Test #1 Flashcards
What is a tissue?
Grouping of similar cells
What is an organ?
A structure with a particular function, made up of 1 or more tissue types
What are the main tissue types? What are their functions?
Epithelial—secretion/barrier
Muscle—force/movement
Nervous—information transport/processing
Connective—structure/support
What is homeostasis?
When the body maintains internal equilibrium
What is the set point?
The reference value for the variable you are trying to regulate.
What is the comparator?
It recognizes when we move to and from a set point
What are regulatory systems and what do they do?
They obtain, integrate and process information and issue commands to effectors. Muscles and glands are considered effectors.
What is a negative feedback system?
Information is used to counteract the influence that created an error signal. A thermostat for example.
What is a positive feedback system?
It amplifies a response and increases deviation from a set point. Ex—breastfeeding.
What is an example of a positive feedback mechanism and why?
Breastfeeding because nerve cells in your nipple signal the brain to release oxytocin, oxytocin causes muscle in breast to contract, breast milk is ejected out of your milk ducts, your baby suckles, and repeat.
Explain the process of eating too many gummy bears in relation to glucose.
The level of glucose in your body increases greatly which then causes the Beta cells in your pancreas to release insulin into the bloodstream and insulin receptors in the liver receive the signal and take up glucose converting it into glucagon for storage.
What do temperatures of hotter than 45°C (113°F) and colder than 0°C (32°F) do to the body?
In those hotter temperatures, protein degradation occurs and in the colder temperatures, cellular dehydration occurs.
What are heat shock proteins (HSP)?
They are proteins that protect the cell from losing integrity by helping them retain protein folding and helping them renature in the face of cell stress/heat.
What are isozymes?
They are enzymes that have the same function but may have different tolerances.
What are isoforms?
Non-enzymes that have the same function.
What does Q10 describe?
It describes how sensitive a metabolic or physiological process is to temperature change.
Metabolism vs. Temperature rise
Metabolism which is a chemical process that helps a body sustain life is faster as temperature rises.
What are homeotherms?
They maintain constant body temperature.
What are poikilotherms?
They have fluctuating body temperature.
What are endotherms?
They change metabolic rate to regulate temperature.
What are ectotherms?
They depend on environment to regulate temperature.
What are the avenues of heat exchange used by ectotherms and endotherms?
Radiation—heat transfer via infrared radiation from warmer to cooler areas
Conduction—heat transfer between objects in direct contact
Convection—heat transfer with a surrounding medium such as air or water
Evaporation—heat transfer as water converts to gas (ex. sweating)
What is vasoconstriction?
The constriction of blood vessels that service the skin to reduce heat loss. The goal is to keep you warmer!
What is vasodilation?
Increased blood flow to the skin increases heat loss and lowers body temperature. This is to make yourself cool down!
What are hot fishes?
They use blood flow to keep temperature warmer than water. They use countercurrent heat exchange through large peripheral arteries near returning veins to keep heat within the muscle.
What is piloerection?
When there is a thick layer of air trapped in feathers/hair that reduces heat loss to surroundings.
What is the thermoneutral zone?
It is where metabolic rate is independent of temperature. Metabolic rate is measured by consumption of O2 or production of CO2. An endotherms thermoneutral zone is bounded by upper and lower critical temperatures.
What is the basal metabolic rate (BMR)?
It is the metabolic rate of a resting animal at a temperature in the thermoneutral zone. The animal is consuming just enough energy to carry out minimal body functions.
What is shivering heat?
It is when skeletal muscles contract, turn ATP to ADP, release heat to warm you up when you are cold or generate fever.
Explain brown fat
Brown fat is packed with mitochondria to generate non-shivering heat which is a process that warms you up without the contraction of the skeletal muscles.
What is thermogenin (UCP1)?
Is it a mitochondrial carrier protein found in brown fat and it is used to generate heat by non-shivering thermogenesis.
What is the brain’s thermoregulatory system?
The hypothalamus because it can lead to heat production as well as heat loss.
What is TRPV1?
It is a protein that recognizes heat and pain.
What is PIEZO2?
It is a protein that allows your body to sense movement and deals with touch.
What is daily torpor?
When small endotherms lower body temperature and metabolic rate during inactive periods to conserve energy.
Describe peptide/protein hormones
These hormones are water-soluble
They can circulate freely
Can be stored in vesicles and released through exocytosis
They bind to external binding sites
Describe steroid hormones
They are lipophilic
Ex. Aldosterone and testosterone
They often deal with intracellular receptors where they bind to and begin transcription
They are not stored, they are made when they are needed
They need help to travel to different parts of the body
What is aldosterone?
It is a steroid hormone that stimulates absorption of sodium by the kidneys and regulates water and salt balance
What is cortisol?
It is the primary stress hormone to help regulate your body’s response to stress. It increases glucose in the bloodstream.
Describe amine hormones
They can be lipophilic or water-soluble
Tyrosine is essential for the production of epinephrine and thyroxine
Epinephrine is water-soluble
Thyroxine is lipophilic
What is thyroxine?
It is an amine hormone that is lipophilic. It plays an important roll in heart and digestive function, metabolism, brain development, bone health and muscle control.
What is epinephrine?
Also known as adrenaline. Plays an important role in your body’s fight or flight response. Has more of an effect on your heart
What is norepinephrine?
Also called noradrenaline. Involved in fight or flight. Stress triggers the release of it. Has more of an effect on your blood vessels
State the different functions of prolactin
Stimulates mammary gland growth and milk production
Regulates salt balance
Stimulates production of egg jelly that surrounds the egg during fertilization
Stimulates nesting, incubation behavior and parental care
What are the characteristics of the nervous system?
Fast
Can turn off quickly
It can rapidly communicate complex information
What are the characteristics of the endocrine system?
Slow
Has to diffuse and circulate
Longer, but more sustained effects
Describe the posterior pituitary
It stores and releases oxytocin and vasopressin that is produced in the hypothalamus
What is oxytocin?
-It stimulates uterine contractions -Stimulates contractions of epithelial cells around the alveolar ducts (milk flow)
-The love and bonding hormone
Describe the anterior pituitary
-Synthesizes and secretes melanocyte stimulating hormone, prolactin, endorphins and growth hormone
-Releases various tropic (acts on another gland) hormones such as thyrotropic hormone, adrenocorticotropin hormone, and gonadotropins
What is vasopressin/ADH?
-It increases water retained by the kidneys
-Causes constriction of peripheral blood vessels to elevate blood pressure
What is the luteinizing hormone?
Females—triggers ovulation and ovarian production of estrogen and progesterone
Makes—stimulates production of testosterone
What is follicle stimulating hormone?
Females—stimulates maturation of ovarian follicles
Males—stimulates spermatogenesis
What are releasing hormones?
They induce the release of hormones from the pituitary.
What are releasing inhibiting hormones?
They block the release of hormones from the pituitary.
What is the portal system?
A major artery feeds the hypothalamus then to the pituitary.
What does the thyroid release?
It releases T3, T4 and calcitonin. Calcitonin is involved in blood calcium regulation and T4 (thyroxine) regulates metabolism
What happens when Ca2+ is too low?
The parathyroid gland releases PTH. Osteoclasts and osteoblasts cause calcium release from bone to blood
What happens when Ca+2 is too high?
Calcitonin is released from the thyroid. Osteoblasts take up calcium to form new bone.
What is calcitonin?
A hormone secreted by the thyroid that lowers blood calcium.
What is a calorie?
The amount of heat needed to raise 1 gram of water 1°C.
What three things does diet need to provide?
Chemical energy to carry out cellular processes. Organic raw materials. Essential nutrients like vitamins and minerals.
What is amylase?
The breakdown of carbs to sugars when released from the salivary glands.
What is peristalsis?
Waves of muscle contractions that move food toward the stomach.
What is chyme?
The mixture of gastric juices and partly digested food.
Where does the most digestion occur?
In the duodenum
Where does the most absorption occur in the stomach?
In the jejunum and ileum
What is the hepatic portal vein?
It carries nutrient rich blood to the liver for storage or conversion.
What is adipose?
Connective tissues storing fat/excess fuel
Why is the liver important in regulating fuel homeostasis?
It is the organ involved in the storage of glucose
Why is the hypothalamus important in regulating fuel homeostasis?
This regulatory system integrates information about fuel state and mobilizes controlled systems as needed.
What is satiety?
It is the state of feeling satisfied with consumption.
What is leptin?
It let’s your brain know you’re in a post absorptive state.
What is ghrelin?
It decreases satiety and lets you know you are hungry.
Where is K+ mainly concentrated?
Inside the cells
Where is Na+ and Cl- mainly concentrated?
Outside the cell
What is osmolarity?
Particles in a fluid
What does hypertonic mean?
A higher concentration of particles outside the cell which cause the cell to shrink.
What does hypotonic mean?
Lower concentration of particles outside of the cells causes the cell to swell.
What does isotonic mean?
Same particle concentration. No net water movement.
What does osmosis do?
It causes water to enter and leave the cells.
What is a nephron?
A tiny filtration system in the kidney. So many of them!
What is the excretory system?
Organs that control volume, concentration and composition of extracellular fluid.
What is filtration?
Removes cells and large molecules
What is secretion?
Modifies the filtrate (fluid collected)
What is reabsorption?
Concentrates the urine
What is Bowman’s Capsule?
Part of the nephron that forms a cup-like sack surrounding the glomerulus. The capsule helps the glomerulus to filter blood.
What is excretion?
To get rid of waste material from the blood, tissues or organs by a normal discharge of sweat, urine or stool.
What is the process of the excretory system?
Body fluid is collected and filtered in the glomerulus, composition of collected fluid is adjusted in the renal tubular and remaining substance is excreted.
What is the osmoregulator?
Controls internal osmolarity independent of environment.
What is osmolarity
The number of solutes in a solutuon
What is hypoosmotic?
Maintaining osmolarity with a lesser concentration of solute in the solution. Freshwater compared to salt water.
What is hyperosmotic?
Maintaining osmolarity with a higher concentration of solute in a solution. Saltwater compared to freshwater.
What are osmoconformers?
They do not actively adjust internal osmolarity, so there ECF is not necessarily the same composition.
What happens in the proximal convoluted tube?
—Section of the nephron between bowman’s capsule and loop of henle
—Most reabsorption of water and solutes occurs in the PCT
—Glomerular filtrate is reabsorbed in PCT
What is the Loop of Henle?
It maintains concentration gradient in the ECF of the medulla
What are the vasa recta?
-They are blood vessels in the medulla
-Blood flowing down the descending vasa loses water and gains solutes
-Blood flowing up the ascending vasa recta gains water and loses solutes
What happens in the distal convoluted tube?
-The DVT and collecting duct finetunes urine composition
-Water reabsorption
What is the effect of the length of the loop of Henle on urine concentration?
Long loops result in very concentrated urine and short loops result in less concentrated urine.
What are endothelial cells?
They line the capillaries of the glomerulus and are fenestrated (have tiny holes)
What is bicarbonate (HCO3-)?
Major buffer in blood and regulates pH systemically.
What does H+ do in the excretory system?
The kidneys remove H+ and add HCO3- when the blood becomes too acidic
What is GFR?
-Glomerular filtration rate is regulated
-A constant GFR requires that blood is supplied to the kidneys under adequate pressure
-A pair of kidneys filters 180L per day
What is the renin-angiotensin-aldosterone system?
A hormone system that regulates blood pressure.
What is renin?
A hormone dealing with blood pressure.
What is diabetes insipidus?
A disorder of salt and water metabolism marked by intense thirst and heavy urination.
What is diabetes mellitus?
Buildup of glucose in the blood.
What is type 1 diabetes?
Pancreas does not produced insulin
What is type 2 diabetes?
Cells become insulin resistant
What is urea?
A substance formed by the breakdown of protein in the liver.
What is the equation for partial pressure?
PO2=Ptotal x molar fraction of 02
If dry air is 20.9% O2, the PO2 of 02 at sea level is 0.209x760mmHg=159mmHg
What is the total atmospheric pressure?
760mmHg
What is Fick’s Law of Diffusion? And what is the equation?
It describes the diffusion rate for gas exchange.
Q=DA((P1-P2)/L)
Rate of diffusion=diffusion coefficient(area over which diffusion occurs)((partial pressure of gas in the mixture)/path length
What is the correlation between atmospheric pressure and altitude?
As atmospheric pressure is higher, altitude is lower. As atmospheric pressure is lower, altitude is higher.
