8.1: Human Body Systems and Homeostasis Flashcards
What is homeostasis?
Homeostasis is a bodily process which maintains certain variables of the internal environment at an equilibrium
What is the average body temp, blood glucose level, and pH of the blood in the human body?
Body Temp: 37°C
Blood Glucose Level: 100mg/mL
pH of Blood: 7.4
What are the 3 components of a feedback system?
A sensor, a control centre, and an effector
What does a sensor do?
- Detects changes in the internal environment
- Sends a signal to a control centre
What does a control centre do?
- Receives information from the sensor
- Sets the range of values the variable should be maintained
- Sends signals to the effectors when needed
What does an effector do?
- Receives impulses from the control centre
- Responds, changing the internal variable
What is a negative feedback system
A homeostatic response which reverses a change in a variable to bring it back to its normal range
What is a positive feedback system?
A homeostatic response which increases or strengthens a change in a variable
Give an example of a negative feedback system in effect
- When exercising the muscles get hot, which makes the temperature of the blood increase
- The body releases sweat to regulate the body’s internal temperature to 37°C
Give an example of a positive feedback system in effect
- In childbirth, the uterus contracts
- To do so, oxytocin is released
- The more oxytocin released, the stronger the contractions until birth
What is a steady state?
- Achieved by self-adjustment
- Death can result if the balance is not maintained
What is a dynamic equilibrium?
- A condition that remains stable with fluctuation limits
- Ex: Body temperature, blood glucose level, etc
What is a hormone?
Produced by the endocrine system which conveys information from organs in the body
What is a pheromone?
A chemical signal used to communicate between different individuals
What is a neurotransmitter?
Chemical signals between cells on a localized scale (between neurons)
