BMSC 207 Midterm | Questions & Answers (100 %Score) Latest Updated 2024/2025
Comprehensive Questions A+ Graded Answers | 100% Pass
Physiology - ✔️✔️The study of the normal functioning of a living organism and its component parts,
including all its chemical and physical processes. Aristotle said it was the knowledge of nature.
Hippocrates said it was the healing power of nature.
Emergent Properties - ✔️✔️Properties of a complex system that cannot be explained by a knowledge of a
systems individual components. A result of complex and nonlinear interactions. We know the structure
of a neuron but how it interacts with others is much more complex than the structure implies. An
example is the human genome project: 1 gene=1 protein but it is actually much more complex than that.
Integrative Science - ✔️✔️Physiology is this. It covers chemistry, molecular biology, cell biology, and
ecology. It is closely tied to anatomy because the structure will provide a physical base for the function.
Cells - ✔️✔️Smallest unit of structure capable of carrying out life processes.
Tissue - ✔️✔️Collection of cells carrying out related functions.
Organ - ✔️✔️Formation of tissues into a structural and functional unit.
Organ System - ✔️✔️Integrated groups of organs.
Body Systems - ✔️✔️It is often common to study each system individually but there is actually a lot of
integration between the organ systems. Some variables are controlled by many systems.
Teleological Approach - ✔️✔️The function or "why"
Ex. Why do red blood cells transport oxygen? Because cells need oxygen and the RBC's bring it.
Mechanistic Approach - ✔️✔️The mechanism or "how"
Ex. How do RBC's transport oxygen? Oxygen bind to hemoglobin in the red blood cells.
,This is much more the focus of physiologists.
10 Organ Systems - ✔️✔️1- Musculoskeletal-skeletal, muscles, bone
2- Integumentary-skin
3- Digestive- stomach, intestines, liver, pancreas
4- Circulatory- heart, blood vessels, blood
5- Respiratory-Lungs, airway
6- Immune- Thymus, spleen, lymph nodes
7- Endocrine- Thyroid gland, adrenal gland
8- Nervous-Brain, spinal cord
9- Urinary- Kidneys, bladder
10- Reproductive- Ovaries, uterus, and testes.
Homeostasis - ✔️✔️The ability to maintain a relatively stable internal environment despite exposure to
external variability. Along with regulation of the internal environment it is a key focus of physiology.
Originally termed by Walter Cannon and means like of similar condition. Conditions in each person vary
slightly.
Homeostasis and Disease - ✔️✔️There can be an external change such as toxic chemicals, physical
trauma, foreign invaders or internal changes such as abnormal cell growth, autoimmune disorders,
genetic disorders that lead the body to attempt to compensate which will either lead to health or a
pathophysiological state.
Pathophysiology - ✔️✔️Abnormal physiology
Extracellular Fluid - ✔️✔️Considered as the internal environment of the body. Surrounding cells it is a
buffer between cells and the external environment. Composed of the plasma and interstitial fluid.
Dynamic Steady State - ✔️✔️the internal environment is in a relatively steady state but is dynamic in that
materials are constantly moving back and forth between the extracellular and intracellular fluid.
,Law of Mass Balance - ✔️✔️If the amount of a substance in the body is to remain constant, any gain must
be offset by an equal loss.
Input: diet-food, water Lungs, Skin, Metabolic production
Output: Pee, feces, lungs, skin, metabolism
The body load is what is typically in the body.
Homeostasis and equilibrium - ✔️✔️These concepts are NOT equal. The ECF and ICF must have different
concentrations for basic survival. When studying this it is much easier to study the plasma rather than
the individual cells. The ultimate goal is to maintain the dynamic steady states of body compartments.
Control Systems - ✔️✔️To maintain homeostasis the body monitors certain key functions/variables. The
variables are kept in a normal range by these control mechanisms. They can be local (one area) or reflex
(through out the body).
Input signal(variable sensed)-Integrating centre(takes in info and decides)-Output signal(try to fix)-
Response(action is taken).
Local Control - ✔️✔️Restricted to tissues or cells involved. Ex. Active cells reduce the amount of oxygen in
the tissue so endothelial cells send local signals which causes vasodialation and oxygen levels are
restored.
Reflex Control - ✔️✔️Long distance signaling- changes are widespread throughout the body (systemic) use
more complex control systems. Any mechanism of this type with use either the endocrine system or the
nervous system. The response loop causes movement in the downward direction while the feedback
loop modulates the response loop and feeds back to ultimately influence the input.
3 types- negative, positive, and feed forward.
The acceptable set point range is variable depending on the parameter and can be either narrow or
slightly broader. Ex. The fish tank.
Reflex control can be antagonistic using two different systems. Think of the heating and cooling of a
house.
Negative feedback loop - ✔️✔️a pathway in which the response opposes or removes the stimulus signal.
It serves to stabilize a system, homeostatic, can restore the initial state but cannot prevent the initial
disturbance.
Ex. Blood glucose and blood glucoagon.
, Positive Feedback Loop - ✔️✔️A more rare type, are not homeostatic, reinforce a stimulus to drive the
system away from a normal value rather than decreasing or removing it. An intervention outside of the
loop will stop the response.
Ex. Oxytocin in birth.
Feedforward Control - ✔️✔️a few reflexes have evolved that allow the body to predict a change is about
to occur.
Ex. Salivation, stomach acid, digestive contractions
Ex. Heart rate increases before exercise
biological rhythms - ✔️✔️Set points change over time due to genetics, constant exposure, or a new
condition.
It is a variable that changes predictably to create repeating patterns or cycles of changes.
Circadian rhythm is a cycle over 24 hours that corresponds to light and dark. Hormones are linked to
these cycles as well.
Membranes - ✔️✔️Separate one compartment from another.
Cell Membrane - ✔️✔️Originally thought to have consisted of one layer of lipids but it is known now that
it is actually a double layer of phospholipids with protein molecules. Carbohydrates attach on the
outside as well. The average composition is about 55% proteins, 45% lipids, and very small levels of
carbohydrates however depending on the cell this changes. The more proteins are present the more
active the cell likely will be.
Functions of a Cell membrane - ✔️✔️1. Physical isolation: separates ICF and ECF, separates cell from
environment.
2. Regulation of exchange with the environment: entry, elimination and release
3. Communication between the cell and its environment: contains proteins that allow for responding or
interacting with external environment.
4. Structural support: Proteins in the membrane are used to make cell-to-cell connections and to anchor
cytoskeleton.
