Chapter 11: Human nervous system Flashcards
What are some examples of things your body must maintain via homeostasis?
Body temperature, blood water, blood ions, blood glucose concentration
What is homeostasis?
The involuntary regulation of a internal environment of an organism to maintain optimal conditions
How does the CNS coordinate your actions?
The brain detects input from the receptors and coordinates a response, motor neurons carry the signal from the brain to the effectors
What are hormones?
Proteins which are released into the bloodstream by certain glands. When they reach their target organ, they can make a change. They are much slower than electrical impulses
What are nerves made of?
Long bundles of individual neurons
What are effectors?
Parts of the body that cause a response to stimuli by moving parts of the body or secreting hormones
What are receptors?
Cells at the beginning of a neuron pathway that detect changes in the environment and generate electrical responses. Fingertips contain the most receptors
Name some examples of receptors
Eyes (react to light), hearing (react to sound and position), taste (react to chemicals in food), smell (react to chemicals in air), touch (react to pain, itch, temperature, touch, pressure)
What are sensory neurons?
A neuron that carries an impulse from a receptor to the brain
What are relay neurons?
The neurons that pass signals along within the brain
What are motor neurons?
The neurons that carry signals from the CNS to muscles and glands
What is the stimulus/response pathway?
Stimulus, Receptor, Neurons, Effector, Response
What is a synapse?
A small gap between the axon of one neuron and the dendrites of another where chemical neurotransmitters can be exchanged
What are dendrites?
The branched beginning of neurons, which can detect neurotransmitters and start an electrical response
What happens at the end of axons?
The signal spreads out into root-like structures at the end of the cell, where it is temporarily converted into a chemical signal, which diffuses across the synapse
What are reflex responses?
Fast, involuntary responses that do not require the brain (e.g. moving your hand away from a hot surface)
What is a reflex arc?
The route if an impulse that bypasses the brain. Sensory neurons -> relay neurons in spine -> motor neurons. You know this response has happened because separate neurons carry an impulse from the relay neurons to the brain
What is the cerebral cortex?
The main, outer part of the brain, which is responsible for memories, consciousness, intelligence and language, and is split up into left and right hemispheres
What is the cerebellum?
A part of the brain near the spinal cord that coordinates muscle movement
What are the 4 lobes of the cerebral cortex?
Frontal (voluntary movements), Parietal (sensory information), Occipital (visual information), Temporal (memories/language)