b2 nerves and hormones Flashcards
(20 cards)
What is the nervous system?
A network of nerve cells that coordinates the body’s responses to changes inside and outside the body.
What is a stimulus?
A change in the environment that is detected by receptors.
What is a receptor?
Cells or groups of cells that detect stimuli (e.g., light, sound, temperature).
What is a sensory neuron?
A nerve cell that carries impulses from receptors to the central nervous system (CNS).
What is a motor neuron?
A nerve cell that carries impulses from the CNS to effectors (muscles or glands).
What is the central nervous system (CNS)?
The brain and spinal cord, which process information and coordinate responses.
What is a reflex action?
An automatic and rapid response to a stimulus that does not involve conscious thought.
How does a reflex arc work?
Stimulus → receptor → sensory neuron → CNS (relay neuron) → motor neuron → effector → response.
What is a synapse?
The gap between two neurons where neurotransmitters are released to transmit impulses.
What is a neurotransmitter?
A chemical that carries signals across a synapse between neurons.
What is the role of hormones?
Chemical messengers released by glands that regulate processes in the body.
What is the endocrine system?
A system of glands that secrete hormones directly into the bloodstream.
What is the difference between the nervous and endocrine systems?
The nervous system uses electrical impulses and is fast but short-lasting. The endocrine system uses hormones, which are slower but have longer-lasting effects.
What gland produces insulin and what does it do?
The pancreas produces insulin, which lowers blood glucose levels.
What gland produces adrenaline and what is its function?
The adrenal glands produce adrenaline, which prepares the body for ‘fight or flight’ in stressful situations.
What is homeostasis?
The maintenance of a stable internal environment in the body (e.g., temperature, water balance).
How is blood glucose regulated?
After eating, the pancreas releases insulin to lower glucose; between meals, glucagon is released to raise glucose levels.
What are effectors?
Muscles or glands that bring about a response to a stimulus.
What is the role of the hypothalamus?
A part of the brain that controls body temperature and links the nervous and endocrine systems.
What is a target organ?
An organ that a hormone acts on.
