Chapter13-1

What is the main function of the Central Nervous System (CNS)?

It consists of the brain and spinal cord and serves as the master controlling and communicating system of the body.

What does the Peripheral Nervous System (PNS) consist of?

The PNS consists of cranial and spinal nerves that link the CNS to the external environment.

What are the two main divisions of the nervous system?

Central Nervous System (CNS) and Peripheral Nervous System (PNS).

What is the difference between afferent and efferent divisions?

Afferent (Sensory) Division sends information from receptors to the CNS, while Efferent (Motor) Division sends signals from the CNS to effectors.

What are the two branches of the Autonomic Nervous System?

Sympathetic division (fight/flight) and Parasympathetic division (rest/repose).

Define sensation and perception.

Sensation is the awareness of changes in the internal and external environment; perception is the conscious interpretation of those stimuli.

What types of receptors respond to stimuli from outside the body?

Exteroceptors.

Where are proprioceptors located, and what do they respond to?

Proprioceptors are found in skeletal muscles, tendons, joints, and ligaments, and they respond to the degree of stretch of the organs they occupy.

What is the functional role of reflexes in the nervous system?

Reflexes are rapid automatic responses to stimuli, facilitating quick reactions without voluntary thought.

What are the steps involved in the reflex arc?

1. Arrival of stimulus and activation of receptor 2. Activation of sensory neuron 3. Information processing 4. Activation of motor neuron 5. Response by effector.

How are reflexes classified based on their complexity?

Reflexes can be classified as monosynaptic (one synapse) or polysynaptic (multiple synapses).

What types of reflexes control skeletal muscle contractions?

Somatic reflexes.

What type of receptors are sensitive to pain-causing stimuli?

Nociceptors.

What are dermatomes?

Regions of the body surface monitored by specific pairs of spinal nerves.

What is the role of the Vagus nerve (X)?

The Vagus nerve is involved in autonomic control of visceral function such as breathing and digestion.

What is the function of the Trigeminal nerve (V)?

It is a mixed nerve that controls sensation in the face and motor functions such as chewing.

What do muscle spindles and Golgi tendon organs measure?

Muscle spindles measure muscle length and tone, while Golgi tendon organs measure tension within tendons.

Explain the role of adaptation in sensory receptors.

Adaptation occurs when sensory receptors are subjected to a continuous stimulus, resulting in decreased response over time.

What is the main function of the Central Nervous System (CNS)?

The Central Nervous System, comprising the brain and spinal cord, acts as the body's master control center, processing information and coordinating actions by sending signals throughout the nervous system.

What does the Peripheral Nervous System (PNS) consist of?

The Peripheral Nervous System is made up of all the cranial and spinal nerves that branch out from the Central Nervous System, connecting it to limbs and organs, thereby linking the CNS to the external environment.

What are the two main divisions of the nervous system?

The nervous system is primarily divided into the Central Nervous System (CNS), which includes the brain and spinal cord, and the Peripheral Nervous System (PNS), which encompasses the nerves that extend throughout the body.

What is the difference between afferent and efferent divisions?

The Afferent Division (Sensory) of the nervous system carries information from sensory receptors throughout the body to the Central Nervous System, while the Efferent Division (Motor) transmits signals from the CNS to various effectors like muscles and glands to elicit responses.

What are the two branches of the Autonomic Nervous System?

The Autonomic Nervous System is further divided into the Sympathetic Division, which prepares the body for 'fight or flight' responses during stressful situations, and the Parasympathetic Division, which promotes 'rest and repose' functions, conserving energy and facilitating maintenance processes.

Define sensation and perception.

Sensation refers to the process of detecting physical energy from the environment and converting it into neural signals, while perception is the cognitive process of interpreting those signals, allowing us to understand and respond to our surroundings.

What types of receptors respond to stimuli from outside the body?

Exteroceptors are specialized sensory receptors that respond to external stimuli, including touch, temperature, pain, and pressure, providing crucial information about the outside world.

Where are proprioceptors located, and what do they respond to?

Proprioceptors, located throughout skeletal muscles, tendons, joints, and ligaments, detect the position and movement of the body by responding to the degree of stretch and tension in the tissues they inhabit.

What is the functional role of reflexes in the nervous system?

Reflexes serve as rapid, automatic responses to specific stimuli, enabling quick reactions and protective responses without the need for conscious thought, thereby enhancing survival.

What are the steps involved in the reflex arc?

The reflex arc involves several steps: 1. A stimulus is detected, activating a receptor; 2. A sensory neuron transmits the signal to the spinal cord; 3. Information is processed within the CNS; 4. A motor neuron is then activated; 5. An effector (muscle or gland) executes a response.

How are reflexes classified based on their complexity?

Reflexes are categorized based on neural pathway complexity: Monosynaptic reflexes involve a single synapse between a sensory and motor neuron, while Polysynaptic reflexes involve multiple synapses, often including interneurons.

What types of reflexes control skeletal muscle contractions?

Somatic reflexes specifically regulate voluntary skeletal muscle contractions and are activated in response to certain stimuli, allowing the body to react quickly.

What type of receptors are sensitive to pain-causing stimuli?

Nociceptors are specialized sensory receptors that respond to potentially damaging stimuli by signaling pain, alerting the body to harmful conditions.

What are dermatomes?

Dermatomes are specific areas of skin that are innervated by sensory fibers from a single spinal nerve root, aiding in the diagnosis of nerve damage or dysfunction.

What is the role of the Vagus nerve (X)?

The Vagus nerve (Cranial Nerve X) plays a critical role in the autonomic nervous system, influencing functions such as heart rate, digestion, and respiratory rate by connecting the brain to the organs in the throat, chest, and abdomen.

What is the function of the Trigeminal nerve (V)?

The Trigeminal nerve (Cranial Nerve V) is a mixed nerve responsible for sensing facial sensations (light touch, pain) and controlling important motor functions related to chewing.

What do muscle spindles and Golgi tendon organs measure?

Muscle spindles are sensory receptors located within muscles that detect changes in muscle length and tone, while Golgi tendon organs, located in tendons, measure the tension exerted on the tendon, providing feedback for muscle coordination.

Explain the role of adaptation in sensory receptors.

Adaptation in sensory receptors refers to the phenomenon where receptor sensitivity decreases over time during constant exposure to a stimulus, allowing the nervous system to prioritize new information over familiar, unchanging stimuli.

What is neuroplasticity?

Neuroplasticity is the ability of the neural networks in the brain to change through growth and reorganization, enabling learning and adaptation.

What are neurotransmitters?

Neurotransmitters are chemical messengers that transmit signals across synapses between neurons, influencing various physiological functions.

What is the role of glial cells?

Glial cells provide support, nourishment, and protection to neurons in the nervous system, and play a role in maintaining homeostasis.

What is the blood-brain barrier?

The blood-brain barrier is a selective permeability barrier that protects the brain from harmful substances and pathogens while allowing essential nutrients to pass.

What is a nodes of Ranvier?

Nodes of Ranvier are gaps in the myelin sheath of axons that facilitate rapid transmission of nerve impulses via saltatory conduction.

What is the function of the somatic nervous system?

The somatic nervous system is the part of the peripheral nervous system that controls voluntary movements of skeletal muscles.

What are cranial nerves?

Cranial nerves are a set of twelve pairs of nerves that emerge directly from the brain, responsible for sensory and motor functions of the head and neck.

What is the function of the Autonomic Nervous System (ANS)?

The Autonomic Nervous System regulates involuntary bodily functions such as heart rate, digestion, and respiratory rate.

What is the significance of the sympathetic nervous system?

The sympathetic nervous system prepares the body for 'fight or flight' response during stressful situations, increasing heart rate and energy mobilization.

What is the significance of the parasympathetic nervous system?

The parasympathetic nervous system promotes 'rest and digest' functions, conserving energy and facilitating bodily maintenance activities.