Physiology Chapter 1 - The Study of Body Function
Features of Homeostasis
- Internal environmental variables (EX: Plasma [glucose]) -Set point value exists for that variable (EX: 70-110 mg glucose/dL of blood) -various inputs and outputs affect the variable (EX: diet and energy metabolism)
Primary Tissues
- Muscle - Nervous - Epithelial - Connective
Homeostasis
- definition: state of relative constancy of internal environment -maintained through negative feedback loops -Ex: body temperature, sodium, glucose, pH
Cells
- exchange wastes and nutrients with their surrounds 1. intracellular fluid conditioned by 2. interstitial fluid conditioned by 3. plasma conditioned by 4. the organ systems it passes through
Dynamic Constancy
- the levels of change over a short period of time but it remains constant over a long period of time - The negative feedback loop is triggered whenever the variable or condition deviates from the set point. Therefore, it is constantly changing. BUT, the conditions are always stabilized above and below the set point within a normal range in a constant and consistent manner.
Three ways to respond to physiological change
-endocrine -paracrine -autocrine
The Heirarchy of Living Systems
1. Cells 2. Tissues 3. Organs 4. Organ Systems 5. Organisms 6. Populations 7. Communities 8. Ecosystems 9. The Biosphere
The Organ Systems
1. Circulatory/Cadiovascular 2. Respiratory 3. Digestive 4. Urinary/Renal 5. Musculoskeletal 6. Immune 7. Nervous 8. Endocrine 9. Reproductive 10. Integumentary
Two important generalization about the balance of homeostasis
1. during any period of time, the total-body balance depends on the relative rates of net gain and net loss to the body 2. The pool concentration depends not only on the total amount of substance in the body but also the EXCHANGES of the substance WITHIN the body
Circulatory/Cardiovascular Sysem
Heart and vessels
Cells
The fundamental unit
Physiology
The study of biological function or how the body works
Immune Syste
WBCs, spleen
Negative Feedback Loop
an increase or decrease in a variable that causes a response to move in the opposite direction towards the original change.
Nervous System
brain, spinal cord, sensory organs
Efferent Pathway
carries information away from the control center (E=Exit)
Afferent Pathway
carries sensory information to the control center
Connective Tissue Function
characterized by large amount of extracellular material-blood, bone, and cartilage
Muscle Tissue Function
for contraction
Nervous Tissue Function
for generation and conduction of electrical events, and related support functions
Epithelial Tissue Function
forms membranes covering and lining body surfaces, or glands comprised of these membranes
Tissues
groups of the same cell type
Urinary/Renal System
kidneys and bladder
Respiratory System
lungs and air passageways
Organisms
multiple organ systems
Organ systems
multiple organs
Organs
multiple tissues with a common function
Musculoskeletal System
muscles, tendons, bones
Reproductive System
ovary, uterus, testes
Endocrine System
pituitary, thyroid, etc
The negative feedback loop requires...
sensor, integrating center, effector
Autocrine Response
signal affects the cells that synthesized the signal
Paracrine Response
signal reaches neighboring cells through the Interstitial fluid (ISF); local communication between the cells
Endocrine Response
signal/message reaches distant(most times) target cells after transport in blood
Integumentary Syste
skin