12U Biology- Homeostasis: A Fine Balance

homeostasis

process by which a constant internal environment is maintained despite changes in the external environment

internal environment

refers to the fluid between our cells (etracellular fluid)

sensor

detects change

integrator

processes info

effector

produces response

negative feedback

process by which a mechanism is activated to restore conditions to their original state

positive feedback

process by which small effect is amplified

Endotherms

organisms that are capable of generating enough heat through metabolism to regulate their own tempurature

Ectotherm

organims that depend on the environment around them to regulate their body tempuratures; unable to generate their own body heat; majority of animals

Thermoregulation

process of keeping body at a constant tempurature

Hypothalamus

monitors body tempuature, sends nerve impulses to skin

Vasodilation

blood vessels supplying blood to skin SWELL/ dialate so more heat is carried by blood to skin where it can be lost to the air

Vasocontriction

blood vessels SHRINK down to reduce heat loss through skin when body temperature is back to normal

Osmosis

water moves from a high concentration to a low one BUT this means it is moving from a low solute concentration to a high one

Osmotic pressure

pressure that results from difference in water concentration on two sides of a membrane

Osmoregulation

regulating osmotic pressure of bodily fluids and cells

Hyperosmotic

higher concentration of solutes

Hypo osmotic

lower concentration of solutes

Iso osmotic

equal solute concentration on both sides of membrane

Glomerulus and Bowman’s Capsule

Filters blood, allowing waste products and excess water; then collects the filtered fluid, known as glomerular filtrate, which eventually forms urine.

Proximal Tubule

It reabsorbs most of the filtered water, essential nutrients like glucose and amino acids, and ions such as sodium and potassium. It also secretes waste products like urea and creatinine. Additionally, helps regulate the body's pH balance and maintains osmolarity by reabsorbing solutes. Overall, it plays a crucial role in urine formation.

Descending limb of the loop of Henle

Permeable to water. It is responsible for reabsorbing water from the filtrate, which helps in concentrating the urine. NaCl becomes concentrated

Ascending limb of the loop of Henle

responsible for reabsorbing sodium and chloride ions from the filtrate. It plays a crucial role in the formation of concentrated urine by creating a concentration gradient in the medulla of the kidney. Permeable to NaCl, resulting in diffusion of NaCle out of the

Distal Tube

selective reabsorption, active + passive transport, nutrients move from blood into filtrate, helps regulate K+ and NaCl

Collecting Duct

urine formation

Afferent

blood going in

Efferent

blood going out

What is label 1?

proximal tubule

What is label 2?

distal tube

What is label 3?

collecting duct

What is label 4?

loop on Henle