Human Nervous System Flashcards
What is the primary function of the human nervous system?
To coordinate and control body activities and responses to internal and external stimuli.
What are the two main divisions of the human nervous system?
The central nervous system (CNS) and the peripheral nervous system (PNS).
What role does the central nervous system play in the human nervous system?
It processes information and coordinates the activity of all parts of the body.
How does the peripheral nervous system contribute to the functioning of the human nervous system?
It connects the central nervous system to the limbs and organs, facilitating communication.
What are the two important parts of the nervous system that you need to understand?
The central nervous system (CNS) and the peripheral nervous system (PNS).
What is impulse conduction in the context of the nervous system?
Impulse conduction refers to the process by which electrical signals are transmitted along neurons.
How do neurons interconnect in the brain?
Neurons interconnect through synapses, where they communicate via neurotransmitters.
What is the primary function of the human nervous system?
The human nervous system is responsible for all human behaviours.
How do comparative studies of nervous systems contribute to our understanding of human behavior?
They provide insights into the behavior and mental processing of different animals, aiding our understanding of the human brain.
What are the key components that will be covered in the section about the human nervous system?
The structure of the neuron, the process of impulse conduction in the neuron, and the structure of the human nervous system.
What are the two main divisions of the human nervous system?
The two main divisions are the Peripheral Nervous System (PNS) and the Central Nervous System (CNS).
What functions does the Peripheral Nervous System (PNS) control?
The PNS controls both volitional (somatic) and non-volitional (autonomic) behaviors.
What are the components of the Central Nervous System (CNS)?
The CNS consists of the brain, brain stem, and spinal cord.
How does the structure of the nervous system reflect its functions?
The structure of the nervous system, with its divisions and components, allows for specialized functions such as voluntary control and automatic regulation.
What are the two main divisions of the peripheral nervous system?
The two main divisions are the somatic nervous system and the autonomic nervous system.
What is the primary function of the peripheral nervous system?
The primary function is to carry signals necessary for the body to survive, including those related to voluntary actions.
What is the primary function of the somatic nervous system?
The somatic nervous system is responsible for conscious and voluntary activities.
What are the two types of neurons in the somatic nervous system?
The two types of neurons are motor neurons (efferent neurons) and sensory neurons (afferent neurons).
What do efferent and afferent neurons do in the somatic nervous system?
Efferent neurons carry information away from the CNS to the muscles, while afferent neurons carry sensory information toward the CNS.
How does the somatic nervous system facilitate communication between the body and the central nervous system?
The somatic nervous system uses a two-way process involving both efferent and afferent neurons to relay information.
What is the primary function of the autonomic nervous system?
It controls involuntary functions of internal organs and glands.
What are the two main divisions of the autonomic nervous system?
The sympathetic and parasympathetic divisions.
How does the sympathetic nervous system respond to fear-inducing stimuli?
It energizes muscles and glands, preparing the body for fight-or-flight.
What role does the parasympathetic nervous system play in the body?
It restores and calms physiological responses to maintain homeostasis.
How do the sympathetic and parasympathetic systems work together?
They operate in tandem to maintain bodily homeostasis.
What are the main components of the Central Nervous System (CNS)?
The CNS is made up of the brain, brainstem, and spinal cord.
What is the primary function of the Central Nervous System?
The primary function of the CNS is information synthesizing.
Why is the Central Nervous System referred to as ‘central’?
It is called ‘central’ because the brain and spinal cord are primarily responsible for processing sensory information.
How do the brain and spinal cord communicate within the Central Nervous System?
They communicate by sending electrical signals through neurons.
Approximately how many neurons are there in the human brain?
There are approximately 100 billion neurons in the human brain.
What is the primary function of the brain in the central nervous system?
The brain acts as the headquarters of the entire nervous system, overseeing activities such as sensation, perception, thinking, awareness, emotions, and planning.
What structures are included in the limbic system and what are their roles?
The limbic system includes the hippocampus, amygdala, thalamus, insula cortex, anterior cingulate cortex, and prefrontal cortex, which regulate emotions and influence behaviors such as fear, aggression, hunger, and memory.
How does the limbic system influence our behavior?
The limbic system influences behaviors related to fear, aggression, hunger, the sleep-wake cycle, sexual desire, and memory.
What is the primary function of the cerebellum?
The cerebellum controls motor movement coordination, balance, equilibrium, and muscle tone.
How do the cerebrum and cerebellum differ in terms of brain function?
The cerebrum oversees processes associated with awareness and voluntary control, while the cerebellum coordinates actions without conscious awareness.
What connects the left and right hemispheres of the cerebrum?
The corpus callosum connects the left and right hemispheres of the cerebrum.
What is meant by the term ‘contralateral’ in relation to brain function?
Contralateral means that each hemisphere of the brain controls the sensory and motor functions of the opposite side of the body.
What role does the cerebral cortex play in the cerebrum?
The cerebral cortex is the outer layer of the cerebrum and is involved in higher brain functions such as thought, language, and sensory processing.
What are the four major parts of a neuron?
Dendrites, cell body (soma), axon, and terminal boutons.
What is the function of the myelin sheath in neurons?
The myelin sheath insulates the axon and allows for faster transmission of electrical signals.
What is an action potential in the context of neuron function?
An action potential is an electro-chemical signal that travels down the axon from the soma to the next neuron.
How do myelinated and unmyelinated neurons differ in signal transmission speed?
Myelinated neurons transmit signals faster than unmyelinated neurons.
What role do terminal boutons play in neuron communication?
Terminal boutons release neurotransmitters at the synapse to communicate with adjacent neurons.
What is an action potential?
An action potential is an all-or-nothing event that occurs when a neuron changes from its resting membrane potential to fire an impulse signal.
What must a neuron reach to initiate an action potential?
A neuron must reach the threshold of excitation to initiate an action potential.
What are the two types of postsynaptic potentials that affect a neuron’s ability to fire?
The two types of postsynaptic potentials are excitatory postsynaptic potential (EPSP) and inhibitory postsynaptic potential (IPSP).
What is the refractory period in relation to action potentials?
The refractory period is the time during which a neuron cannot fire another action potential because it is returning to its resting state.
What happens during the absolute refractory period?
During the absolute refractory period, the neuron cannot send a new impulse because sodium channels are inactive.
What distinguishes the relative refractory period from the absolute refractory period?
In the relative refractory period, the neuron can respond to a stimulus but requires a stronger stimulus than normal to fire an action potential.
What is the synaptic cleft and its function?
The synaptic cleft is the small space between adjacent neurons that allows nerve impulses to pass from one neuron to another.
How do neurotransmitters function in the synapse?
Neurotransmitters are chemicals released from the terminal buttons of one neuron that travel across the synaptic cleft to bind with receptors on the dendrites of another neuron.
What determines whether a neuron will fire after receiving neurotransmitters?
A neuron will fire if the excitatory effects of neurotransmitters exceed the inhibitory effects, reaching the firing threshold.
What happens to neurotransmitters that are not accepted by receptor sites?
They are removed from the synapse through breakdown by enzymes or reuptake into the transmitting terminal buttons.
What role do receptor sites play in neurotransmitter function?
Receptor sites on dendrites accept neurotransmitters that fit their specific shape, influencing the neuron’s likelihood to fire.
What is the primary process through which the nervous system communicates?
The nervous system communicates through an electro-chemical process.
What is the action potential in a neuron?
The action potential is a rapid change in electrical charge that occurs when a neuron transmits a nerve impulse.
How does the action potential travel along the axon?
The action potential travels along the axon by jumping from one Node of Ranvier to the next.
What is the refractory period in neural communication?
The refractory period is a brief time after a neuron fires during which it cannot fire again.
What does it mean for the action potential to operate in an all-or-nothing manner?
It means that once the threshold is reached, the neuron fires completely or not at all; it cannot fire partially.
What are neurotransmitters?
Chemical substances produced in the body that affect emotion, cognition, and behavior.
What is the function of acetylcholine (ACh)?
Stimulates muscle contractions and regulates memory, sleeping, and dreaming.
How is dopamine related to mental health disorders?
Increased dopamine is linked to schizophrenia, while decreased dopamine is associated with Parkinson’s disease.
What role do endorphins play in the body?
They act as natural pain relievers and are linked to feelings of pleasure.
What is GABA and its significance?
GABA is the major inhibitory neurotransmitter in the brain, helping to reduce anxiety.
What is the effect of excess glutamate in the brain?
It can cause overstimulation, leading to migraines and seizures.
How does serotonin affect mood?
Low levels of serotonin are associated with seasonal depression and mood regulation.
What is the difference between an agonist and an antagonist in relation to neurotransmitters?
An agonist mimics neurotransmitter effects, while an antagonist inhibits them.
What are the two main components of the nervous system?
The central nervous system and the peripheral nervous system.
How do neurons in the central nervous system communicate?
Neurons communicate by releasing action potentials.
What role do neurotransmitters play in the nervous system?
Neurotransmitters are chemicals that transmit signals across synapses between neurons.
How do the parts of the brain influence human behavior?
The parts of the brain work together to determine everyday human behavior.
What is the absolute refractory period in neurons?
It is the process whereby a neuron does not respond to normal stimulation.
Define action potential.
A transient all-or-nothing transmission of impulse conducted down the axon when the membrane potential reaches the threshold of excitation.
What is an agonist in the context of neurotransmitters?
An agonist is a drug that has chemical properties similar to a particular neurotransmitter and mimics its effects.
What does an antagonist do in relation to neurotransmitters?
An antagonist is a drug that reduces or inhibits the normal effects of a neurotransmitter.
What is the function of the autonomic nervous system?
It controls involuntary functions of the internal organs and glands.
What role does the axon play in a neuron?
The axon sends information to another neuron or to the muscles and glands.
What is the central nervous system composed of?
It includes the brain, the brainstem, and the spinal cord.
What is the function of the myelin sheath?
It insulates the axon of the neuron, which is necessary for conducting neural impulses.
What is the role of neurotransmitters?
They relay signal impulses across the synapses among neurons.
What does the term ‘synapse’ refer to?
It is the process whereby neurons use electrical and chemical messages to communicate with each other at the synaptic cleft.
