Vertebrae Homeostasis and Negative Feedback

Nervous System

Brain, spinal cord and peripheral nerves.

Communication b/w cells of the body through electrical signals and release neurotransmitters into small gaps

Skeletal Muscle

Skeletal muscle, bones, tendons and ligaments.

Support the body voluntary movement, and facial expressions

Cardiovascular System

Heart, blood vessels and blood.

Transport molecules thru body thru blood.

Respiratory System

Lungs, pharyx, trachea, bronchi

Bring oxygen into body and CO2 out

Renal System

Kidneys, ureters, bladder, urethra.

filter blood to regulate acidity, blood volume, and ion conc. and eliminate waste.

Physiology

The study of chemical and physical processes that control the function of living organisms.

Homeostasis

Process of maintaining stable internal environment compatible for life in the face of a changing external environments.

Most organ systems contribute to systemic homeostasis (except reproductive)

What is homeostatiscally regulated?

• Glucose conc.

• O2/ CO2 conc.

• Metabolic waste conc.

• pH

• Water/ion conc.

• Fluid Vol/ BP

• Temp

Negative Feedback Control

Primary mechanism for homeostasis.

External change → triggers change in regulated variable in internal env. → triggers rxn to oppose the change and return regulated variable toward normal.

Set point

Desired level of regulated variable

Sensors

Detect level of regulated variable and provide input to integrating center. (thermoreceptors central and peripheral)

Integrating center

Compares set point to actual level of regulated variable.

It sends output to effectors(sweat glands, blood vessels, in skin and skeletal muscles) to return regulated variable toward set point. (hypothalmus)

Error signal

Difference b/w actual level and set point

Negative feedback loop example

Thermoregulation

Homeothermic animals- have a set body temp, need to regulate it (mammals and birds)

Poikilothermic animals- no set temp, can survive in wide range of temp. (fish, amphibians, reptiles, and most invertebrates)

Radiation

thermal energy as electromagnetic waves (radiator)

Conduction

thermal energy through contact

Evaportatio

heat loss thru evaporation of water (sweating or insensible water loss)

Convection

heat transfer by movement of fluid/ air