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Questions and Answers
The nervous system has billions of __________.
The nervous system has billions of __________.
neurons
One function of the nervous system is controlling __________ and glands.
One function of the nervous system is controlling __________ and glands.
muscle
The Central Nervous System is responsible for interpreting incoming __________ information.
The Central Nervous System is responsible for interpreting incoming __________ information.
sensory
The __________ is the primary center for regulating and coordinating body activities.
The __________ is the primary center for regulating and coordinating body activities.
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The __________ carries impulses to and from the spinal cord.
The __________ carries impulses to and from the spinal cord.
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Neuroglia nourishes the __________ cells in the brain and spinal cord.
Neuroglia nourishes the __________ cells in the brain and spinal cord.
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Meninges are the membranes that cover the __________.
Meninges are the membranes that cover the __________.
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An __________ is an agent that directly influences an activity by exciting a sensory organ.
An __________ is an agent that directly influences an activity by exciting a sensory organ.
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Each pair of spinal nerves is connected to a segment of the cord by two pairs of attachments called ______.
Each pair of spinal nerves is connected to a segment of the cord by two pairs of attachments called ______.
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The 8 cervical nerves supply the ______, neck and diaphragm.
The 8 cervical nerves supply the ______, neck and diaphragm.
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The 12 thoracic nerves supply the muscles of the ______ and back.
The 12 thoracic nerves supply the muscles of the ______ and back.
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The 5 lumbar nerves supply the lower ______ and some parts of the lower limb.
The 5 lumbar nerves supply the lower ______ and some parts of the lower limb.
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The olfactory cranial nerve is responsible for the sense of ______.
The olfactory cranial nerve is responsible for the sense of ______.
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The vagus nerve stimulates digestive organs, internal organ functions such as heart rate and respiratory ______.
The vagus nerve stimulates digestive organs, internal organ functions such as heart rate and respiratory ______.
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The somatic sensory fibers deliver impulses from skin, skeletal muscles and ______.
The somatic sensory fibers deliver impulses from skin, skeletal muscles and ______.
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The motor division of the Peripheral Nervous System carries impulses away from the ______.
The motor division of the Peripheral Nervous System carries impulses away from the ______.
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The autonomic nervous system controls the activity of smooth and ______ muscles.
The autonomic nervous system controls the activity of smooth and ______ muscles.
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The ______ state is characterized by calming responses and maintaining homeostasis.
The ______ state is characterized by calming responses and maintaining homeostasis.
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The basic structural and functional unit of the brain and nervous system is called a ______.
The basic structural and functional unit of the brain and nervous system is called a ______.
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The brain is protected by the skull and ______.
The brain is protected by the skull and ______.
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During embryonic development, the prosencephalon is also known as the ______.
During embryonic development, the prosencephalon is also known as the ______.
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Study Notes
Overview of the Nervous System
- Small yet complex, comprising billions of neurons.
- Weighs approximately 2 kg (3% of total body weight) and controls communication within the body.
Functions of the Nervous System (C.R.I.M.E.)
- Controlling muscle and glands.
- Receiving sensory input from the environment.
- Integrating information for processing and response.
- Maintaining homeostasis, or stable internal conditions.
- Establishing and maintaining muscle activity.
Key Terms
- Neuropeptide: Specialized protein messengers involved in mental functions.
- Neuroglia: Cells that nourish and support neurons in the brain and spinal cord.
- Meninges: Membranes covering the brain, providing protection.
- Myelinated: Neurons surrounded by a myelin sheath for faster impulse transmission.
- Neuron: Basic nerve cell responsible for receiving and transmitting impulses.
- Nerve: Bundle of neuron fibers outside the central nervous system (CNS).
- Instinct: Immediate awareness without reasoning or discovery.
- Stimulus: Agent influencing activity, evoking sensory responses or muscular contractions.
- Impulse: Wave of excitation transmitted by nerve fibers and muscles.
Divisions of the Nervous System
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Central Nervous System (CNS): Main control center interpreting sensory information and coordinating responses.
- Brain: Primary regulatory center for body activities, processing information.
- Spinal Cord: Conducting pathway for reflex actions and information between the brain and the body.
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Peripheral Nervous System (PNS): Transmits impulses to and from the CNS.
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Spinal Nerves: 31 pairs connecting to specific spinal cord segments, facilitating impulse transmission.
- Cervical Nerves: Supply limbs, neck, and diaphragm.
- Thoracic Nerves: Supply muscles of chest and back.
- Lumbar Nerves: Supply lower abdomen and parts of the lower limbs.
- Sacral Nerves: Supply reproductive organs.
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Spinal Nerves: 31 pairs connecting to specific spinal cord segments, facilitating impulse transmission.
Cranial Nerves (12 pairs)
- Olfactory: Responsible for sense of smell.
- Optic: Responsible for vision and visual acuity.
- Oculomotor: Controls eyelid opening and pupil constriction.
- Trochlear: Governs oblique eye movement.
- Trigeminal: Related to facial sensation and mastication.
- Abducens: Manages lateral eye movement.
- Facial: Controls facial expressions and tear production.
- Vestibulocochlear: Involved in hearing and balance.
- Glossopharyngeal: Responsible for taste and swallowing.
- Vagus: Stimulates internal organ functions, including the heart and digestive organs.
Functional Classifications of the PNS
-
Sensory Division (Afferent): Nerve fibers conveying information from sensory receptors to the CNS.
- Somatic Sensory Fibers: Deliver impulses from skin, muscles, and joints.
- Visceral Sensory Fibers: Transmit information from internal organs and blood vessels.
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Motor Division (Efferent): Carries impulses away from the CNS to initiate actions.
- Somatic Nervous System: Controls voluntary movements of skeletal muscles.
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Autonomous Nervous System: Regulates involuntary actions of smooth and cardiac muscles.
- Parasympathetic Division: Promotes a calming state, supporting digestion and energy conservation; lowers heart rate and blood pressure.
Neurons
- Basic structural and functional units of the nervous system.
- Cell Body (Perikaryon): Central portion responsible for metabolism and gene expression.
- Dendrites: Tree-like structures conducting impulses to the cell body.
- Axon: Transmits nerve impulses away from the cell body.
The Brain
- Control center of the nervous system, weighing about 3 pounds, with a structure that is soft, spongy, and pinkish gray.
- Composed of over 100 billion neurons and demands continuous oxygen and glucose supply.
- Major components include:
- Brain Stem
- Cerebrum
- Cerebellum
Brain Development
- Begins during the 4th week of embryonic development, forming three major vesicles:
- Prosencephalon (Forebrain): Divides into Telencephalon (cerebrum) and Diencephalon (thalamus, hypothalamus).
- Mesencephalon (Midbrain)
- Rhombencephalon (Hindbrain): Divides into Metencephalon (cerebellum, pons) and Myelencephalon (medulla oblongata).
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Description
Test your knowledge on the fundamental components and functions of the human nervous system. This quiz covers various aspects including structure, organization, and the role of neuroglia. Perfect for students studying biology or health sciences.
