Life science Flashcards
What is the two main parts of the nervous system?
Central Nervous System (CNS) and Peripheral Nervous System (PNS)
What does the CNS consist of?
Brain and spinal cord
What does the PNS consist of?
sensory receptors and nerves
What is the main function of the CNS?
CNS: Examines the information received, and then sends out messages to tell different parts of the body what they should do.
What is the main function of the PNS?
PNS: Continuously inform the CNS of changing conditions and transmit the decisions made by the CNS back to effector organs.
What are neurons?
Neurons: Specialised cells that transmit and receive messages in the form of an action potential (electrical impulses).
What is the axon?
Axon: Is a single, tube like, extension that transmits neural information away from cell body through axon terminals and terminal buttons to other neurons or cells.
What are dendrites?
Dendrites: Small threads arranged around the cell body. Dendrites are the part of a neuron that receives input information from other cells.
What is the myelin sheath?
Myelin Sheath: White, fatty substance covering the axon. The myelin sheath is an insulating layer, which allows electrical impulses to transmit quickly and efficiently along the nerve cells.
What is the axon terminal?
Axon Terminal: are the small branches at the end of an axon. Each axon terminal has a small knob like swelling at its tip called terminal button.
What is the axon terminal button?
Axon Terminal Button: is the button-like endings of axon terminals where the message is passed from this neuron to other neurons or the effector organ.
How is a neuron similar to other cells?
Neurons have a nucleus, cytoplasm and cell membrane.
What are the different neurons?
Sensory Neuron, Interneuron, Motor Neuron
What does the Sensory Neuron do?
Sensory Neuron: receives stimuli information from sensory receptors and carries information as an impulse to CNS.
What does the interneuron do?
Interneuron: enables communication between sensory or motor neurons and the CNS
What does the motor neuron do?
- Motor Neuron: carries impulses from CNS to the effectors.
What is the stimuli in taste buds on the toungue?
taste buds on the tongue detects chemical stimuli in the mouth
What is the stimuli in retina cells in the eyes?
retina cells in the eye detect light/visual stimuli
What is the stimuli in cochlear cells in the ear?
cochlear cells in the ear detect sound waves/auditory stimuli
What is the stimuli in thermoreceptors?
thermoreceptors detect heat/temperature stimuli
What is the function of a neurotransmitter?
Neurotransmitters are a chemical messenger, which carry the signal over the synapse between neurons.
What is a synapse?
Small gap between neurons
How are messages transmitted between neurons?
When the electrical impulse reaches the axon terminals, the neurotransmitters are released into the synapse. The neurotransmitters quickly cross the synapse and bind to receptors on the dendrite of the next neuron. This binding of the neurotransmitter to the receptor on the dendrite triggers the neuron to transmit the message as an electrical impulse along its length.
What are disadvantages of the synapse?
They slow the passage of a message along a nerve and many poisons affect neurotransmitters, which can stop the nerve impulse travelling between neurons.
What are the parts of the brain?
Cerebrum, cerebellum, medula, spinal cord
What part of the brain thinks?
Frontal lobe of cerebrum
What part of the brain controlls breathing?
Medulla
What part of the brain gives sensations of touch?
Parietal lobe of cerebrum
What part of the brain helps keep balance when riding a bike?
Cerebellum
What are two situations you can get permanent brain damage?
Traumatic brain injury (could be from car accidents, blows to the head, sports injuries, falls or accidents, or physical violence)
Acquired brain injury (such as from poisoning or exposure to toxic substances, infection, strangulation, choking, or drowning, stroke, heart attacks, tumours, aneurysms, neurological illnesses or abuse of illegal drugs)
What is the Sensory Neuron function and how long does it last
Gives us an awareness of our environment through our senses (sight, hearing, smell, taste and touch).
Lasts a few seconds.
What is the short term memory function and how long does it last?
The capacity for holding a small amount of information in an active, readily available state for a short interval.
Lasts 18 to 20 seconds.
What is the long term memory function and how long does it last?
Stores an unlimited amount of information for very long time, possibly permanently.
Can last perminently
What is the role of the effector?
The effector is a molecule (e.g. hormone), a cell, or an organ that responds to a signal from the modulator and produces a response.
What is the role of the receptor?
The stimulus is detected by a receptor in the body and a message gets sent along the sensory neuron to the modulator
What is working memory?
Working memory is the small amount of information that can be held in one’s mind and used in the execution of cognitive tasks. When working on a task, your brain is focused on the task and processes the information involved. The part of the brain used to process this information is called the working memory – so working memory is your cognitive processing.
What is role of the stimulus?
A change in the external or internal environment.
What is the role of the response?
Response – the effector initiates the response to the stimulus, which produces a change in the function of the target cell, organ or organism in response to the initial stimulus.
What is the role of the modulator?
(also called processing centre) – receives signal from receptors, processes the information and sends a signal to the effector via motor neurons. The modulator is usually the brain or spinal cord.
What is an example of a reflex action?
Couching, sneezing and blinking
What are conscious actions that are considered reflex actions?
Swallowing, breathing, scratching, fidgeting, smiling
What is the role of receptors?
Receptors serve as specialised structures in our body responsible for detecting a wide array of stimuli including light, sound, touch, temperature, chemicals, and pain. When a stimulus is encountered, receptors detect the change in the environment and pass this information onto the sensory neuron in the form of an electrical signal. Without receptors, our nervous system would not receive information about changes from our internal or external environment and, hence, would not be able to send signals to allow us to respond appropriately to our environment.
What side of the cerebrum helps with answering questions?
Left hemisphere
What is homeostasis?
The maintenance of a relatively stable internal environment despite changes in the external environment.
What is a reflex action when you are cold?
Shivering
What is a reflex action when food enters your windpipe?
Coughing
What is a reflex action when you are hungry and smell food?
Salivating
What is a reflex action when you spend a long time in the sun on a hot day?
Sweating
What is the role of negavite feedback in homeostasis?
Negative feedback occurs when the response counters the stimulus and returns the system back to the normal (optimal) state. Negative feedback plays a crucial role in homeostasis because it is the regulatory mechanism that works to maintain balance by detecting and responding to deviations from a set point or ideal value.
In negative feedback, a change in a physiological variable, such as body temperature, blood sugar level, or blood pressure, is detected by sensory receptors. The receptors then send a signal to the control centre in the brain, which processes the information and determines the appropriate response. The response is carried out by effectors, such as muscles or glands, which act to counteract the initial change and bring the variable back to its set point or ideal value.
For example, when body temperature rises above the set point, the thermoreceptors in the skin and brain detect the change and send a signal to the hypothalamus, which is the part of the brain that is the control centre for body temperature. The hypothalamus then sends a signal to the sweat glands to produce sweat, which evaporates and cools the body down. As the body temperature returns to its set point, the negative feedback loop is completed, and the response is turned off.
What is the response when impulse is sent along a sensory neuron to the brain?
Bright light is shone in the eye (Stimulus)
What is the response when your pupils dilate?
Receptors detect change in light intensity (Receptor)
What is the response when impulse is sent along a motor neuron to iris muscle?
Impulse is sent along a sensory neuron to the brain
What is the response when iris muscles contract?
Impulse is sent along a motor neuron to iris muscle
What is the response when bright light is shone in the eye?
Brain processes information and decides on a response (Modulator)
What is the response when receptors detect change in light intensity?
Iris muscles contract (Effector)
What is the response when the brain processes information and decides on a response?
Pupil dilates (Response)
What is a homeostatic response to body temperature drops?
Effector arm muscles contract; Response: put on jumper
Effector arm and leg muscles contract; Response: turn heater on
Effector arm and leg muscles contract; Response: jump up & down, run around
What does it mean to follow the herd?
To follow the herd is a strong urge to conform to the people around you. It influences behavior as people are scared of standing out and looking stupid to their peers/
How did the human zoo fire alarm experiment demostrate following the herd?
When no one was reacting, the person in the group didn’t do anything as no was doing anything.
If a person is on their own, they evacuate as they didn’t need to conform to a group as their wasn’t one.
How do social norms influence behavior?
We learn social normal young in our life and they stick with us. If someone acts against these social norms we think they are strange or something is wrong with them. People feel embarrased to act against social norms.
How does the human zoo pickpocket experiment demostate following the herd?
The person in the group saw and so did the rest but no one spoke up so the man didnt react.
How does our clothes affect following the herd?
The way we dress contributes as if we dress more respectable someone seems inclined to help.
Why do people follow authority figures even if what they ask seems weird?
People listen to authority figures even if it hurts an individual because it is difficult to refuse a person in uniform as they are scared something might happen to them if they disagree.
What is the desire to be equal?
The desire to be equal can happen when you are being put down. An example is from human zoo when people with brown eyes were making fun of blue eye people and a guy from the blue guy group tried to be on level with the brown eye.
Sally used to find it hard to concentrate on her homework while she was listening to her music. However, over a period of time, she realised that she could easily concentrate on her homework while listening to her music. Explain why her music is no longer distraction for Sally.
When exposed to the same distraction multiple times, overtime the brain can learn that the distraction is irrelevant stimulus information and should be ignored, hence, freeing up the brain’s working memory to fully focus on the task. In this case, Sally has developed a high tolerance for music due to listening to it multiple times over an extended period of time while doing her homework. Hence, her brain has learnt to quickly identify the music as a distracting stimuli and ignores it allowing Sally to fully focus her attention on her homework.
How does alcohol impacts working memory?
Alcohol contains ethanol, which interferes with the balance of neurotransmitters in the brain resulting in reduced central nervous system activity. In terms of the working memory, this results in a slower reaction time when performing cognitive tasks as it will now take the brain longer to process stimuli and respond to it. Additionally, a person is more likely to have poorer performance when completing a task due to the slower processing speed.
