Homeostasis Flashcards
Themes in physio
- structure and functions are closely related
- living organisms need E
- info flow coordinates body function
- homeostasis maintains internal stasis
Homeostatis helps maintain:
- temp
- pH
- glucose levels
- calcium levels
- osmolarity
- b.p.
- protein conformation
- optimal enzyme function
Def of homeostasis:
maintenance of stable internal environment within healthy range despite change to outside environment
2 major control systems:
- nervous system
- endocrine system
Basic components needed for nervous and endocrine system:
- sensors
- controllers
- effectors
Functions of sensors:
- monitor regulated variables (pH/temp)
- compares level to set point
- sends signal to controller
Functions of controllers:
- CNS or endocrine gland
- responds to receptor signal
- sends message to effectors to return toward homeostasis
Functions of effectors:
- muscles, glands, specialized cells
- responds to signals from controller
- corrects imbalances / adj body function to meet current needs
Nervous system:
- sends signal via nerves
- transmitted by electrical impulses
- neurotransmitters send chem signal via synapse
- fast response
- local response
- short term regulation
Endocrine system:
- sends signal via hormones
- transmitted by hormones from endocrine glands
- hormones sent via blood from effector organs
- slow response
- widespread effect
- long term regulation
Negative feedback:
- most common
- controllers stimulate effectors to return to normal
- example: blood sugar regulation
Positive feedback:
- controllers move system farther from set point
- example: contractions during child birth
Levels of control:
- cellular: DNA to RNA to proteins
- local (small area): cell factors, paracrine reactions
- systemic (large area): CNS, endocrine
levels of organization from smallest to largest?
atoms, organism, molecules, cells, tissues, organs, organelles, organ system
- atoms
- molecules
- organelles
- cells
- tissues
- organs
- organ system
- organism
Cells are the _____ of life
basic unit
Cells have:
- cellular membrane
- sub-cellular structures
- membrane-bound organelles
- water
- macromolecules
Examples of macromolecules:
- carbs
- proteins
- fats
- nucleic acids
T/F: carbohydrates are the main E storage molecules
T
Proteins are used for…
specificity and structure
T/F: fats are not barriers for water soluble molecules
F, they are barriers and are non H2O soluble
Nucleic acids help with ______
encoding of genetic info
Tissues are groups of similar ____ working together to do a similar function
cells
Epithelial tissue covers and lines…
all hollow organs
Functions of epithelial tissue:
- protection
- secretion
- absorption
- communication
Connective tissues are located…
between other tissues
Functions of connective tissue:
- connect
- support
Connective tissue are specialized in…
- bone
- tendon
- cartilage
- blood
Muscle tissue is used for…
- movement
- is excitable and contractile
Nerve tissue is used for…
- regulation and communication
- is excitable and conducive
