Chapter 1-Homostasis Flashcards
What is physiology?
The study of how living organisms function and integration of the parts of the body
What are the four general types of tissues?
The four general types of tissues are
(1) muscle tissue
(2) nervous tissue
(3) epithelial tissue
(4) connective tissue
What is physiological genomics?
The integration of molecular biology with physiology.
What is pathophysiology?
Physiology of disease states.
What is the simplest structural unit into which a complex multicellular organism can be divided?
Cells
What is the process of transforming an unspecialized cell into a specialized cell?
Cell Differentiation
What do differentiated cells with similar properties aggregate to form?
Tissues
What are the four types of generalized tissues?
(1) muscle tissue, (2) nervous tissue, (3) epithelial tissue, and (4) connective tissue
What structure does different types of tissues form?
Organs
What do different organs together form?
Organ systems
What does skeletal muscle do?
Skeletal muscle are attached through tendons and ligaments to bones and produce movement.
What is the skeletal muscle controlled by?
The voluntary nervous system
Where’s cardiac muscle found?
The heart
Where’s smooth muscle found?
In many tubes of the body such as the blood vessels and gastrointestinal tract.
What are cells?
Cells are the simplest structural units into which a complex organism can be divided and still retain the functions characteristic of life.
What are tissues?
Specialized cells that associate with similar cells to form tissues.
What are organs?
Two or more of the four kinds of tissues arranged in various proportions and patterns.
What is an organ system?
A collection of organs that together perform an overall function
What’s extracellular fluid?
The fluid present in the blood and in the spaces surrounding cells. The total volume of extracellular fluid is the sum of the plasma and interstitial fluid.
What is interstitial fluid?
Extracellular fluid which lies around and between cells.
What’s plasma?
Plasma is the fluid portion of the blood in which the various blood cells are suspended.
What’s the interstitium?
The space containing interstitial fluid
What is intercellular fluid?
The fluid inside cells
What’s compartmentalization?
It’s barriers between compartments that determine which substances can move between them
What’s homeostasis?
It’s a state of dynamic constancy in which a given variable may vary in the short term but is stable and predictable when averaged over the long term.
How are homeostatic responses mediated?
The compensating mechanisms that mediate such responses are performed by homeostatic control systems.
What’s a steady state?
A system in a steady state in which a particular variable is not changing but in which energy must be added continuously to maintain a constant condition
What’s equilibrium?
A state where a particular variable is not changing and no input of energy is required to maintain consistency
What’s a set point?
Operating point
What’s negative feedback?
An increase or decrease of the variable being regulated brings about responses that tend to move the variable in the direction opposite or negative to the original change
What’s positive feedback?
Acceleration of a process that leads to an explosive system. Less common than negative feedback.
Can set points change?
Set points for many regulated variables can be physchologically reset to a new value.
How are parameters controlled?
Multiple systems usually control a single parameter which permits regulation to occur even when one of the systems is not functioning properly because of disease.
What’s Feedforward regulation?
Feedforward regulation anticipates changes in regulated variables and improves the speed of the body’s homeostatic responses and minimizes the amount of deviation from the set point.
What’s a reflex?
A specific involuntary, unpremeditated, unlearned built in response to a particular stimulus
What are learned or acquired reflexes?
Motions that are in large part automatic, stereotyped, and unpremeditated because a lot of conscious effort was spent learning them.
What’s a reflex arc?
The pathway mediating a reflex.
What’s a stimulus?
A detectable change in the internal or external environment
What’s a receptor?
The receptor detects environmental change when a stimulus acts upon it
What’s the integrating center?
The integrating center interprets the signal that is relayed from the receptor
What’s an afferent pathway?
I’m the pathway between the receptor and the integrating center
What’s an effector?
The output from the integrating center is sent to the effector which is the last component in the system whose change in activity constitutes the response of the system
What’s the efferent pathway?
The pathway that the command to change activity travels from the integrating center to the effector
What’s a hormone?
A type of chemical receptor that is secreted into the blood on by cells of the endocrine system
What are local homeostatic responses?
Responses initiated by change in the external or internal environment and they induce an alteration of cell activity with the net effect of counteracting t the stimulus that occurs only in the area of the stimulus
What are intercellular chemical messengers?
There are three categories of chemical messengers: hormones, neurotransmitters, and paracrine or autocrine substances
What’s a hormone ‘s function?
A messenger that helps the endocrine cell communicate with its target cells with the blood acting as a delivery system
What are neurotransmitters?
Chemical messengers that are released from the endings of neurons onto other neurons, muscle cells, or gland cells.
What are paracrine substances?
Messengers synthesized by cells and released once given the appropriate stimulus, into the extracellular fluid and diffuse to neighboring cells
What are autocrine substances?
They are secreted by a cell into the extracellular fluid and then acts upon the cell that secreted it
What’s acclimatization?
The improved functioning of an already existing homeostatic system. They are usually reversible. Unless it is induced very early in life it can be developmental acclimatization and may not be reversed
What’s a circadian rhythm?
A 24 hour cycle of variations in which is a Feedforward system that anticipates waking and sleeping body temperature hormone concentrations in the blood, excretion of ions in the urine, and many other functions undergo circadian variation
What’s entrainment?
Environmental factors provide timing cues that set the hours of the rhythm
What’s a free-running rhythm?
The sleep-wake cycle that persists in the absence of environmental cues.
What’s a phase shift?
Environmental cues that reset the internal clock
How does the body regulate the circadian rhythms?
The pacemaker of the hypothalamus receives input from the eyes and sends out signals to the pineal gland which secretes melonin
How is the balance of the body achieved?
By matching inputs and outputs. Total body balance of a substance may be negative, positive, or stable balance
