Flashcards in Lecture 25-Nervous System Deck (57):
The nervous system handles:
Our bodies detect stimuli (sensory input) through __________ __________ in the sensor, and the signal is transmitted through __________.
Sensory neurons, interneurons
Analyze and interpret information, and make decisions.
After the signal is transmitted through interneurons, and then the resulting signal travels through:
Communicate with effector cells.
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.
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.
Signals travel through the axon via:
Provides electrical insulation.
Myelin sheath is produced by:
Schwann cells and oligodendrocytes
Gaps in the myelin sheath that result in saltatory conduction.
Nodes of Ranvier
Fast signal 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).
The electrical potential generated by ion differential across a membrane.
__________ 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.
At resting potential, the concentration of __________ ions is high outside the neuron cell.
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.
Opening Na+ channels. Increases permeability to Na+. Net diffusion of Na out of neuron. Inside neuron becomes more positive.
Depolarization reaches the threshold and opens most __________ channels (potassium channels remain closed). Massive influx of __________ into neuron.
Action potentials and conducted in a cascade-like manner along __________.
Depolarization of the action potential spreads to:
After depolarization of the action potential spreads to neighboring regions, the previous membrane gets:
Membrane cannot be re-stimulated: prevents potentials from traveling backwards.
Nervous system involving neurons evolved about:
The brain provides __________ __________.
_________ matter: neuron cells bodies, dendrites, unmyelinated axons.
__________ matter: bundled axons with myelin sheaths.
Filled with cerebrospinal fluid (supply nutrients and hormones. Carry away wastes).
Convents information to and from the brain. Generates basic patterns of locomotion and produces reflex.
The body's automatic responses to certain stimuli.
Examples are reflexes are:
Knee-jerk reflex and the infant grasping reflex
The human brain has _____ major parts.
What are the 4 major parts of the human brain?
Brain stem, diencephalon, cerebrum, and the cerebral cortex
The brainstem is the site for:
These make up the brainstem:
Midbrain, and the pons & medulla oblongata
Receives and integrates sensory information.
__________ and __________ __________ transfer information between PNS and midbrain. Control automatic homeostatic functions (breathing, heart activity, digestion).
Pons, medulla oblongata
Important for coordinating motor control.
Relay station for information flow in the body.
3 main parts of the diencephalon:
Thalamus, hypothalamus, and epithalamus
Pineal gland, source of melatonin.
Main input center for sensory information going to the cerebrum.
Important region for homeostasis, sexual behavior, fight-or-flight response, pleasure.
Controls muscle contraction, learning, emotion, memory, and perception.
The cerebral cortex is the site of:
The __________ __________ is divided into left and right cerebral hemispheres.
The cerebral cortex is divided into left and right cerebral hemispheres and connected by the: