Most organs in the body can now be considered _____ organs
endocrine
A ______ for a specific hormone will have a protein receptor molecule that binds the hormone. The binding of the hormone to the receptor will trigger a biochemical reaction that will lead to a _____ response
target cell, physiological
Hormones can either ____ or _____ specific functions in a cell.
activate, inhibit
_____ organs are organs with cells that respond to hormones
Target
_____ are molecules that convey information between cells
____ are intracellular molecules that mediate the action of primary messengers.
Primary messengers
Secondary messengers
____ alter membrane electrical potential. Produced by neurons, released directly onto their target cells at the synapse.
Neurotransmitters (NT)
Neurotransmitters (NT) can ____ or ____ the membrane
hypo or hyperpolarize
_____ are produced by neurons, released directly onto their target cells at the synapse
Neuropeptides
Neuropeptides act either as ____ or as _____
growth factors, neuromodulators
_____ are primary messengers that alter a neuron’s response to neurotransmitters.
Neuromodulators
Neuromodulators by themselves they do not alter the _____, but when they bind to a neuron, prior to the binding of a neurotransmitter they can either enhance or inhibit the neuron’s response to the NT.
membrane action potential
The drug Valium functions as a neuromodulator, enhancing the action of _____ , an inhibitory neurotransmitter that decreases responses to anxiety inducing stimuli
GABA
____ are signaling molecules that act within the same organ that produces them. They are not secreted into the blood to reach their target cells. Example:
Paracrines
Growth Hormone
____ are a subset of paracrines. These are passed directly from neighboring cells, often through gap junctions. Examples (2)
Juxtacrines
Insulin and Glucagon
____ are primary messenger molecules such as hormones can also act on the cell that produces them.
Autocrines
_____ are signaling molecules produced by the immune system. They can act locally but also can travel in the blood, as immune cells are often found in the blood
Cytokines
Norepinephrine is a _____ when it is released by neurons, a _____ when secreted into the blood by the adrenal medulla and a _____ when released by immune cells.
neurotransmitter, hormone, cytokine
Estrogen is a hormone produced by the ovary, an _____ hormone that stimulates the function of the ovarian cells that produce it, and a _____ when it alters neuron function.
autocrine, neuromodulator
A cell can respond to multiple _____ molecules at the same time. Each may alter the level of a different second messenger molecule or they may work together to alter the level of the same second messenger molecule.
primary messenger
The physiological responses a cell exhibits will depend on the balance of _____ molecules within it at any given moment.
second messenger
Constant communication between the these three systems. Each modifies the functions of the others
Endocrine
Nervous
Immune
The three systems produce the same ______ which act through the same _____ systems, thus they are all constantly in communication with each other. All 3 systems are ____
primary messengers, secondary messenger
sensory
Anger with hope/will to live (FIGHT):
Amygdaloid Central Nucleus→Hypothalamus→SNS→_______
lAdrenal Medulla Norepinephrine
Fear (FLIGHT):
Amygdaloid Central Nucleus→Hypothalamus→SNS→_______
Adrenal Medulla Epinephrine
Give up (DESPAIR): Hippocampus→Hypothalamus→CRH →Anterior Pituitary→ACTH→\_\_\_\_\_
Adrenal Cortex Cortisol
Excessive cortisol strongly suppresses ______ can also cause: (5)
the immune system
- osteoporosis
- hypertension
- atherosclerosis
- DM
- muscle wastage
Variable Homeostasis examples (3)
- Temperature
- Blood glucose
- Blood flow
____ is the optimal level of variable
Set Point
_____ convey the information from the sensors to the integrating center. Transfers information to integrating center
Afferent Pathways
_____ contains the set point. Receives information about the variable and other relevant variables from many different sensors. Compares the level of the variable to the ideal level and activates effectors to change the variable Integrating Center
Integrating Center
_____ carry information from the integrating center to the effectors
Efferent Pathways
____ are cells that act to change the variable (muscle, secretory cells, immune cells, endocrine cells, etc.)
Effectors
Only a few physiological variables (a.k.a. parameters) do not change their set points. True homeostatic variables include (3)
- pH
- osmotic pressure
- ion concentrations of Ca²⁺, Na⁺, K⁺
Consequently, the ____ can not afford to allow its set point to vary
nervous system
_____ is the maintenance of an ideal internal environment. _____ of the body is response to the environment
Homeodynamics, Coordination
_____: Loss of ability to respond to a changing environment
Theory of Aging
Homeodynamics difference from homeostasis: The SET POINT _____
_____ is the set point of the moment in response to all internal and external conditions influencing the body
changes (not a constant environment)
Settling Point
Variables that change set points constantly: (6)
- hormone levels
- nutrient levels
- blood pressure
- heart rate
- respiratory rate
- glomerular filtration rate
Variables that change set points with circadian rhythms: (2)
Temperature
hormone levels
Variables that change in response to pathological conditions (to help body cope with the pathology): (3)
- temperature,
- hormone levels
- cytokines etc.
Variables that change in response to reproductive state: (5)
- Temperature
- hormone levels
- cytokines
- CO2 level
- glucose etc.
Homeostatic/homeodynamic mechanisms can contain all elements within a _____
Example:
single cell
Beta cell of pancreas - measures blood glucose levels and secretes Insulin to lower blood glucose levels when blood glucose levels get too high
Homeostatic/homeodynamic mechanisms can involve the _____
Example: response to major stress _____
entire body
“fight or flight response”
Homeostatic/homeodynamic mechanisms can involve several _____ or _____
organs, cell types
The _____ is a major site of hormone destruction. Failure can lead to an increased half life of _____–> increased action
liver, steroid hormones
_____ proteins protect enzyme from destruction and excretion
Carrier
____ proteins prevent the action of the hormones
Inhibitory binding
____ prevent the action of hormones
Antibodies