisphere to the other
the corpus callosum contains about 200 million axons

Question 6

Homotopic fibres

Answer 6

connect corresponding regions of the cortex in the two hemispheres

Question 7

Heterotopic fibres

Answer 7

connect different cortical regions of the two hemispheres

Question 8

Ipsilateral fibres

Answer 8

connect adjacent regions within the same hemisphere

Question 9

Limbic system

Answer 9

The hippocampus and parts of the cortex that surround it are involved in learning and memory rather than emotional behaviour
amygdala- fear conditioning/mediating emotions
hippocampus- formation of long term memories
cingulate gyrus- emotional processing in response to pain

Question 10

Basal ganglia

Answer 10

a collection of nuclei buried deep within each hemisphere that are classified as grey matter
caudate nucleus- (‘nucleus with a tail’)
putamen- (‘shell’)
globus pallidus- (‘pale globe’)

The nuclei of the basal ganglia are responsible for controlling movement, particular those aspects that are highly automatised or involuntary (such as walking. The basal ganglia are dysfunctional in patients with Parkinson’s disease.

Question 11

Diencephalon

Answer 11

the second major devision of the forebrain is the diencephalon. It surrounds the third ventricle, in the middle of the brain, and consists of two major parts: the thalamus and hypothalamus

Question 12

Thalamus

Answer 12

forms the dorsal part of the diencephalon. It is a major relay station for sensory information being conveyed to the cerebral cortex

Question 13

lateral geniculate nucleus and medial geniculate nucleus (part of the thalamus)

Answer 13

Lateral geniculate nucleus receives information from the retina of the eye and sends axons to the primary visual cortex

Medial geniculate nucleus receives information from the inner ear and sends axons to the primary auditory cortex

Question 14

Hypothalamus

Answer 14

controls the autonomic nervous system and the endocrine system; it also regulates survival behaviours such as fighting, feeding, fleeing and mating

Question 15

Mesencephalon (tectum & tegmentum)

Answer 15

located towards the base of the brain, and is anatomically the junction between the cerebrum and spinal cord

Question 16

tectum (superior and inferior colliculi)

Answer 16

Superior colliculi have a role in both auditory and visual processing, and may also have an important role in spatial organisation

Inferior colliculi play a critical role in auditory processing, and in particular our ability to localise sounds in the environment

Question 17

tegmentum (reticular formation)

Answer 17

formed from complex networks of axons and dendrites. The reticular formation, which is widely connected with various parts of the brain and spinal cord, plays a vital role in sleep, arousal (the ability to remain conscious and alert), and various reflexes. Damage to this part of the brain stem can cause coma or death.

Question 18

tegmentum (substantia nigra)

Answer 18

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Question 19

Metencephalon and Myelencephalon

Answer 19

the two divisions of the hindbrain

Question 20

Metencephalon (pons)

Answer 20

the pons lie on the ventral surface of the brainstem. It contains several nuclei important for regulating sleep and arousal; it also relays information form the cerebral cortex to the cerebellum, via the cerebellar peduncles

Question 21

Myelencephalon (medulla)

Answer 21

the medulla links the hindbrain to the spinal cord, and contains neurons important for autonomic functions like respiration and heart rate

Question 22

Metencephalon (cerebellum)

Answer 22

• has more neurons than the cortex
• important role in motor function/ rapid changes in motor function
• makes adjustments to what muscles are doing
• Damage leads to subtle forms of motor impairment and difficulties with balance

Question 23

Spinal column

Answer 23

24 individual vertebrae 
cervical- neck
thoracic- chest 
lumbar- lower back 
sacral- pelvic region

Question 24

Spinal foramen

Answer 24

the hollow channel in which the spinal cord resides

Question 25

What is the purpose of the spinal cord?

Answer 25

to transmit somatosensory information (touch, temperature and pain) from the body to the brain, and to distribute motor axons to the various organs (glands and muscles)

Question 26

Spinal cord

Answer 26

Grey matter is surrounded by white matter (cell bodies are on the inside)
surrounded by 3 meninges
31 pairs of spinal nerves (to receive and convey information)

Question 27

dorsal and ventral roots

Answer 27

the dorsal root emerges from the dorsolateral surface of the spinal cord and the ventral root emerges from the ventrolateral surface

The fibres contained within the pair of roots emerging from each side of the spinal cord join together as they exit from gaps in the vertebrae, and form and individual spinal nerve

Question 28

What purpose do the spinal nerves serve?

Answer 28

the purpose of the spinal nerves is to receive information form the sensory receptors they innervate, and convey information from the brain to the glands and muscles of various parts of the body

Question 29

Dorsal root ganglia

Answer 29

afferent somatosensory
afferent neuron axons- dorsal roots
afferent cell bodies- dorsal root ganglia

Question 30

Ventral root ganglia

Answer 30

efferent, motor (muscles and glands)
efferent neuron axons- ventral root
efferent cell bodies- grey matter of spinal cord

Question 31

cranial nerves

Answer 31

serve the sensory and motor functions of the head and neck

Question 32

Autonomic nervous system

Answer 32

• regulates smooth muscle, (skin, blood, vessels, eyes, walls and sphincters of internal organs), cardiac muscles and glands
• controls blood pressure, temperature, digestion, sexual functioning
• consists of two antagonistic systems the sympathetic (arousing) and parasympathetic (calming)
• opposite functional consequences
• while one system is active the other one is inactive
• both have distinct neural pathways despite working together

Question 33

where are the cell bodies of the sympathetic nervous system located?

Answer 33

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Question 34

where are the cell bodies of the parasympathetic nervous system located?

Answer 34

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