Flashcards in BIOL 0800 Reading- Chapter 1 Deck (67):
What is physiology?
The study of how living organisms function
What is physiological genomics?
The study of the integration of molecular biology with physiology; explains how the changes are produced at the level of the gene by external or internal stimuli
What is the simplest structural unit into which a complex multicellular organism can be divided and still retain the functions characteristic of life?
What is cell differentiation?
The process by which cells transform into specialized cells
What are the four main cell categories?
Muscle, nerve, epithelial, and connective-tissue
What are the three types of muscle cells?
Skeletal, cardiac, and smooth
What are tissues?
Differentiated cells with similar properties aggregated together
What are the four general types of tissues?
Muscle, nervous, epithelial, and connective
What are muscle cells?
Specialized to generate mechanical force, attached through other structures to bones, produce movement, attached to skin; voluntary contraction
What are cardiac muscle cells?
Found only in the heart, generate force to contract the heart and pump blood into circulation; involuntary
What are smooth muscle cells?
Surround many body tubes; contract to decrease the diameter of shorten the length of the tubes; involuntary
What is a neuron?
Specialized to initiate, integrate, and conduct electrical signals to other cells
What provides the major means of controlling the activities of other cells?
What is a nerve?
An extension of neurons packaged in connective tissue to carry signals to the body
What are epithelial cells?
Specialized for the selective secretion and absorption of ions and organic molecules and for protection; named according to shape
What are the four main shapes of epithelial cells?
Cuboidal, columnar, squamous, and ciliated
What kind of epithelium lines the inner surface of the trachea?
Ciliated to help mucus into the trachea and mouth
What do basolateral and apical mean?
The sides of cells anchored to the basement membrane or facing the interior (lumen), respectively
What is one defining feature of the two sides of all epithelial cells?
Both sides often are responsible for different functions
What kind of junction holds together epithelial cells?
Tight junctions to form boundaries between body compartments and to function as selective barriers to regulate the exchange of molecules
Why are epithelial cells connected by tight junctions along their lateral surfaces?
To form boundaries between body compartments and to function as selective barriers to regulate the exchange of molecules
Give an example of the differentiated functions of the basolateral and apical membranes of kidney tubule cells.
Basolateral side: transport glucose out of the cell and into the bloodstream; Apical side: transport glucose into the epithelial cell itself for energy
What are connective-tissue cells?
Connect, anchor, and support the structure of the body
What is the difference between loose and dense connective tissue?
Loose comprises the meshwork of cells and fibers underlying epithelial layers; dense is tough/rigid to comprise tendons and ligaments
What are the four types of connective tissue?
Bone, cartilage, adipose, and blood
What is the function of the extracellular matrix?
Connective tissue; surrounded each cell; provides scaffold for cellular attachments, and transmits into through chemical messengers to help regulate activity/migration/growth/differentiation
What are the proteins of the ECM?
Fibers: collaged and elastin (rope and elastic esque)
What percentage of the extracellular fluid is plasma?
What is plasma?
The fluid portion of blood
What percentage of the extracellular fluid is interstitial fluid?
What is interstitial fluid?
Fluid that lies around and between cells
What is the interstitium?
The space containing interstitial fluid
What is the comparison of the concentration of dissolved substances in the plasma and interstitial fluid? Why??
Essentially the same, because as the blood flows through small vessels, it exchanges substances with the interstitial fluid, except for proteins
Where is the concentration of proteins higher, the plasma or interstitial fluid?
In the plasma
Where is the concentration of proteins higher, the extracellular fluid or the intracellular fluid?
Intracellular: this concentration imbalance is useful for transporting materials in and out of the cell; also regulates growth, metabolism, etc.
What fluid possesses most of the body's water? Plasma, interstitial, and intracellular?
Intracellular (approximately 2/3)
How is compartmentalization achieved?
By barriers between compartments, the properties of which determine selective permeability
Is homeostasis dynamic or static? List an example.
dynamic constancy: temperature fluctuations based on time of day, blood glucose levels
What are homeostatic control systems?
The compensating mechanisms that mediate responses of the body to reach homeostasis
What is a steady state?
A system in which a particular variable is not changing but in which energy must be continually added to maintain a constant condition
How does steady state differ from equilibrium?
Equilibrium requires no input of energy to maintain a constant condition
Does the thermoregulatory system exhibit positive or negative feedback?
Negative: an increase of decrease in the variable regulated brings about responses that move the variable in the opposite direction
Which is more common, positive or negative feedback?
What is a set point?
The operative point; the steady-state, where it's "supposed" to be
How does fever relate to set point and homeostasis?
When you're sick, your body sets the set point for the temperature higher to prevent infection proliferation
What does the term "clashing demands" refer to in regards to homeostasis?
That homeostasis brought about for one variable might be achieved only by moving others away from their set points
What is feedforward regulation?
A regulation system that anticipates changes in regulated variables such as internal body temperature of energy availability, improves the speed of the body's homeostatic responses, and minimizes fluctuations in the level of the variable being regulated (reduces amount of deviation from set point)
Give two examples of feedforward regulation.
Smelling food preps the digestive system for digestion; feeling cold on the outside preps the inside sensors to warm up in preparation for cold
Does feedforward always occur from external or internal environmental detectors?
Nope: learning! Like increased heart rate before a race.
What is a reflex arc?
The pathway mediating a reflex: a stimulus is detected by a receptor and acts upon it to produce a signal relayed to the integrating center, traveling along the afferent pathway, which is then sent as a net effect of total afferent input to the effector along the efferent pathway
What are afferent and efferent pathways?
The afferent pathway is the path along which the stimulus's message is sent to the integrating center, and the efferent pathway is the path along which the final message (a combined net effect of different stimulus inputs) is passed on to the effector
Do all stimulus-effector reflex arcs use negative feedback?
No: smelling food does prep the stomach for digestion, but it doesn't eliminate or decrease food smells
Which two tissues are the major effectors of biological control systems?
Muscle and gland
What is the most common effector of a gland tissue?
Give an example of a cell acting as both a receptor and an integrating center.
Gland cells that secrete insulin: act as an integrating center by secreting insulin during low blood glucose levels, but also act as a receptor by detecting low blood glucose levels
Give an example of a local homeostatic response.
Very metabolically active cells secrete substance to the interstitial fluid that widens local blood vessels to increase the rate at which nutrients are delivered and waste is removed
How do hormones and neurotransmitters differ?
Hormones are secreted by endocrine glands into the blood to reach specific target cells, whereas neurotransmitters are secreted from the end of a neuron to a neuron/muscle cell/gland cell and is not released into the blood
What are paracrine substances?
Chemical messengers involved in local communication between cells; synthesized and released by cells, given the appropriate stimulus, and diffuse into neighboring cells; often quickly inactivated by neighboring enzymes to avoid diffusion into the bloodstream
What are the three methods of transportation of chemical agents for hormones, neurotransmitters, and paracrine substances?
Through blood stream to target cells, across synapse to neuron/muscle/gland cell, and diffusion into neighboring cells and deactivation by enzymes
Can stimuli for the release of paracrine or autocrine substances affect neurotransmitters and hormones negatively?
Yes: consider norepinephrine in the kidneys: as a neurotransmitters, it constricts blood vessels, but also causes other kidney cells to secret paracrine substance that cause the same vessels to dilate: the paracrine substances keep the norepinephrine from acting too strongly
What are two non-chemical-messengers-in-ECF methods of intercellular communication?
Gap junctions (substance move through connecting cytosol) and juxtacrine signaling (chemical messengers are in the cell membrane and allows linking up with another cell)
What is the difference between adaptation and acclimatization?
And adaptation is a favorable characteristic, but acclimatization is the improved functioning of an already existing homeostatic system
What is a developmental acclimatization?
Irreversible because it occurred during a critical period, like barrel-chestedness in Andes Mountain dwellers
What do biological rhythms have to do with homeostasis?
Add an anticipatory component, a feedforward without detectors
What is the pacemaker of the body?
The suprachiasmatic nucleus in the hypothalamus
How does the suprachiasmatic nucelus of the hypothalamus function?
Sends output to the pineal gland in the brain to secrete melatonin