Introduction to General Physiology Flashcards
study of the biological functions of organs and their interrelationships
physiology
what does physiology study
interplay of factors that affect growth (connectedness)
Physiological difference between plants and animals:
Plants
- mostly producers
- unlimited scheme of growth
- non-motile. Must rely on immediate nutrient source
- use large amounts of CO2
- conserve nitrogen
- transport fluids/flood through vascular tissues
- grow throughout their lifetime
Physiological difference between plants and animals:
Anima
- consumers
- limited scheme of growth
- motile
- give off CO2
- gives of nitrogen as waste
- transport food via bloodstream
- reach a certain age and growth more or less stops
Father of modern physiology
Claude Bernard (1813-1878)
What did Claude Bernard observe
internal environment remains remarkably constant despite changing conditions in the external environment
in 1932, he coined the term homeostasis to describe this stable internal environment
Walter Cannon
when did Walter Cannon coin the term homeostasis
1932
Two themes of Physiology
- integration
- homeostasis
takes in oxygen and removes waste gases
respiratory system
responsible for delivering the oxygen to all parts of our bodies
cardiovascular system
distributes nutrients and oxygen
blood
eliminates metabolic wastes
- Urinary system
- Respiratory system
unabsorbed matter
feces
nitrogen-containing metabolic waste products
urine
Biological Hierarchy
- Molecule
- Organelle
- Cell and tissue
- Organ
What are the four tissue types
- connective tissue
- muscle (contractile) tissue
- nerve tissue
- epithelial tissue
binds together or supports cells, other tissues/ organs
connective tissue
- contracts on stimulation
- movement, posture, and heat production
muscle (contractile) tissue
conducts nerve impulses throughout the body
nerve tissue
- covers all body surfaces
- lines all cavities
- forms glands
- protective barrier against the environment
epithelial tissue
What are the Major Organ Systems
- integumentary
- skeletal
- muscular
- circulatory
- lymphatic
- respiratory
- digestive
- urinary
- reproductive
- nervous
- endocrine
Definitions of homeostasis
- dynamic equilibrium inspite of multiple stimuli
- maintained by negative feedback
ability to maintain a relatively stable internal environment in an ever-changing outside world
homeostasis
what state is the internal environment of the body in
dynamic state of equilibrium
factors that interact to maintain homeostasis
- chemical
- thermal
- neural
the body function within relatively __ __
narrow limits
Homeostatic Control Mechanisms
- receptor (sensor)
- control center
- effector
produces change in variable
stimulus
detects change
receptor
information sent along afferent pathway to control center
input
what pathway does the input pass to go to the control center
afferent pathway
information sent along efferent pathway to effector
output
what pathway does the output pass to go to the effector
efferent pathway
Organ systems that accomplish regulation of homeostasis
- nervous system
- endocrine system
detects changes (stimuli) in the body
receptor
determines a set point for a normal range
control center
causes the response determined by the control center
effector
Different types of feedback
- negative feedback
- positive feedback
regulatory mechanism in which a change in a controlled variable triggers a response that opposes the change
negative feedback
what does negative feedback do to the intensity of the stimulus
decreases or eliminates it
negative feedback causes the organ systems to what?
change in opposite direction from stimulus
example of negative feedback
regulation of blood glucose levels
decrease blood sugar level
insulin
increase blood sugar level
glucagon
enhances or exaggerates the original stimulus so that the activity is accelerated
positive feedback mechanism
why is positive feedback considered positive?
results in change occuring in the same direction as the original stimulus
what do positive feedback mechanisms usually control
infrequent events
example of positive feedback
- blood clotting
- childbirth
positive feedback usually does not maintain __
homeostasis
characteristic of positive feedback
- short in duration
- infrequent
cause homeostatic imbalances
most diseases
example of homeostatic imbalances
- chills
- fevers
- elevated white blood count
reduces our ability to maintain homeostasis
aging
occurs when the body cannot get rid of excess heat
Heat stress
what happens when a disturbance of homeostasis or the body’s normal equilibrium is not corrected
illness
