Lecture 29: Anatomy And Physiology IV (nervous System) Flashcards
What is a neuron?
A cell that transmits information by electrical impulses
What is an impulse?
An electrical charge
What is the cell body?
The main part of the cell
What are the dendrites?
The extensions that receive information
What is an axon?
The extension that sends information
What is the axon hillock?
The cone shaped thickening that leads to axon
What myelination?
The myelin sheath in the neuron
What are the nodes of ranvier?
The gaps between the neurons
What is white matter?
The myelinated axons of the CNS
What does it mean for neurons to be unmyelinated?
It means that there is no myelin sheath
What is grey matter?
Unmyelinated axons in the CNS
What are multipolar neurons?
Neurons with multiple extensions or many dendrites and 1 axon
What are bipolar neurons?
Neurons with two extensions with one dendrite and one axon
What are unipolar neurons?
Neurons with one extension where one side is the dendrite and the other side is the axon
What are sensory neurons?
Afferent neurons that receive input from the peripheral body parts from sensory receptors. In addition, most are unipolar or bipolar neurons
What are interneurons?
Neurons found in brain and spinal cord. They conduct impulses from one part of the brain/spinal cord to another. In addition, most of them are multipolar
What are motor neurons?
Efferent neurons that conduct impulses from brain/spinal cord to muscles. In addition, most of the are multipolar
What is neuroglia?
The “nerve glue” that nourishes and supports the neurons
What are microglial cells?
The phagocytose bacteria and cellular debris. If there are blood borne immune cells, they have limited access to CNS
What are oligodendrocytes?
They provide insulating myelin sheath around axons in the CNS
What are Schwan cells?
They provide insulating myelin sheath around axons in PNS
What are astrocytes?
They are found between blood vessels and neurons of CNS and regulate nutrient flow.
What is the blood brain barrier?
The chemicals flowing into the brains are tightly regulated
What are satellite cells?
They are cells that control the chemical environment and nutrient flow to neurons in PNS
What are ependymal cells?
They are cells that produce cerebrospinal fluid in CNS
What is a synapse?
It is the gap between a neuron and another cell
What is the presynaptic neuron?
The neuron sending the information
What is the post synaptic neuron?
The neuron that is receiving the information
What is the synaptic transmission?
Sending a message across a synapse
What are neurotransmitters?
Chemical signals that travel across synapse to rely information
What is adrenaline ?
The fight or flight, stress neurotransmitters for physical boost
What is noradrenaline?
It is the fight or flight, stress neurotransmitters for heightened awareness
What is dopamine?
A neurotransmitters for pleasure, motivation, and repeat behaviors
What is serotonin?
It is the mood, happiness, regular sleep, exercise, and light exposure neurotransmitters
What is GABA?
Aminobutyric acid that is calming and can be found in alcohol and chamomile tea
What are endorphins?
Neurotransmitters for euphoria and pain relief. Also, for exercise and excitement
What is the resting potential?
The electrical charge difference in a resting nerve cell
What is an action potential?
The change in electrical charges along axon in firing neuron
What is the threshold potential?
The amount of depolarization at axon hillock before axon fires (-55mV). Also, the all or nothing potential
What is depolarization?
It is when gated channels open and allow sodium ions to flow into cell. Additionally, the inside becomes less negatively charged
What is repolarization?
When gated channel allow for potassium ions to flow out of the cell. Restores positive charge outside of the cell
At what rate do unmyelinated axons travel?
O.5 m/s which is slow
At what rate do myelinated axons travel?
120 m/s which is fast
What is a nerve?
Bundle of axons
What are the cerebral hemispheres in the cerebrum?
Left and right
What is the corpus callosum in the cerebrum?
What connects the cerebral hemispheres
What happens when the corpus callosum is cut?
It can treat seizures but this is the last resort
What is alien hand syndrome?
It is when one can’t consciously control a hand
What is the split brain syndrome?
It is where each hemisphere has its own perception
What is the cerebral cortex?
The outer layer and gray matter
What is the frontal lobe responsible for?
Reasoning, planning, motivation, reward, and consequence
What is the parietal lobe responsible for?
Spatial sense, navigation, and touch
What is the temporal lobe responsible for?
Hearing, language comprehension, and memory(anterograde)
What is the occipital lobe responsible for?
Vision, color differentiation, and motion perception
What is the thalamus?
Receives sensory impulses (except smell) and relays to cerebral cortex
What is the hypothalamus?
Maintains homeostasis by linking nervous system and endocrine system
What is the limbic system responsible for?
It is a combination of brain areas. It controls emotions and guides behavior by causing unpleasant feelings
What is the brain stem?
It is what connects the cerebrum to spinal cord
What is the midbrain?
Reflex centers
What are the pons?
Relay sensory impulses to cerebrum
What is the medulla oblongata?
It controls vital visceral activity such as cardiac center, vasomotor center, and respiratory center.
What is reticular information?
Scattered network of nerve fibers in the brain stem. It controls awareness, decreased activity. Leads to sleep,, and impaired activity leads to coma
What is cerebellar cortex?
The thin layer of gray matter on surface. It integrates body position from sensory input with movements of skeletal muscle to maintain posture. Any damage leads to uncoordinated movements
What are ascending tracts?
They carry sensory information to the brain
What are descending tracts?
They carry motor instructions to muscles
