Homeostasis
What is the definition of homeostasis?
The maintenance of a stable internal environment.
What does the endocrine system use to send signals?
Hormones
What are the two main divisions of the nervous system?
Central nervous system (CNS) and peripheral nervous system (PNS).
Which part of the neuron receives signals from other cells?
Dendrites
Which receptor detects light?
Photoreceptors
Which two body systems mainly maintain homeostasis?
Nervous and Endocrine
Which gland is often called the "master gland" of the endocrine system
Pituitary Gland
What are the two main components of the central nervous system (CNS)?
Brain and spinal cord
What is the resting potential mV of a neuron?
-70mV
What type of receptor detects chemicals, such as in taste and smell?
Chemoreceptors
What is the difference between negative and positive feedback in homeostasis?
Negative feedback reverses a change to return conditions to normal; positive feedback amplifies a change.
Name two hormones produced by the pancreas and their functions.
Insulin (lowers blood glucose) and glucagon (raises blood glucose).
What is the role of the myelin sheath in nerve transmission?
It insulates the axon and speeds up impulse transmission.
What ion movement causes depolarisation during an action potential?
Sodium (Na⁺) ions moving into the cell.
Which receptor detects changes in pressure, vibration, or touch?
Mechanoreceptors
What mechanisms does the body use to regulate temperature.
Sweating and vasodilation when hot, shivering and vasoconstriction when cold.
How does the endocrine system differ from the nervous system in terms of speed and duration of response?
Endocrine responses are slower but longer-lasting; nervous responses are fast and short-lived.
What is the difference between afferent and efferent neurons?
Afferent neurons carry signals to the CNS (sensory), while efferent neurons carry signals away from the CNS (motor).
How is a nerve impulse transmitted across a synapse?
Neurotransmitters are released from vesicles, diffuse across the synaptic cleft, and bind to receptors on the next neuron.
How do nociceptors help protect the body?
They detect pain, warning the body of injury or harmful stimuli.
Explain how the body maintains blood glucose levels after eating a high-sugar meal.
The pancreas releases insulin, which stimulates cells to take up glucose and the liver to store it as glycogen.
Explain how the hypothalamus and pituitary gland work together to regulate hormone release.
The hypothalamus detects changes and releases hormones that signal the pituitary, which then releases hormones to regulate other glands.
Outline the path of a reflex arc from stimulus to response.
Stimulus → receptor → sensory neuron → interneuron in spinal cord → motor neuron → effector (muscle/gland).
Explain how the resting membrane potential is maintained in neurons.
The sodium-potassium pump actively moves Na⁺ out and K⁺ in, creating an electrochemical gradient.
Explain how thermoreceptors in the skin contribute to homeostasis.
They detect temperature changes and send signals to the hypothalamus, which triggers responses like sweating or shivering.