Homeostasis test Flashcards
(34 cards)
What is homeostasis?
Body’s tendency to seek and maintain a condition of internal balance
What are feedback systems?
Mechanisms that regulate bodily processes using feedback loops
Negative feedback loop example?
High glucagen levels trigger insulin release to reduce blood glucose
Positive feedback loop example?
Oxytocin increases during childbirth to intensify uterus contractions
What is a neuron?
A nerve cell that transmits electrical impulses through the nervous system
What is continuous conduction?
Signal travels the entire length of and unmyelinated axons slowly (5 m/s)
What is saltatory conduction?
Signal jumps between nodes in myelinated axon (150 m/s) making it faster
What is an action potential?
A brief and quick electrical charge that travels down an axon caused by ion shifts
What is resting potential?
The neuron’s inactive state with a -70 mV charge inside the membrane
Threshold potential value?
-55 mV, the point at which an action potential is triggered
What happens during depolarization?
Na+ enters the cell, reversing membrane potential to +35 mV
What is a synapse?
The junction where neurons communicate via neurotransmitters across the synaptic cleft
What is the peripheral nervous system (PNS)?
All nerves outside the brain and spinal cord.
Types of cellular transport?
Passive (diffusion), Active (primary, secondary), and Membrane-Assisted (endocytosis/exocytosis)
Endocrine system glands?
Hypothalamus, pituitary, thyroid, parathyroid, adrenals, pancreas
Hormones from anterior pituitary?
Growth hormone, and others affecting growth and development
Hormones from posterior pituitary?
ADH (water retention), oxytocin (contractions)
Thyroid and parathyroid hormones?
Calcitonin (thyroid), PTH (parathyroid) regulate calcium
Pancreas hormones?
Insulin (lowers blood sugar), glucagon (raises blood sugar).
Types of hormones?
Steroid (fat-soluble, acts inside cell), non-steroid (water-soluble, acts via secondary messengers)
Short-term stress response?
Fight or flight: epinephrine and norepinephrine (Adrenaline)
Long-term stress response?
Cortisol helps body endure chronic stress
Compare nervous vs endocrine systems
Nervous: fast, short-lived, electrical; Endocrine: slow, long-lasting, hormonal
Similarities of nervous and endocrine systems
Coordinate body function, use signaling, affect target cells
