1
Q
In four legged animals what does dorsal: ventral mean?
A
Back and belly
2
Q
what does Cranial: caudal mean?
A
Head end and tail end
3
Q
What does proximal: distal mean?
A
Close to and far away
4
Q
In four legged animals what does anterior: posterior mean?
A
front end and back end
- in a four-legged animal it means the same thing as cranial: caudal
5
Q
What does rostral mean?
A
Nose or mouth end
6
Q
What does Medial: lateral mean?
A
Towards the midline or away from it
7
Q
What does anterior: posterior mean in two legged animals?
A
The same as ventral and dorsal: belly and back
8
Q
What does superior: inferior mean in two legged animals?
A
position in the vertical axis - closer to head or feet
9
Q
What does cephalic: caudal mean?
A
Head: tail end (cephalic is sometimes used instead of cranial)
10
Q
What is the frontal plane?
A
Sliced from the front
11
Q
What is the sagittal plane?
A
Cut into left and right
12
Q
What is the transverse plane?
A
Cut horizontally
13
Q
What are motor/ efferent neurones?
A
Neurones that carry a signal towards a target tissue or organ, in order to make something happen
14
Q
What are sensory/ afferent neurones?
A
Sensory neurones detect changes in the environment and carry signals about that change to the central nervous system
15
Q
What does the autonomic nervous system do?
A
The autonomic nervous system (ANS) controls many of our bodies’ involuntary responses to its environment. It is divided into the sympathetic nervous system and the parasympathetic nervous system.
16
Q
What is one of the reasons we have a nervous system?
A
So we can move
17
Q
What do sponges, jellyfish (invertebrates) ect. have instead of a nervous system?
A
A nerve net
18
Q
What do more advanced invertebrates (arthropods) have as their nervous system?
A
- ventral cord (compared with dorsal cord in vertebrates)
- brain
19
Q
When did the vertebrate brain appear?
A
- Small collection of neuronal control circuits (primitive brain) in amphioxus (cephalochordate)
- Higher in the evolutionary change we can see a brain with brain divisions common to all vertebrates (e.g. a shark brain): olfactory bulb, cerebral hemispheres, cerebellum, optic tectum, brain stem containing medulla oblongata
- Mammals: neocortex (enables us to process complex information)
20
Q
What four sections is the central nervous system of vertebrates split up into?
A
- forebrain
- midbrain (part of brain stem)
- hindbrain/ rhombencephalon (part of brain stem)
- spinal cord
21
Q
What does the forebrain contain?
A
Telencephalon: cortex and olfactory bulb
Diencephalon: thalamus and hypothalamus
22
Q
What does the midbrain contain?
A
Mesencephalon: tectum and tegmentum
23
Q
What does the hindbrain contain?
A
Pons
Medulla
Cerebellum (separate from brain stem)
24
Q
What are the three layers of cells in an embryo?
A
Endoderm (linings of organs; viscera)
Mesoderm (bones and muscles)
Ectoderm (nervous system and skin)
25
How does the nervous system develop?
- first the ectoderm starts to become specialised
- a streak forms down the middle
- Specialisation in the neural plate - a region which is going to become the nervous system
- Specialisation in a region which is going to become the epidermis (there is a neural plate border between these two regions)
- The middle of the neural plate starts to dip down – the neural plate folds and fuses to form the neural tube (continuous layer of epidermis with neural tube and neural crest beneath it)
- CNS develops from the walls of the neural tube. PNS (peripheral nervous system) derives from the neural crest
- The notochord arises from the mesosome and will eventually develop into the vertebral column, it helps with the orchestration of the changes that the neural tube undergoes
- As the neural tube closes it zips up from the middle and the closing carries on to the anterial and posterial end, you end up with a pore at each end which need to close
26
What happens if the anterial pore of the neural tube doesn't close and what is this called?
- the brain won't develop
| - anencephaly
27
What happens if the posterior neural tube doesn't close and what is this called?
- there is a gap in the vertebral column and portion of spinal cord poking out of the baby’s back
- called Spina bifida
28
What is important in the closure of pores and what may interfere with this?
- folic acid
| - some anti epilepsy/bipolar drugs interfere with folate metabolism and increase risk of Spinal bifida
29
What happens in a 3-4 week embryo in regards to the neural tube?
there are three swellings at the rostral end of the neural tube becoming the primary vesicles – the forebrain, midbrain and hindbrain
30
What ventricles do we have in the brain, where are they located and what are the filled with?
- Ventricles contain CSF (cerebrospinal fluid)
- We have four ventricles
- Two lateral ventricles
- Third ventricle in the centre
- Fourth ventricle at the bottom
31
How are the ventricles in the brain connected?
Ventricles connected by canals – interventricular foramen, cerebral aqueduct and central canal which extends down to the brain stem (which is also hollow and fluid filled)
32
What is the spinal cord protected and surrounded by?
Protected by spinal column, surrounded by meninges and cerebrospinal fluid (CSF)
33
What does the spinal cord do?
It is the primary channel for messages from skin, joints and muscles to brain and from brain to periphery
34
What do the dorsal roots of the spinal cord contain and how are they arranged?
- sensory, afferent neurones
- there is a collection of fibres from sensory neurones – the cell bodies are located in the dorsal root ganglion. They have an single process an axon which splits into two – one bit goes to the periphery where it picks up the information and the other part goes into the spinal cord
35
What do the ventral roots of the spinal cord contain and how are they arranged?
- motor, efferent neurones
- The ventral root contains motor neurones which leave the spinal cord through the ventral root and the join the neurones of the dorsal root to form a nerve
36
What is a nerve?
A bundle of nerve fibres
37
What shape can you see in the spinal cord and why?
you see a butterfly shape made of grey matter (neuron cell bodies). Surrounding this you see white matter (myelinated axons)
38
What does the brain stem do and what does it contain?
- Oldest part of the brain – decision matrix. Controls vital functions
- Contains:
Midbrain – movement, sensory input: eyes, ears
Hindbrain – pons, medulla
39
Where are the pons and medulla located?
At the base of the brain
40
What does the pons do?
swells out from ventral surface of brain stem. Important relay between cortex and cerebellum
41
What does the medulla do?
Important in control of blood pressure and respiration (important in autonomic nervous system)
42
What happens with brain stem damage?
- Either due to a direct injury to the brain stem or an injury to somewhere else in the brain:
- Hydrocephalus or haemorrhage – build up of fluid in the skull from an injury to somewhere else in the brain.
Fluid will lead brain to be pushed downwards and the brain stem will be pushed down through the spinal cord hole leads to coning
- Severe cases can lead to ‘coning’. Damage to the medulla causes respiratory arrest
43
What is the cerebellum and what does it do?
- An ‘old’ part of the brain
- Movement control centre
- Extensive connections to cerebrum and spinal cord. Contains at least as many neurons as both cerebral hemispheres
44
Why does alcohol produce movement problems?
because there are particular receptors in the cerebellum which are very sensitive to alcohol
45
Give an example of a disease of the cerebellum
ataxias – aberrant movement coordination (seems like you are drunk)
46
What is it called if someone doesn't have a cerebellum?
Cerebellum agenesis
47
Where is the Thalmus and what does it do?
Located at the centre of the brain. Controls input to the cortex
48
Give features of the cerebral cortex (cerebrum)
• Newest part of the brain in terms of evolution
• Clear division between two halves along sagittal fissure
• The bigger the cortex compared to it’s body size is related to it’s cognitive abilities (larger cerebral cortex -> larger cognitive ability)
- number of neurons related to 'intelligence'
49
What does the cerebral cortex control?
- Voluntary actions
- Cognition
- Perception/ awareness
50
What is the difference between the cortex in mammals and reptiles and birds?
* Mammals have a more complex 6-layer structure of the cortex = neocortex
* Reptiles and bird only have 3 layers
51
What is the neocortex?
complex 6-layer structure of the cortex
52
What is consistent and inconsistent in terms of the neocortex with mammals?
Different sizes, same general 6 layer structure within mammals
53
What is the problem with increasing processing power in the cortex and how is it overcome?
- To increase intelligence need to increase processing power
- Cortical neurons represent processing power = increased number of cortical neurons (thin layer at surface)
- But:
- Skull is confined structure, want to keep volume + mass to minimum
- Big heads harder to protect than little ones
- So:
- We fold the cortex
- Extensive folding in humans and dolphins
- Gives bigger surface area without increasing the volume of head
54
What is the top and the bottom of the fold in the cortex called?
- Top of fold called a gyrus (the peak)
| - Bottom of fold called a sulcus (the trough)
55
What is the frontal cortical love concerned with?
- voluntary actions, motor actions, speech control and emotion
Somatomotor cortex deals with motor information
56
What is the parietal cortical lobe concerned with?
- deals with sensory information and language
| Somatosensory cortex – sensory information
57
What is the occipital cortical lobe concerned with?
involved in processing visual information
58
What is the temporal cortical lobe concerned with?
memory, sensory and language function
59
Why are the somatomotor cortex and somatosensory cortex very important?
they control and receive information to and from particular parts of the body
60
What does decussation mean?
'to become crossed'
61
What does it mean that in the mammalian nervous system we see contralateral motor and sensory pathways?
the right side of the brain controls and receives sensory signals from the left side of the body and vice versa.
62
Why do we see contralateral motor and sensory pathways?
Because the motor pathways leading from the cortex to the spinal cord and the sensory pathways from the spinal cord to the cortex decussate at the level of the medulla
63
What is a consequence of the decussation of the mammalian nervous system?
that an injury or stroke on the right side of the brain will produce paralysis or weakness on the left side of the body.
Excitable Cells
flashcards
Decks in class (22)
# Cards
-
Nervous system - structure and development63
-
Cells of the Nervous System87
-
Excitable cells in plants and microbes17
-
Water, membranes and ions72
-
Electrochemical Gradients22
-
The Nernst Equation21
-
Action Potentials31
-
Transmission within Neurons43
-
Synapses36
-
Neurotransmitters33
-
Synaptic Integration17
-
Electrophysiology22
-
Optogenetics and Dyes20
-
Sensory pathways: vision44
-
Hearing, Chemical senses and touch33
-
Muscle 167
-
Muscle 244
-
Learning and Memory 135
-
Learning and memory 219
-
Rhythms and sleep43
-
Neurotechniques 2: structural exploration of the brain26
-
Neuropathologies43
