Introduction to the Nervous System Flashcards
In the nervous system, cells communicate by rapid, specific __________ and _____________ signals.
electrical, chemical
List and define the 3 overlapping functions of the nervous system. Think of an example of each function.
Sensory Input - Information gathered by sensory receptors about internal and external changes
Ex. Eyes
Integration - Processing and interpretation of sensory input
Motor Output - Activation of effector organs (muscles and glands) to produce a response
Ex. Muscles activated to get water
What anatomical structures make up the central nervous system?
Brain and Spinal Cord
Integration and control center
Interprets sensory input and dictates motor output based on reflexes, current conditions, and experience
What anatomical structures male up the peripheral nervous system?
Portions of the nervous system outside of the CNS - the nerves extending from the brain and the spinal cord
Spinal Nerves - to/from the spinal cord
Cranial Nerves - to/from the brain
Ganglia - collections of neuron cell bodies
What are the functions of the CNS?
Interprets sensory input and dictates motor output based on reflexes, current conditions, and experience
What are the functions of the PNS?
Communication lines that link all parts of the body to the CNS
The PNS is divided into the ___________ and ___________ divisions.
Sensory (Afferent), Motor (Efferent)
What is the function of sensory (afferent) division?
Keeps the CNS constantly informed of events going on inside and outside the body
What specific types of fibers make up the sensory division?
Somatic Sensory Fibers - convey impulses from skin, skeletal muscles, and joints to the CNS
(Responsible for voluntary movements)
Visceral Sensory Fibers - convey impulses from visceral organs to the CNS
(Responsible for involuntary movements)
What is the function of motor (efferent) division?
Transmits impulses from the CNS to the effector organs (muscles and glands)
What are the 2 divisions of the motor division of the PNS?
Somatic Nervous System
Autonomic Nervous System
Which of these is responsible for our voluntary movements? Our involuntary movements?
Somatic Nervous System (voluntary)
Autonomic Nervous System (involuntary)
What are the 2 divisions of the involuntary division (autonomic)?
Sympathetic
Parasympathetic
Which division is responsible for “rest and digest”? How about “fight or flight”?
Parasympathetic (“rest and digest”)
Sympathetic (“fight or flight”)
What are the 2 major cell types of the nervous system? What is the function of each cell type?
Neuroglia/Glial Cells - “nerve glue”; small cells that surround and wrap the delicate neurons while completing other important functions
Neurons - excitable nerve cells that respond to stimuli by changing their membrane potential and transmitting electrical signals
Which type do we have more of in terms of quantity?
There’s way more glial cells, about 10 to 50 times
List the 4 main types of neuroglia in the CNS
Astrocytes
Microglial Cells
Ependymal Cells
Oligodendrocytes
Astrocyte -
What is each type shaped like? Where could you find it?
- Shaped like sea anemones
- Cling to neurons, synaptic endings, and capillaries
Microglial Cells -
What is each type shaped like? Where could you find it?
- Small, ovoid
- Migrate towards injured neurons
Ependymal Cells -
What is each type shaped like? Where could you find it?
- Range in shape from squamous to columnar
- Line the central cavities of the brain and the spinal column
Oligodendrocytes -
What is each type shaped like? Where could you find it?
- Branched cells
- Line up along thicker nerve fibers in the CNS and wrap their processes around to form insulating myelin sheaths
Glioblastoma – the most common and aggressive type of primary brain cancer – typically develops in which type of neuroglial cell? In which lobes of the brain?
Astrocytes, frontal or temporal lobes
List the 2 major neuroglial cells in the PNS. What is each of their functions?
Myelin sheaths in the CNS are formed from _______________________.
Oligodendrocytes
