Podcast
Questions and Answers
What type of cells support neurons but do not generate action potentials?
What type of cells support neurons but do not generate action potentials?
Which part of the central nervous system is responsible for regulating fine sensations and higher cognitive functions?
Which part of the central nervous system is responsible for regulating fine sensations and higher cognitive functions?
What structure acts as the blood-brain barrier?
What structure acts as the blood-brain barrier?
Which division of the nervous system is characterized by immediate automatic activities?
Which division of the nervous system is characterized by immediate automatic activities?
Signup and view all the answers
How does synaptic transmission typically occur between neurons?
How does synaptic transmission typically occur between neurons?
Signup and view all the answers
Which part of the brain includes the midbrain, pons, and medulla?
Which part of the brain includes the midbrain, pons, and medulla?
Signup and view all the answers
Which of the following describes the axo-dendritic synapse?
Which of the following describes the axo-dendritic synapse?
Signup and view all the answers
What is primarily produced by oligodendrites in the nervous system?
What is primarily produced by oligodendrites in the nervous system?
Signup and view all the answers
What type of synapse involves the axon of one neuron connecting to the dendrites of another neuron?
What type of synapse involves the axon of one neuron connecting to the dendrites of another neuron?
Signup and view all the answers
Which type of synaptic vesicles is associated with rapidly acting transmitters such as acetylcholine?
Which type of synaptic vesicles is associated with rapidly acting transmitters such as acetylcholine?
Signup and view all the answers
What function do voltage-gated calcium channels serve in the presynaptic terminal?
What function do voltage-gated calcium channels serve in the presynaptic terminal?
Signup and view all the answers
What role does synapsin play in synaptic transmission?
What role does synapsin play in synaptic transmission?
Signup and view all the answers
What is the characteristic width of the synaptic cleft?
What is the characteristic width of the synaptic cleft?
Signup and view all the answers
What type of receptors are ionotropic receptors primarily associated with?
What type of receptors are ionotropic receptors primarily associated with?
Signup and view all the answers
What is the role of stenin in the synaptic transmission process?
What is the role of stenin in the synaptic transmission process?
Signup and view all the answers
What triggers the release of the neurotransmitter from the presynaptic terminal?
What triggers the release of the neurotransmitter from the presynaptic terminal?
Signup and view all the answers
Study Notes
Nervous System Overview
- Two regulatory systems exist: the nervous system and the endocrine system
- Nervous System: Rapid activities, like muscle contractions
- Endocrine System: Slow activities, like metabolism
Nervous System Organization
-
Histology:
- Glial cells: Support neurons; do not produce action potentials; 50 times more numerous than neurons
- Microglial cells: Scavenger cells (phagocytic)
- Oligodendrites: Produce and maintain myelin sheaths
- Astrocytes: Form the blood-brain barrier (BBB)
- Neurons: Structural units of the central nervous system (CNS); generate action potentials
- Glial cells: Support neurons; do not produce action potentials; 50 times more numerous than neurons
-
Anatomy:
-
Central Nervous System (CNS):
- Brain: Cerebrum (cerebral hemispheres, basal ganglia), Diencephalon (thalamus, hypothalamus), Brain stem (midbrain, pons, medulla), Cerebellum
- Spinal cord: 31 segments (8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal)
-
Central Nervous System (CNS):
-
Functional Divisions:
- Sensory Division: Receptor → afferent tracts → center
- Motor Division: Center → upper and lower motor neurons → organ
-
Integrated Centers:
- Spinal cord: Immediate automatic functions (walking, reflexes)
- Lower brain levels (brain stem & diencephalon): Regulate respiration, cardiovascular system (CVS), gastrointestinal tract (GIT)
- Higher brain levels (cortex): Fine sensations, motor control, language, memory, thinking, sleep, wakefulness
Synaptic Transmission
- Transmission of an impulse between neurons
- Electrical Transmission: Extremely rare in humans (e.g., vestibular nuclei); low-resistance gap channels connect neurons
- Chemical Transmission: Release of a neurotransmitter from a presynaptic neuron to act on a postsynaptic neuron
Synapse Structure and Function
-
Synapse: Junction between neurons, dynamic structure
-
Types of Synapses:
- Axo-dendritic: Most numerous, least excitable
- Axo-somatic
- Axo-axonic: Least numerous, most excitable, low firing level at axon hillock
-
Functions of Synapses:
Synaptic Anatomy
-
Presynaptic Terminal (knob):
- Many mitochondria to synthesize and release neurotransmitters
- Synaptic vesicles: Three types:
- Small clear vesicles: Rapidly acting (acetylcholine, glycine, glutamate, GABA)
- Small granular vesicles: Catecholamines
- Large granular vesicles: Slowly acting neuropeptides
- Synaptic Cleft: 30-50 nm wide, filled with extracellular fluid
-
Postsynaptic Membrane: Contains receptors specific to neurotransmitters, two types:
- Ionotropic receptors: Ligand-gated channels (Na+, K+, Cl−)
- Metabotropic receptors: G protein-coupled receptors
Mechanism of Synaptic Transmission
- Neurotransmitter Release: Action potential opens Ca2+ channels in the presynaptic neuron; Ca2+ triggers release
- Neurotransmitter Activity: Transmitter crosses the cleft, binds to receptors on postsynaptic membrane, causing changes in ion fluxes & potential (RMP)
-
Removal of Transmitter:
- Diffusion away from cleft
- Enzymatic inactivation
- Active reuptake (to axon terminal)
- Removal by glial cells
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
This quiz covers the major aspects of the nervous system and its organization. It includes topics such as histology, anatomy of the central nervous system, and functional divisions of sensory and motor pathways. Test your knowledge on the fundamental concepts that govern nervous system functions.
