Physiology II study notes for final exam Includes all concepts from all chapters.
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Physiology II Final Exam Review
- From one cell to many (embryo to adult) there is differentiation which means specialization
(complexity) in all tissues, organs, and cells...
- Specialization requires communication to maintain whole body function, your body coordinates
these functions by:
o the brain sends commands (hormones (blood), neurotransmitters (nerves))
o the brain receives info (feedback)
o through regulation of in/out and is adaptable to changes
- Homeostasis is maintaining a relatively constant internal environment: temperature, blood
glucose, blood pressure.
- Sensitivity of the detector (receptor) determines the range of oscillation, some effectors have
very specific effects, others more general, local homeostatic mechanisms do not involve the
integrating centre, antagonistic effectors improve responsiveness.
- A Set Point is the desired physiological value, the hierarchy of importance determines which
variables have priority
- The steady state is the normal range of values above/below the set point and requires energy to
- An error signal is any deviation from the set point
- Relative Constancy means that the “set point” is actually a range of acceptable values
(dynamic). The set point is adaptive and can be reset. For homeostasis to work your body needs
sensors and receptors, effectors and nerve hormones.
- The classic homeostatic regulation mechanisms are negative feedback vs. Positive feedback vs.
Negative Feedback: is the coordination of responses, a signal is detected and a response
counteracts the initial stimulus, it returns the body to its original state. Negative feedback is the
most common homeostatic regulation mechanism.
Homeostatic Reflex Loop:
1) What is the variable being maintained relatively constant
2) Where are the receptors detecting the changes in the variable
3) Where is the integrating center that collects info and sends out instructions through efferent
4) What are the effectors and how do they impact the variable
Antagonistic Effectors: are 2 systems that are in opposition from each other-
Temperature – sweating, vasodilatation vs. Shivering, vasoconstriction
Heart rate – parasympathetic nerves vs. Sympathetic nerves
Blood Glucose – insulin vs. Glucagon
Positive Feedback: not an attempt to restore homeostasis, it strengthens the stimulus. Transcription
factors regulate production of certain genes and are also an example of positive feedback.
Responses add to the initial stimulus and strengthen it, do not return the body to its original state,
and are not commonly used in your body.
Feed Forward: is anticipatory, occurs in anticipation of an event, and prepares the body for
imminent challenges. For example the food in your stomach induces insulin release before you eat,
or the body of a runner at the starting line in a race is preparing for the upcoming exercise through
Levels of Regulation: intracellular, intercellular, and tissue are Intrinsic controls, systems and
organisms are Extrinsic controls.
Intrinsic controls: are local control mechanisms inherent to an organ
Extrinsic controls: initiated outside an organ, accomplished by nerves and the endocrine system
Respiratory System: Chapter 13 pgs. 471-516
Functions of the respiratory system:
- Brings oxygen - Removes CO2 - Regulates Ph (hydrogen ion concentration)
- Defence against infection - Sound Production
Lung Structure: Conducting zone- determines airflow
Consists of: Trachea, bronchi, bronchioles, and terminal bronchioles
Conducting zone is a low resistance pathway
Walls are reinforced with a ring of cartilage
Warms, humidifies, and filters air
No gas exchange
Respiratory zone- consists of: respiratory bronchioles, alveolar ducts, and alveolar
Enables gas exchange
300 million alveoli total
Total surface area is 700 square feet
Cellular composition of lungs:
- All airways are lined with cuboidal epithelial cells, ciliated in the conducting zone, mucous
secreting epithelial cells in the conducting zone
- Bronchioles wrapped with smooth muscle cells, bronchiodialation (good) and
- Macrophages in airways and alveoli remove airborne particles and bacteria, called resident
- Type 1 alveolar cells are flat epithelial cells, and take up the majority of the alveolar wall
- Type 2 alveolar cells are rounded epithelial cells which secrete surfactant which allows alveoli to
stay in an open state
Steps of respiration:
Ventilation: exchange by bulk flow
Gas exchange: O2 and CO2 exchange by diffusion
Gas Transport: O2 and CO2 carried in blood by bulk flow
Gas Exchange: O2 and CO2 exchange by diffusion
Cellular Respiration: Use of O2 production of CO2
Structure: Trachea, Lung, Intrapleural fluid, Parietal pleura, and Visceral pleura
- Air flow requires a pressure gradient: high pressure to low pressure, resistance is determined by
the airway diameter.
- F= flow
Delta P= pressure difference
Atmospheric pressure: the pressure exerted by the weight of the gas in the atmosphere on objects
on the Earth`s surface. 760 mmhg
Intra-alveolar pressure: pressure within the alveoli 760 mmhg
Intrapleural pressure: pressure within the pleural sac the pressure exerted outside the lungs within
the thoracic cavity.
- Inspiration occurs because the lung pressure is < than atmospheric pressure
- Expiration occurs when atmospheric pressure is < than lung pressure
- Mmhg = millimetres of mercury
- The thorax is a closed chamber that is bounded by muscles (diaphragm on bottom: intercostals
on sides). A change in volume causes a change in pressure
The Relation between Volume and Pressure:
- Boyles law: a change in volume results in a change in pressure
From one cell to many (embryo to adult) there is differentiation which means specialization (complexity) in all tissues, organs, and cells Specialization requires communication to maintain whole body function, your body coordinates these functions by: the brain sends commands (hormones (blood), neurotransmitters (nerves)) the brain receives info (feedback) through regulation of in/out and is adaptable to changes. Homeostasis is maintaining a relatively constant internal environment: temperature, blood glucose, blood pressure. Sensitivity of the detector (receptor) determines the range of oscillation, some effectors have very specific effects, others more general, local homeostatic mechanisms do not involve the integrating centre, antagonistic effectors improve responsiveness. A set point is the desired physiological value, the hierarchy of importance determines which variables have priority. The steady state is the normal range of values above/below the set point and requires energy to maintain. An error signal is any deviation from the set point.