Podcast
Questions and Answers
What initiates the process of synaptic transmission at the axon terminal?
What initiates the process of synaptic transmission at the axon terminal?
Which type of channel is primarily responsible for allowing the influx of calcium ions during neurotransmitter release?
Which type of channel is primarily responsible for allowing the influx of calcium ions during neurotransmitter release?
What effect does the high concentration of Ca2+ in the presynaptic cell have?
What effect does the high concentration of Ca2+ in the presynaptic cell have?
What is the role of neurotransmitters after they are released into the synaptic cleft?
What is the role of neurotransmitters after they are released into the synaptic cleft?
Signup and view all the answers
What outcome occurs if the summated graded potentials reach the neuron threshold potential?
What outcome occurs if the summated graded potentials reach the neuron threshold potential?
Signup and view all the answers
What is the main function of the somatic nervous system?
What is the main function of the somatic nervous system?
Signup and view all the answers
Which type of PNS sensory neuron is responsible for detecting changes in temperature?
Which type of PNS sensory neuron is responsible for detecting changes in temperature?
Signup and view all the answers
Which part of the nervous system includes the brain and spinal cord?
Which part of the nervous system includes the brain and spinal cord?
Signup and view all the answers
Electroreceptors are predominantly responsible for the reception of which type of stimuli?
Electroreceptors are predominantly responsible for the reception of which type of stimuli?
Signup and view all the answers
What type of neurons are responsible for carrying signals from the periphery to the central nervous system?
What type of neurons are responsible for carrying signals from the periphery to the central nervous system?
Signup and view all the answers
What does the autonomic nervous system control?
What does the autonomic nervous system control?
Signup and view all the answers
Which type of receptor is specifically responsive to pain stimuli?
Which type of receptor is specifically responsive to pain stimuli?
Signup and view all the answers
The peripheral nervous system primarily consists of which of the following?
The peripheral nervous system primarily consists of which of the following?
Signup and view all the answers
What occurs during repolarization of the membrane potential?
What occurs during repolarization of the membrane potential?
Signup and view all the answers
What is hyperpolarization in the context of membrane potential?
What is hyperpolarization in the context of membrane potential?
Signup and view all the answers
During which phase is it impossible to trigger a second action potential?
During which phase is it impossible to trigger a second action potential?
Signup and view all the answers
During the relative refractory period, what is the state of the Na+ channels?
During the relative refractory period, what is the state of the Na+ channels?
Signup and view all the answers
What primarily drives the repolarization of the membrane during an action potential?
What primarily drives the repolarization of the membrane during an action potential?
Signup and view all the answers
What describes the state of K+ channels during the Absolute Refractory Period?
What describes the state of K+ channels during the Absolute Refractory Period?
Signup and view all the answers
What results from voltage-gated Na+ channels closing during an action potential?
What results from voltage-gated Na+ channels closing during an action potential?
Signup and view all the answers
Which statement is true about the refractory periods of action potentials?
Which statement is true about the refractory periods of action potentials?
Signup and view all the answers
What role does the sodium/potassium ATPase pump play after an action potential?
What role does the sodium/potassium ATPase pump play after an action potential?
Signup and view all the answers
Which phase could potentially lead to a state where the membrane potential is less than -70 mV?
Which phase could potentially lead to a state where the membrane potential is less than -70 mV?
Signup and view all the answers
What structure is primarily responsible for transferring sound from the middle ear to the inner ear?
What structure is primarily responsible for transferring sound from the middle ear to the inner ear?
Signup and view all the answers
Which part of the ear begins the transformation of sound waves into electrical impulses?
Which part of the ear begins the transformation of sound waves into electrical impulses?
Signup and view all the answers
Which taste receptor cell is NOT one of the five primary taste types?
Which taste receptor cell is NOT one of the five primary taste types?
Signup and view all the answers
What is the function of the tympanic membrane?
What is the function of the tympanic membrane?
Signup and view all the answers
Which structure helps the cochlea to expand and vibrate?
Which structure helps the cochlea to expand and vibrate?
Signup and view all the answers
Which part of the ear is specifically responsible for carrying sound waves to the inner ear?
Which part of the ear is specifically responsible for carrying sound waves to the inner ear?
Signup and view all the answers
How does the cochlea convert mechanical signals into neural signals?
How does the cochlea convert mechanical signals into neural signals?
Signup and view all the answers
What is the role of the semicircular canals in the inner ear?
What is the role of the semicircular canals in the inner ear?
Signup and view all the answers
What is the primary function of olfactory receptor cells?
What is the primary function of olfactory receptor cells?
Signup and view all the answers
Which part of the brain do olfactory signals specifically transmit to?
Which part of the brain do olfactory signals specifically transmit to?
Signup and view all the answers
What type of sensory information do olfactory receptor cells mainly process?
What type of sensory information do olfactory receptor cells mainly process?
Signup and view all the answers
Which of the following best describes the role of the olfactory cortex?
Which of the following best describes the role of the olfactory cortex?
Signup and view all the answers
In what way do olfactory receptor cells originally interact with their environment?
In what way do olfactory receptor cells originally interact with their environment?
Signup and view all the answers
Which of the following statements is true about olfactory receptor cells?
Which of the following statements is true about olfactory receptor cells?
Signup and view all the answers
What type of molecular signals do olfactory receptor cells primarily process?
What type of molecular signals do olfactory receptor cells primarily process?
Signup and view all the answers
What happens to the signals received by olfactory receptor cells in the brain?
What happens to the signals received by olfactory receptor cells in the brain?
Signup and view all the answers
Which sensory system is primarily responsible for the sense of smell?
Which sensory system is primarily responsible for the sense of smell?
Signup and view all the answers
Where are olfactory receptor cells located?
Where are olfactory receptor cells located?
Signup and view all the answers
What type of neuron is responsible for detecting painful stimuli?
What type of neuron is responsible for detecting painful stimuli?
Signup and view all the answers
Which part of the autonomic nervous system is primarily responsible for the 'fight or flight' response?
Which part of the autonomic nervous system is primarily responsible for the 'fight or flight' response?
Signup and view all the answers
How do the preganglionic and postganglionic neurons differ in the sympathetic nervous system?
How do the preganglionic and postganglionic neurons differ in the sympathetic nervous system?
Signup and view all the answers
Which neurotransmitter is released by the postganglionic neuron in the sympathetic nervous system to target effector organs?
Which neurotransmitter is released by the postganglionic neuron in the sympathetic nervous system to target effector organs?
Signup and view all the answers
What primary role does the parasympathetic nervous system serve in the body?
What primary role does the parasympathetic nervous system serve in the body?
Signup and view all the answers
Which of the following effects is NOT associated with an active sympathetic nervous system?
Which of the following effects is NOT associated with an active sympathetic nervous system?
Signup and view all the answers
Acetylcholine is utilized as a neurotransmitter in which part of the autonomic nervous system?
Acetylcholine is utilized as a neurotransmitter in which part of the autonomic nervous system?
Signup and view all the answers
What is the primary function of acetylcholinesterase in the autonomic nervous system?
What is the primary function of acetylcholinesterase in the autonomic nervous system?
Signup and view all the answers
What effect does an active parasympathetic nervous system have on heart rate?
What effect does an active parasympathetic nervous system have on heart rate?
Signup and view all the answers
Which statement about ganglia is true?
Which statement about ganglia is true?
Signup and view all the answers
Which type of sensory neurons detects changes in temperature?
Which type of sensory neurons detects changes in temperature?
Signup and view all the answers
Why is the sympathetic nervous system sometimes referred to as the 'fight or flight' system?
Why is the sympathetic nervous system sometimes referred to as the 'fight or flight' system?
Signup and view all the answers
What physiological change is NOT induced by the sympathetic nervous system?
What physiological change is NOT induced by the sympathetic nervous system?
Signup and view all the answers
Which pathway initiates hormonal release from the adrenal medulla in the sympathetic nervous system?
Which pathway initiates hormonal release from the adrenal medulla in the sympathetic nervous system?
Signup and view all the answers
Study Notes
The Neuron
- Neurons are the functional units of the nervous system
- Key structures include the soma (cell body), dendrites (receiving signals), axon (sending signals), axon terminals (synaptic signal transmission), axon hillock (connection between soma and axon) , myelin sheath (fatty insulation for axon, increases speed), oligodendrocytes (CNS), Schwann cells (PNS), nodes of Ranvier (gaps in myelin), and saltatory conduction (action potential jumps across nodes).
Action Potentials: Part 1
- Action potentials are rapid changes in membrane potential across a membrane
- Governed by relative ion ratios in intracellular and extracellular spaces
- Resting potential is ~-70mV maintained by Na+/K+ ATPases, which actively transport ions against their concentration gradient, requiring ATP cleavage.
- Depolarization occurs when the membrane potential reaches -55mV threshold, voltage-gated Na+ channels open, allowing Na+ to flow into the cell.
- Neuron threshold potential is -55 mV
- Steps of an Action Potential: resting state, depolarization, repolarization, hyperpolarization, and return to resting state.
Action Potentials: Part 2
- Repolarization: voltage-gated K+ channels open, allowing K+ out of the cell, returning the membrane potential to negative values
- Absolute refractory period: impossible to trigger a second action potential due to Na+ channels inactivation
- Relative refractory period: very difficult to trigger a second action potential due to membrane hyperpolarization (potential below -70mV) with Na+ channels closed but not inactivated.
Synaptic Transmission
- Synaptic transmission is the transmission of chemical signals between neurons across a synapse
- The synapse is the space between two neurons, including the presynaptic and postsynaptic neurons
- Neurotransmitters (NTs) are messenger molecules released by the presynaptic neuron and received by the postsynaptic neuron at ligand-gated ion channels
- Excitatory postsynaptic potentials (EPSPs): depolarize the membrane (open Na+ channels)
- Inhibitory postsynaptic potentials (IPSPs): hyperpolarize the membrane (open K+ channels)
- Summation of EPSPs and IPSPs at the axon hillock determines if an action potential is generated
- Examples of neurotransmitters: Glutamate (main excitatory NT in the CNS), Dopamine (reward motivation), Epinephrine and Norepinephrine (fight or flight), Acetylcholine (muscle signaling).
- Action potential finishes at the axon terminal causing voltage-gated Calcium channels to open allowing a large influx of Ca2+ into the presynaptic cell.
- The high concentration of Ca2+ triggers exocytosis of NTs from transport vesicles
- The NTs cross the synaptic cleft and bind to ligand-gated ion channels on the postsynaptic membrane.
- Either an excitatory or inhibitory postsynaptic graded potential results from this interaction
- All newly formed graded potentials summate at the axon hillock
Central Nervous System: Part 1
- The central nervous system (CNS) consists of the brain and spinal cord.
- Embryonic development stages of the brain include forebrain (telencephalon and diencephalon), midbrain (mesencephalon), and hindbrain (metencephalon and myelencephalon).
- These regions develop into specific parts of the mature brain, some examples include: forebrain -> cerebrum, midbrain -> midbrain, hindbrain -> pons, cerebellum, and medulla oblongata
Central Nervous System: Part 2
- The developed brain cortex has four lobes (frontal, temporal, occipital, and parietal)
- The cerebellum coordinates movement
- Main components of the brainstem are the midbrain, pons, medulla oblongata, and reticular formations
- The limbic system is responsible for emotions, memory, learning, and motivation
- Key components of the limbic system include the thalamus, hypothalamus, hippocampus, and amygdala.
- Spinal cord is the nervous tissue that connects the brain to the body
- Meninges are three layers of protective membrane (dura mater, arachnoid, and pia mater)
Peripheral Nervous System: Part 1
- The peripheral nervous system (PNS) extends from the CNS
- PNS contains both sensory (afferent) and motor (efferent) neurons
- Sensory neurons are associated with mechanoreceptors, nociceptors (pain), thermoreceptors, chemoreceptors, and electroreceptors.
- Motor neurons associated with somatic nervous system; involved with voluntary actions of skeletal muscles and autonomic nervous system; involved in involuntary actions of smooth muscles, cardiac muscle, and effector organs
Peripheral Nervous System: Part 2
- Autonomic nervous system is divided into sympathetic and parasympathetic systems
- Sympathetic and parasympathetic nervous systems use acetylcholine
- Ganglia are clusters of nerve cell bodies in the PNS.
Special Senses: Audition + Gustation
- Audition (hearing): outer ear (takes in sound waves), middle ear (tympanic membrane transfers sound, three bony ossicles (malleus, incus, stapes for transferring and amplifying), inner ear (cochlea converting sound to neural signals via transduction)
- Gustation (taste): taste receptor cells, signals sent to the thalamus and gustatory cortex
Special Senses: Vision + Olfaction
- Vision: cornea (protects and focuses light), iris and pupil (control light entering), lens (focuses the image onto the retina), retina (contains photoreceptors rods and cones (low light and color, respectively), fovea (high acuity vision), optic nerve (transmits visual signals to brain), optic disc (blind spot), sclera (protective outer layer), choroid (vascular layer between sclera and retina)
- Olfaction (smell): olfactory receptor cells that sense smell and send signals to olfactory cortex and thalamus
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
