Chapter 3 Flashcards
What is the nervous system?
Information highway with a collection of hundreds of billions of specialized and interconnected cells through which messages are sent between the brain and the body.
What is the Central Nervous System (CNS) made up of?
The brain and the spinal cord.
What is the Peripheral Nervous System (PNS)?
Neurons that link CNS to our skin, muscles, and glands.
What does the Endocrine System do?
The chemical regulator of the body.
Contains glands that secrete hormones.
Evolutionary psychologists are interested in what?
In structures, processes, or organs that are genetically the same for everyone.
Keywords - same genetics
What do Behaviour geneticists look for?
Individual differences incur genes to see if these relate to individual differences in thinking, feeling and behaving.
What is a neuron?
A cell in the nervous system whose function is to receive and transmit information.
Neurons are made up of what three parts?
- Soma (cell body) - contains the nucleus of the cell to keep it alive.
- Dendrite - branching, tree-like fibre that collects information from other cells and sends the info to the soma.
- Axon - long, segmented fibre that transmits info away from the cell body toward other neurons or to the muscles and glands.
What is the myelin sheath?
Layer of segmented fatty tissue surrounding the axon of a neutron.
Insulates and allows faster transmission of the electrical signal.
What is the Node of Ranvier?
The gaps between the segmented tissues on the myelin sheath. The segments allow for more efficient transmission of info down the axon.
What is the terminal button?
Axons branch out toward their ends and at the tip of each branch is a terminal button.
What are the electrical signals transmitted by neurons called?
Action potentials.
Neurons can be classified into what three groups?
- Sensory neurons
- Motor neurons
- Relay neurons
What do sensory neurons do?
Nerve cells that carry nerve impulses from sensory receptors towards the central nervous system and brain.
When these nerve impulses reach the brain, they are translated into ‘sensations’, such as vision, hearing, taste and touch.
What do motor neurons do?
They are the nerve cells responsible for carrying signals away from the central nervous system towards muscles to cause movement.
They release neurotransmitters to trigger responses leading to muscle movement.
Where are motor neurons located?
Motor neurons are located in the brainstem or spinal cord (parts of the central nervous system) and connect to muscles, glands and organs throughout the body.
What are the two types of motor neurons, and what do they do?
Upper motor – neurons that travel between the brain and the spinal cord.
Lower motor - neurons that travel from the spinal cord to the muscles.
What does a relay neuron do?
Aka interneuron - allows sensory and motor neurons to communicate with each other.
Relay neurons connect neurons within the brain and spinal cord.
Easy to recognize, due to their short axons.
What is a neurotransmitter?
A chemical that relays signals across the synapses between neurons.
Neurotransmitters travel across the synaptic space between the terminal button of one neuron and the dendrites of other neurons where they bind to the dendrites in the neighbouring neurons.
What is the reuptake?
The process in which neurotransmitters that are in the synapse are reabsorbed into the transmitting terminal buttons, ready to be released again after the neuron fires.
Some medications inhibit the reuptake of neurotransmitters, allowing the neurotransmitter to remain in the synapse for longer and increasing its effectiveness.
What is an agonist?
A drug that has a chemical property similar to a particular neurotransmitter, which allows it to mimic the effects of a neurotransmitter.
When ingested, it binds to the receptor sites in the dendrites to excite the neuron, acting as if MORE of the neurotransmitter had been present.
What is an antagonist?
A drug that reduces or stops the normal effects of a neurotransmitter.
Which glands in the endocrine system are responsible for the production of hormones?
The pancreas, thyroid, and ovaries.
They secrete insulin, melatonin, and testosterone into the bloodstream.
What are hormones responsible for?
For maintaining regular bodily functions, such as growth, digestion, energy and so on.
Define homeostasis.
Endocrine and nervous system work together to create a stable, balanced, and optimal function of the body’s physiological systems.
The body uses both chemical and electrical systems to create homeostasis.
What does the hypothalamus do?
Regulates basic biological needs and sends signals to adjust the endocrine system in response to changing needs via the pituitary gland - “master controller” of the endocrine system.
The pituitary gland signals commands to change the production of hormones to glands in endocrine system.
What are androgens?
Masculizing hormones that cause male sex characteristics. Linked to sex drive in all genders.
Produced mainly in testes in men and ovaries in women, and also in adrenal glands.
Testosterone is the most important androgen.
What is estrogen?
Feminizing hormones that cause female secondary sex characteristics to develop at puberty.
Regulate female fertility linked to learning and memory for all genders.
Produced mainly in ovaries in women, testes in men, and also in adrenal glands.
What do adrenal glands do?
Adrenal hormones are produced by adrenal glands above kidneys in response to physical or emotional stress or threat. They produce epinephrine and norepinephrine, the hormones responsible for our reactions to stress.
Release of cortisol, epinephrine/adrenaline and norepinephrine is activated by the sympathetic nervous system. Active in the flight-or-fight response.
What do endorphins do?
Reduce pain and induce pleasure. Released when under stress.
Similar effects to natural opiates such as morphine. Sometimes classified as neurotransmitters or neuromodulators. Referred to here as hormones for convenience.
What does melatonin do?
Promotes sleep and helps to regulate circadian rhythm. (Physical, mental, and behavioural changes that follow a 24-hour cycle).
Released by pineal gland.
What does the cerebral cortex do?
A very large and highly developed outer layer of the forebrain responsible for memory, social interactions and emotions.
What does the brainstem consist of, and what does it do?
The hindbrain includes the brainstem, cerebellum, pons, reticular formation, and medulla.
Responsible for breathing, attention and motor responses.
The brain stem begins where the spinal cord enters the skull and forms the medulla - area of the brain stem that controls heart rate and breathing.
What does the medulla do?
The area of the brain stem that controls heart rate and breathing.
What does the pons do?
The spherical shape above the medulla is the pons.
Structure of the brain stem helps control movements of the body, such as chewing, and carries sensory info to other area of the brain.
What does the reticular formation do?
A narrow network of neurons that runs through the medulla and the pons.
Filters out excess stimuli coming into the brain from the spinal cord.
Relays the remainder of the signals to other areas of the brain.
Reticular formation plays roles in walking, eating, sexual activity and sleeping.
What does the cerebellum do?
“Little brain” consists of two wrinkled ovals behind the brain stem.
Functions to coordinate voluntary movement.
