Biopsychology Flashcards
(33 cards)
What is the function of the human nervous system?
It is a body-wide system of nerve cells that collects information from the world, processes this information, and takes action by directing body organs and muscles via the transmission of electrochemical messages.
What are the components and functions of the Central Nervous System (CNS)?
The CNS consists of the brain and spinal cord.
• The Brain: Responsible for all conscious and most unconscious processing.
• The Spinal Cord: Receives and transmits information and is involved in some reflex processing.
What does the Somatic Nervous System do?
It controls skeletal muscles responsible for movement.
• It is a voluntary system, meaning it operates under conscious control.
What does the Autonomic Nervous System control?
It controls internal organs and glands.
• It is an involuntary system, meaning it operates without conscious control.
What are the functions of the Sympathetic Nervous System?
• Increases bodily activities.
• Releases noradrenaline.
• Activates in response to stress (Fight or Flight response).
• Increases heart rate, sweating, and breathing rate.
• Dilates pupils.
• Inhibits digestion.
What are the functions of the Parasympathetic Nervous System?
• Decreases bodily activities.
• Releases acetylcholine.
• Activates during rest (Rest and Digest).
• Decreases heart rate, sweating, and breathing rate.
• Constricts pupils.
• Stimulates digestion.
What is homeostasis in relation to the nervous system?
Homeostasis is the regulation of the internal environment. Under normal conditions, it involves a balance between the sympathetic and parasympathetic systems to maintain stability in the body.
What are neurons and their general function?
Neurons are the basic building blocks of the nervous system. They are specialised nerve cells that process and transmit messages through electrical and chemical signals.
What are the three main types of neuron and their functions?
• Sensory neurons: Carry messages from the PNS to the CNS.
• Relay neurons: Connect sensory neurons to motor or other relay neurons. Found mainly in the CNS.
• Motor neurons: Carry messages from the CNS to effectors (muscles and glands).
What are the main structural features of a neuron?
• Cell body (soma): Includes a nucleus that contains genetic material.
• Dendrites: Branch-like structures that receive messages from other neurons.
• Axon: Carries impulses away from the cell body down the neuron.
• Myelin sheath: Fatty layer that protects the axon and speeds transmission.
• Nodes of Ranvier: Gaps in the myelin sheath that help speed up transmission.
• Terminal buttons: Communicate with the next neuron across a synapse.
What is meant by ‘firing of a neuron’ or action potential?
When a neuron is activated by a stimulus, the inside of the cell becomes positively charged for a split second, creating an electrical impulse that travels down the axon to the terminal button.
What is synaptic transmission?
Synaptic transmission is the process by which neighbouring neurons communicate with each other by sending chemical messages across the synapse.
What is the structure of a synapse?
A synapse includes:
• Presynaptic terminal (axon terminal of sending neuron)
• Synaptic vesicles containing neurotransmitters
• Synaptic cleft (gap between neurons)
• Postsynaptic receptor sites on the receiving neuron.
What is a neurotransmitter?
A chemical that diffuses across the synapse to the next neuron, transferring the signal. Each neurotransmitter has a specific molecular structure and fits specific receptor sites on the postsynaptic neuron.
Give two examples of neurotransmitters and their effects.
• Acetylcholine (ACh): Found at neuromuscular junctions; causes muscles to contract.
• Serotonin: Affects mood and social behaviour.
What is the difference between excitatory and inhibitory neurotransmitters?
• Excitatory neurotransmitters increase the likelihood of a neuron firing (e.g., adrenaline).
• Inhibitory neurotransmitters decrease the likelihood of firing (e.g., serotonin).
The net effect of a neurotransmitter depends on the balance between excitatory and inhibitory influences.
What is summation in synaptic transmission?
Summation refers to the process by which the excitatory and inhibitory influences on a neuron are added together. If the net effect is excitatory and reaches the threshold, the neuron will fire an action potential.
What is the endocrine system and what does it do?
The endocrine system works alongside the nervous system to control vital functions in the body. It acts much more slowly than the nervous system but has widespread and powerful effects by using glands that produce hormones.
What are glands and what do they do in the endocrine system?
Glands such as the thyroid gland produce hormones. Hormones are secreted into the bloodstream and affect any cell in the body that has a receptor for that hormone.
How do hormones affect the body?
Hormones affect cells in several organs or throughout the entire body, leading to many diverse and powerful responses.
Give an example of how a hormone affects the body.
The thyroid gland produces the hormone thyroxine, which increases heart rate and affects cells throughout the body, increasing metabolic rate. This impacts growth rates in the body.
What is the pituitary gland and why is it important?
The pituitary gland is the major endocrine gland, located in the brain. It is often called the “master gland” because it controls the release of hormones from all the other endocrine glands in the body.
How do the endocrine system and autonomic nervous system (ANS) work together in the fight or flight response?
When a stressor is perceived, the hypothalamus triggers activity in the sympathetic branch of the ANS. This changes the body from its normal resting state to a state of physiological arousal, preparing for fight or flight.
What hormone is released during the fight or flight response and from where?
Adrenaline is released from the adrenal medulla (part of the adrenal gland) into the bloodstream.
