Podcast
Questions and Answers
What is primarily responsible for transmitting orders from the CNS to muscles and glands?
What is primarily responsible for transmitting orders from the CNS to muscles and glands?
Which division of the nervous system specifically controls voluntary movements?
Which division of the nervous system specifically controls voluntary movements?
What structural component carries signals from the CNS to the effector organs?
What structural component carries signals from the CNS to the effector organs?
Which type of pain receptor is activated by strong pressure and sharp objects?
Which type of pain receptor is activated by strong pressure and sharp objects?
Signup and view all the answers
Which part of the nervous system is primarily involved in processing reflex actions?
Which part of the nervous system is primarily involved in processing reflex actions?
Signup and view all the answers
The third order neuron in sensory pathways transmits signals to which part of the nervous system?
The third order neuron in sensory pathways transmits signals to which part of the nervous system?
Signup and view all the answers
What role do afferent fibers play in the nervous system?
What role do afferent fibers play in the nervous system?
Signup and view all the answers
Which type of pain receptor is most likely to respond to environmental irritants and chemical substances?
Which type of pain receptor is most likely to respond to environmental irritants and chemical substances?
Signup and view all the answers
Which of the following best describes the primary function of the motor nervous system?
Which of the following best describes the primary function of the motor nervous system?
Signup and view all the answers
Which term best describes the function of the motor category in the cerebral cortex?
Which term best describes the function of the motor category in the cerebral cortex?
Signup and view all the answers
What is a primary role of motor neurons within the peripheral nervous system?
What is a primary role of motor neurons within the peripheral nervous system?
Signup and view all the answers
In the anatomical organization of the nervous system, which of the following structures is NOT part of the motor nervous system?
In the anatomical organization of the nervous system, which of the following structures is NOT part of the motor nervous system?
Signup and view all the answers
What is the primary role of the associative areas in the cerebral cortex?
What is the primary role of the associative areas in the cerebral cortex?
Signup and view all the answers
Which of the following structures is involved in protecting delicate nervous tissue through a cushioning effect?
Which of the following structures is involved in protecting delicate nervous tissue through a cushioning effect?
Signup and view all the answers
Which type of neuron is primarily responsible for transmitting motor signals away from the central nervous system?
Which type of neuron is primarily responsible for transmitting motor signals away from the central nervous system?
Signup and view all the answers
Which of the following accurately describes the relationship between the central and peripheral nervous systems?
Which of the following accurately describes the relationship between the central and peripheral nervous systems?
Signup and view all the answers
What is the function of the Dura mater within the central nervous system?
What is the function of the Dura mater within the central nervous system?
Signup and view all the answers
What is the significance of the corpus callosum in the context of motor functions?
What is the significance of the corpus callosum in the context of motor functions?
Signup and view all the answers
Which arterial structure directly supplies blood to the brain?
Which arterial structure directly supplies blood to the brain?
Signup and view all the answers
Which part of the brain plays a significant role in coordinating voluntary motor activity?
Which part of the brain plays a significant role in coordinating voluntary motor activity?
Signup and view all the answers
What sequence of events occurs at the synaptic junction for neurotransmitter release?
What sequence of events occurs at the synaptic junction for neurotransmitter release?
Signup and view all the answers
Which type of sensation is NOT typically processed by the motor nervous system?
Which type of sensation is NOT typically processed by the motor nervous system?
Signup and view all the answers
What is the primary role of the motor cortex within the motor nervous system?
What is the primary role of the motor cortex within the motor nervous system?
Signup and view all the answers
Which type of movement is characterized by the use of distal limb muscles?
Which type of movement is characterized by the use of distal limb muscles?
Signup and view all the answers
Which brain structure is responsible for converting the idea of voluntary movement into a motor plan?
Which brain structure is responsible for converting the idea of voluntary movement into a motor plan?
Signup and view all the answers
What differentiates skilled movements from fine and gross movements?
What differentiates skilled movements from fine and gross movements?
Signup and view all the answers
Which component of the motor system is primarily involved in executing the planned movement?
Which component of the motor system is primarily involved in executing the planned movement?
Signup and view all the answers
Which of the following describes the function of the cerebellum in the motor nervous system?
Which of the following describes the function of the cerebellum in the motor nervous system?
Signup and view all the answers
How are voluntary movements primarily communicated from the brain to the muscles?
How are voluntary movements primarily communicated from the brain to the muscles?
Signup and view all the answers
What is the implication of a dysfunction in the basal ganglia for movement?
What is the implication of a dysfunction in the basal ganglia for movement?
Signup and view all the answers
In the context of voluntary movement, what role do association areas in the cortex play?
In the context of voluntary movement, what role do association areas in the cortex play?
Signup and view all the answers
What is the defining characteristic of gross movements in the motor system?
What is the defining characteristic of gross movements in the motor system?
Signup and view all the answers
Study Notes
Nervous System Overview
- The nervous system controls rapid bodily activities.
- It gathers and processes information from sensory organs to initiate a response.
Intended Learning Outcomes
- Outline the classification of the nervous system.
- Recognize the anatomical organization of the nervous system.
- Identify the major levels of central nervous system (CNS) functions.
- Understand different types of sensations.
- Identify parts of the motor nervous system and identify lesions.
- Define synapse and identify its functional anatomy across different junctions.
- Recognize the sequence of neurotransmitter release at synaptic junctions.
Organization of the Nervous System
- The nervous system is divided into central and peripheral systems.
- The central nervous system (CNS) includes the brain and spinal cord.
- The peripheral nervous system (PNS) encompasses nerves transmitting signals to and from the CNS.
Anatomical Organization of the Nervous System (CNS)
- The CNS, including brain and spinal cord, is housed within the skull and vertebral column.
- The PNS is comprised of nerves that extend between the CNS and peripheral tissues.
- The PNS consists of cranial nerves (12 pairs) originating from the brain and spinal nerves (31 pairs) from the spinal cord.
- Individual PNS fibers are extensions of sensory or motor neurons.
Central Nervous System: Brain
- The brain is divided into four main parts: cerebrum, diencephalon, brainstem, and cerebellum.
- Cerebral ventricles are interconnected cavities filled with cerebrospinal fluid (CSF).
Cerebrum: Two Cerebral Hemispheres
- The cerebrum's surface is convoluted, consisting of gyri and sulci.
- The cerebral cortex, a thin outer layer of gray matter, comprises neuron cell bodies.
- White matter, beneath the cortex, is a thick core formed of myelinated axons.
- The corpus callosum connects the right and left cerebral hemispheres.
- Each hemisphere is divided into four lobes: frontal, parietal, occipital, and temporal.
- Lobes contain specific areas for functions like visual, auditory, and sensory processing.
Cerebrospinal Fluid (CSF)
- CSF is secreted by choroid plexuses in the walls of cerebral ventricles.
- The total volume of CSF is roughly 150 mL.
- CSF turnover is approximately 500 mL per day.
- CSF acts as a cushion for the brain, preventing injury to delicate nervous tissue.
Increased Intracranial Pressure (IICP)
- Normal IICP ranges from 5-15 mmHg.
- IICP can result from tumor growth, edema, excess CSF, or hemorrhage.
- Clinical hallmarks include headache, vomiting, and papilledema (optic disc swelling).
Blood Supply to the Brain
- The brain requires a substantial blood supply (15-20% of total cardiac output) due to its high metabolic rate.
- The blood-brain barrier separates circulating blood from brain tissue, and plays a role in drug design.
- The Circle of Willis is a circulatory anastomosis supplying blood to the brain.
Structure of Neurons
- Neurons exhibit diverse shapes and sizes but generally possess a cell body (soma), dendrites, an axon, and axon terminals.
- Dendrites receive input, the axon transmits impulses away from the soma, and axon terminals release neurotransmitters.
Synapses
- Synapses are the junctions between neurons.
- Chemical synapses are the predominant type, relying on neurotransmitter release.
- Electrical synapses involve electrical coupling via gap junctions.
Action of Neurotransmitters
- Released neurotransmitters diffuse across the synaptic cleft.
- They bind to specific receptor proteins.
- Neurotransmitter action can be excitatory or inhibitory.
Major Levels of CNS Functions
- The cerebrum and cerebral cortex are the highest functional levels, processing and analyzing information.
- The brainstem controls life-sustaining functions and relays sensory input and motor output.
- The spinal cord processes reflexes and transmits signals between the brain and the body.
Sensory Nervous System
- The sensory nervous system carries information about the external and internal environment to the CNS.
- It gathers sensory input, integrates it, and transmits it to the CNS and eventually to motor systems. Sensory pathways involve three types of neurons: first-order, second-order, and third-order neurons.
Sensations
- The main function of the sensory system is to detect changes in both the internal and external environment.
- This includes general sensation (like pain, temperature, pressure), special sensations (vision, hearing, taste, smell) , and organic sensations (hunger, thirst).
Pain Sensation
- Pain is a common sensation, warning of potential tissue damage.
- Nociceptors are pain-sensitive nerve endings activated by various stimuli.
- Pain can be classified into several types, including cutaneous, deep, and visceral pain.
Peripheral Neuropathy
- Peripheral neuropathy is a general term encompassing diseases affecting peripheral nerves, causing motor, sensory, or autonomic dysfunction.
Motor Nervous System
- The motor nervous system sends commands from the CNS to muscles and glands, enabling voluntary movement, coordination of movement.
- It includes upper motor neurons (UMNs) and lower motor neurons (LMNs).
Motor Reflexes
- Reflexes are involuntary responses to stimuli.
- The monosynaptic reflex (e.g., muscle stretch reflex) involves a simple pathway with one synapse.
- The polysynaptic reflex (e.g., flexor withdrawal reflex, crossed extensor reflex) involves more complex pathways with multiple synapses.
Upper and Lower Motor Neurons
- Upper motor neurons originate in the brain and activate lower motor neurons.
- Lower motor neurons project from the spinal cord to muscles and glands.
Motor Lesions
- Damage to upper motor neurons (UMNs) typically results in weakness or paralysis in the body's opposite side and hyperreflexia or spasticity.
- Damage to lower motor neurons (LMNs) results in weakness or paralysis affecting the same side of the body and hyporeflexia.
The Cerebellum
- The cerebellum is crucial for coordinating voluntary movements, maintaining muscle tone, and equilibrium.
- Cerebellar damage can lead to problems with incoordination and balance.
The Basal Ganglia
- The basal ganglia are essential for regulating muscle tone, initiating voluntary movements, and controlling automatic movement.
- Dysfunction of the basal ganglia produces motor problems like slow movements, tremors, and rigidity.
Let's Think Together
- Chemical synapses are the most prevalent synapse type in humans.
Additional Note
- Afferent nerves send information to the central nervous system (CNS), while efferent nerves send information from the CNS.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Test your understanding of the nervous system with this comprehensive quiz. Cover topics such as the classification, organization, and functions of the central and peripheral nervous systems. Dive into the anatomy of the nervous system and learn about synapses and neurotransmitter functions.
