Nervous System Flashcards
The Nervous System
The nervous system is a complex network of cells and structures in the body that coordinates and controls bodily functions. It transmits signals between different parts of the body and the brain, allowing for responses to stimuli, regulating functions, and enabling communication between the brain and the rest of the body.
What is the Nervous System divided into?
1) The Central Nervous System (CNS)
2) The Peripheral Nervous System (PNS)
What does the Central Nervous System (CNS) consist of?
1) Brain
2) Spinal cord
What is the Peripheral Nervous System (PNS) divided into?
1) Somatic Nervous System
2) Autonomic Nervous System
What is the Autonomic Nervous System divided into?
1) Sympathetic Nervous System
2) Parasympathetic Nervous System
What is the role of the Central Nervous System?
Process and interpret sensory information, control and coordinate bodily functions as well as facilitate higher cognitive functions, such as thinking, memory and decision-making. It is responsible for receiving input from the sensory organs, making decisions based on that input, and sending appropriate responses to muscles and glands.
What is the role of the Brain?
The brain processes information and sends signals to the rest of the body through the spinal cord.
What are the 4 main lobes of the Brain?
1) Frontal
2) Parietal
3) Occipital
4) Temporal
(see where they are positioned as well)
1) Frontal
Responsible for higher order functions, e.g., planning, abstract reasoning and logic.
2) Parietal
Integrates information from the different senses.
3) Occipital
Processes visual information.
4) Temporal
Processes auditory information.
Brain stem
Connects the brain and spinal cord and controls involuntary processes, including our heartbeat, breathing and consciousness.
Spinal Cord
Transfers messages to and from the brain, and the rest of the body. Responsible for simple reflex actions that do not involve the brain.
What is the role of the Peripheral Nervous System?
Connects the Central Nervous System (CNS) to the rest of the body, including limbs and organs. It transmits sensory information from the body to the CNS and carries out motor commands from the CNS to muscles and glands. It is made up of nerves outside the brain and spinal cord.
What is the role of the Somatic Nervous System?
The SNS allows conscious control over actions and helps us interact with the environment. It controls voluntary movement and relays sensory information to the Central Nervous System. It is responsible for the transmission of sensory input from sensory receptors, e.g., in the skin, to the brain, as well as providing muscle responses via the motor pathway.
What is the Somatic Nervous System made up of?
1) Sensory receptors - carry information to the brain and spinal cord.
2) Motor pathways - allow the brain to control movement.
What is the role of the Autonomic Nervous System?
Regulates involuntary bodily functions, such as heart rate, digestion, breathing and blood pressure. It operates automatically without conscious control and has a major role in homeostasis, which maintains internal bodily conditions.
What is the Autonomic Nervous System made up of?
Only consists of motor pathways.
What is the role of the Sympathetic Nervous System (SNS)
- Prepare the body for ‘fight or flight’ responses in stressful or emergency situations.
- Impulses travel from the sympathetic nervous system to organs in the body to help us prepare for action when we are faced with a dangerous situation.
- It activates physiological changes that help the body respond to perceived threats, such as increasing the heart rate to increase blood flow to organs and increase the movement of adrenaline around the body, and pupil dilation to increase light entry into the eye and enhance vision (especially in the dark).
- It inhibits other processes, e.g., digestion, urination and salivation to increase energy for other essential functions.
- Through this, the sympathetic nervous system primes the body for action, enhances alertness and physical capability in times of danger.
What is the role of the Parasympathetic Nervous System (PNS)
- Promote the ‘rest and digest’ functions of the body, helping it return to a state of calm and maintain homeostasis after a stressful situation.
- It counteracts the effects of the Sympathetic Nervous System by slowing down heart rate, lowering blood pressure, stimulating digestion and conserving energy.
- The Parasympathetic Nervous System helps the body recover and regenerate, supporting normal, everyday functioning when there is no immediate threat or stress.
Similarities - CNS - Brainstem vs Spinal Cord
Both control involuntary processes (brain stem controls breathing and the spinal cord controls involuntary reflexes)
Differences - CNS - Brain vs Spinal Cord
Brain provides conscious awareness and allows for higher-order thinking, while the spinal cord allows for simple reflex responses.
The brain consists of multiple regions responsible for different functions, whereas the spinal cord has one main function.
Similarities - PNS - SNS (part of ANS) vs Somatic NS
Both respond to external stimuli. The sympathetic nervous system responds to external stimuli by preparing the body for fight or flight and the somatic nervous system responds to external stimuli by carrying information from sensory receptors to the spinal cord and brain.
Differences - PNS - ANS vs Somatic NS
Autonomic nervous system consists of two sub-components, whereas the somatic nervous system doesn’t have any.
Autonomic nervous system controls internal organs and glands, while the somatic nervous system controls muscles and movements.
Autonomic nervous system only has motor pathways whereas somatic nervous system has sensory and motor pathways.
