Chedy - theme 2

Question 1

Homeostasis:

Answer 1

A process in which the body’s internal environment is kept stable. 37ºC, pH 7.365, blood glucose 5 mmol/L, blood pressure 120/80 mmHg, constant concentration of water and electrolytes.

Question 2

How concentration of water/electrolytes are controlled:

Answer 2

Na+, Cl-, and organic solutes in ECfluid influence how much water enters/leaves the cell. Must be regulated to maintain proper cell volume.

Question 3

Intercellular regulatory mechanisms: variables to be regulated (4)

Answer 3

Set point - normal value for variable
Sensor/receptor - monitors the variable
Integrator - compares signals from sensor to the set point
Effectors - compensates for differences between actual value and set point (glands, muscles, organs, other structures)

Question 4

Different kinds of regulation:

Answer 4

Negative feedback, positive feedback, feed-forward regulation, conditioned stimulus

Question 5

Examples of negative and positive feedback:

Answer 5

Neg: sweating to lower body temp, insulin vs blood sugar
Pos: childbirth

Question 6

Let’s talk about childbirth and pos feedback:

Answer 6

Body asks for supraphysiological response (push levels outside of normal range). Oxytocin intensifies contractions, which signals the release of more oxytocin.

Question 7

WHAT SECRETES OXYTOCIN?

Answer 7

POSTERIOR PITUITARY GLAND!

Question 8

Feedforward regulation:

Answer 8

Body begins preparing for a change, sometimes before the stimulus happens. Speeds up responses to deviations from set point. Result from learning or is modified by learning. PAVLOV.

Question 9

Conditioned stimulus:

Answer 9

Feedforward processes associated with irrelevant stimuli.

We both took psych.