Homeostasis

What does homeostasis mean?

Maintaining optimal internal conditions.

What is a feedback system in homeostasis?

Regulates internal conditions through feedback mechanisms.

What are the components of feedback systems?

Receptor, control center, effector.

How do negative and positive feedback systems differ?

Negative maintains stability; positive amplifies change.

What role do buffers play in pH maintenance?

Stabilize pH by neutralizing acids or bases.

What is the most important buffer in the body?

Negative feedback systems regulate pH.

How do proteins act as buffers?

Regulated by homeostatic feedback systems.

What are the main structures of the CNS?

Brain and spinal cord; process information and control functions.

Why is the nervous system critical for homeostasis?

Monitors conditions and sends signals to maintain stability.

How is the spinal cord protected?

Surrounded by vertebrae and meninges.

What is the function of the blood-brain barrier?

Controls substance entry to protect the brain.

What happens when the sympathetic nervous system is stimulated?

Slows digestive organ activity.

What distinguishes neurons from glial cells?

Neurons transmit signals; glial cells support and protect.

What are Schwann cells?

Insulate myelinated neurons, speeding up action potentials.

What is resting membrane potential?

Charge difference across a neuron's membrane.

What factors contribute to resting membrane potential?

Ion concentrations, channel permeability, sodium-potassium pump.

How does the sodium-potassium pump work?

Moves 3 Na+ out and 2 K+ in, maintaining charge gradient.

What occurs during action potential transmission?

Rapid influx of Na+ followed by K+ outflow.

What is polarization in neurons?

Charge difference essential for impulse transmission.

How does the sodium-potassium pump maintain resting potential?

Uses ATP for active transport of ions.

What effect does tetrodotoxin have on action potentials?

Blocks sodium channels, preventing depolarization.

How does cocaine affect neural transmission?

Blocks reuptake of dopamine, increasing its levels.

What is the natural role of dopamine?

Provides pleasure sensation.

Why might cocaine be addictive?

Causes a massive dopamine influx, leading to dependency.

What happens when cholinesterase is blocked?

Acetylcholine accumulates, causing muscle contraction.

How do neonicotinoids kill insects?

Cause continuous nerve stimulation, leading to death.

What is the function of the endocrine system?

Regulates body functions through hormones.

What is a hormone?

Chemical messenger that regulates physiological processes.

How do the nervous and endocrine systems work together?

Coordinate responses to stimuli.

What triggers hormone release during stress?

Hypothalamus signals pituitary to release ACTH.

What is the role of the thyroid gland?

Regulates metabolism like a thermostat.

What are the effects of epinephrine?

Increases heart rate, blood flow, and energy availability.

What happens with low hGH secretion?

Can lead to pituitary dwarfism.

How do kidneys interact with the endocrine system?

Regulate hormones and maintain homeostasis.

What is the role of the nephron?

Filters blood and forms urine.

What is glomerular filtration?

Process of filtering blood to form urine.

What is the importance of sodium removal in the nephron?

Essential for water reabsorption and concentration.

How do kidneys maintain blood pH?

Regulate ion concentrations and excrete acids/bases.

What happens during dehydration?

Kidneys conserve water, reducing urine output.

What is the effect of untreated renal insufficiency?

Leads to uremia from waste accumulation.

What is the role of osmoreceptors?

Regulate water reabsorption based on blood osmotic pressure.

What happens when blood pressure is low?

Kidney function decreases, affecting filtration.

What is the effect of caffeine on hydration?

Promotes dehydration by increasing urine output.

What is the significance of the albumin to creatinine ratio?

Indicates kidney function and potential damage.

How does atherosclerosis affect kidney function?

Reduces blood flow, leading to acute kidney failure.