The Brain (Kapitel 2)

Question 1

Decribe the difference between Multipolar Neurons, Bipolar Neurons & Unipolar Neurons

Answer 1

Multipolar: Many dendrites, a single axon (most commen type of neuron)
Bipolar: Single dendrite, single axon (commen in sensory systems, as vision)
Unipolar: Single extension axon, going in two directions after leaving the cell body (transmit touch information from the from the body to the spinal cord)

Question 2

In a broad sense, there are 3 kinds of neurons with different tasks, name them.

Answer 2

Motorneurons, Sensory Neurons and Interneurons (most commen).

Question 3

What is an ‘Axon Hillock’ ?

Answer 3

A Coneshaped area from which the axon originates out of the cell body. Functionally, the integration zone of the neuron.

Question 4

Explain the term ‘Axon collateral’

Answer 4

A branch of an axon from a single neuron.. When the axon devides into several branches.

Question 5

Name the four basic types of Glial cells, and their primary function.

Answer 5

1. Astrocyte: ‘Suckerlike’, feet on blood vessels, regulating local blood flow to provide supplies for neurons, when they are active. Astrocytes receive synapses directly from neurons and also surround and monitor the activity of nearby neuronal synapses.
2. Microglial cell: Small cells, continually extending and withdrawing very fine processes that, when they contact a site of damage, form a spherical containment zone around the injury #thebrainscleanupcrew.
   3 & 4: Oligodendrocytes & Schwann cells: Perform myelination. Oligodendrocytes in the brain and spinal cord, and Schwanns in the rest of the body.

Question 6

What is meant by ‘Edema’ ?

Answer 6

The Swelling of tissue, especially in the brain, in response to injury.

Question 7

Locate and describe ‘Nodes of Ranvier’

Answer 7

A gap between successive segments of the myelin sheath, where the axon membrane is exposed.

Question 8

What characterizes ‘multiple sclerosis’ ?

Answer 8

Widespread degeneration of myelin.

Question 9

The different nerves of the body can be divided into three distinct systems, name them.

Answer 9

Cranial nerves, spinal nerves and automatic nervous system.

Question 10

How many cranial nerves are there, and what is there primary job?

Answer 10

12, (1 leftsided and 1 rightsided in each pair).
Serve the sensory and motor systems of the head and the neck. Directly entering or leaving the bain without ever joining the spinal cord.

Question 11

3 cranial nerves are exclusively sensory pathways. Name the three.

Answer 11

The olfactory nerve (smell), the optic nerve (vision) and vestibulocochlear nerve (hearing and balance).

Question 12

5 cranial nerves are exclusively motor pathways from the brain. Name the five.

Answer 12

1. The Oculomotor
2. The Trochlear
3. The Abducens
   all three = eye movement
4. The Spinal accessory (neck muscles)
5. The Hypoglossal (tongue muscles)

Question 13

Where does the Vagus nerve (cranial nerve) run?

Answer 13

The Vagus (latin; wandering) nerve extends far from the head, running to the heart, liver and intestines.

Question 14

What is the function of the ‘dorsal (back) root of the spinal cord’ and the ‘ventral (front) root of the spinal cord’ ?

Answer 14

The dorsal root of the spinal cord, consists of sensory projections(!) from the body to the spinal cord.

&

The ventral root consists of motor(!) projections from the spinal cord to the muscles.

Question 15

I hvilket år udgav Prince pladen ‘Purple Rain’ ?

Answer 15

‘Purple Rain’ udkom i 1984.

Question 16

Each spinal nerve is named according to the segment of spinal cord to which it is connected. There are 6 different regions of spinal cord. Try and name them, from the top and down.

Answer 16

Cervical (8 segments)

Thoracic (12 segments)

Lumbar (5 segments)

Sacral (5 segments)

Coccygeal (1 segment)

Bonus info:
= 31 paris of nerves down the spinalcord.

Question 17

Explain what ‘autonomic ganglia’ is.

Answer 17

Collections of nerve cell bodies, belonging to the autonomic divison of the peripheral nervous system, that are found in various locations and innervate major organs. They are found in various locations in the body outside the CNS.

Question 18

Whats the deal with preganglionic and postganglionic neurons?

Answer 18

Autonomic neurons within the brain and spinal cord send their axons to innervate all the major organs. The central neurons that innervate the ganglia are known as preganglionic autonomic neurons; the ganglionic neurons that innervate the body are known as postganglionic neurons.

So,

Preganglionic -> Postganglionic -> Organs

Question 19

Explain the main difference and functions of the sympathetic- and parasympathetic nervous system.

Answer 19

In genereal, sympathetic activation prepares the body for action: blood pressure increases, the pupils of the eyes widen, and the heart quickens. (Simply called the fight or flight response).

In contrast, the parasympathetic nervous system generally helps the body to relax, recupate and prepare for future action. (Simply called rest and digest response).

Question 20

What does the enteric nervous system govern?

Answer 20

The enteric nervous system, is an extensive meshlike system of neurons that governs the functioning of the gut.

Question 21

What sulcus separates the precentral gyrus and the postcentral gyrus?

Answer 21

Central Sulcus.

Question 22

What does saggital- coronal- and horizontal plane mean?

Answer 22

Saggital: Devides the body into right and left halves.

Coronal: Devides the body into a front (anterior) and back (posterier).

Horizontal: Devides the brain into upper and lower parts.

Question 23

Explain the mening of ‘efferent’ and ‘afferent’ .

Answer 23

We call an axon, tract, or nerve ‘afferent’ (arrive) if it carries information into a region that we are interested in, and ‘efferent’ (exit) if it carries information away from the region of interest.

Question 24

What is Medial and what is Lateral?

Answer 24

Medial: “Toward the middle”
Lateral: “Toward the side”

Question 25

Hvad sagde Troldmanden til Gartneren?

Answer 25

“Har i potter?”

Question 26

Why is white matter white, and why is gry matter grayish?

Bonus question: Based on your answer to the first quistion, what are their primary processes then?

Answer 26

White matter is white, primarily because it consists of largely of axons with white myelin sheaths.

Gry matter, on the other hand, are dominated by cell bodies.

(Bonus answer: Gray matter primarily processes information, while white mostly transmit information).

Question 27

What is Dorsal and what is Ventral?

Answer 27

Dorsal: “Toward or at the back”
Ventral: “Toward the belly”

Question 28

What is the forebrain also called?
What is the midbrain also called?
What is the hindbrain also called?

Answer 28

Prosencephalon (forebrain), Mesencephalon (midbrain) & Rhombencephalon (hindbrain).

Question 29

Where is cerebellum located, and what is it involved in?

Answer 29

At the back of the brain, dorsal to the pons, it is involved in the central regulation of movement.

Question 30

What 3 entities does the Brainstem consist of?

Answer 30

The Midbrain, Pons & Medulla.

Question 31

What is a ‘tract’?

Answer 31

A bundle of axons found within the central nervous system.

Question 32

What is a pyramid cell?

Answer 32

A type of large nerve cell that has a roughly pyramid-shaped cell body; found in the cerebrel cortex. The Pyramidal cell also has several dendrites (called basal dendrites) that spread horizontally from the cell body.

Question 33

What does the Basal Ganglia consist of?

Answer 33

Caudate nucleus, globus pallidus, subthalamic nucleus, putamen and substantia nigra (all important for movement). It is found deep within the cerebral hemispheres.

Question 34

What is the Hippocampus important for?

Answer 34

Primarily Learning and Memory.

Question 35

What can you say about the Thalamus?

Answer 35

The thalamus is a complex cluster of nuclei that acts as a switchbox, directing almost all incoming sensory information to the appropriate regions of the cortex for further processing, and receiving back from the cortex to control which sensory information is transmitted.

Question 36

What can you say about the Hypothalamus?

Answer 36

It is packed with discrete nuclei involved in many vital functions, such as hunger, thirst, temperature regulation, sex, and many more. Because the hypothalamus controls the pituitary gland, it serves as the brain’s main interface with the hormonal systems of the body.

Question 37

What is ‘Superior Colliculi’ and ‘Inferior Colliculi’ called all together? And what are their different functions?

Answer 37

Taken together, the colliculi are referred to as ‘The Tectum’. The superior colliculi process visual information; the inferior colliculi process information about sound.

Question 38

Ventral to the cerebellum lies … ?

Answer 38

The Pons.

Question 39

Where can the ‘Purkinje cell’ be located?

Answer 39

It’s a type of large nerve cell in the cerebellar (as in Cerebellum) cortex. Its in the middle layer.

Question 40

There are three cellular layers in the cerebellum, name the three.

Answer 40

From the surface and inwards.
Molecular layer
Purkinje cell layer
Granule cell layer

Question 41

What are the pons important for?

Answer 41

Within the pons are important motor control and sensory nuclei, including several nuclei from which cranial nerves arise (ex. the vestibulocochlear (VIII) cranial nerves).

Question 42

Specialized support systems protect and nourish the Brain. What are the three protective membranes called, the envelopes the brain and spinal cord?

Answer 42

The Meninges.

Question 43

What lies between the brain and the skull?

Answer 43

Between a tough outer sheet called ‘the dura mater’ and the delicate ‘pia mater’ that adheres tightly to the surface of the brain, a webby substance called the arachnoid suspends the brain in a bath of cerebrospinal fluid (CSF).

Question 44

In the cerebral ventricles of the brain, what specialized membrane produces CSF by filtering blood?

Answer 44

The Choroid Plexus.

Question 45

Hvis adspurgt, foretrækker Christian Houborg så en India Pale Ale eller en frisk Heineken?

Answer 45

India Pale Ale.

Question 46

What is the ‘Circle of Willis’?

Answer 46

At the base of the brain, the major cerebral arteries are joined via communicating arteries to form a structure called the Circle of Willis. It is formed by the joining of the carotid and basilar arteries.

Question 47

Shortly explain how Magnetic Resonance Imaging works.

Answer 47

A noninvasive technique that uses magnetic energy to generate images that reveal some structural details in the living brain.

Question 48

Shortly explain how positron emission tomography (PET) works.

Answer 48

A technique for examining brain function by combining tomography with injections of radioactive substances used by the brain.

Question 49

Shortly explain how functional MRI (fMRI) works.

Answer 49

Magnetic resonance imaging that detects changes in blood flow and therefore identifies regions of the brain that are particularly active during a given task.

Question 50

Shortly explain how transcranial magnetic stimulation (TMS) works.

Answer 50

Localized, noninvasive stimulation of cortical neurons through the application of strong magnetic fields.