Lec 2/3 Flashcards
1
Q
Neuroaxis for animals?
A
same plane as the ground
2
Q
Neuroaxis for humans?
A
tilted by 90 degrees
3
Q
Why are directional terms given in biology?
A
In biology, directional terms are given with respect to the organism’s body axis.
These terms are important for navigating creatures with unusual body planes or lifestyles.
4
Q
What is a coronal section?
A
a coronal section is cut in a vertical, from the crown of the head down, yielding a frontline’s view of the brain’s internal structures
5
Q
What is a horizontal section?
A
the view or the cut falls along the horizon, is usually viewed looking down on the brain from above, a dorsal view
6
Q
What is a sagittal section?
A
cut lengthways from front to back and viewed from the side, a medial view. Imagine the brain oriented as an arrow - in Latin, Sagitta
7
Q
The nervous system is organized into ________________
A
the central and peripheral divisions
8
Q
What does the central nervous system consist of?
A
Brain
Spinal cord
9
Q
What does the peripheral nervous system consist of?
A
Somatic nervous system
Autonomic nervous system
10
Q
What is the brain and spinal cord encased by?
A
The brain is encased by the skull, the spinal cord is encased by the vertebrae
11
Q
What type of connections are in the peripheral nervous system?
A
- sensory connections to receptors in the skin
- motor connections to body muscles
- sensory and motor connection to internal organs
12
Q
What are the two divisions and subdivisions of the peripheral nervous system?
A
Somatic (meaning “body”) nervous system:
- Efferent (outgoing) nerves: Motor nerves that connect the CNS to the skeletal muscles.
- Afferent (incoming) nerves: Sensory nerves that carry information from the sense organs to the CNS.
Autonomic (independent, out of our control) nervous system: Regulates homeostasis.
- Sympathetic nervous system (SNS): Arousing. “Fight or flight.”
- Parasympathetic nervous system (PNS): Calming. “Rest and digest.” (Also for returning to homeostasis)
13
Q
What are some of the things the parasympathetic nervous system does?
A
- contracts pupils
- constricts bronchi
- slows heart beat
- stimulates activity in stomach/intestines
- dilates vessels
14
Q
What are some of the things the sympathetic nervous system does?
A
- dilates pupils (enhanced vision)
- relaxes bronchi (increased air to lungs)
- accelerates/strengthens heartbeat
- inhibits activity in the stomach/intestines (blood sent to muscles)
- contracts vessels (increased blood pressure)
15
Q
What are ventricles?
A
The brain is cushioned and supported by a series of inter-connected hollow spaces
The ventricles are clearly visible in coronal and horizontal sections of the brain.
16
Q
What happens to ventricles during stress?
A
They are enlarged when there is cell loss
This is because stress causes us to lose brain cells and this results in a loss of brain volume in the skull. The ventricles enlarge to account for the extra space in the skull (because of volume loss)
17
Q
What are the brain and spinal cord protected by?
A
protected by special membranes called meninges.
18
Q
What happens when the meninges is infected?
A
When these membranes are infected, meningitis results
19
Q
What is the meninges made up of?
A
Dura matter
Arachnoid
Pia matter
20
Q
What view does a coronal section yield?
A
a frontal view
21
Q
What view does a horizontal section yield?
A
a dorsal view
22
Q
What view does a sagittal section yield?
A
a medial view
23
Q
What does dura mean?
A
hard
24
Q
What does arachnoid mean?
A
means spidery (looks like a spider web) where the CSF circulates
25
What does Pia mean?
means pious because it's very thin - stuck into the surfaces of the skull
26
What is the CSF?
fills the ventricles and circulates around the brain and spinal cord.
Provides cushioning for the brain as it is encased in the skull (however not very good at protecting)
27
What allows the brain to float comfortably in the skull?
CSF possesses a similar density to the brain
28
What is the CSF made of?
Like plasma, CSF contains glucose, various salts, and minerals, but unlike plasma it contains very little protein - this is why it looks black when you image the brain
29
a few ________ of ___________________ are all that separate the brain from the dangers of the outside world
millimetres; skin, bone, and muscle
30
What is the blood-brain barrier?
The tight gaps between endothelial cells (cells that line the blood vessels) that prevent large molecules from passing into the brain
what separates brain tissue from the bloodstream.
One of the protective mechanisms of the nervous system; prevents potentially lethal substances from entering the brain
31
Why is the blood-brain barrier not perfect?
Lipophilic and gases can pass this barrier so it’s not perfect.
specialized proteins can use active transport to pass through
32
___________ cannot enter the brain
hydrophilic proteins
33
What is the Area Postrema?
(back part of bran) responsible for vomiting – if you injested a toxin that passed the blood brain barrier the first area it will hit is the area postrema and this will make you vomit to get the toxin out
34
Who is Santiago Ramon y Cajal?
Santiago – first person to take images of brain cells – traced images of what he saw through the microscope
Saw dendritic spines
35
What do dendritic spines do?
Dendritic spines- allow increased surface area – more contact
36
What are neurons?
The basic information processing units of the brain.
| Are specialized cells that are specialized for transferring information from one place to another.
37
What are glial cells?
- Support and modulate neurons’ activities.
- Creates the myelin sheath - increases the conductivity of neurons
- Makes contact with the blood vessels and provides the active transport of nutrients from the circulatory system to the neurons
- Glial cells actually have much of an active role in the nervous system (they can actually communicate between each other)
38
How many neurons are in the brain?
Approximately 80 billion in the human brain.
39
How many glial cells are in the brain?
Approximately 100 billion in the human brain.
40
What can you use to see the neurons?
Apply Golgi stains that only penetrate certain proteins –only stick to neurons, or cell membranes. Slices of cells and apply stains to them.
41
Why are neurons organized and what happens when it isn't?
All these neurons are orientated in the same direction – very organized to enhance cell communication – in schizophrenia and certain psychiatric disorders this organizal structure does not occur
42
What are the specialized structures that make up neurons?
-Dendrites (“tree”)
Gather information from other neurons.
-Cell body (also known as the soma)
Core region; contains the nucleus and DNA.
-Axon hillock
Junction of the cell body and axon, summing all the electrical changes that occur across the cell membrane. Where the action potential is generated
-Axon
Carries information to be passed onto other cells.
-Terminal button
Knob at the tip of an axon that conveys information to other neurons.
Connects with dendrites of other neurons.
43
__________ tells us a little bit about their function
form of a cell
44
What are axons covered in?
Myelin sheath
45
What is myelin sheath?
- a fatty substance produced by glial cells.
- One glial cell will myelinate multiple neurons because it wraps around it
- Acts like insulation - resists the flow of ions in and out of the cell. It keeps the electrical energy intact so it can increase the speed and efficiency of electrical signal conduction.
46
What are Schwann cells?
specialized glial cells that myelinate the neurons in the PNS. 1 to 1 ratio - 1 glial cell wraps around 1 axon
47
What is grey matter?
Areas of the nervous system composed of cell bodies and blood vessels.
Axons are combined/pooled here
Ex. Cerebral cortex, subcortical nuclei, etc.,
48
What's white matter?
Areas of the nervous system rich in fat-sheathed neural axons.
Ex. Subcortical white matter, corpus callosum, etc.,
49
Why is there more white matter than grey matter?
More white matter because more glial cells (white matter is made up of myelinated neural axons)
50
_________________ are a result of malfunction in the white matter
Lots of disorders/diseases
51
What are tracks?
- Large collections of axons in the CNS are called tracks.
- Tracks connect nuclei to each other in the brain.
- White matter consists mostly of tracks (myelinated axons)
52
What are nerves?
A large collection of axons forming connections in the PNS.
| Examples: Phrenic nerve (arising from C3-C5, it controls the diaphragm).
53
What is a nucleus (pl nuclei)?
- A distinct cluster of neural cell bodies (grey matter) forming a functional group.
- They anatomically release similar neurotransmitters, and express similar proteins.
- When they are active, they send a signal (eat the food, turn of the light you’re tired)
Examples: Ventral Tegmental Area (VTA), Arcuate Nucleus (ARC) etc.,
54
What can nuclei be distinguished by?
Nuclei can be distinguished by their structure, chemical composition, and function.
55
What are groupings of cell bodies called?
cerebral cortex (grey matter)
56
What does the cerebral cortex do and what does it consist of?
The cortex is the site of our higher level functions, consciousness, and many other important things.
Information output and input (awareness)
The cerebral cortex is part of a larger structure called the cerebrum.
divided into two hemispheres, each which have 4 lobes
- frontal lobe
- occipital lobe
- parietal lobe
- temporal lobe
57
How did the brain develop over time?**
We added more cells in a posterior to anterior direction as we evolved. Throughout evolution as the hominids gained increasing cognitive capabilities, we added more cells. The human brain started with just breathing, heart rate, feeding. The cortex was a flat sheet of tissue that crumpled into itself to stay inside the skull. The more bumps and folds – higher intelligence
58
the ______ is crossed - ________ controls________ and vice versa
CNS; left side of brain; right side of brain
59
How is language different for left and right handed people?
Language is a lateralized function –for most of us this is on the left side
Right handed people – 99 percent have the language center on the left side
Left handed people can have their language function on left side (60 percent) right side (20 percent), or both (20 percent)
60
How is epilepsy treated?
Epilepsy- corpus callosotomy; cut middle of the brain to separate the two cerebral hemispheres -this reveals you have two brains in your head
61
What is the organization of neurons like in the cortex?
Neurons in the cortex tend to have a uniform, grid-like organization.
This is rather like how suburbs are organized.
The comparison makes sense because both suburbs and the cerebral cortex are the most recently developed parts of cities and brains respectively.
62
What is the organization of neurons like in the subcortical and brainstem?
neurons in subcortical and brainstem nuclei tend to have a more irregular organization.
To continue the analogy, this is like how the innermost parts of old cities often have a confusing and sporadic layout.
The inner city, like the deepest regions of the brain, shows evidence of an ancient history.
63
What is subconscious experience?
when some information doesn’t get to your cortex (emotional centers occur subcortically)
64
What is the appearance of the cerebral cortex and why?
The cerebral cortex has a characteristically wrinkled appearance. This is a space-saving tactic. By crumpling up, the cortex is able to fit more grey matter into the same amount of space.
65
What is the gyrus (pl gyri)?
“ring, circle”
| A bump or convolution between grooves.
66
What is the sulcus (pl sulci)?
“furrow, trench”
| A groove between gyri.
67
What are the external features of the brain?
Cerebrum (brain)
Cerebellum (little brain)
Brain stem
68
What is the cerebrum?
"brain"
| Major structure of the forebrain consisting of two virtually identical hemispheres (left and right).
69
What is the cerebellum?
"little brain"
Involved in motor coordination, and possibly other mental processes
size translates to speed of species (bigger more, faster and smaller slower)
70
What is the brain stem?
Comprises the deep structures of the brain. Connects the brain to the spinal cord.
Critical for sustaining life (respiration, blood pressure, etc.,)
oldest part
71
What does the frontal lobe do?
- Motor control.
- Executive functions
- planning
- inhibits lower brain regions
- most susceptible to pathology. Newest part of the brain
72
What does the occipital lobe do?
“back of skull”
| -Vision
73
What does the parietal lobe do?
“wall”
- Touch sensation.
- Sense of self in space.
74
What does the temporal lobe do?
- Auditory sensation.
- Language perception.
- Gustatory (taste) functions.
- Math
- Some memory function
75
What is the corpus callosum?
“firm body” - connects the two cerebral hemispheres, allowing both sides of the brain to work together.
76
What are circuits?
Neurons group together to form nuclei. Nuclei that are connected to other nuclei via tracks form circuits
Some specific circuits control some specific function – one of these specific circuits/functions is the limbic system
77
What is the limbic system and what does it consist of?
“edge/border” – is important for emotions, memories, and can be affected by psychological disorders and drug addiction. It is an older region. It consists of three major parts.
- Cingulate cortex
- Amygdala
- Hippocampus
78
What is the cingulate cortex?
“encircling/belt”
| -Involved in emotional processing and memory.
79
What is the amygdala?
“almond”
- base of hippocampus
- Involved in fear, aggression, and emotionally charged memories.
80
What is the hippocampus?
“seahorse”
- Involved in the formation of long-term memories.
- spatial processing, anxiety regulation
81
What happens in the brain when you're hungry?
the limbic system is activated
82
What is the basal ganglia and what are the 3 main parts?
Different groups of cell bodies that together in symphony are involved in controlling movement. They are also important in learning and memory, and in particular learning “habits”. The basal ganglia consist of three main parts:
- Caudate nucleus
- globus pallidus
- putamen
83
How does a new motor function become a habit?
When you are aware of something, you are using your cortex. As you get better at motor tasks and functioning, the information goes to the basal ganglia. Ex. First learning how to drive, you are hyperaware (using your cortex). With more driving experience, this motor task goes to your basal ganglia where it becomes second nature to you
84
What two parts make up the striatum?
The caudate nucleus – “tail” - and putamen – “shell” - are together known as the striatum – “striped”.
85
What does the globes pallidus mean?
“pale globe”
86
What is the substantia nigra?
“black substance” - is part of the midbrain. It contains numerous dopaminergic neurons that project into the basal ganglia.
Parkinson’s Disease involves the death of DAergic neurons in the substantia nigra.
87
What does basal mean?
low
88
What are the 3 regions of the brain stem?
Diencephalon
Midbrain
Hindbrain
89
What is the diencephalon and what are the two parts?
“di” means two and “cepha” means head
-Thalamus – “inner chamber”
All sensory information (except smell) passes through the thalamus en route to the cortex. Sensory nerves converge here before they hit the cortex (like the relay station
-Hypothalamus – “below/under thalamus”
Controls homeostasis, regulates hormone secretion from the pituitary gland.
90
What is the midbrain?
Contains neurons that produce dopamine that project to various other brain regions.
91
What is the hindbrain and what are the two parts?
```
- Pons – “bridge”
Connects the cerebellum to the brainstem.
REM sleep, non REM sleep
- Medulla – “marrow”
Controls breathing & heart rate.
Connects the brain to the spinal cord.
```
92
How was the brain engineered?
evolution does not tend to remove old things that still work.
It may add new improvements on top of the old standbys, but it typically leaves old things alone as long as they aren’t causing any problems.
Newly evolved regions like the cortex sit atop older regions (the limbic system), and those in turn sit atop even older regions (the brainstem).
93
What is the source of brain troubles?
The brain was not engineered all at once – it was built up bit by bit and the end result of this is a very fragile and rickety machine.
As we will see, our brains and genes are not always well-suited to the modern world
94
What is neuroscience?
Neuroscience is a multidisciplinary science devoted to the understanding of the nervous system. The brain is one of the most complex systems in the universe, and understanding how it functions is among the most challenging questions in science.
95
What was the historical view of mental illness?
Abnormal behavior has existed since the dawn of time
It was usually assumed that people fell victim to demonic possession as a punishment for their sins.
Given this, it is perhaps not surprising that many exorcism rituals involved physical pain
Treated by shamans, priests, exorcists
…mystical explanations still common today
96
Where does the word lunatic come from?
came from the idea that when the moon changes it causes mental illness
97
How was Electroconvulsive Therapy invented?
in the 1920s, it was observed that epileptics rarely had schizophrenia (this turned out to be false). From this came the idea that mental illness could be cured by artificially inducing seizures.
A modern version of ECT is still in use today for patients with severe depression that is not responsive to drugs or therapy.
ECT is often effective, but nobody knows why it works
98
What did the medical model propose?
The medical model proposes that it is useful to think of abnormal behaviour as a disease…Thomas Szasz and others argue against this model, contending that psychological problems are “problems in living,”rather than psychological problems.
99
How did clinicians decide if a behaviour is normal/abnormal?
clinicians rely on the following criteria:
1. Is it deviant, or does it violate societal norms,
2. Is it maladaptive, that is, does it impair a person’s everyday behaviour, and
3. Does it cause them personal distress?
All three criteria do not have to be met for a person to be diagnosed with a psychological disorder…diagnoses involve value judgments.
Antonyms such as normal vs. abnormal imply that people can be divided into two distinct groups, when in reality, it is hard to know when to draw the line.
100
What is diagnosis?
Which illness is it?
| look at all possible causes (not just ticking off a list of symptoms) this is why it is hard to diagnose mental illness
101
What is etiology?
What caused it?
| a combination of causes
102
What is prognosis?
What are the short / long-term consequences?
| What's the treatment going to be like?
103
What is epidemiology?
the study of the distribution of mental or physical disorders in the population
what environmental factors are contributing to an increase in illness?
104
What is prevalence?
the percentage of a population that exhibits a disorder during a specified time period.
how common is it?
105
What is lifetime prevalence?
the percentage of people who have been diagnosed with a specific disorder at any time in their lives
106
What is the DSM?
A taxonomy of mental disorders was first published in 1952 by the American Psychiatric Association
group of American psychiatrists decided without consultation with everyone what the causes of mental health disorders were (it was not very good)
107
What is the DSM like today?
This classification scheme is now in its 4th revision, which uses a multi-axial system for classifying mental disorders.
108
Explain the multi-axial system of DSM
The diagnoses of disorders are made on Axes I and II, with most falling on Axis I.
The remaining axes are used to record supplemental information.
Axis III: physical disorders
Axis IV: type of stress they have experienced
Axis V: estimates the individual’s current level of adaptive functioning
109
What is the goal of the multi-axial system?
to impart information beyond a traditional diagnostic label
110
What did David Rosenhan do in 1969?
fed up with the DSM and decided to do an experiment to show DSM is not very good. He employed grad students and told them that they should go to an ER and say they hear voices in their head “empty, thud and hollow” if they were asked anything else, no answer. Everyone was diagnosed with schizophrenia and got locked up. We dehumanize mental health patients and he wanted to change that
111
What is the DSM 5?
Multi-axial system eliminated
Removes artificial distinctions between medical and mental disorders
Organization reflects relationship between disorders
E.g., developmental disorders listed first; dementia-related disorders listed last
Some disorders removed, others added
