Lecture 25-Nervous System Flashcards
Our bodies detect stimuli (sensory input) through __________ __________ in the sensor, and the signal is transmitted through __________.
Sensory neurons, interneurons
The nervous system handles:
Information processing
Analyze and interpret information, and make decisions.
Interneurons
After the signal is transmitted through interneurons, and then the resulting signal travels through:
Motor neurons
Communicate with effector cells.
Motor neurons
Consists of the brain and spinal cord.
Central nervous system (CNS)
Consists of all the nerves out of the spinal cord connecting to organs.
Peripheral nervous system (PNS)
Sensory system responds to both __________ and __________ stimuli.
External, internal
Examples of external stimuli:
Light, sound, touch, hear, smell, and taste
Examples of internal stimuli:
Blood pressure, blood chemical level, muscle tension, blood sugar
A neuron consists of:
Cell body, dendrites, and axon
Junction where chemical information is passed on.
Synapse
Signals travel through the axon via:
Action potential
Provides electrical insulation.
Myelin sheath
Myelin sheath is produced by:
Glial cells
Glial cells:
Schwann cells and oligodendrocytes
Gaps in the myelin sheath that result in saltatory conduction.
Nodes of Ranvier
Fast signal conduction.
Saltatory conduction
All cells have a __________ __________ across plasma membrane.
Membrane potential (voltage)
Non transmitting neurons have a __________ potential between -60 and -80 millivolts (they have a __________ charge).
Resting, negative
The electrical potential generated by ion differential across a membrane.
Resting potential
__________ ions and __________ ions play an essential role in forming resting potential.
Potassium (K+) and Sodium (Na+)
At resting potential, the concentration of __________ ions is high inside the neuron cell.
Potassium (K+)
At resting potential, the concentration of __________ ions is high outside the neuron cell.
Sodium (Na+)
Changes in the membrane potential occur because neurons contain:
Gated ion channels
Opening K+ channels. Increases permeability to K+. Net diffusion of K+ out if neuron, inside neuron becomes more negative.
Hyperpolarization
Opening Na+ channels. Increases permeability to Na+. Net diffusion of Na out of neuron. Inside neuron becomes more positive.
Depolarization
Depolarization reaches the threshold and opens most __________ channels (potassium channels remain closed). Massive influx of __________ into neuron.
Na+
Action potentials and conducted in a cascade-like manner along __________.
Axons
Depolarization of the action potential spreads to:
Neighboring regions
After depolarization of the action potential spreads to neighboring regions, the previous membrane gets:
Repolarized
Membrane cannot be re-stimulated: prevents potentials from traveling backwards.
Refractory period
Nervous system involving neurons evolved about:
500 MYA
The brain provides __________ __________.
Integrative power
_________ matter: neuron cells bodies, dendrites, unmyelinated axons.
Gray
__________ matter: bundled axons with myelin sheaths.
White
Filled with cerebrospinal fluid (supply nutrients and hormones. Carry away wastes).
Ventricles
Convents information to and from the brain. Generates basic patterns of locomotion and produces reflex.
Spinal cord
The body’s automatic responses to certain stimuli.
Reflexes
Examples are reflexes are:
Knee-jerk reflex and the infant grasping reflex
The human brain has _____ major parts.
4
What are the 4 major parts of the human brain?
Brain stem, diencephalon, cerebrum, and the cerebral cortex
The brainstem is the site for:
Homeostasis
These make up the brainstem:
Midbrain, and the pons & medulla oblongata
Receives and integrates sensory information.
Midbrain
__________ and __________ __________ transfer information between PNS and midbrain. Control automatic homeostatic functions (breathing, heart activity, digestion).
Pons, medulla oblongata
Important for coordinating motor control.
Cerebellum
Relay station for information flow in the body.
Diencephalon
3 main parts of the diencephalon:
Thalamus, hypothalamus, and epithalamus
Pineal gland, source of melatonin.
Epithalamus
Main input center for sensory information going to the cerebrum.
Thalamus
Important region for homeostasis, sexual behavior, fight-or-flight response, pleasure.
Hypothalamus
Controls muscle contraction, learning, emotion, memory, and perception.
Cerebrum
The cerebral cortex is the site of:
Information processing
The __________ __________ is divided into left and right cerebral hemispheres.
Cerebral cortex
The cerebral cortex is divided into left and right cerebral hemispheres and connected by the:
Corpus callosum
Neurons are arranged according to the part if the body that:
Generates the sensory input
