Biomechanics - Regulation

Question 1

What must organisms be able to do?

Answer 1

Maintain and regular their internal environment despite changes in the external one

Question 2

What is the mechanism used to maintain a more stable internal environment?

Answer 2

Homeostasis

Question 3

Is the internal environment constant?

Answer 3

No, it does change slightly but homeostasis is the process to reduce this change

Question 4

What are the three functional components of homeostasis? What do they do?

Answer 4

• Sensor: to detect change from some internal variable
• Control centre: processes data from sense and initiate response
• Effector: to implement the response

Question 5

What is the normal value or range of variables called? What is it set by?

Answer 5

Set point, determined by control centre

Question 6

How does a change in the set point create a response?

Answer 6

Change in the ‘value’ of the variable creates stimulus which is measured by sensors and is detected by control centre which then creates response to return it back to its set point

Question 7

What kind of process is homeostasis? What is this?

Answer 7

Negative feedback, when something changes creating a response to counteract the change

Question 8

What part of the brain controls the body temperature?

Answer 8

hypothalamus

Question 9

What are the sensors in the body? Where are they in the body?

Answer 9

Nervous system (e.g. neurons), in blood vessels, sweat glands and muscles

Question 10

What does control and coordination of homeostasis depend on?

Answer 10

The endocrine system and nervous system

Question 11

What does the endocrine system do?

Answer 11

Transmit chemical signals (e.g. hormones) to respective cells throughout blood through the blood

Question 12

Signalling by hormones and nervous system differ?

Answer 12

Hormone: affect on or more regions throughout the body, is slow acting but has long lasting effects but only affects cells which has receptors for it
Nervous system: transmit between specific locations giving individual information based on pathway, info transferred very fast and is received by only neurons, muscle cells and endocrine cells

Question 13

What do physiological systems of animals operate in?

Answer 13

A fluid environment

Question 14

what does the operation of physiological in fluids require in terms of maintaining?

Answer 14

Concentration of water and solutes must be maintained within narrow limits

Question 15

What is the maintaining of water and solutes in the body called? What is this process largely based on?

Answer 15

Osmoregulation, based on controlled movement of solutes between internal fluids and external environment

Question 16

What is osmolarity?

Answer 16

The solute concentration of a solution and determines the movement of water across a selectively permeable membrane

Question 17

What are the three different types of solutions and what is their water movement?

Answer 17

• Iso-osmotic: osmotic concentration is equal so no net flow of water
• hypo-osmotic: where there is high H2O concentration/low solute concentration and this flows to hyper-osmotic solutions which has a low H2O concentration/high solute concentration

Question 18

What do the cells selectively permeable membranes do?

Answer 18

Seperate the intracellular medium (e.g. cytoplasm) from the extracellular medium (interstitial fluid)

Question 19

How is the osmolarity of interstitial fluid mainly determined by?

Answer 19

The concentration of sodium ions (e.g. salt)

Question 20

What is the water balance of humans as day? What makes this up?

Answer 20

2.5L in, 2.5L out
In: liquids = 1.5L, food = 0.75L, metabolism = 0.25L
Out: Urine = 1.5L, evaporation = 0.9L, faeces = 0.1L

Question 21

What are the function of the kidneys?

Answer 21

Water and salt homeostasis by filtration, reabsorption, secretion and excretion

Question 22

Briefly describe the functions of the kidney

Answer 22

Filtration: pressure filtering of body fluids
Reabsorption: reabsorbing valuable solutes
Secretion: separating the toxins + other solutes from body fluids and transporting to the bladder
Excretion: removal of the toxins from body

Question 23

Explain how filtration works

Answer 23

The blood pressure forces fluid from blood into the tubule of the nephron where the amount of water and salt that are reabsorbed are controlled by vasopressin and aldosterone

Question 24

What is a nephron?

Answer 24

A function unit of a kidney where blood flows into a filtration unit and the filtrates flow down a filtration tube while getting reabsorbed based on its permeability

Question 25

What is vasopressin and aldosterone? what are their functions?

Answer 25

They are both hormones that regulate the reabsorption of salts and water into the blood stream

• Vasopressin = increases the reabsorption of water
• Aldosterone = increase the reabsorption of salts

Question 26

What stimulates vasopressin and aldosterone production?

Answer 26

• Vasopressin = increase in osmolarity (concentration of solutes), decrease in blood pressure
• Aldosterone = decrease in blood pressure and increase in water concentration

Question 27

What inhibits vasopressin and aldosterone production?

Answer 27

• Vasopressin = increase in blood volume

- Aldosterone = increase in osmolarity

Question 28

If someone suffered sever blood loss, how would the production of vasopressin and aldosterone change? Why

Answer 28

Both would increase as water and salts are being lost so the body want to retain both of those

Question 29

If someone became dehydrated, how would the production of vasopressin and aldosterone change? why?

Answer 29

Vasopressin increases while aldosterone decreases as there is less water in the body so more water needs to be retained and salts need to be lost as well

Question 30

What principle does vasopressin and aldosterone operate on?

Answer 30

Negative feedback

Question 31

Where are vasopressin and aldosterone produced?

Answer 31

vasopressin = pituitary gland
aldosterone = adrenal cortex

Question 32

(Random question) What is the difference in collage between loose connective tissue vs fibrous connective tissue? Why

Answer 32

fibrous has more collage to be stronger