WEEK 1: Chapter 2 Flashcards
Transmit information in the form of electric signaling
Neurons
Provide metabolic support, protection, and insulation
Glial cells
Convert physical stimuli into electrical signals
Sensory neuron
Direct bio-behavioral responses appropriate for the situation
Motor neuron
In brain and spinal cord; form interacting neural circuits; responsible for conscious sensations, recognition, memory, decision-making, cognition.
Interneurons
Cell body
Soma
Receive information from other cells across the synapse between
Dendrites
Conducts signal from cell body to terminal
Axon
Each neuron receives/integrates information from many cells
Convergence
Information may be transmitted from one neuron to a few or thousands of other neurons
Divergence
______ and ______ are constantly modified and can change in size, shape and in response to changes in synaptic transmission.
Dendrites and Spines
Terminal buttons have ____________ containing _______________ chemicals
Synaptic vesicles and Neurotransmitter
Are breaks in the myelin sheath, where action potentials are regenerated.
Nodes of Ranvier
Most axons are wrapped with _________, a fatty insulating coating created by layers of glial cells
Myelin Sheath
___________: Proteins that promote or obstruct formation of mRNAs by binding to the ______________ of the gene, modifying its rate of transcription
Transcription factors: promoter region
Production of complementary mRNA from DNA; takes place in nucleus
Transcription
_____________: Building protein molecules by linking amino acids specified by mRNA; takes place on ___________ in the cytoplasm
Translation and Ribosomes
Control of gene expression by chromosome modifications that don’t affect the DNA code
Epigenetics
Form myelin sheaths in the PNS, wrap one axon, promote regeneration of damaged axons
Schwann cells
Form myelin sheaths in the CNS; wrap many axons
Oligodendroglia
Structural support for neurons; modulate the extracellular environment; take up excess neurotransmitters
Astrocytes
Remove dying cells by phagocytosis at sites of nerve damage; source of immune response in the CSN
Microglia
Proteins made in the soma must be transported to the axon terminals
Axoplasmic transport
Depends on structures in the ____________–microtubules and neurofilaments that provide the cell shape
Cytoskeleton
Form a track for protein transport to the axon terminals, and back
Microtubules
Motor protein activated. Packet with newly synthesized protein
Anterograde
Motor protein activated. Organelle carrying waste materials
Retrograde
Proteins in the cell membrane include: _________, ___________, _____________, and _______________
Receptors, enzymes, ion channels, and transporters
Opens when a ligand binds to a receptor
Ligand-gated channel
Opens when electrical potential across the membrane is altered
Voltage-gated channel
_____________: inside of cell is more negative than outside: -70 millivolts (mV); it is _________.
Resting membrane potential and polarized
Elements that are more concentrated outside the cell
Na+ and Cl-
Helps maintain the ion distribution.
Na+-K+ pump
Rapid change in membrane potential that is propagated down the length of the axon
Action potential
Are Small, Transient Changes in Membrane Potential
Local Potentials
A stimulus opens Na+ channels to allow a few ions into cell; inside of cell becomes slightly more positive (excitatory)
Depolarization
A stimulus opens Cl- channels to allow a few ions into cell; inside of cell becomes more negative (inhibitory)
Hyperpolarization
Neurotransmitters act on the postsynaptic membranes; effects are called _______________________ or ______________________.
Excitatory postsynaptic potential (EPSPs) or Inhibitory postsynaptic potentials (IPSPs)
Graded - the larger the stimulus, the greater the magnitude of _________ or __________
Summation (integration)
Na+ channels close and cannot be opened for a fixed period-the_____________
Absolute refractory period
When summation of local potentials reaches the threshold of ______, many voltage-gated _______channels open, and it rushes into the cell, and membrane potential jumps to _______.
-50 mV, Na+, +40 mV.
In myelinated axons, regeneration of the action potential occurs only at nodes of Ranvier; faster transmission; uses less energy for Na+-K+ pumps
Saltatory conduction
______ and ______ alter Axon Conduction
Drugs and Poisons
Block voltage-gated Na+ channels
Local anesthesia (Novacaine)
Some ___________ bind to closed Na+ channels, prolonging the refractory state of the channel, slowing down the firing rate.
Antiepileptic Drugs
In shellfish exposed to red tides block Na+ channels throughout the nervous system, when the _________ is ingested
Neurotoxins
Brain and Spinal cord
Central nervous system (CNS)
All nerves outside Central nervous system
Peripheral Nervous system
Peripheral nervous system. ______________ controls voluntary muscles with spinal nerves and cranial nerves
Somantic system
Controls function of organs and glands with autonomic nerves and some cranial nerves.
Autonomic nervous system
Nerves carry information to the spinal cord; soma are in the dorsal root ganglia
Sensory afferent
Nerves result in voluntary movement; soma are in ventral horn
Motor efferent
Serve head and neck; not all are mixed nerves; some innervate glands and organs
Cranial nerves
Division dominates during times of stress, excitement, and exertion; the “fight-or-flight” system.
Sympathetic
Division dominates when energy reserves can be conserved and stored for later use.
Parasympathetic
Layers of tissue that cover and protect brain and spinal cord.
Meninges
Outermost layer; toughest
Dura mater
Has a weblike sublayer (subarachnoid space) filled with cerebrospinal fluid (CSF)
Arachnoid
Thin layer on top of nerve tissue
Pia mater
Acts like a cushion that helps protect your brain and spinal. Surrounds brain and spinal cord, fills cerebral ventricles and central channel in the spinal cord; formed in the choroid plexus
Cerebrospinal Fluid
__________: gray matter contains neuron cell bodies; white matter is myelinated axons; enlarges into the ___________–medulla, pons, and midbrain
Spinal cord and brain stem
Regulates heart rate, digestion, respiration, blood pressure, coughing, vomiting
Medulla (myelencephalon)
Pons and cerebellum
Metencephalon
Collection of nuclei that influence arousal, attention, sleep, and muscle tone
Reticular formation
Axons extend to many forebrain areas; neurons use norepinerphrine; cause arousal, increased vigilance, and attention
Locus coeruleus
Neurons use serotonin; axons reach all forebrain areas; regulate sleep, aggression, impulsiveness, emotion, etc.
Dorsal and median raphe nuclei
Sensorimotor Center
Cerebellum
Connects to pons by axon bundles
Cerebellar Peduncles
Contains parts of the visual and auditory systems
Tectum
(Midbrain) has two divisions
Mesencephalon
Periaqueductal gray (PAG), Substantia nigra, ventral tegmental area
Tegmentum
Modulation of pain; rich in opioid receptors; important site for morphine binding.
Periaqueductal gray (PAG)
Long axons innervate the striatum in the basal ganglia; use dopamine; critical for initiation and modulation of movement.
Substantia nigra
Use dopamine; some axons extend into limbic system-the mesolimbic tract
Ventral Tegmental area (VTA)
Thalamus and hypothalamus
Diencephalon
Receives sensory and motor information and passes it on to the cortex
Thalamus
Receives information about the internal environment and coordinates with the limbic system to maintain internal states (homeostasis)
Hypothalamus
_____: stress response depends on interaction of the hypothalamus, pituitary gland, and adrenal gland
HPA axis
Paraventricular nucleus in the hypothalamus secretes _________________.
Corticotropin releasing factor (CRF), anterior pituitary secretes adrenocorticotropic hormone (ACTH), adrenal cortex increases secretion of cortisol
Integrates emotional responses and regulates motivated behavior and learning
Limbic system
Closely associated with establishment of new long-term memories and spatial memory
Hippocampus
Coordinates various components of emotional responses through profuse connections with other brain areas
Amygdala
Are involved in motor control.
Basal Ganglia
Neural pathway that connects the hemispheres
Corpus Callosum
The Cerebral Cortex is divided into Four Lobes
Parietal, occipital, temporal, frontal
Conscious awareness of sensory experience and initial processing
Primary cortex
Analyzes information from primary areas, providing perception of the stimulus. Also where memories are stored.
Secondary Cortex
Higher-order perceptual functions needed for purposeful action
Tertiary association areas
Primary motor cortex mediates voluntary muscle movements; secondary motor cortex stores memories for well-learned motor sequences.
Frontal Lobe
Critical for making decisions, planning actions, and evaluating optional strategies. This area is impaired in many psychiatric disorders.
Prefrontal Cortex
_____ and ________ brains have many similarities and some differences
Rat and Human Brains
