Lecture 2 Flashcards
Why is studying physiology important?
it is the foundation upon which we build our knowledge of what “life” is, how to treat disease, and how to cope with stresses imposed upon our bodies by different
environments/conditions
-Physiology is beautiful
-It will broaden your scientific outlook
-It helps you realize that body functions are integrated
-Physiology is a work-in-progress
What are the 6 layers of the human body, from smallest to largest
- Chemical
- Cellular
- Tissue
- Organs
- Systems
- Organism
What are the 4 types of macromolecules on the chemical level
Nucleic acids, proteins, lipids, carbohydrates
What part of the cell carries out functions
Organelles
What is unique about stem cells?
A stem cell is essentially a “blank” cell, capable of becoming another
more differentiated cell type in the body, such as a skin cell, a muscle cell, or a
nerve cell
What are the 4 major tissue types?
- Nervous
• Specialized in impulse production and transmission
– Muscle
• Specialized for contracting and generating tension
– Epithelial
• Specialized for surface lining and exchange
– Connective
• Specialized for connecting and supporting
how many types of tissue are present in all organs
2 or more different types
What are the 11 body systems?
circulatory digestive respiratory urinary skeletal muscular integumentary immune nervous endocrine reproductive
What components of the internal environment maintain homeostasis
– Temperature
– Volume & pressure
– Composition( Nutrients, gases, waste products, pH, salt and other electrolytes)
What does the cell membrane do? why is it important?
The CELL MEMBRANE is chiefly responsible for
maintaining homeostasis inside a living cell using
different methods to transport molecules in and out of
the cell.
it is important because: -Too much water can burst the cell -Too many wastes can poison the cell -The cell cannot tolerate any great variations in ion conditions.
What are the 4 jobs of the cell membrane
- Isolate the cytoplasm from the external environment
- Regulate the exchange of substances (gases and ions)
- Communicate with other cells
- Identification (proteins and carbohydrates on its
surface)
What are the 6 integral types of membrane proteins and what are their functions
receptor-binds to chemical messengers such as hormones sent by other cells
enzyme-breaks down a chemical messenger and terminates its effect
ion channel-A channel protein that is constantly open and allows ions to pass into and out of the cell
gated ion channel-A gated channel that opens and closes to allow ions through only at certain times
cell-identity marker-A glycoprotein acting as a cell identity marker distinguishing the body’s own cells from foreign cells
cell-adhesion module-binds one cell to another
What is the difference between passive and active transport? what are 3 examples of each?
-Passive Transport cell doesn’t use energy 1.Diffusion 2.Facilitated Diffusion 3.Osmosis
-Active Transport cell does use energy 1.Protein Pumps 2.Endocytosis 3.Exocytosis
What type of channels perform diffusion? how does it work?
-Protein channels are holes or pores in the membrane
formed by an integral membrane protein
-Allow small molecules to freely diffuse across
membranes(Water, Ions)
-Can be selectively permeable (Na+, K+ channels)
What are the 2 types of gated channels? are they passive or active?
Voltage-gated and Ligand-gated channels
They are passive channels
how are water soluble substances passed
membrane proteins
What is active transport? what’s one example?
• Active transport is the movement of a substance across of membrane against it’s concentration gradient • Requires Energy!!! (i.e. ATP) – e.g. Na+/K+ Pump
What are the 2 different types of gradients
chemical gradient = difference in solute concentration across a membrane
electrical gradient = difference in charge across a membrane
What is the difference between endocytosis and exocytosis
endocytosis=cell eating
exocytsosis=cell dumping
Can active transport be blocked? what’s an example?
-Membranes & Ion channels can be stopped from transporting molecules with inhibitors
which either destroy the membrane protein or just plug it up
-Examples include botulinum and poison
What does botulinum and black widow venom antagonize?
the release of acetylcholine
What are 2 control systems that maintain homeostasis?
• Nervous system
– Controls and coordinates bodily activities that require
rapid responses
– Detects and initiates reactions to changes in external
environment
• Endocrine system
– Secreting glands of endocrine systems regulate
activities that require duration rather than speed
– Controls concentration of nutrients and, by adjusting
kidney function, controls internal environment’s
volume and electrolyte composition
What is needed for a control system to maintain homeostasis?
– Detect deviations from normal in the internal
environment that need to be held within narrow
limits
– Integrate this information with other relevant
information
– Make appropriate adjustments in order to restore
factor to its desired value
What are the 2 types of feedback? what does feedforward mean?
• Feedback - refers to responses made after change has
been detected
– Types of feedback systems
• Negative
• Positive
• Feedforward - term used for responses made in
anticipation of a change
What are the 3 components of a feedback loop?
• Receptor/Sensor – monitors a controlled condition • Control center – determines next action • Effector – receives directions from the control center – produces a response that changes the controlled condition
What is the 4 step process of the homeostasis of blood pressure?
- Baroreceptors in walls of blood vessels detect an increase in BP
- Brain receives input and signals blood vessels and heart
- Blood vessels dilate, HR decreases
- BP decreases
What’s an example of a positive feedback system?
Pregnancy(increased stretching of cervix releases more oxytocin, more oxytocin increases the stretching of the cervix)
Other examples: • Reproductive hormone cycles in females • Action potentials in nerve cells • Uterine contractions during childbirth
What are some examples of negative feedback?
- control of car speed up a hill
- control of body temperature
What are the 4 steps of feedback control?
- A change in the regulated variable results in altered activity of the sensor
- The sensors change in activity will cause a change in the feedback controller
- Feedback controller alters the activity of one or more effector(s)
- The effector(s) acts on the regulated variable to return it to is original state
What is feedforward control? what are some examples?
• Feed Forward:
– Happens before the error signal is detected(anticipatory)
– Because they do not respond directly to changes in
homeostatic variable feed forward responses can be
wild and uncontrolled
Examples
- salivation, male erection, response to pending exercise
What are the 4 stages of feed forward control?
- Disturbance is measured prior to a change in homeostasis
- This disturbance activates the feed forward controller
- Feed forward controller alters the activity of one or more effector(s)
- The effector(s) acts on the regulated variable to preempt any change caused by
the disturbance
What are the 4 components of feed forward control?
– Measurable Disturbance
– Feed Forward Controller
– Effector
– Regulated Variable
What is receptor mediated control? how does it work? what’s an example?
Receptor Mediated Control=A way to control the effectors
Signalling Molecule(ex.insulin)-Receptor Protein-Intracellular Signal -Molecules-Target Protein(s)-Response
feedback control of blood glucose-Receptor Mediated signalling triggers both activation of insulin production and increased glucose uptake (outflow from blood glucose pool)
What’s an analogy for receptor mediated control?
Satellite signal-Satellite Dish-Cable Box-Television-The Witcher
