lecture homeostasis

define homeostasis

Maintaining a stable internal environment

positive feedback

Feedback that tends to magnify a process or increase its output.

negative feedback

A type of regulation that responds to a change in conditions by initiating responses that will counteract the change. Maintains a steady state.

Homeostatic inbalances result in?

1. Disorder: Any abnormality of structure or function

2. Illness characterized by signs and symptoms

set point

the point at which one's body tries maintain

normal range

range of values around the set point that do not cause a reaction by the control center

effectors

cause responses that alter conditions in the internal environment

affector

a neuron that transmits sensory information

explain positive feedback loop of childbirth

When the fetus stimulates the placenta to make prostaglandins, the prostaglandins stimulate the placenta smooth muscle to contract, contractions push the baby's head against the cervical opening at the base of the uterus, activating pressure receptors, engaging a nerve cell based process, releasing oxytocin from the posterior pituitary, stimulating more contractions, pushing the baby's head more strongly against the cervical opening. Overall, increasing cervical pressure increases activation of pressure receptors, increases stimulation of uterine contractions through prostaglandin production from placenta and oxytocin from posterior pituitary. Diagram for this in notes.

pitocin

Hormone, induces labor

concentration, thermal or pressure gradient

different values in two different loctions

independent variable

The experimental factor that is manipulated; the variable whose effect is being studied.

Independent variables in the homeostasis lab

exercise or no exercise

dependent variable

The outcome factor; the variable that may change in response to manipulations of the independent variable.

what was the dependent variables in the homeostasis lab

changes in carbon dioxide and oxygen

Was CO2 consumed or produces in cell respiration

produced

Is oxygen consumed or produced in cell respiration

consumed

When graphing your data in the homeostasis lab was the change in oxygen

positive or negative

negative ( consumed )

the homeostatic set point for the bodies pH is

7.4

When CO2 mixed with water what is produced

carbonic acid

What happens to the pH as more carbon dioxide is produced by the body

becomes more acidic

How does the body maintain pH by controllng CO2 levels in the body

breathe out more ( increase respiration )

Where are the pH detectors in the blood located

carotid arteries

10 minutes after exercise what happens to the CO2 production levels

less CO2 is produced, respiration slows

10 minutes after exercise what happens to the O2 consumption

less oxygen is consumed , respiration slows

Which of the four tests is best to use to detect glucose?

Benedict's Test

What color change occurs in the benedict indicator in the presence of glucose ( blue no glucose )

orange / red

What indicator is used to test for starch

IKI ( iodide potassium Iodine ) turns from brown to black or violet

When blood glucose is high , what hormone is produced

insulin

What organ produces insulin

pancreas

What effect does insulin have on glucose

lowers blood sugar by increasing uptake by cells and causes the liver to convert blood sugar to glycogen

what hormone is released when the blood sugar is low

glucagon

What organ secrete glucagon

pancreas

what effect does glucagon have on blood sugar

increases blood sugar by breaking down glycogen into glucose