Podcast
Questions and Answers
What is the function of the endocrine system in maintaining body homeostasis?
What is the function of the endocrine system in maintaining body homeostasis?
- Releasing hormones into the blood (correct)
- Interpreting sensory information
- Producing electrical nerve impulses
- Issuing instructions to body organs
Which organ serves as the integrating and command center of the nervous system?
Which organ serves as the integrating and command center of the nervous system?
- Heart
- Brain (correct)
- Spinal cord
- Endocrine system
What percentage of the total body weight does the adult human brain approximately weigh?
What percentage of the total body weight does the adult human brain approximately weigh?
- 1%
- 7%
- 5%
- 3% (correct)
What is the approximate diameter of the human spinal cord?
What is the approximate diameter of the human spinal cord?
Which system in the body controls with rapid electrical nerve impulses?
Which system in the body controls with rapid electrical nerve impulses?
What is the weight of the spinal cord approximately?
What is the weight of the spinal cord approximately?
What is the main role of the nervous system?
What is the main role of the nervous system?
Which term describes the ability of an organism or organ to detect external stimuli?
Which term describes the ability of an organism or organ to detect external stimuli?
What type of response does motor output in the nervous system lead to?
What type of response does motor output in the nervous system lead to?
How does the nervous system communicate with body cells?
How does the nervous system communicate with body cells?
What is the general role of sensory input in the nervous system?
What is the general role of sensory input in the nervous system?
Which part of the nervous system decides if action is needed based on sensory input?
Which part of the nervous system decides if action is needed based on sensory input?
What type of cells form a barrier between capillaries and neurons in the brain?
What type of cells form a barrier between capillaries and neurons in the brain?
Which type of cells dispose of debris, dead brain cells, and bacteria in the brain?
Which type of cells dispose of debris, dead brain cells, and bacteria in the brain?
Which cells produce fatty insulating coverings called myelin sheath around nerve fibers in the central nervous system?
Which cells produce fatty insulating coverings called myelin sheath around nerve fibers in the central nervous system?
What type of cells protect and cushion neuron cell bodies?
What type of cells protect and cushion neuron cell bodies?
Which cells form myelin sheath around nerve fibers in the peripheral nervous system?
Which cells form myelin sheath around nerve fibers in the peripheral nervous system?
What is the main function of neurons?
What is the main function of neurons?
Which part of a neuron contains the nucleus and serves as the metabolic center?
Which part of a neuron contains the nucleus and serves as the metabolic center?
What is the function of axons in a neuron?
What is the function of axons in a neuron?
Where are most neuron cell bodies located?
Where are most neuron cell bodies located?
What structures produce myelin sheaths in neurons?
What structures produce myelin sheaths in neurons?
Which part of a neuron conducts impulses toward the cell body?
Which part of a neuron conducts impulses toward the cell body?
What is the main function of conductivity in neurons?
What is the main function of conductivity in neurons?
During depolarization of a neuron's membrane, what ion flows inside the membrane?
During depolarization of a neuron's membrane, what ion flows inside the membrane?
What occurs during repolarization of a neuron's membrane?
What occurs during repolarization of a neuron's membrane?
How does the action potential move along the entire axon of a neuron?
How does the action potential move along the entire axon of a neuron?
What part of a neuron plays a key role in communicating with another neuron at a synapse?
What part of a neuron plays a key role in communicating with another neuron at a synapse?
What is the significance of myelin sheath in nerve impulse propagation?
What is the significance of myelin sheath in nerve impulse propagation?
Flashcards
Astrocytes function
Astrocytes function
Form a barrier between capillaries and neurons, controlling the brain's chemical environment and protecting from harmful substances.
Microglia function
Microglia function
Dispose of debris (dead cells, bacteria) in the brain.
Ependymal cells function
Ependymal cells function
Line brain cavities, circulate cerebrospinal fluid, and create a protective cushion.
Oligodendrocytes function
Oligodendrocytes function
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Satellite cells function
Satellite cells function
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Schwann cells function
Schwann cells function
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CNS
CNS
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PNS
PNS
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Nervous System function
Nervous System function
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Sensory input
Sensory input
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Integration
Integration
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Motor output
Motor output
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Neuron structure
Neuron structure
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Cell body
Cell body
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Dendrites
Dendrites
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Axon
Axon
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Axonal terminals
Axonal terminals
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Myelin sheath
Myelin sheath
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Nodes of Ranvier
Nodes of Ranvier
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Action potential
Action potential
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Sodium-potassium pump
Sodium-potassium pump
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Endocrine System
Endocrine System
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Neurotransmitters
Neurotransmitters
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Study Notes
Supporting Cells in the Nervous System
- Astrocytes: abundant, star-shaped cells that form a barrier between capillaries and neurons, protecting from harmful substances and controlling the chemical environment of the brain.
- Microglia: spider-like phagocytes that dispose of debris, dead brain cells, and bacteria.
- Ependymal cells: line cavities of the brain and spinal cord, helping circulate cerebrospinal fluid and forming a protective cushion around the CNS.
- Oligodendrocytes: produce fatty insulating coverings called myelin sheath around nerve fibers in the CNS.
- Satellite cells: protect and cushion neuron cell bodies.
- Schwann cells: form myelin sheath around nerve fibers in the PNS.
Organization of the Nervous System
- The nervous system does not work alone to regulate and maintain body homeostasis; the endocrine system is a second important regulating system.
- The endocrine system produces hormones that are released into the blood, bringing about deliberate effects.
Structural Classification of the Nervous System
- The nervous system is divided into two main subdivisions: CNS (brain and spinal cord) and PNS (nerves outside the CNS).
- The CNS acts as an integrating and command center, interpreting sensory information and issuing instructions.
- The adult human brain weighs about 3 pounds (1,300-1,400 g) and is about 2% of the total body weight.
- The spinal cord weighs about 35 gm, is 42-45 cm in length, and has a diameter of about 2cm.
Functions of the Nervous System
- The nervous system is the master controlling and communicating system of the body.
- It has three main functions: sensory input, integration, and motor output.
- Sensory input involves gathering information from inside and outside the body.
- Integration involves processing and interpreting sensory input and deciding on a response.
- Motor output involves responding to integrated stimuli, activating appropriate body effectors (muscles or glands).
Neurons
- Neurons are nerve cells specialized to transmit messages (nerve impulses).
- They have three main regions: cell body, dendrites, and axon.
- The cell body contains the nucleus and metabolic center of the cell.
- Dendrites are armlike fibers that conduct impulses toward the cell body.
- Axons are fibers that conduct impulses away from the cell body, ending in axonal terminals.
- Axonal terminals contain vesicles with neurotransmitters and are separated from the next neuron by a synaptic cleft.
Nerve Fiber Coverings and Impulses
- Schwann cells produce myelin sheaths in a jelly-roll-like fashion, with nodes of Ranvier (gaps) at regular intervals along the axon.
- Myelin sheaths increase the speed of impulse transmission.
- An action potential is generated when a stimulus depolarizes the neuron's membrane, allowing sodium ions to flow in and potassium ions to flow out.
- The sodium-potassium pump restores the original membrane configuration, requiring ATP.
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Description
Test your knowledge on the organization of the nervous system with this quiz based on Chapter 7 of 'Essentials of Human Anatomy & Physiology Seventh Edition' by Elaine N. Marieb. Learn about the functions, classifications, and structures of the central and peripheral nervous systems, nervous tissue, neurons, and neuroglia.
