Ch1 Flashcards
(130 cards)
The nervous system has two main types of cells
neurons and glia
Receive information and send it to other cells
Neurons
Support the neurons in many ways.
Glia
The adult human brain has about
86 billion neurons
In the late 1800s, scientist – used new staining techniques to show that there is a small gap between the end of one neuron’s fiber and the next neuron
Santiago Ramón y Cajal
Two scientists of the late 1800s and early 1900s are widely recognized as the main founders of neuroscience—
Charles Sherrington and the Spanish investigator Santiago Ramón y Cajal (1852–1934).
Golgi’s Staining Technique
Camillo Golgi developed a method using silver salts to stain nerve cells. This technique allows researchers to see the structure of individual neurons
Microscopy and the Nervous System
Before the late 1800s, the structure of the nervous system was poorly understood due to limitations in microscopy. The use of Golgi staining revolutionized research, allowing for the clear visualization of individual nerve cells.
The outer boundary of a cell that controls what enters and exits. It is semi-permeable and regulates the flow of essential substances like water, oxygen, sodium, potassium, calcium, and chloride.
Plasma Membrane
Found in all animal cells (except red blood cells), the nucleus contains the chromosomes, which house the cell’s genetic material.
Nucleus
The “powerhouse” of the cell, responsible for producing energy (ATP). Mitochondria have their own DNA, distinct from the nuclear DNA, and can vary genetically. Abnormal mitochondrial function is linked to conditions like autism and depression.
Mitochondria
Structures that produce proteins, which are essential for the cell’s structure and function. Some are free-floating, while others are attached to the endoplasmic reticulum (ER).
Ribosomes
A network of tubes that transports proteins synthesized by ribosomes to various parts of the cell
Endoplasmic Reticulum (ER)
Contains the nucleus and other essential cell structures
Soma (Cell Body)
Branched extensions that receive signals from other neurons
Dendrites
A long, thin extension that transmits signals away from the soma to other cells
Axon
The endings of the axon where the neuron communicates with other neurons or muscles
Presynaptic Terminals
carry signals from the brain and spinal cord to muscles and glands. It has a soma located in the spinal cord, with dendrites that receive incoming signals and an axon that transmits impulses to muscles.
Motor Neurons
carry information from sensory receptors (like touch or light) to the central nervous system (spinal cord and brain). It have a special structure at one end, adapted to detect specific stimuli (e.g., light, sound, or touch).
Sensory neurons
Golgi vs. Cajal
The debate between Golgi (who believed neurons merged) and Cajal (who showed that neurons remained separate) remains central to understanding how the nervous system functions.
A long, thin fiber that carries electrical impulses away from the cell body. The term comes from the Greek word for “axis.” They are typically of constant diameter but can be over a meter long (e.g., axons from the spinal cord to the feet)
Axon
Many axons are covered by an insulating layer. This speeds up the transmission of signals. In vertebrates, it is interrupted by gaps known as nodes of Ranvier.
Myelin Sheath
These neurons carry information into a structure (e.g., sensory neurons bring information from sensory organs to the nervous system
Afferent Neurons
These neurons carry information away from a structure (e.g., motor neurons transmit signals from the brain to muscles or glands).
Efferent Neurons