Basics of the Human Body Flashcards
Anatomy
science of structure
Physiology
science of body functions
Human Body Hierarchy
Chemical level, cells, tissues, organs, organ systems
Chemical level subdivisions
atoms and molecules
Human body atom composition
65% O, 18% C, 10% H, 3% N, 2% Ca, 1% P
95% of atomic structure is composed of
O, C, H, N
Molecules
2 or more atoms joined together
In humans, most common molecule is
water (60-70%)
4 Biologically important organic molecules
proteins, carbs, nucleic acids, lipids
Cells
smallest structural and functional units of the human body
Tissues
groups of cells and the surrounding materials that work together to perform a particular function
Organs
composed of two or more tissues working together to provide specific functions
Organ systems
one or more organs that provide a common function
Basic characteristics of living things
High level of organization, composed of cells, metabolism, respond and move, homeostasis, differentiation and growth, reproduction, and evolution
Metabolism
sum of all biochemical process of cells, tissues, organs, and organ systems
Responsiveness/movement
able to detect and respond to changes in the environment
Homeostasis
ability to maintain equilibrium of the body’s internal environment
Differentiaion/growth
process a cell undergoes to develop from an unspecialized cell to a specialized one; increase number and size of cells, tissues, organs, and the body
Reproduction
formation of new cells for growth, repair, or replacement; production of new individual
Evolution
genetic change within populations from generation to generation due to genetic mutations and natural selection
Homeostasis is produced by
interaction of organ systems and regulatory processes
2 body systems that largely control homeostasis
nervous and endocrine
Nervous system
detects changes and sends nerve impulses to counteract disruption rapidly
Endocrine system
regulates homeostasis by secreting hormones more slowly
Homeostasis is continually disrupted by
internal and external stimuli
Components of a feedback loop
receptor, control center, effector
Negative feedback loop
stimulus disrupts homeostasis, receptors notice and tell control center, which makes effectors work and allow return to homeostasis
Negative feedback loop example
blood pressure regulation
Positive feedback loop
self-amplifying change, receptors detect and send signals to control center, which tells effectors to do something, which sends more signals to receptors until interrupted
Positive feedback loop example
childbirth
