Midterm 1 Flashcards
What are the two main divisions of the Nervous System
Central NS and Peripheral NS
What is the purpose of the Somatic NS
Interact with external environment through sensory neurons to send information afferently from muscles/skin to CNS
What divisions does the PNS have
Somatic NS and Autonomic NS
What nerves do the Somatic NS use
Afferent Nerves
Function of the Autonomic NS
Regulating the internal environment of the body. Afferent nerves carry signals from the organs to CNS. Efferent nerves also carry signals back to organs to regulate.
What are the divisions of the Autonomic NS
Sympathetic Nerves and Parasympathetic Nerves
Function of Sympathetic Nerves
Mobilize energy in threatening situations
Function of Parasympathetic nerves
Conserve energy/ rest and digest. constrict lung passages, slow heart rate etc.
What is the Autonomic Tone
The individualized dial that controls the balance between sympathetic and parasympathetic response
What does the CNS consist of
The Spinal Cord and the brain
What is the inner core of the spinal cord made of
(H shaped), made of cell bodies and unmyelinated axons
What is the outer cylinder in the spinal cord made of
Myelinated Axons
Explain rostral and Caudal
Rostral is both up the spinal cord and front toward the nose.
Caudal is down the spinal cord and toward the back of the head
Explain Dorsal and Ventral
Dorsal is the top of the head in the brain and the back in the spine
Ventral is down toward the jaw in the brain and front toward the belly in the spine
Explain Anterior and Posterior
Anterior= toward the face/ belly
Posterior = toward the back of head/ back
Explain Lateral and Medial
Lateral= toward the outside
Medial= toward the middle
in a coronal plane
The three places along which the brain can be cut?
Coronal, Sagittal, Horizonal
What are the Five divisions of the Brain
Telencephalon
Diencephalon
Mesencephalon
Metencephalon
Myelencephalon
What is the Myelencephalon consist of (aka Medulla) and where is it
Has A lot of myelin
Composed of tracts carrying signals between the brain and body
The 2nd bottom section of the brainstem (just above the tube)
What does the Metencephalon consist of and where is it
Consists of the Pons and the Cerebellum
Sits just above the Myelencephalon
(cerebellum is the side section)
What is the Pons
Consists of fibre tracts rooting things to different parts of the brain. Its part of the reticular formation and the metencephalon
What is the Cerebellum
Part of the Metencephalon
Highly folded part of the brain.
has 50% of all the neurons in the brain.
Very connected to the cortex
Plays a role in movement and timing
What does the Mesencephalon consist of and where is it
Composed of the Tectum and Tegmentum
in the midbrain, above the pons
What is the tectum
the ‘roof’ of the mesencephalon
contains nuclei that receive and relay visual information (superior colliculi)
auditory information (inferior colliculi)
What is the tegmentum
floor of mesencephalon
Contain nuclei related to motor function and pain
What is the Reticular Formation
‘Net’ of nuclei that span across the brainstem. (myel, met, mesen)
Play roles in arousal, respiratory reflexes, cardiac reflexes etc.
What does the Diencephalon consist of and where is it
Thalamus and Hypothalamus
Right in the center of the head
the Thalamus
2 lobed structure
Contain Nuclei that process and relay information between receptors and cortex
nuclei can be specific or nonspecific
involved in consciousness?
Functions of the Hypothalamus
Involved in Hormones so sleeping, temperature, sex, hunger
Also regulates body processes using the pituitary gland
its the bottom part of the diencephalon
list the Subcortical structures of the Telencephalon
Basal Ganglia
Limbic System
Cerebral Cortex
What is the Basal Ganglia
A Collection of nuclei connected to the cortex, thalamus and midbrain
involved in movement and learning
Divisions of the Limbic system
Hippocampus which does spatial memory and Amygdala which plays a role in emotion
Explain the structure of a fold in the brain
Top of bump= gyrus
Bottom/fold = sulcus
How many layers does most of the cerebral cortex have
Six!
What is Lissencephaly
the Disorder that occurs if folding in the brain is interrupted due to cells not migrating normally during development
drives seizures, muscle spasms, developmental delays, smaller head size and more
Most don’t live past 10
What is the Corpus Callosum
the largest tract (commissure) in the telencephalon connecting the left and right sides of the brain
List the four cortical lobes
Frontal, Parietal, Temporal, Occipital
List the fissures of the brain
Lateral Sulcus (temporal/frontal lobe)
Central Sulcus (frontal/parietal lobe)
Longitudinal Fissure (left/right sides)
List the Functions of the CSF
The Cerebrospinal Fluid
1 is buoyancy, to reduce the weight of the brain so as to not put pressure on lower structures
2 is protection, to reduce injury to brain upon head impact
3 is chemical stability, to rinse waste through the blood-brain barrier and bring in nutrients as well as maintain PH
List the two processes of Neurons
Axons and Dendrites
What properties do neurons have for electrical communication
Membrane
Extracellular fluid
different environment within the neuron
How does the Neuron regulate its internal environment
Using the fatty membrane
1. passive diffusion
2. facilitated diffusion through channels
3. active transport, requiring pumps
Resting membrane potential of a healthy neuron
-75mV
Inside of a neuron should be negative
how is the resting membrane potential of a neuron maintained
Through sodium-potassium pumps
What do the Sodium Potassium pumps do
take 3 sodium from inside, push them out
push in 2 potassium from outside
(all positive charges)
requires 2/3rd of brains energy
When is an action potential fired
When charge on the neuron membrane exceeds -55mV
List the stages of an action potential
Rising Phase: sodium channels open, sodium floods the cell. Potassium channels also open so potassium leaves the cell.
Repolarization phase: charge hits +45mV, sodium channels close, potassium still open
Hyperpolarization: Potassium channels start to close, restored cells resting potential
How does the action potential conduction spread down the axon
Sodium floods the cell at a particular location, these ions spread out and diffuse, making the adjacent part of the cell more positive, spreading the action potential process down the cell
List the two functions of Action potentials
Sensory cells fire action potentials in response to certain stimuli (heat/light etc.)
Based on inputs of other cells since action potentials can trigger neurotransmitters to be released
The three parts of a synapse?
Presynaptic neuron
Postsynaptic Neuron
Space between them (synapse)
List the three types of neurotransmitters
Excitatory= makes neuron fire action potential
Inhibitory = make neuron less likely to fire action potential
Modulatory= trigger other changes in neurons
What are neurotransmitters
Molecules that allow neurons to communicate
What is an agonist drug
Drug that works by binding to a receptor and activating its effect.
e.g dopamine agonist causes effects of dopamine
What is an antagonist drug
Binds receptors in a way that prevents its effects.
e.g Narcan binds to opioid receptors and prevents opioid drugs from binding to them
Three ways that neurotransmitters are cleaned up
- Diffuse away into surrounding fluid
- Broken down by enzymes
- reuptake using glia
What do Reuptake Inhibitors do
Act on the reuptake transporter to block or weaken its function
So the Neurotransmitter stays in the synaptic cleft longer and exaggerates its impact in the brain
List 3 types of Glia
Oligodendroglia
Provides myelin for unmyelinated neurons
Schwann Cells
Work in PNS, wrapping around axons
Microglia
Respond to injury or disease, and eat up debris so they don’t damage cells (also trigger immune response)
What are astroglia/ astrocytes
The Largest glial cells
Support the blood brain barrier
holds the end of the neurons together, maintaining synapses
Explain the Blood-Brain barrier
a filter around brain capillaries that dictates what enters and affects the system
- a wrapper of astrocyte cells
