Study Guide Flashcards
know the three functional properties of myelin
1: provides protective insulation over nerve cell
2: It allows the electrical impulses to travel quickly between neurons
3: It maintains the strength of the signals down the axon
What are the names of the glial cells that act as the myelin sheath in the CNS and PNS
- Schwann cells – wrap around axons of neurons in the peripheral nervous system to form myelin
- Oligodendrocytes. – their dendrites/extensions wrap around axons of neurons in the central nervous
system (CNS) to form myelin
For Schwann cells, what is the difference between a neurilemma and myelin?
Neurolemma is the outermost layer of nerve fibers in the peripheral nervous system.
Mylen- a fatty substance that surrounds and insulates axons
Neural Conduction:
1. For each of the following phases of action potential, know how voltage is changing,
what cations are moving during each phase, and what direction those cations are
moving (intracellularly or extracellularly)
i. Depolarization
ii. Repolarization
iii. Hyperpolarization
- Depolarization – Sodium moving intracellularly. Causes depolarization to move from (-70 mV) (+30 mV).
- Repolarization – Switching back to negative intracellular. sodium channels close and potassium (K+) channels open resulting in potassium leaving the cell. Causing positive influx of intracellular charge
- Hyperpolarization – Intracellular space temporarily becomes more negative than resting membrane potential. Potassium channels are slow to close allowing excessive K+ to leave
- Results in the intracellular voltage temporarily becoming more negative than RMP
Arrange the meninges layers from most outer (closest to scalp) to most inner (closest to brain).
ESAP
Subdural Mater: contains veins carrying blood and
metabolic waste out of the brain
Arachnoid: contains the subarachnoid space which
contains cerebrospinal fluid
Pia Mater: Contains arteries supplying oxygen and
nutrients to the brain
What does “Meninges” translate to?
Membrane
What is primary function of Broca’s area?
Coordination of tongue, soft palate, and larynx for speech (frontal)
Which lobe is associated with receiving/interpreting sounds and smells?
Temporal Lobe
What form does transport take in the blood-brain barrier?
Transcellular
Why is the blood-brain barrier restrictive? (Select all that apply).
Pericytes: the end-feet of astrocytes envelope the
blood cells reducing “leaking” of materials between
the blood and brain
Astrocytes: Cells that sparsely line the blood vessel.
Pericytes have contractile proteins that pull
endothelial cells together thereby bringing them into
closer proximity
Tight Junctions: Intercellular adhesion molecules
(similar to buttons for a shirt) that reduce paracellular
transport
What is the difference between continuous and saltatory conduction?
Continuous conduction occurs in neurons with unmyelinated axons whereas saltatory conduction occurs in neurons with myelinated axons.
saltatory (“leaping”) conduction – Axons are covered by
myelin (discussed next session) causing the depolarization
wave to “leap” down the axon rather than spread like a
wave
What is the major functional difference between the parasympathetic and sympathetic nervous systems?
PNS- Rest and digest
SNS- Fight of flight
DAP
1: Dura mater: contains veins carrying blood and metabolic waste out of the brain.
2: Arachnoid – contains the subarachnoid space which
contains cerebrospinal fluid (CSF)
Arachnoid granulations – allows CSF to diffuse into
the dura mater space (sinus)
This will allow cerebral waste to be transported to the
circulatory system to be filtered
3: Pia mater – Contains arteries supplying oxygen and
nutrients to the brain (formation of CSF)
The cerebrospinal fluid is produced from selective filtration of blood (plasma) circulating to the
brain
located between the arachnoid and pia mater meninge
what primary substances are removed from the blood to create CSF
What is the common transport mechanism at the blood brain barrier (how do substances cross the BBB; paracellularly or transcellularly)?
transcellular transport is more common
at the capillary level, blood exchanges
nutrients and wastes with surrounding tissues
What is unique about the BBB that is not found in regular capillary beds around the body?
- Astrocytes – the end-feet of astrocytes envelope the
blood cells reducing “leaking” of materials between
the blood and brain - Pericytes – Cells that sparsely line the blood vessel.
Pericytes have contractile proteins that pull endothelial cells together thereby bringing them into closer proximity - Tight Junctions – Intercellular adhesion molecules (similar to buttons for a shirt) that reduce paracellular
transport
What molecular groups can be added to make a substance more lipophilic?
CAM
1. Carboxyl groups (COO, COOH),
- acetyl groups (C2H3O)
- methyl groups (CH3)
4 major divisions of the brain and their respective functions.
- Cerebrum
- Diencephalon
- Cerebellum
- Brain Stem
Cerebrum
Frontal lobe:
1. Primary Motor Area – Neurons that initiate conduction and contraction of skeletal muscles
2. Prefrontal Cortex – involved in memory, decision-making/problem solving, and conscious thought.
1. Also contains Broca’s area, or motor speech area. Control of tongue, larynx, and soft palate coordination to form complex, specific sounds (language, speech)
Parietal:
receives messages from sensory/afferent neurons
( Primary Somatosensory Area – Receives sensory information (touch, pain, etc.).
Somatosensory association area – combines sensory information with memory to help
determine what an object is by touch alone.
Temporal: Temporal Lobe is mainly associated with receiving and interpreting sounds and
smells
Occipital: is mainly associated with receiving and interpreting sight/vision
The cerebellum helps maintain coordination, balance, and positioning.
The medulla oblongata in the brain stem controls the homeostasis of blood gases.
(Diencephalon) thalamus
direct sensory information to
the correct lobes of the cerebrum
(Diencephalon) hypothalamus
regulates negative
feedback control mechanisms (body
temperature, food intake, water balance)
The Brain Stem
The Brain Stem is composed of three distinct
regions:
1. The Midbrain
2. The Pons
3. The Medulla Oblongata
The Midbrain
The Medulla Oblongata
MO is responsible for the automatic control of
blood gases (i.e., O2 and CO2)
The respiratory center (respiratory muscle control)
The cardiac center (heart rate and strength control)
Vasomotor center (control of smooth muscles in blood
vessels [vasodilation and vasoconstriction)