Physio Exam 1 Flashcards
how many neurons does the human brain have
about 86 billion
it is very important for our neurons to
rest
dendrites
These are branch-like extensions from the neuron’s cell body. They receive signals from other neurons and pass them to the cell body.
axon
long, thin extension from the cell body. carries the electrical signal from the cell body to the other end of the neuron, called the terminal button.
cell body
This is the main part of the neuron where all the important stuff happens. It contains the nucleus (which holds the neuron’s DNA) and helps process the signals that come in from the dendrites.
terminal button
small knobs at the end of the axon. When the signal reaches here, the terminal button helps send it to the next neuron by releasing chemicals.
synaptic vessels
These are tiny sacs located in the terminal buttons. They store neurotransmitters, which are chemicals that help transmit the signal from one neuron to another.
neurons are…
cells in our bodies that send and receive messages
unipolar neuron + function
only one extension coming out of the cell body.
often involved in sending messages to muscles (motor neurons), helping the body move
bipolar neuron + function
two extensions: one on each end of the cell body.
They usually help with sensory tasks, like processing what you see or hear.
multipolar neurons + function
many extensions from the cell body.
They do a lot of the heavy lifting in the brain, sending messages between different parts of the nervous system.
multipolar interneuron + function
special type of multipolar neuron that connect different neurons together.
They act like bridges, helping different neurons communicate and share information.
what are glial cells
support neurons that perform electrical signals
are like a support staff for neurons. They help keep the brain and nervous system running smoothly.
what are the astrocytes
“helpers” for neurons.
They provide insulation, support the structure of the brain, and clean up waste (housekeeping).
what are microglia
“clean-up crew.”
They get rid of waste and damaged parts of the brain (pruning), but sometimes they can be overactive and cause problems.
They also help protect the brain like the immune system by recognizing invaders and try to stop them
what is the myelin sheath
the “insulation” around neurons, helping signals move faster.
what are the oligodendrocytes
cells that create the myelin sheath in the Central Nervous System (the brain and spinal cord).
what are the schwann cells
create the myelin sheath in the Peripheral Nervous System (the rest of the body).
rostral or anterior
front of the face / towards head
caudal or posterior
back of the face / towards feet
dorsal
top back side
ventral
bottom belly side
lateral
towards side of body
medial
towards middle of body
cross section / frontal section / coronal plane
like slicing the body in half from the front to the back. Imagine cutting a loaf of bread to see the front and back parts.
horizontal plane
slicing the body in half horizontally to separate the top and bottom, like cutting a sandwich across.
sagittal plane
slicing the body right down the middle (or a little to the side), separating the left and right sides
ipsilateral
same side of body, left leg + left arm
contralateral
diff side of body, left leg + right leg
CNS
command center of your body.
Brain: The boss that controls everything, located inside the skull
Spinal Cord: The big bundle of nerves that sends messages between the brain and the rest of your body, protected by the vertebral column (your spine/backbone).
PNS
messenger that carries information between the CNS and the rest of your body (arms, legs, etc.).
two parts: somatic NS and autonomic NS
somatic NS
voluntary actions, like when you move your muscles on purpose.
sensory neurons in somatic NS
Carry information from your senses (like touch, except vision) to the brain.
voluntary motor neurons in somatic NS
Carry messages from the brain to your muscles, so you can move.
autonomic NS
handles automatic processes, like breathing or your heart beating, without you thinking about it.
sympathetic NS + controlled by
“fight or flight” system, which kicks in when you’re stressed or in danger. It’s controlled by nerves in the thoracic and lumbar areas of your spine.
parasympathetic NS + controlled by
helps you calm down after stress, allowing you to relax, think, and manage emotions. It’s controlled by nerves in your cranial (head) and sacral (lower back) areas.
spinal cord as part of the CNS
thick cable of nerves that sends messages between your brain and body
white and gray matter
white: “message wires” aka nerves run up and down
gray: where signals are processed
describe the ventral root
part of the spinal cord that sends motor output (movement signals) from the spinal cord to your muscles.
describe the dorsal root
brings sensory input (feelings like touch) from your body to the spinal cord and includes the Dorsal Root Ganglion, which is like a little hub where sensory signals get organized.
describe the cauda equina in CNS
bundle of nerves at the very bottom of your spinal cord. It looks a bit like a “horse’s tail” and helps control things like your legs and lower body.
describe spinal nerves
part of the peripheral NS and theres 31 pairs ; one for each segment cervical, thoracic, lumbar, and sacral
describe cranial nerves + most important one
part of peripheral NS
the vagus nerve, which is part of the Parasympathetic Nervous System (PNS). It helps you calm down and relax by controlling things like your heart rate and digestion.
cerebral cortex is
outer layer of your brain, responsible for things like thinking, memory, and decision-making.
sulci / sulcus on cerebral cortex
These are the small grooves or folds on the surface of your brain. They help increase the surface area, so the brain can fit more neurons.
fissures on cerebral cortex
deeper grooves in the brain. Think of them as bigger, more prominent cuts that divide the brain into sections.
gyri / gyrus in cerebral cortex
bumps or ridges between the sulci and fissures. They also help increase the brain’s surface area.
foramen magnum in cerebral cortex
large hole at the base of your skull where your brain connects to your spinal cord.
ventricular system in cerebral cortex
network of fluid-filled spaces inside the brain. The fluid helps protect the brain and keep it healthy.
Lateral ventricles
two large spaces in the brain that hold most of the cerebrospinal fluid.
third ventricle
narrow space in the middle of the brain that connects the lateral ventricles to the 4th ventricle
fourth ventricle
space near the bottom of the brain that helps fluid move to the spinal cord.
cerebral aqueduct
narrow channel that connects the third and fourth ventricles, letting fluid flow between them.
central canal
tiny channel running down the middle of the spinal cord that continues the fluid flow from the fourth ventricle. example: CSF
functions of the cerebral cortex
it is the thoughts and feelings that we have, it evolved last, responsible for thinking, memory, and control of movement
describe corpus callosum in the cerebral cortex
it is a connecting set of fibers, its kinda big, connects axons between two hemispheres which allows them to communicate - makes sure both sides of the brain work together
describe the forebrain
front part of your brain that controls important things like emotions, movement, and processing information.
describe telencephalon in your forebrain
section that includes the cerebral cortex, limbic system, and ganglia
describe the cerebral cortex in the forebrain
outer layer of the brain that handles thinking, problem-solving, and voluntary movements.
describe limbic system in forebrain
Manages emotions, memories, and how we respond to things.
describe basal ganglia in forebrain
Helps with movement and learning habits.
describe the thalamus in the diencephalon
Acts like a relay station, sending sensory information (like touch and sound) to the right parts of the brain.
describe the hypothalamus in the diencephalon
Controls body functions like hunger, thirst, and temperature. It also influences emotions and sleep.
how many lobes in the telencephalon, how big
four, largest section of brain
central sulcus in telencephalon
groove that runs through the central part of our brain
lateral fissure in telencephalon
starts in side eye and back into brain also a dividing groove
frontal lobe includes the
Primary motor cortex which controls movement.
Prefrontal cortex (including the orbitofrontal cortex) which handles attention, setting goals, and decision-making.
describe the parietal lobe
Primary somatosensory cortex: Processes touch, pain, and temperature. Helps with some vision, especially understanding where things are (this is called the “dorsal” pathway).
describe the temporal lobe
Primary auditory cortex: Processes sound. helps with learning, memory, and some aspects of vision (how we recognize things).
describe the occipital lobe
Primary visual cortex: Handles vision, allowing us to see and process what we’re looking at.
explain the PTO junction
parietal temporal occipital
parietal helps w touch
temporal helps w hearing and memory
occipital helps w seeing
explain the association cortex
takes info from diff senses and combines them so you can understand what happens around you. you become self aware
limbic system explanation
part of brain that helps with emotions, memory, and controlling responses
hippocampus explanation
helps with learning and storing memories
the cingulate gyrus does what
controls attention and manages emotions
the amygdala does what
handles emotions especially fear
anterior cingulate gyrus does what
helps with self control and notices conflicts or problems
the insula does what
handles feelings of disgust
the posterior part senses what happens inside your body
the anterior part gathers info and helps figure out what your body needs
the fornix does what
helps with processing memories
the basal ganglia is…
part of the brain that helps with habits and movements we’ve learned well like walking or typing
what are the three main parts of the basal ganglia
globus pallidus, caudate, putamen
the caudate and the putamen form what which helps with
striatum which helps with focus and self control
the anterior cingulate gyrus and anterior insula do what in the striatum and what also helps with this?
they join with the basal ganglia to help manage self control and handle problems
the prefrontal lobe helps w this and decision-making and control
how does the brain process info
top-down and bottom-up processing
the nucleus accumbens is what and connects to
it is involved in feelings of pressure and drives
it connects to the hypothalamus and the VTA which also influence pleasure and motivation
the diencephalon is what
part of brain that acts like a relay station by sending info to different areas
in diencephalon, the thalamus…
is the main relay station that passes info to key parts of the brain like areas for thinking and sensory processing
lateral geniculate nucleus
sends visual info to brain / occipital lobe
medial geniculate nucleus
sends auditory info to brain / temporal lobe
ventral posterior nucleus
sends touch and body sensation info to the brain / primary somatosensory cortex
ventral lateral nucleus
sends movement related info to motor areas of the brain / primary motor cortex
the hypothalamus controls what
basic needs; hunger, thirst, and temperature
the ANS which handles breathing and heart rate like functions
and the endocrine system which manages hormones through the pituitary gland
what parts of the brain does the hypothalamus communicate with
cortex and prefrontal cortex
nucleus accumbens
cingulate gyrus and limbic system
basal ganglia
lower brain
what is the brainstem
the part of the brain that connects to the spinal cord and controls basic life functions
brainstem includes the diencephalon which is
a section w the thalamus and hypothalamus
the midbrain helps with
movement, vision, and hearing
the hindbrain does what
it includes parts like the cerebellum and medulla which control balance, coordination, and automatic functions like breathing
the midbrain is a
small part of the brain that helps with vision, hearing, movement, and some basic reactions
what do the superior and inferior colliculi do
superior helps with vision and inferior with hearing
describe the periaqueductal gray matter
handles pain and instinctive behaviors
describe the VTA
linked to feelings of pleasure and reward
describe the substantia nigra
black susbtance
controls movement and when the axons degenerate this degenerates therefore can cause parkinsons disease / muscle degeneration
describe the red nucleus
helps with movement, especially sudden ones like the startle reflex
two main parts of the hindbrain and what they do
medulla and pons they both help control automatic body functions like HR and breathing
medulla monitors touch and body sensations
pons controls sleep and wake cycles
the locus coerulues does what
helps with staying alert, paying attention and responding to stress / arousals
reticular formation or reticular activating system explanation
controls arousal and filters sensory info
the cerebellum does what
helps with balance, coordination, and movements you’ve practiced and learned
