Homeostasis + examining cells

Question 1

Define Homeostasis

Answer 1

The ability of a living organism, cell, tissue to maintain a state of internal balance

Question 2

Explain negative feedback loops

(add an example)

Answer 2

A sensor detects a stimulus (change in the internal balance) which causes an effector to correct this change. This stops when the effector stops

eg Blood glucose levels

Question 3

Explain positive feedback loops

(add an example)

Answer 3

A sensor detects the stimulus and the effector then increases the original stimulus

eg blood clotting or cervix stretching

Question 4

what is core body temperature?

Answer 4

36.5-37.5 C

Question 5

What temperature is considered hot?

Answer 5

37.5-38 C

Question 6

What temperature and conditions are considered a fever?

Answer 6

> 38 C
Pale sweaty skin; stomach, arm and leg cramps

Question 7

What temperature and conditions are considered heat stroke?

Answer 7

> 40 C
Flushed dry skin, hot to the touch, strong bounding pulse

Question 8

What temperature and conditions are considered heat exhaustion?

Answer 8

> 40 C
Unconsciousness, seizures, confusion, headache, dizziness

Question 9

What temperature and conditions are considered mild hypothermia?

Answer 9

32.1-35 C
Shivering, fatigue, slurred speech, confusion, stiffness

Question 10

What temperature and conditions are considered severe hypothermia?

Answer 10

28.0-32.0 C
Shivering stops, rigid muscles, slow and weak pulse

Question 11

What temperature is considered cold?

Answer 11

35-36.5 C

Question 12

When is a person classified as dead due to the cold?

Answer 12

Once they have been warmed (pump with warm fluids) to above 28 C and are still unresponsive

Question 13

what is the normal physiological pH range?

Answer 13

7.35-7.45

Question 14

At what pH range does alkalosis occur?

Answer 14

7.45- 7.8

Question 15

At what pH range does acidosis occur?

Answer 15

7.0- 7.35

Question 16

At what pH ranges do the tissues die?

Answer 16

Below 6-7 and above 7.8-9

Question 17

how does doubling H+ concentration change pH?

Answer 17

Causes an increase in pH by 0.3

Question 18

what is aluminium hydroxide used for?

(why?)

Answer 18

Acid neutraliser

mildly alkaline but insoluble

Question 19

what buffer system do cells use?

Answer 19

Sodium Phosphate Buffering system/ Bicarbonate buffer in RBCs

Question 20

What proportion of total body water does the Intracellular fluid account for?

Answer 20

2/3

Question 21

What proportion of extracellular fluid volume is the interstitial fluid?

Answer 21

3/4

Question 22

What proportion of total body water does the interstitial fluid make up of a healthy man?

Answer 22

1/4