Midterm 1 Flashcards
How has the perspective on mental illness evolved over time?
Historically, behaviours that indicated mental illness were given supernatural explanations (witches, demons, evil spirits)
Christians treated this with exorcism which was sometimes (during middle ages) accompanied with violence as it was thought that possession was due to sins.
Trepanation - surgical procedure in which holes were drilled into the skull to let out spirits
What did Aristotle believed the _____ was responsible for thought
heart - he thought the brain was there to cool off the blood
What did pre-renaissance philosophers believe about thoughts, memory and emotion?
They believed that cognitive processes were contained in a special fluid in the ventricular system
Dissection and vivisection occurred in ancient times but then stopped. When did it return?
During the renaissance period
______ is considered the father of neurology
Thomas Willis
_______ believed that a non-physical out interfaced with the physical body at the pineal gland
Ren Descartes (cartesian dualism)
_____ was the first to measure the speed of a nervous impulse
Herman von Helmholtz
_____ invented neuronal staining in order to see what neurons looked like for the first time
Camillo Golgi
Who is Paul Broca?
The first to correctly localize a certain part of the cerebral cortex
He noticed that an area in the left frontal lobe was damaged in patients that had lost their ability to speak, now known as the Broca’s area
What are the 3 directional terminology classes ?
Dorsal (top) vs. ventral (bottom)
Anterior (front) vs. posterior (back)
Medial (midline) vs. lateral (towards the side)
What are the 3 planes when viewing the brain?
Coronal (though the top of your head)
Horizontal (through the forehead)
Sagittal (down the middle)
The nervous system is organized into the _____ and ______ divisions
central & peripheral
The central nervous system is comprised of the _____ and _______
brain & spinal cord
The peripheral nervous system is comprised of the _______ and _______ nervous system
somatic & autonomic
Contrast the efferent and afferent nerves
These are located in the somatic nervous system
Efferent nerves (outgoing) are motor nerves that connect the CNS to the skeletal muscles
Afferent nerves are sensory nerves that carry info from the sensory organs to the CNS
The function of the autonomic nervous system is to ________
regulate homeostasis
What is the autonomic nervous system comprised of ?
Sympathetic nervous system (SNS): arousing, fight or flight
Parasympathetic nervous system (PNS): calming, rest and digest
Each hemisphere controls the other half of the body (ex. hemi-sympathecotimized cat)
What is the ventricular system?
A set of 4 ventricles which are inter-connected hallow spaces that cushion and support the brain
they are filled with CSF which contain glucose, salts, and minerals
When the ventricles are moved to one side or enlarged it is a sign of _______
mild brain damage
The brain and spinal cord are protected by special membranes called ______
meninges
The ______ protects the brain from many drugs, infections, and other compounds that circulate in the blood
BBB
What are the two types of brain cells?
Neurons - basic information processing units (~80bill)
Glial cells - support and moderate neuron activity, create myelin sheath (~100bill)
What are the structures of the neuron?
Dendrites - gather info from other neurons
Cell body/soma - contains nucleus and DNA
Axon hillock - connects cell body and axon
Axon - carries info to other cells
Terminal bottom - tip of axon that conveys info by connecting with dendrites of other neurons
______ myelinated axons in the CNS and _______ myelinated axons in the PNS
oligodendrocytes and schwann cells (both glial cells)
What are the differences between white and grey matter?
While matter is fat-sheathed neuronal axons
Grey matter is areas of the NS composed of cell bodies and blood vessels
Contrast tracts and nerves
Tracts are collections of axons in the CNS that connect nuclei to each other and are mostly white matter
Nerves are collections of axons in the PNS
______ is a distinct cluster of neuronal cell bodies forming a functional group
Nucleus
The brains outer later of grey matter is celled the _______
cerebral cortex
What is the difference in neuronal organization between the cortex and the subcortical regions?
Cortex: neurons have a uniform, grid-like organization (suburbs)
Subcortical regions: neurons have an irregular organizations (old cites)
Why is the brain wrinkled?
In order to increase SA without having a larger skull
A _____ is a bump or convulsion between grooves and a ______ is a groove (trench) between gyri
gyrus; sulcus
What are the 3 major components of the brain? What are their functions?
Cerebrum - major structure of the forebrain, higher order thinking
Cerebellum - involved in motor coordination
Brainstem - connects the brain to the spinal cord and essential for life (respiration, BP, etc.)
Name the functions of the 4 lobes of the cerebral cortex
Frontal - motor control, executive functioning
Occipital - vision
Parietal - touch sensation, proprioception
Temporal - auditory sensation, language perception, gustatory (speech is on left hemisphere)
The ____ connects the two cerebral hemisphere
Corpus callosum
What is the function of the limbic system? What does it consist of?
The limbic system is important for emotions, memories and can be affected by psychological disorders and drugs. It is composed of:
Cingulate cortex - emotional processing and memory
Amygdala - fear, aggression, and emotional memories
Hippocampus - formation of LTM
The ____ is a region of the cortex hidden within the lateral sulcus
Insula
sometimes considered part of the limbic system, involved in interception, self-awareness and emotions
What is the structure and function of the basal ganglia?
Basal ganglia are involved in controlling movement, learning, memory, and in particular ‘habits’. It consists of 3 parts:
Striatum (consists of the caudate nucleus and putamen)
Globus pallidus
Substantia Nigra - part of the midbrain that projects DAergic neurons into the basal ganglia
_______ involves death of DAergic neurons in the substantia nigra
Parkinson’s disease
What are the regions and functions of the brain brain stem?
Diencephalon:
- Thalamus (sensory info except for smell pass through encore to cortex)
- Hypothalamus (controls homeostasis, regulates hormone secretion from pituitary gland)
Midbrain: contains neurons that produce DA that project to other brain regions
Hindbrain:
- Pons (connects cerebellum to brainstem)
- Medulla (controls breathing, HR, connects brain to spinal cord)
The tendency for particles to move from one place to other is called the ______ and is measured in ____
electrical protenial; volts
What does it mean to say a neuron is polarized?
There are more negatively charged ions inside the membrane than outside
The resting potential is _____
-70mv
What electrical charge do you see during an action potential?
During an action potential the membrane potential briefly goes up to around +30mv then returns below -70mv and then returns to equilibrium
How long to action potentials take?
They are localized and take about 1mc
You can measure them one at a time or over larger-time scales, known as spikes
Any changes that moves a neuron towards a positive charge is known as _____
depolarization
Depolarization is local but propagates down an axon. This cycle can continue indefinitely. This is an example of a ______
positive feedback look
What is the direction of an action potential?
Dendrites > cell body > axon > axon terminals
How to the axon terminals send a signal to another neuron?
Axon thermals release NTs which are either cations (+) or anions (-) into the synaptic cleft. These NTs bind with receptors on the post-synaptic cleft.
If there is enough cations to depolarize the cell an action potential will continue though the post-synaptic neuron and so on..
What are the different types of post-synaptic potentials?
Excitatory post-synaptic potentials (EPSP) have an influx of cations, depolarizing the cells increasing chance of AP
Inhibitory post-synaptic potentials (IPSP) have an influx of anions, hyperpolarzing the cell decreasing chance of AP
What occurs if a neuron receives an IPSP and an EPSP input at the same time?
It is cancelled out
The voltage required to trigger an action potential is ____
-50mv
Post-synaptic potentials are graded.
True or false
True
What are the major classes of NTs?
Amino acids: Glu, Glycine (Gly), GABA
Monoamines: DA, NE, EP, 5-HT
Peptides: Vasopressin, oxytocin, Neuropeptide Y
Other: Ach, Adenosine, Anandamide, Nitric oxide
_____ are molecules that bind to an activate receptors
Ligands
Ex. neurotransmitters and hormones
Explain which voltage gated ion channels are involved in action potentials
The cell membrane of a neuron contains channels. During the resting state these channels are closed and the inside is more negative than the outside (polarized). The AP causes voltage gated Na+ channels to open and since the charge is more positive on the outside of the cell it drives Na+ into the cell.
The inside now becomes temporarily more positive (depolarized) and voltage gated K+ cells open allowing K+ to exit the cell, repolarizing the cell.
Na+ ions diffuse down the membrane to the nodes of ranvier and causes a change of voltage, opening the Na+ channels and repeating the process.
The Na+/K+ pump (removes 3 Na+ and brings in 2 K+) rests the polarity once the AP has propagated down the axon
How are NTs deactivated once they have sent their message?
Diffusion: diffuse away from the synaptic cleft
Degradation: enzymes break down NTs into inactive molecules
Reuptake: Proteins called reuptake transporters recycle NTs back into pre-synpatic cell
Glial cells: absorb NTs
What is the history of developmental biology?
~2000yrs ago people believed in preformation: human embryo was a miniature version of an adult that just got bigger
This was replaced be epigenesis in mid-1800s: the idea that living things come into from gradually
In the 19th century they discovered evolution in that all vertebrates arose from a common ancestor
Describe the development on the nervous system
Day 1: human zygote is a single cell
Day 2: Cell divides and continues dividing
Day 15: emerging embryo if formed by several sheets with a raised area called an embryonic disc
Day 49: embryo reseumbles a miniature person
Day 100: brain begins to resemble that of a human
7 months: formation of gyri and sulci
9 months: very distinct human brain
Following gastrulation, what 3 germ layers does the embryo have?
Endoderm: future viscera
Mesoderm: future muscle and bone
Ectoderm: future skin and nervous system
- a portion is set aside for the neural plate which roles itself up into a neural tube
- Cells migrate inward become the neural crest
- The neural tube breaks free from the ectoderm, moving ventrally to rest dorsal to the notochord
A cell that is induced by Bmp and Want will be _____ and cells that are induced by Shh will be _____
dorsal (ectoderm, roof plate) - mainly sensory
Ventral (notochord and floor plate) - mainly motor
What do neural stem cells do?
They line the neural tube and ventricles forming the sub ventricular zone
They have capacity for self-renewal and can give rise to progenitor cells
What do progenitor (precursor) cells divide into?
They divide either into:
Neuroblasts which develop into interneurons or pyramidal neurons (mature neuronal cells)
Glioblasts which develop into oligodendrocytes or astrocytes (mature glial cells)
Progenitor cells continue to divide throughout your entire life.
True or false.
False - they eventually produce non-dividing cells
Stem cells remain capable of producing neuronal and glia throughout adulthood.
True or False
True
What are neurotrophic factors? Provide two examples
Chemical compounds that act to support growth and differentiation of neurons
Ex. Epidermal growth factor (EGP) stimulates stem cells to produce progenitor cells; Basic Fibroblast Growth Factor (bFGF) stimulates stem cells to produce neuroblasts
What are the 7 stages of neurodevelopment?
- Cell birth
- Cell migration (travel to final destination)
- Cell Differentiation
- Cell maturation (dendritic and axonal growth)
- Synaptogeneisis (formation of synapses)
- Cell death
- Myelongenesis
The _______ is a major site of cell proliferation where active cell division takes place
sub ventricular zone
The outside cordial layers are developed first
True or false
False - inside layers are developed first
Radial glia form ladders that developing neurons club to reach their appropriate layer of the cortex
The tip of a developing axon is called the ______. What do they respond to?
growth cone
They extend flipodia which feel around the environment, directing the growth cone toward the strongest source of growth factor signals.
They respond to cell-adhesion molecules (CAMs) and trophic molecules/growth factors that are secreted by target cells to attract or repel axons