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- University of Alabama - Birmingham
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- Biology 409
- Wibbles
- Lecture 1 Notes
Lecture 1 Notes
Biology 409 with Wibbles at University of Alabama - Birmingham
About this deck
By: islam shaaban
Created: 2011-06-13
Size: 61 flashcards
Views: 53
Created: 2011-06-13
Size: 61 flashcards
Views: 53
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Physiology
The study of the processes that support "life".
Claude Bernard
Developed the concept of homeostasis.
Homeostasis
The body maintains a constant "internal environment" despite changes in the external environment.
What percent of the body is fluid?
Approximately 60% or 42 Liters of fluid.
How much does Intracellular Fluid (ICF) make up of the human body?
Approximately 2/3 of the body.
How much does Extracellular Fluid (ECF) make up of the human body?
Approximately 1/3 of the body.
What is ECF ?
The fluid portion of blood (i.e Plasma).
ECF is in the a constant motion around the body.
What is ICF ?
The Interstitial Fluid (i.e the fluid between tissue cells)
How does ECF travel through the body?
ECF travels through Blood vessels, then Capillaries, and finally into interstitial spaces in the tissues.
How far are most cells from capillaries?
Most cells are with in 50 um of a capillary, therefore they are constantly bathed in ECF.
What does ECF represent?
- ECF represents the "internal environment" of Homeostasis.
- This allows the body to attempt to maintain a constant condition in the internal environment (i.e ECF)
Why does ECF need to be recirculated in order to maintain Homeostasis?
Because cellular metabolism uses nutrients and produces wastes, so there is a constant need to refresh ECF.
What are the major physiological parameters that must be controlled in the ECF in order for tissue cells maintain Homeostasis?
1) Gases ( O2 and CO2)
2) Nutrients ( Glucose, Fatty acids, and Amino acids)
3) Waste products ( CO2 and Urea)
4) pH ( normally 7.4 in ICF and ECF)
5) Electrolytes ( Na+, K+, Cl-, Ca++, etc.)
6) Temperature ( 37ºC )
What is Negative Feedback ?
A change in a physiological parameter (e.g. blood pressure) results in a response a response that has an opposite effect and thus helps restore parameter back to original (i.e. normal) value.
How are changes in blood pressure sensed by the body?
Blood pressure changes in the body are sensed by "Baroreceptors" in the Aorta and Carotid Sinuses that communicate with "Vasomotor Center" in the medulla ( a portion of the brain-stem).
What is the body's response to decreased blood pressure?
In response to decreased blood pressure the Vasomotor center can increase blood pressure by:
1. Increasing heart rate.
2. Increasing heart contraction strength.
3. Increasing peripheral vasoconstriction .
4. Stimulate release of epinephrine (i.e. adrenalin) from the adrenal glands. epinephrine reinforces step 1 through 3.
This is an example of Negative Feedback.
What is the body's response to increased blood pressure?
In response to increased blood pressure the Vasomotor center can decrease blood pressure by:
1. Decreasing heart rate.
2. Decreasing heart contraction strength.
3. Decreasing peripheral "Vasoconstriction" of blood vessels (results in "vasodilation" )
What is Positive Feedback?
- A change in a physiological parameter feeds back to cause an even greater change in the same direction.
- This normally leads to a major change in a physiological state it is very rare compared to negative feedback.
- examples of Positive Feedback :- Childbirth, Blood clotting, and initial portion of an "action potentials"
What are the various physiological levels at which homeostasis is controlled?
1. Molecular Level
2. Cellular and Organ Level
On a molecular level how is oxygen binding and release controlled?
- The primary control is at the level of a single molecule (Hemoglobin).
- Hemoglobin binds O2 in the lungs and only releases O2 to tissues that need oxygen (only given off in areas with low oxygen)
How is carbohydrate metabolisms and glucose levels in the blood controlled?
- They controlled through Hormones that are released from the Pancrease.
Why is it important to keep blood glucose levels relatively constant?
- It is important to keep a constant supply of glucose because the CNS needs a constant supply of glucose since neurons rely on glucose not glycogen (i.e. neurons do not store glycogen)
What two hormones control the concentration of glucose in plasma? and where are these hormones formed?
1. Insulin
2. Glycogen
* The hormones are produced from the Islets of Langerhans in the Pancreas*
What are properties of Insulin?
- It is a peptide hormone that is produced and released from the β cells of the pancreatic Islets of Langerhans.
- It is produced when there is an abundance of glucose in the blood.
How does Insulin function?
- it increases the cellular uptake of glucose.
- it increases glycogenesis within many cells (i.e production of glycogen).
How is Glucose stored?
- Glycogen is a large "storage form" for carbohydrates and is composed of many glucose molecules.
What are the properties of Glycogen?
- A peptide hormone that is produced and released from the α cells of the pancreatic Islets of Langerhans.
- Glycogen is normally produced when glucose levels are low in the blood.
How does Glycogen function?
- Glycogen has a strong effect on the liver ( liver cells can be up to 8% glycogen by weight).
- Increases Glycogenolysis (metabolism of glycogen, i.e. the breakdown of glycogen into glucose).
- Increases Gluconeogenesis (production of glucose from fats or proteins)
- Thus glucose is mobilized from liver cells and moves into the blood, thus increasing blood glucose levels.
How is Ca++ controlled in plasma?
- Ca++ is controlled by the thyroid and parathyroid gland.
Why is it important to keep Ca++ levels relatively constant in the ECF?
- Because Ca++ is used to initiate a variety of Intracellular events (e.g. muscle cell contraction, neurotransmitter release, etc,)
- Ca++ affects the excitability of neurons and muscles.
What is Hypocalcemia?
- Hypocalcemia is low Ca++in the ECF which increases excitability (opposite of whats anticipated).
- The decrease of Ca++causes an increase of Na+ permeability of cell membranes which can cause muscle spasms.
What is Hypercalcemia?
- Hypercalcemia is high Ca++ in the ECF which decreases excitability.
- Ca++is also important in blood clotting.
What are the two hormones that control calcium levels?
* Two hormones control Ca levels in the blood*
- Calcitonin
- PTH ( parathyroid hormone)
What are the properties of Calcitonin?
- Is a peptide hormone produced and released from the "C cells" of the thyroid.
- It is released in response to high Ca++levels in the blood.
How does Calcitonin function?
- It decreases the amount of Ca in the blood and ECF by increasing the Ca++ deposition of bones ( Ca++ is stored in bones).
- It can also indirectly increase Ca++ in urine by blocking the release of PTH (i.e. excess Ca is given off in the urine).
What are the properties of PTH?
- PTH (parathyroid hormone) is a peptide produced and released from the parathyroid glands in response to low Ca++levels in the blood.
How does PTH function?
- PTH then increases the amount of Ca++in the blood
- it stimulates mobilization of Ca++ from bones
- it stimulates absorption of Ca++ from the digestive tract.
- It stimulates re absorption of Ca++ in the kidneys
Thermoregulation
- The hypothalamus is the central nervous system CNS.
- It contains a hypothalmic thermoreguatory center that receives temperature input from the skin, from the CNS and body organs.
How does the body respond to cold temperature?
- In response to cold temp, the CNS initiates a variety of responses.
1) Shivering: skeletal muscle contractions generates heat (up to 5 fold increase in heat production)
2) Peripheral vasoconstriction: (prevents heat loss)
3) Behavioral responses: (keep limbs close to body, etc)
How does the body respond to warm temperatures?
- In response to warm temperature
1) Peripheral Vasodilation (loss of heat to enviroment)
2) Sweating (evaporating heat loss)
What are properties of the Cell Membrane?
- cell membrane in not rigid (Fluid Mosaic Model)
- Lipid bilayer (38% of membrane weight)
- Lipid bilayer is composed of (25%) phospholipids and (13%) Cholesterol both molecules have Hydrophilic and Hydrophobic regions.
- Lipid bilayer is a major barrier to water soluble substances (electrolytes, glucose, urea)
Why is the lipid bilayer important to the cell?
- It allows cells to selectively determine water soluble contents within the cell.
- Lipids in the lipid bilayer also act as reservoir of substrata for producing hormones and second messengers.
What are properties of membrane carbohydrates?
- 3% of cell membrane
- Carbohydrates are normally associated with cell surface (i.e. outer surface of membrane), and they are attached to either proteins or lipids (thus forming glycoprotiens or glycolipids).
Why are membrane carbohydrates important?
- Cellular identification
1) Cell to cell adhesion: carbohydrates are "sticky" and allow the cells to identify and attach to cells of the same type.
2) Immune system recognation: They contribute to "self vs non-self" recognition of cells.
3) Endocrine system recognition: Many cell surface hormone receptors that have carbohydrates attached, they contribute to hormone/ receptor recognition.
What are properties of Membrane Proteins?
- 55% of membrane weight
- Proteins perform most of the specific membrane functions
- There are two types Integral Proteins and Peripheral Proteins .
What are Integral Proteins?
- They protrude through the membrane.
- Many form structures such as ion channels, hormone receptors, carrier proteins for active and facilitated diffusion.
What are Peripheral proteins?
- They normally associate with the inner surface of the membrane.
- They may be attached to integral proteins.
- Many fuction as enzymes or factors controlling enzymes (e.g. adenylyl cyclase, G protiens).
What is the cytosol ?
- The fluid portion of the cytoplasm, It contains mane molecules that are either dissolved or suspended in cytosol.
what are the functions of the cytosol?
A) Cytosol contains many metabolic enzymes that help regulate the production and degradation of sugar, amino acids, fatty acids, and nucleotides (e.g. enzymes for glycolysis).
B) Cytosol contains "free" ribosomes( not attached to endoplasmic reticulum), some protein synthesis occurs in cytosol. This protein synthesis is responsible for producing many proteins used in the cytosol ( e.g. proteins such as metabolic enzymes for glycolysis).
C) Storage of fats and carbohydrates.
why store fats and carbohydrates?
- They can be used, when needed, for energy production.
- They can be stored as Fats or Carbohydrates
What are the properties of Fats?
- Fats: fat droplets
- There are small fat droplets in many types of cells.
- Adipose tissue (i.e. fat tissue) is composed of cells that are specialized for fat storage.
- They contain huge fat droplet that occupies almost the entire cytosol.
What are the properties Carbohydrates?
- Glycogen granules are polymers f large number of glucose molecules.
- Glycogen granules exert less of an osmotic effect than individual glucose molecules.
- liver cells and muscle cells have the greatest stores of glycogen.
*Liver cells: normally up to 8% is glycogen by weight.
*Muscle cells: up to 3% is glycogen by weight.
What is the properties of the Endoplasmic Reticulum (E.R)?
- Its a network of fluid filled tubules and vesicles.
- the wall of the ER are lipid bilayers.
- It is often called the "intracellular factory" because it produces and packages a variety of substances.
- Molecules produced in ER are packaged in "transition vesicles" and often transferred to golgi complex.
What are the properties of the rough E.R.?
- Rough ER has ribosomes attached.
- also known as Granular ER
- Ribosomes used for protein production (e.g. protein hormones, etc).
Why do ribosomes attach to E.R?
It allows for the packaging of newly produced proteins.
what are the properties of smooth E.R.?
- Also known as agranular
- No ribosomes are attached.
- But it contains lipid synthesizing enzymes (e.g.important for the production of membrane lipids, such as phospholipids)
- It is also where steroid hormones are produced.
- It acts as a specialized intracellular structure for Ca++ storage in skeletal muscles.
What are the properties of the Golgi complex?
- It is composed of stacks of agranular vesicles with lipid bilayer walls.
- It is closely associated with the E.R. and it receives maternal from E.R.
What are the function of Golgi complex?
- The Golgi complex is important for processing of "raw" materials into their finished product (e.g. conversion of a precursor hormone to an active hormone).
How does the Golgi Package products?
- Packaging and directing of products to final destinations
- Packaging refers to the types of proteins placed into the vesicle's membrane.
- They type of "packaging" determines what the vesicle transports.
- They type of "packaging" also determines the destination of the vesicle some are "intracellular vesicles" such as lysosomes others are "secretory vesicles".
What are the properties of Lysosomes?
- They serve as the "intracellular digestive system". They are produced by the golgi complex.
- They are vesicles that contain "hydrolase" digestive (e.g. hydrolases can breakdown proteins into amino acids, and breakdown of glycogen to glucose, by the process of "hydrolysis.
- Vesicles help protect cell from self digestion.
- They can combine with vesicles produced "endocytosis". The enzymes breakdown contents of endocytotic vesicle (e.g. this is how phagocytic WBC engulf and destroy bacteria).
What are the properties of Peroxisomes?
- They are small vesicles produced by E.R.
- They contain "oxidases" (used to oxidize substances)
- Oxidases detoxify some substances (e.g. ethanol is broken down by Peroxisomes in liver cells).
- Oxidases also breakdown fatty acids into acetyl-Co-A.
About this deck
By: islam shaaban
Created: 2011-06-13
Size: 61 flashcards
Views: 53
Created: 2011-06-13
Size: 61 flashcards
Views: 53
About StudyBlue
STUDYBLUE makes things that make you better at school.
Things like online flashcards with photos and audio.
Things like personalized quizzes and friendly reminders about when (and what) to study next.
Think of it as a digital backpack™: access to all of your study materials online and on your phone.
STUDYBLUE exists to make studying efficient and effective for every student, for free. Join us.
“I have used this website for three exams, and I see a huge difference in my test results.”
Naj
Naj