Homeostasis Quiz 1 Flashcards
What is homeostasis?
The process of maintaining relatively constant internal conditions or equilibrium.
How is homeostasis maintained?
Homeostatic Control systems
- sensor
- integrator
- effector
Explain negative feedback systems
Response reduces initial stimulus, brings it back to equilibrium when out of it
Explain positive feedback systems
Moves variable farther from steady state does not help with homeostasis (labour)
What type of thermoregulation do humans use?
Endotherms
Describe endotherms
-Warm blooded animals
-Constant body temp regardless of environment
-temp slightly varies from peripheral to core of body
-can maintain wide range of temps because of feedback loop
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Describe the endotherm feedback loop
- thermoreceptors alert nervous system
- hypothalamus integrates info and initiates response
What response does the hypothalamus initiate for a temp drop?
Construction of arteries
Shivering and Goosebumps to generate heat
Raised hairs to trap air and maintain heat
What is the response by the hypothalamus for temp increase ?
Relaxation of arteries(vasodilation) increase blood flow to skin
-secrete sweat, removes thermal energy
What metabolic processes produce waste?
Lungs- co2
Large intestine- toxic wares and indigestible products
Liver- transforms chemicals and toxins
How are nitrogenous waste products removed from the body? How does it work?
Deamination (occurs in liver, produces ammonia, ammonia is converted in liver to urea)
What is the function of kidneys?
Filter waste from blood, balance blood pH, maintain water balance
What do nephrons do? And where are they located?
Formation of urine
Within cortex and medulla
Draw a nephron
In notes
Describe the process of what happens in the nephron
In bowman’s capsule blood comes into glomerulus via afferent arteriole large molecules like RBCs and proteins cannot pass through membrane. Dissolved substances diffuse into bowman’s capsule from glomerulus. This substance then travels to proximal tubule where H2O, Na+, glucose are reabsorbed ( twisty structure for greatest surface area). Ammonia, H+, and K+ moves into nephron through diastole and proximal tibulas. Substance then travels to loop of henle. Where H2O reabsorbed in descending and Na+ reabsorbed in ascending. Once urine has been produced leaves via collecting ducts. Enter ureter and then bladder out urethra.
What do the kidneys do to maintain homeostasis?
Maintain water levels
React to low blood pressure
Explain how water is maintained in the body?
H2O reabsorption at distal tubule and collecting ducts can be controlled, in henle and proximal it cannot be. Osmoreceptors in hypothalamus monitor water in blood (sensor), OR sends signal to pituitary gland. Pituitary gland releases ADH. ADH increases reabsorption of water in distal tubules abs collecting ducts by making them more permeable. When H2O in blood increases OR is not triggered release of ADH is inhibited nephrons will not reabsorb portion of water
What does the kidney do to react to low blood pressure?
Baroreceptors recognize decrease in blood pressure, receptors release renin into blood, renin converts angiotensinogen to angiotensin. This constricts the blood vessels, trigger thirst , targets adrenal glands (integrator), these release aldosterone (effector), aldosterone increases Na+ reabsorption. Water moves out of nephron into peritubular capillaries because of the change in osmotic pressure
Describe the endocrine system
- system of glands that regulated bodily functions via hormone ms secreted into bloodstream
- slow acting responses
- includes hypothalamus, pituitary gland, thyroid gland, parathyroid glands, adrenal glands, pancreas, and gonads.
Describe hormones
Chemical regulators that are made in one part of the body but affect other parts
