BIOS255 COMPREHENSIVE EXAM
REVIEW COMPLETELY SOLVED!!
Homeostasis - ANSWER* Presence of stable internal environment
* Failure to maintain homeostasis leads to illness or death
Homeostatic Regulation - ANSWERPhysiological adjustment to preserve homeostasis
in variable environments
Feedback - ANSWERStimulation of a receptor triggers response that changes
environment at that receptor
Negative Feedback - ANSWER* Effector opposes or negates the original stimulus
* Minimizes change
* Primary mechanism of homeostatic regulation in the body
* Dynamic process: Set point varies with varying environments & activity levels
Negative Feedback Receptors - ANSWERTemperature receptors in skin & brain are
stimulated & send signals to the control center
Negative Feedback Control Center - ANSWERThe temperature control center received
information from the two sets of temperature receptors & sends commands to the
effectors
Negative Feedback Effectors - ANSWERSweat glands & smooth muscle in the walls of
blood vessels supplying the skin respond
Positive Feedback - ANSWER* Stimulus produces a response that exaggerates or
enhances the original change (rather than opposing it)
* Tends to produce extreme responses
* Does not restore homeostasis
Positive Feedback Loop - ANSWER* Escalating cycle
* Typically occurs when a potentially dangerous or stressful process must be completed
quickly before the body can restore homeostasis
Steps of Positive Feedback in Blood Clotting - ANSWER1. Damage to cells in the blood
vessel wall releases chemicals that begin the process of blood clotting
2. The chemicals start chain reactions in which cells, cell fragments, & soluble proteins
in the blood begin to form a clot
3. As clotting continues, each step releases chemicals that further accelerate the
process
4. This escalating process is a positive feedback loop that ends with the formation of a
blood clot, which patches the vessel wall & stops the bleeding
, Epithelial Tissue - ANSWER* Epithelia
* Glands (Exocrine & Endocrine)
Functions of Epithelial Tissue - ANSWER* Provide physical protection
* Control permeability
* Provide sensation
* Produce specialized secretions
Characteristic of Epithelial Tissue - ANSWER* Specialized contacts with other cells
* Polarity (different ends of cell do different things)
* Avascularity (NO blood supply)
* Regeneration (can divide to make new cells)
* Cellularity (lots of cells in close contact)
Characteristics of Epithelial Tissue: Specialized Contacts - ANSWEREpithelial cells are
held close together by cell junctions
Features of Epithelial Tissue - ANSWER* Surfaces: Apical surface-Faces exterior of
body or internal space; Base- Attached to underlying tissues
* Polarity: Refers to structural differences between exposed & attached surfaces
Connective tissue overview - ANSWER* Varies widely in appearance & function (Found
throughout the body, but never exposed to surface)
* Ranges from highly vascular to avascular
* Many contain sensory receptors that detect pain, pressure, temperature, & other
stimuli
3 basic components shared by connective tissues - ANSWER1. Specialized cells
2. Extracellular protein fibers
3. Fluid called ground substance
Extracellular Protein Fibers - Reticular Fibers - ANSWERStrong & form branching
network
Extracellular Protein Fibers - Collagen Fibers - ANSWERThick, very strong
Extracellular Protein Fibers - Elastic Fibers - ANSWERSlender, very stretchy
Connective Tissue Ground Substance - ANSWER* Clear & colorless
* Viscous (syrupy) due to presence of proteoglycans & glycoproteins
* Allows substances to travel between blood capillaries & cells
Cartilage overview - ANSWER* Matrix is a firm gel containing chondroitin sulfates
(cartilage), polysaccharide dervatives
* Only 1 type of cell (chondrocyte)
REVIEW COMPLETELY SOLVED!!
Homeostasis - ANSWER* Presence of stable internal environment
* Failure to maintain homeostasis leads to illness or death
Homeostatic Regulation - ANSWERPhysiological adjustment to preserve homeostasis
in variable environments
Feedback - ANSWERStimulation of a receptor triggers response that changes
environment at that receptor
Negative Feedback - ANSWER* Effector opposes or negates the original stimulus
* Minimizes change
* Primary mechanism of homeostatic regulation in the body
* Dynamic process: Set point varies with varying environments & activity levels
Negative Feedback Receptors - ANSWERTemperature receptors in skin & brain are
stimulated & send signals to the control center
Negative Feedback Control Center - ANSWERThe temperature control center received
information from the two sets of temperature receptors & sends commands to the
effectors
Negative Feedback Effectors - ANSWERSweat glands & smooth muscle in the walls of
blood vessels supplying the skin respond
Positive Feedback - ANSWER* Stimulus produces a response that exaggerates or
enhances the original change (rather than opposing it)
* Tends to produce extreme responses
* Does not restore homeostasis
Positive Feedback Loop - ANSWER* Escalating cycle
* Typically occurs when a potentially dangerous or stressful process must be completed
quickly before the body can restore homeostasis
Steps of Positive Feedback in Blood Clotting - ANSWER1. Damage to cells in the blood
vessel wall releases chemicals that begin the process of blood clotting
2. The chemicals start chain reactions in which cells, cell fragments, & soluble proteins
in the blood begin to form a clot
3. As clotting continues, each step releases chemicals that further accelerate the
process
4. This escalating process is a positive feedback loop that ends with the formation of a
blood clot, which patches the vessel wall & stops the bleeding
, Epithelial Tissue - ANSWER* Epithelia
* Glands (Exocrine & Endocrine)
Functions of Epithelial Tissue - ANSWER* Provide physical protection
* Control permeability
* Provide sensation
* Produce specialized secretions
Characteristic of Epithelial Tissue - ANSWER* Specialized contacts with other cells
* Polarity (different ends of cell do different things)
* Avascularity (NO blood supply)
* Regeneration (can divide to make new cells)
* Cellularity (lots of cells in close contact)
Characteristics of Epithelial Tissue: Specialized Contacts - ANSWEREpithelial cells are
held close together by cell junctions
Features of Epithelial Tissue - ANSWER* Surfaces: Apical surface-Faces exterior of
body or internal space; Base- Attached to underlying tissues
* Polarity: Refers to structural differences between exposed & attached surfaces
Connective tissue overview - ANSWER* Varies widely in appearance & function (Found
throughout the body, but never exposed to surface)
* Ranges from highly vascular to avascular
* Many contain sensory receptors that detect pain, pressure, temperature, & other
stimuli
3 basic components shared by connective tissues - ANSWER1. Specialized cells
2. Extracellular protein fibers
3. Fluid called ground substance
Extracellular Protein Fibers - Reticular Fibers - ANSWERStrong & form branching
network
Extracellular Protein Fibers - Collagen Fibers - ANSWERThick, very strong
Extracellular Protein Fibers - Elastic Fibers - ANSWERSlender, very stretchy
Connective Tissue Ground Substance - ANSWER* Clear & colorless
* Viscous (syrupy) due to presence of proteoglycans & glycoproteins
* Allows substances to travel between blood capillaries & cells
Cartilage overview - ANSWER* Matrix is a firm gel containing chondroitin sulfates
(cartilage), polysaccharide dervatives
* Only 1 type of cell (chondrocyte)
