Week 1 Review Flashcards
How does physiology differ from anatomy?
anatomy describes the structure; physiology examines how the structure functions
define tissue
collections or groupings of differentiated cells possessing similar properties plus their extracellular matrix
What are the 4 main types of tissue?
- muscle tissue
- nerve tissue (brain and ganglion)
- epithelial tissue (organ lining)
- connective tissue (blood, bone, tendons, ligaments, fat)
define organ
Group of tissues in a living organism that perform a similar function
define organ system
two or more organs working together in the performance of a specific body function
Define the extracellular matrix. What is its function?
A three-dimensional network of extracellular macromolecules, such as collagen, enzymes, and glycoproteins, that provides structural and biochemical support of surrounding cells. Function depends on the tissue type
What is the primary function of muscle tissue?
- specializes in force production
- cellular components reflect this specialization
What are the 3 types of muscle tissue?
skeletal, cardiac, and smooth
What is the essential characteristic of epithelial tissue?
- rapid repair
- closely packed cells that create a barrier
- 7 different types
What are the primary functions of epithelial tissue?
- creates barrier b/w 2 environments
- provides protection (ex: stratified epithelium protects from radiation, desiccation, and invasion of foreign organisms)
- regulates movement of molecules b/w fluid compartments
- secretory function: hormones/glands, sweat, mucous, enzymes
Identify 3 places in the body where you would find epithelial tissue.
- Skin
- Covering of visceral organs
- Linings of body openings, ducts, cavities, and tubes
- Walls of ureters and urinary bladder (Transitional epithelium)
simple squamous epithelium
- single layer of flat, tightly bound cells
- diffusion and filtration
- found in capillary walls, alveoli of lungs, covering visceral organs, lining body cavities
simple cuboidal epithelium
- single layer of cube shaped cells
- excretion, secretion, absorption
- found in surface of ovaries, lining kidney tubules, salivary ducts
simple columnar epithelium
- single layer of non ciliated, tall, column shaped cells
- protection, secretion, absorption
- lines most of the GI tract
simple ciliated columnar epithelium
- single layer of ciliated, column shaped cells
- transportive role thru ciliary motion
- lines uterine tubes
pseudo-stratified ciliated columnar epithelium
- single layer of ciliated, irregular shaped cells (many goblet cells)
- protection, secretion, ciliary movement
- lines respiratory passageways
stratified squamous epithelium (keratinized)
- numerous layers containing keratin
- outer layers flat and dead
- protection
- found in epidermis of skin
stratified squamous epithelium (nonkeratinized)
- numerous layers lacking keratin
- outer layers moist and alive
- protection and pliability
- lines oral and nasal cavities, vagina, and anal canal
stratified cuboidal epithelium
- 2 layers of cube shaped cells
- strengthening of luminal walls
- found in sweat glands, salivary glands, and pancreas
transitional epithelium
- numerous layers of round, nonkeratinized cells
- distention
- found in ureters and bladder
Assume an area of the body is subjected to constant wear. Would you expect this area to be covered by an epithelial layer? If so, why?
Yes, because epithelial tissue can rapidly repair itself when damaged (ex: skin and GI tract)
What is the distinguishing characteristic of connective tissue?
- Very few cells, lots of material in the intracellular space.
- Large amounts of extracellular matrix or CT matrix.
loose (areolar) connective tissue
provides space for the presence of blood vessels, nerve fibers, and other structures (ex: dermis)
dense regular connective tissue
collagen fibers densely packed and oriented parallel, leaving very little room for cells or ground substance (ex: tendons and ligaments)
Dense irregular connective tissue
collagen fibers densely packed, but oriented irregularly, leaving very little room for cells or ground substance (ex: joint capsules, dermis, muscle fascia, fascia around organs)
intracellular fluid compartments
- inside the cell
- contain majority of the body’s fluid
extracellular fluid compartments
- outside the cell
- blood plasma
- tissue fluid aka interstitial fluid
- CSF
- tubular ultrafiltrate (kidney tubules)
- sweat/mucous
Edema results from an increased fluid movement from…
Intracellular compartment to extracellular compartment (ex: spraining your ankle, or swelling in your fingers due to gravity)
define homeostasis using a concrete example
- homeostasis is a physiological function that fluctuates within a predictable and narrow range (dynamic constancy)
- ex: thermoregulation; thermostat keeps house within desirable temp range
Normal serum glucose levels are between 75 and 110 mg/dL. Relate this fact to homeostatic control.
- After eating a meal, carbs are broken down, absorbed across the intestinal epithelium, and released into the blood. Glucose levels then increase, but mechanisms restore it back down to the normal conc.
- Low glucose levels, glucagon brings glucose levels back up
Describe glucose homeostasis over a 24 hour period. How is this pattern maintained? Is maintaining this pattern important, and if so, why?
Glucose levels fluctuate within a narrow range which results in dynamic consistency (diabetes is a pathology of glucose homeostasis)
Define a biological negative feedback mechanism. What does that mechanism control and how does it achieve that control?
- An increase or decrease in the variable being regulated brings about responses that tend to move the variable in the direction opposite (negative to) of the direction of the original change
- This mechanism controls homeostasis by attempting to reverse the initial change
Explain what a positive feedback mechanism is.
A self-amplifying cycle in which one change leads to even more significant changes in the same direction
Explain why clotting is a positive feedback loop.
- When there is a break/tear in a blood vessel, the body is stimulated and signals are sent to the brain to activate clotting where platelets adhere to the site and release chemicals. These chemicals attract more platelets, clotting proceeds, and the feedback cycle ends after clot seals break.
- Imperfect bc we would not want to have a continuous output of the clotting factors due to it potentially resulting in even greater adverse effects
What is the central or essential difference between a negative and a positive feedback mechanism?
- Negative feedback is a corrective mechanism activated by the body that brings about responses that tend to move the variable in the opposite direction of the original change
- Positive feedback is a way for the body to produce significant changes in a short period of time. Continuous increase in output. Much less common
What is the relative distribution of fluids between intracellular and extracellular compartments? Describe the movement of fluids between compartments under conditions of high environmental temperatures.
- In the body, water moves constantly into/out of fluid compartments as conditions change (moves from high to low concentrations)
- Dehydration: fluids move from inside of the cell (intracellular) into the intravascular compartment in order to preserve blood vol.
- The vascular tree then reduces blood flow in the periphery in order to help further preserve that blood vol.
define the basement membrane
Links the epithelial membrane to underlying extracellular matrix
What structures found on the cell surface of tracheal epithelium contribute to the movement of fluids? What happens when these structures become non-functional?
- Cilia are important for sweeping mucus and dust up the bronchi and trachea and takes it to the pharynx where it can be swallowed
- Dysfunction leads to impaired mucus clearance, chest infections, and progressive destruction of lung architecture
Describe the structural interface between the capillaries and the alveoli, what happens at it, and how its structure contributes to physiologic events that occur.
- Simple squamous epithelium allows for gas exchange to occur
- Best for gas exchange due to having the simplest anatomy of all epithelial cells (one flat layer)
What is transitional epithelium? How does the structure/anatomy of this epithelium contribute to the function of the organ where it is found?
- Stratified epithelium that helps accommodate for stretching within the organ tissue
- Cells lie on top of one another when the bladder is empty, and as it fills they stretch out to lay flat
- As fluid pressure increases, the layer of transitional epithelium becomes thinner and allows for the bladder to expand, and then reverts back to its normal size when the pressure decreases
What is fascia? What is meant by “tubular ultrafiltrate”?
- Fascia = dense irregular connective tissue found along with muscles and around organs
- Tubular ultrafiltrate = filtration of blood for reabsorption or excretion in the glomerular capsule of the kidneys
Explain what is meant by “within normal limits”. Relate this notion to a “set point”.
- To stay within an acceptable range.
- Set point refers to “upper and lower” ranges that the physiological value fluctuates within
What is needed to maintain homeostasis in the image of a runner shown in slide 59? What happens when this runner is no longer able to maintain homeostasis?
- Increase in HR, bringing O2 to muscles due to running up inclines
- Increase in respiratory rate in order to maintain O2 and CO2 exchange
- Increases in sweating to bring body temperature down
Explain how vasodilation contributes to maintaining body temperature.
- Vasodilation decreases blood pressure
- Blood then carries heat to the surface of the skin to release it into the air, reducing body temperature
Explain how vasoconstriction contributes to maintaining body temperature.
- Vasoconstriction increases blood pressure
- Retains body heat by directing the blood flow to surround the visceral organs and keep away from the surface of the skin
Explain how orthostatic hypotension represents a failure to maintain homeostasis. (Slide 70)
- Orthostatic hypotension = inability to maintain BP when body changes positions, resulting in low BP
- Lying down → standing up, BP falls (stimulus)
- BP receptors respond (sensor)
- Sensory nerve fibers send signal to medulla oblongata (integration center)
- Response sent through motor nerve fibers to the heart to increase HR (effector)
- Rise in BP (negative feedback response)
What is the difference between the thermoregulatory challenge caused by a fever and by engaging in exercise?
- With a fever, normal thermoregulation is defective bc the set point of the hypothalamus is changed by molecules released by infectious agents
- Why we rapidly go from sweating to shivering
- If set point is elevated, body begins to sweat
- If set point is decreased, body begins to shiver
What is meant by physiologic reserve? What happens to that reserve as we age? How do you think these changes impact the practice of physical therapy?
- Physiologic reserve is the excess physiologic capacity in organs and biological systems
- Gives us a “cushion” to keep us safe and help counter AEs of diseases or injury
- As we age, the reserve tends to decrease over time as cell numbers and cell functions decline
- Since older individuals have less reserve, it makes it more difficult for them to counteract the effects of their disease/injury as compared to younger individuals
A decrease in mean arterial pressure is detected by A. an effector. B. an integrating center. C. a sensor. D. a chemical messenger.
C. a sensor
Homeostasis is best thought of as being a state of A. constant fluctuation. B. stasis. C. dynamic constancy. D. inconsistency
C. dynamic constancy.
Which of the following is NOT a primary tissue of the body? A. nervous B. epithelium C. muscular D. osseous
D. osseous
Membranes are formed by \_\_\_\_\_\_ tissue. A. nervous B. muscular C. neuroglial D. epithelial
D. epithelial
Cells that are as wide as they are tall have a(n) \_\_\_\_\_\_\_\_\_\_\_\_ shape. A. squamous B. cuboidal C. columnar D. rectangular
B. cuboidal
The \_\_\_\_\_\_\_\_\_\_\_\_ is a protein and polysaccharide layer that attaches epithelial tissue to the underlying connective tissue. A. goblet cell B. epidermis C. basement membrane D. plasma membrane
C. basement membrane
The primary structural protein of basement membranes is A. keratin. B. collagen C. melanin. D. myosin.
B. collagen
Which of the following is a function of simple squamous epithelium? A. protection B. diffusion C. distention D. transport through ciliary action
B. diffusion
What feature is the main characteristic of connective tissue?
A. large amount of closely packed cells
B. large amount of extracellular material
C. the ability to conduct a current
D. small amount of extracellular material
B. large amount of extracellular material
What protein is present in large amounts in connective tissue? A. collagen B. keratin C. enamel D. mucin
A. collagen
The main body compartment that is inside cells is the \_\_\_\_ compartment. A. extracellular B. interstitial C. intercellular D. intracellular
D. intracellular
Which of the following is NOT true of the extracellular fluid compartment?
A. It is made up of blood plasma and interstitial fluid.
B. Its volume is regulated by the kidneys.
C. It makes up 65% of the total body water.
D. All are true.
C. It makes up 65% of the total body water.
