IOS255 Comprehensive Exam Review Already Graded
A
Homeostasis - ANSWER>>* Presence of stable internal environment
* Failure to maintain homeostasis leads to illness or death
Homeostatic Regulation - ANSWER>>Physiological adjustment to preserve
homeostasis in variable environments
...
BIOS255 Comprehensive Exam Review Already Graded
A
Homeostasis - ANSWER>>* Presence of stable internal environment
* Failure to maintain homeostasis leads to illness or death
Homeostatic Regulation - ANSWER>>Physiological adjustment to preserve
homeostasis in variable environments
Feedback - ANSWER>>Stimulation 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 - ANSWER>>Temperature receptors in skin & brain are
stimulated & send signals to the control center
Negative Feedback Control Center - ANSWER>>The temperature control center
received information from the two sets of temperature receptors & sends commands to
the effectors
Negative Feedback Effectors - ANSWER>>Sweat 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 - ANSWER>>1. 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
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 - ANSWER>>Epithelial 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 - ANSWER>>1. Specialized cells
2. Extracellular protein fibers
3. Fluid called ground substance
Extracellular Protein Fibers - Reticular Fibers - ANSWER>>Strong & form branching
network
Extracellular Protein Fibers - Collagen Fibers - ANSWER>>Thick, very strong
Extracellular Protein Fibers - Elastic Fibers - ANSWER>>Slender, 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)
* Avascular
, Osseous Tissue (Bone Tissue) - ANSWER>>* Connective tissue with solid, crystalline
matrix
*Small volume of ground substance
* 2/3 of matrix is calcium salts (provide strength)
*Mostly calcium phosphate
* Some calcium carbonate
* Many collagen fibers (provide flexibility)
* Strong, somewhat flexible, resistane to shattering
Muscle Tissue - ANSWER>>* Specialized for contraction to cause movement
* Movement of the body
* Movement of blood around the cardiovascular system
* Movement of materials along the digestive tract
The Epidermis is Composed of Strata (layers) - ANSWER>>* Primary cell type in
epidermis is keratinocyte=produce keratin
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller winniewaweru. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $13.99. You're not tied to anything after your purchase.