Physiology- Exam A-chapter1 – Flashcards
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(T/F) The final equilibrium state reached by a molecule that enters a cell by facilitated diffusion is the same as that for a molecule that enters the cell by diffusion.
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True
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At any given time it is possible to see endocytotic vesicles docked to intracellular organelles such as those which may receive their contents for modification, synthesis, packaging, and then release. Which organelle would be most likely to be involved in this process as a destination for a transport vesicle formed for this purpose along the plasma membrane?
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Golgi apparatus
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The component of the plasma membrane that acts as a selective barrier to diffusion of polar molecules is the integral proteins.
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False
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What process lowers blood plasma levels of cholesterol-containing lipoproteins?
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clathrin-dependent, receptor-mediated endocytosis
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What is the best description of a secondary active transport process that cotransports an amino acid with Na+?
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Both Na+ and the amino acid bind on the side of the membrane where the Na+ concentration is higher, and both are transported to the side of the membrane where the Na+ concentration is lower.
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Which of the following statements regarding the diffusion of a nonpolar solute X across a cell membrane is correct?
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At equilibrium the net flux of X across the cell membrane is zero.
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Which of the following statements about epithelial cells and epithelial transport is NOT correct?
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The plasma membrane of epithelial cells that faces the inside of a hollow or fluid-filled chamber in the body is called the basolateral membrane.
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Active transport, facilitated diffusion and osmosis all directly require the expenditure of metabolic energy.
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False
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Which of the following statements about the Na+-K+ ATPase pump is false?
a) It transports Na+ and K+ in a 1:1 ratio.
b)Its activity requires the expenditure of metabolic energy.
c) It is constantly active in all cells.
d) It binds to, and hydrolyzes, ATP.
e) It transports Na+ out of cells and K+ into cells.
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It transports Na+ and K+ in a 1:1 ratio.
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In active transport, the affinity of any given binding site for the molecule to be transported changes as the site goes from facing one side of the membrane to facing the other side.
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True
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cell
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simplest unit of a multicellular unit that can be divided and retain functions characteristic of life
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cell differentiation
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process of transforming an unspecialized cell into a specialized cell
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4 types of cells:
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muscle, connective-tissue, epithelial, neurons
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3 muscle types
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cardiac, smooth, skeletal
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differentiated cells with similar properties aggregate to form these:
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tissues
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____ combine to form ____, which work together to form____.
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tissues, organs, organ systems
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_____ are specialized to generate force
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muscles
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skeletal muscle
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1) attached through structures to bone to produce movement of limbs and trunks
2) voluntary control
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cardiac muscle and smooth muscle both have____ control
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involuntary
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cardiac muscle
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heart
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smooth muscle
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surrounds tubes in our bodies
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neuron
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1) specialized to integrate, and conduct electrical signals in other neurons, stimulate a gland and secrete substances or a muscle to contract
2) control activity of other cells
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nerves
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Carries signals from many neurons between the nervous system and other parts of the body
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epithelial cells
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specialized for selective secretion and absorption of ions and organic molecules, and for protection
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connective-tissue cells
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1) connect, anchor, and support the structures of the body
2) bone, cartilage, adipose (fat-storing) tissue
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connective tissue for the _____
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ECM- extracellular matrix
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2 functions of the ECM
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1) provide a scaffold for cellular attachments
2) transmits info in the form of chemical messengers to the cells to help regulate their activity, migration, growth, and differentiation
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internal environment
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fluids that surround cells and exist in the blood
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Body compartments
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intracellular fluid + extracellular fluid
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intracellular fluid
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1) fluid contained within the cells of the body
2) 67% of fluid in the body
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extracellular fluid
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1) fluid in the blood and in the spaces surrounding the cells
2) 20-25% = plasma
3) 75-80% = interstitial fluid- lies around + in between cells
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Homeostasis
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complex, dynamic process that regulates the adaptive responses of the body to changes in external/internal environment
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Feedback systems
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feedback systems and feedforward regulation
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negative feedback
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move variable towards original value; opposite of direction of original change
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positive feedback
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accelerates a process
ex. childbirth
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feedforward regulation
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anticipates changes in regulated variables such as internal body temperature or energy availability, improves the speed of the body's homeostatic responses and minimizes fluctuations in the level of the variable being regulated (reduces deviation from the set point)
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reflex
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-specific, involuntary, unpremeditated, "built-in" response to a particular stimuli
-learned or acquired
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reflex arc
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pathway mediating a reflex
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stimulus
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detectable change in the external/internal environment
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receptor
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detects environmental change
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afferent pathway
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"carry to" intergrating center
stimulus->receptor-> Intergrating center
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efferent pathway
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"carry away" from the intergrating center
intergrating center-> effector-> response
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local homeostatic responses
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initiated by a change in external/internal environment and induces an alteration of cell activity w/ net effect of counteracting the stimulus
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hormone
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type of chemical messenger secreted into the blood by cells of the endocrine system
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chemical messengers
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hormones, neurotransmitters, and paracrine and autocrine substances
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What describes a homeostatic control system
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when blood glucose becomes elevated above normal, hormones are released that cause glucose uptake from the blood into the cells
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neurons function to:
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-signal a muscle to contract
-stimulate a gland
-conduct impulses
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Which 3 include epithelial cells as part of their structure
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-airways
-skin
-intestines
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_____ _______ is a term used to describe the compartment of the body containing fluid that surrounds all cells; this compartment is regulated by homeostatic control systems to allow the survival of cells
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internal environment
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what is the term for a specific, involuntary, unpremeditated, response to a particular stimuli
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reflex
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apical side
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the region of an epithelial cell's membrane that faces away from the interstitial fluid
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basolateral side
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the region of an epithelial cell's membrane that faces the interstitial fluid
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The extracellular matrix is composed by _____ and its functions are to
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connective tissue... provide a scaffold for cellular attachments and transmit information in the form of chemical messengers between cells
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what are the components of the extracellular matrix
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-proteins
-polysaccharides
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In which of the following does a change in a variable activate a reflex that increases the change in that variable
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positive feedback loop
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Anatomical structure is a determinant of the structure's_____.
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function
