lecture 1 Flashcards
is homeostasis equilibrium?
no! homeostasis is a dynamic steady state
negative feedback system
the feedback reduces the initial stimulus to regain homeostasis
positive feedback system
the feedback enhances the stimulus and moves the system away from homeostasis
example of a positive feedback loop
(labour)
stimulus= baby drops, presses on cervix
sensor= stretch receptors in cervix
integrating center= brain releases oxytocin
effector= smooth muscles of the uterus
response= increased contractions
feedforward control
initiation of a response in anticipation of the stimulus
example of feedforward control
salivating at the thought or smell of food
increased ventilation at the beginning of exercise
name the 10 systems
- circulatory
- digestive
- endocrine
- immune
- integumentary
- musculoskeletal
- nervous
- reproductive
- respiratory
- urinary
circulatory system (structures and function)
structures= heart, blood vessels, blood
transports material between cells of the body
digestive system
structures= stomach, intestine, liver, pancreas
conversion of food into particles that can be transported into the body, elimination of wastes
endocrine system
structures= thyroid gland, adrenal gland
coordination of body function through synthesis and release of regulatory mechanisms
immune system
structures= thymus, spleen, lymph nodes
defense against foreign invaders
integumentary system
structures= skin
protection from external environment
musculoskeletal system
structures= skeletal muscles, bone
support and movement
nervous system
structures= brain, spinal cord
coordination of body function through electrical signals and release of regulatory molecules
reproductive system
structures= ovaries, uterus, testes
perpetuation of the species
respiratory system
structures= lungs, airways
exchange of oxygen and carbon dioxide between the internal and external environment
urinary system
structures= kidneys, bladder
maintenance of water and solutes in the internal environment, removal of waste
lumen
the interior of hollow organs
cytoplasm
the interior of cells
explain the division of body’s fluid compartments
ICF intracellular fluid (2/3)
ECF extracellular fluid (1/3)
2 components of the ECF
interstitial fluid= between the circulatory system and the cells
blood plasma= the liquid matrix of blood
70kg male (60% water): explain division of liquid in liters
42L total
ECF (1/3)
- plasma 3L
- interstitial fluid 11L
ICF (2/3)
- 28L
