L12: NERVOUS SYSTEM AND SENSORY SYSTEM Flashcards
What’s the guy’s name discussed in a lecture about his mass killing and suicide?
Charles Witman
What did they find in Charles Whitman postmortem results?
tumor in the middle of his brain
What type of tumor did Charles have?
Glioblastoma
What is a Glioblastoma made up of?
a tumor made up of glial cells
What are glial cells?
the support cells of the brain
What part of the brain got compressed with Charles’s tumour? What does it do?
the amygdala - emotion regulation
Could you compare our brain function to a computer?
NO
What does the bottom tier scoop the brain represent?
- survival/ maintaining life
- oldest tier
- reptiles
What does the middle scoop of the brain repersent?
- instinct/ emotion/ memory
- mouse
What does the third scoop of the ice cream represent?
- cognition/problem-solving/ social skills
- primates
What does the medulla oblongata do?
coordinates information dealing with breathing rhythms, blood pressure, heart rate
What does the cerebellum do?
coordinates subconscious regulation of voluntary movements, regulates posture and balance
What does the midbrain do?
helps maintain muscle tone, sends some sensory data to higher brain centers in the forebrain, alertness
What regulates homeostasis and integrates the nervous and endocrine systems?
Hypothalamus
What is commonly referred to as the “emotional brain”
The limbic system.
What is commonly referred to as “the gateway to the consciousness.”
The thalamus
What is the cerebral cortex responsible for?
responsible for our capacity to talk and calculate, gives us our conscious sense of the world
What is divided into 4 lobes:
The cerebrum
What are the four lobes called that divides the cerebrum:
-Occipital
-Temporal
-Parietal
-Frontal
What looks like highly folded tissues with “bumps” and “grooves”
the brain
the ___ is divided into 2 halves …
cerebrum
What is the cerebrum separated by:
the Longitudinal Fissure
The Longitudinal fissure has ______ _____ between them.
extensive connections between them
Left half of the brain controls ….
the right side of the body
the right half of the brain controls …
the left side of the body
Lateralization…
means that one-half of the brain seems to have a specialization for certain tasks
“Gyri” refers to the…
bumps on the brain
What function does the precentral gyrus have?
motor cortex
What function does the post-central gyrus have?
sensory cortex
The brain has evolved with…
___ lobes
___ halves
___ units
- 4 lobes
- 2 halves
- functional units
The brain is…
___dular
____ connected
made up of ___
modular
interconnected
made up of neurons
A specialized electrically excitable cell is called …
a neuron
“antenna” receiving info from different cell types is called
dendrites
Where is the information processed in the axon?
the cell body
How is processed information passed to other cells?
via axons
Axons terminal connections are called…
synapses
How are neurons electrically excitable?
the electrical current is generated by a flow of ions through ion channels in the cell membrane
All cells contain….
ions
Are all cells excitable?
NO
The action potential is what transmits…
the information from the cell body of one axon, through the axon and across the synapse onto another cell
Energy is required for what type of transport?
Active transport
What are the two types of passive transport?
Simple and facilitated diffusion.
Active transport is facilitated by …
carrier proteins
The difference between simple and facilitated diffusion:
-with simple the molecules slip between phospholipids
-with diffusion facilitated by carrier proteins or channel proteins
At rest there are more _____ charged ions inside the cell then outside: known as
Negatively charged ions, known as resting membrane potential
What triggers ion channels to open?
if the cell body is sufficiently stimulated
When can the positively charged Na+ ions cross the membrane ?
when the ion channels open
When the membrane potential is raised in a more positive direction its referred to as …
depolarization
At what point does depolarization occur?
occurs at the axon hillock
What is the axon hillock?
the point where the cell body begins to turn into the axon
What is an action potential?
A self-sustaining electrical signal that travels away from the body of the neuron
What is the action potential dependent on ?
the positively charged ions movie across the plasma membrane
Why is the plasma membrane in a polarized state?
because there is a difference of electrical charges across the plasma membrane
What is the feedback loop?
This influx of sodium causes further depolarization of the membrane (making the inside even more positive).
This depolarization opens even more sodium channels, leading to more sodium ions entering the cell, which further depolarizes the membrane, continuing the cycle of channel opening.
This creates a positive feedback loop, where each step in the process amplifies the next.
Action potential move along the axon in only….
one direction, keeping the signal from being lost
T/F: the action potential remains consistently strong as it moves from one end of the axon to the other and does not weaken with distance
A strong stimulus will initiate action potentials more often, but any individual action potential will be no stronger than any other because…
its is an all or none event
_____ axons can carry signals more rapidly than _____ axons
- myelinated
- unmyelinated
What insulates axons?
myelin sheath
What are the gaps between the myelin sheath called?
Nodes of Ranvier
Where is the site of action potentials?
Node of Ranvier
What is the myelin sheath?
- made of fatty material
- produced by glial cells which surrounds the axons
A ____ is made up of many individual neurons that bundle together with supporting cells, blood vessels and connective tissues to form major communication pathways.
a nerve
Do myelin sheaths speed up or slow down by the presence of action potentials?
speed up
Action potential is ___ at each node, allowing the signal strength to jump rapidly from _____
regenerated, one node of Ranvier to the next
Examples of neurotransmitters:
dopamine,epinephrine, melatonin
what is the release of chemical messengers triggered by the AP at the axon terminal called?
neurotransmitters
Whats a neuro transmitters main function?
to signal the next cell in the line of communication across the synapse
____ recives information
dendrites
___ pass on information
axons
Synaptic clef….
The synaptic cleft is the microscopic gap between neurons (or between a neuron and another cell), essential for the transfer of chemical signals during neurotransmission
Depending on the type of neurotransmitter released and receptor-activated, the receiving cell is either …
activated or inhibited.
What 3 things can happen to a neuro transmitter at the synaptic cleft?
- removed
- destroyed
- inactivated
What is known as the functional unit of the brain?
neurons
Whats another name for cell body?
Soma
Whats the parts of the PNS?
the nerves outside the CNS and the somatic and automatic systems
What makes a sensory neuron a sensory neuron?
- sensory neurons must be in a physical place exposed to the environment ( internal vs external)
- sensory neurons must contain receptors in their membranes that are capable of being activated by things in the environment
- sensory neurons must be connected centrally
Doesn’t matter if you have 23 neurons or 94893 billion there useless unless ….
there interconnected centrally
How many sensory receptors do humans have?
5
chemoreceptors
photoreceptors
mechanoreceptors
thermoreceptors
pain receptors
What are the names of the two classes of photoreceptors in the human eye
rods
and
cones
Photo receptor found in our retina that allows us to see images in shades of gray in dim light
rods
Photoreceptors found in our retina that functions best in bright light and transmits information in color
cones
How can we perceive the world in 3D even if our eyes our 2D?
Light activates neurons in the brain. The brain then looks at the pattern of neuron activity and uses that information to create a mental picture or understanding of what we’re seeing.
What was the neuroscience dogma?
that neurogenesis was impossible after birth
What is “brain plasticity”?
Brain plasticity refers to the brain’s ability to change and adapt by forming new synaptic connections, especially when certain areas of the brain are used more or less.
Is the brain only plastic in early childhood?v
The brain remains plastic even in adulthood, although it is especially plastic in early childhood.
What does the phrase “use it or lose it” mean in relation to brain plasticity?
It means that if you regularly use a part of your brain, it will grow stronger and more connected, but if you don’t use it, that area may become less active or shrink.
What happens in the brain when you lose a part of your body?
The brain regions that are used to process information from that body part become “up for grabs,” meaning they may take on new functions or adapt to control other body parts.
What is Phantom Limb?
Phantom limb is a phenomenon where people who have lost a limb still experience sensations in the missing limb, sometimes feeling pain or touch in parts of their phantom limb.
What does brain plasticity suggest about body perception?
it suggests that our body perception is easily manipulated by the brain, as demonstrated by the phenomenon of phantom limb pain.
How can damage to the brain affect behavior or personality?
If a part of the brain loses its function, it can directly alter behaviour and personality, like phineas gage
How can a stroke affect personality?
physical abilities can recover after a stroke, it can lead to profound changes in behavior and personality, as emotional responses and decision-making abilities may be altered.
What example is used to discuss personality change after brain damage?
The example of Charles Whitman, who had a brain tumor that may have influenced his actions and behavior, highlighting how brain changes can affect behavior.
Is there a single part of the brain that controls consciousness?
No, consciousness arises from the sum of neurons firing in interconnected brain regions, rather than from a single part of the brain.
