Homeostatis and Hypothalamus 1 Flashcards
What are Maslow’s Hierarchy of needs?
- Physiological (food, water)- maintain homeostasis and stay alive
- Safety needs ( shelter, survival)
- Social needs( love, friendship, approval)
- Esteem needs (feelings of self worth)
- Self-actulization ( becoming our ideal self)
What is the drive reduction Theory?
Behaviors are motivated by the drive to maintain biological homeostasis. When a biological need arises, we feel an internal tension.
What is an example of the drive reduction theory?
We eat when we are hungry and find warmth when we are cold.
What are the other types of drives?
Survival: hunger, thirst, warmth
Reproduction: Sex, Affection
Social: Affiliation, Approval, Self-Esteem
What are the functions of the hypothalamus?
Regulate the body’s homeostasis, regulate autonomic and endocrine systems. It is connected to the pituitary and pineal gland.
What drives does the hypothalamus regulate?
Hunger, Thirst, Sleep
Body temp, blood presuure
Sexual desire
Reward motivation
Stress Responses
Basal Metabolism
Set point
What does the hypothalamus trigger when energy stores are low?
Triggers release of the hormone ghrelin which motivates eating behavior.
What does the hypothalamus trigger when energy stores are high?
Triggers realize of the hormone leptin which reduces appetite.
What is basal metabolism?
how the body uses and burns calories by default.
What is set point?
Body’s naturally preferred weight. Genetic differences can impact basal metabolism and set point (body shape, distribution of fat cells).
What does the hypothalamus regulate in terms of sexual desires for both men and women?
GnRh- Gonadotropin releasing hormone.
What are the other sex hormones that are regulated?
Testosterone, estrogen, progesterone. “Bonding” hormones like oxytocin as well.
What hormone increases sexual desire in both men and women?
Testosterone.
What was the difference found in gay and straight men?
Difference in hypothalamic areas.
Stress is a deviation from…
Homeostatis
- metabolic priorities shift
-physical and mental energy redirected
What systems does stress effect in the body?
Affects most systems in the body
- nervous system
- musculoskeletal system
- cardiovascular system
-gastrintestinal system
-endocrine system
-reproductive system
-immune system
What does stress mentally impact?
it impacts attention, perception, memories, emotions
What are homeostatic systems maintained or changed by?
Maintained or Changed by “control loop”.
What do Control Loops involve?
1)Measurement
-sensors, receptors
-ex. Receptors that detect body temperature
2)Comparison
-Set points, goal states
-ex. temperature higher or lower than set point (98.6)
3)Adjustment
-Effectors- muscles, glands, internal organs
-ex. sweat to cool the body, shiver to warm the body
What is a negative feedback loop?
Used to maintain system at a set point. Output inhibits more output.
What is a positive feedback loop?
Used to amplify or accelerate system output. Output of the system increases more output.
What is a feed-forward System?
Used to change a set point in preparation for future demands. Inputs from additional sensors or control systems to predict future needs. May link several negative/positive feedback loops together. Can dynamically adjust response without lag or delay.
Examples of Negative Feed Back Loop?
Thermostat: Temp too low->increase heat–>temp goes up–>heat turns off.
When there is enough hormone, stop making the hormone.
Regulation of Blood Pressure
What are negative feedback loops used to maintain?
Used to maintain set-points.
What are negative feedback widely used in?
basal metabolism, blood pressure, and body temp.
What is the con of a negative feedback loop?
There is a delay in response. Sensors detect a deviation from the set point, then effect a response, and the response takes time to restore the set point.
What is blood pressure monitored by?
Baroreceptors.( sensitive to stretching of blood vessels and heart chambers.
What is blood pressure regulated by?
Changes in cardiac output (heart pumping) and changes in vasoconstriction (blood vessels)
What do baroreceptors do when the blood pressure is too high?
Baroreceptors fire more–> cardiac output decreases and blood vessels dilate–>blood pressure decreases.
What do baroreceptors do when the blood pressure is too low?
Barorecpetors fire less–>cardiac output increases and blood vessels constrict–>blood pressure increases.
What are examples of positive feed back loop?
Blood Clotting/Wound Healing : platelets release clotting factors that attaract more platelets.
Lactation: Breastfeeding increases milk production. Milk supple increases with more breastfeeding.
Childbirth: Oxytocin causes contractions causes the release of oxytocin, increasing the strength of the contractions.
When does a positive feedback loop end?
When it reaches a goal state and that triggers the negative feedback to stop it. For example, the baby is born, wound is healed. Turn off positive feedback loop.
What are examples of feed-forward system?
Heart rate and blood pressure increase before excercise
Saliva and gastric acid production before food is eaten
Increase energy/alterness during the day, decrease at night (For sleep)
