Terms in this set (283)
Name a few key differences between eukaryotic and prokaryotic cells..
Eukaryotes have a membrane-bound nucleus, membrane bound organelles and are larger than prokaryotes.
Eukaryotes have more than one chromosome.
Prokaryotes do not have an ER, mitochondria or a GA.
Where is rRNA made?
What is manufactured in the Rough ER?
Proteins are synthesised in the Ribosomes.
Proteins are modified in the Matrix.
What is the SER responsible for?
Lipid synthesis, drug detoxification, steroid synthesis and vesicle synthesis (besides proteins).
What distinguishes a cell wall from a cell membrane?
The cell wall is stronger, thicker and more rigid. It is made of / contains cellulose.
What is the role of the Golgi Apparatus (GA)?
Modifies proteins and ships to other locations using transport, secretory and membrane vesicles.
The organelle responsible for cellular respiration is..
The mitochondria are the site of which two processes?
The Kreb's Cycle and ETC & Oxidative Phosphorylation
The cytoplasm of a chloroplast is called the..
How many membranes do chloroplasts have?
Two, inner and outer
Where in chloroplasts do the LDR of photosynthesis take place?
Stacks of thykaloid sacks are called..
What do lysosomes do?
Digest endocytosed materials using pH sensitive digestive proteins.
What is the role of a central vacuole?
Stores water (due to high solute conc.) to release when needed. Aids in plant cell's turgidity.
What are vesicles for?
Transport and storage. Can contain excess materials in a cell.
Name three key differences between plant and animal cells
Plant cells have a cell wall as well as a cell membrane.
Cell shape: Plant -> rectangular/fixed. Animal -> round/irregular
Presence of chloroplasts.
Do prokaryotes have lysosomes or peroxisomes?
Give size ranges for eukaryotic and prokaryotic cells.
Eukaryotic -> 10-100 um
Prokaryotic -> 1-10 um
Genetic recombination in Prokaryotes proceeds by..
Partial, unidirectional transfers
Define facilitated diffusion
Passive transport of molecules across a biological membrane via trans-membrane proteins.
Define Active Transport
Movement of molecules across a cell membrane against their concentration gradient using ATP (primary) or an electrochemical gradient (secondary).
Name contributing factors to water potential
Osmotic pressure, Hydrostatic pressure, Oncotic pressure, Gravimetric, Humidity
Define a Carbohydrate
Carbon, Hydrogen and Oxygen
Polyhydroxy aldehydes and ketones
Give the general formula for a Carbohydrate
Cm(H2O)n (there are exceptions)
Saccharide is a synonym for a
The 4 groups of carbohydrates are..
Monosaccharides, Disaccharides, Polysaccharides and Oligosaccharides
The four monosaccharides are..
glucose, ribose, galactose and fructose
Sucrose = ...
glucose + fructose
Lactose = ...
glucose + galactose
Maltose = ...
2 x glucose
Name three disaccharides..
Sucrose, Lactose and Maltose
What are monosaccharides for?
Fuel for metabolism
If monosaccharides are unused they are converted to..
Polysaccharides like Starch and Glycogen.
What is Glycogen and where is it made/found?
multibranched polysaccharide of glucose, stored and made primarily in the liver and muscle cells.
Cellulose is a polymer of..
What is the bond linking the two units of a disaccharide?
What kind of reaction links mono units into a disaccharide?
Name two hexose sugars..
Glucose and Fructose
Name a pentose sugar..
What bond is characteristic of proteins?
Peptide bond. RONH
Primary protein structure is..
a chain of amino acids
Name two typical secondary protein structures. Define secondary protein structure.
Alpha Helix, Beta-pleated sheet.
H-bonding between backbone amino and carboxyl groups.
Tertiary protein structure is..
The arrangement of secondary structures, a protein's geometric shape. Also defined by its atomic coordinates.
Quaternary protein structure is..
3D structure of different proteins bonded together into multiple subunits.
Name two structural and two contractile proteins..
Structural -> Collagen and Elastin
Contractile -> Actin and Myosin
Give examples of proteins involved in transport, signalling, and any others
Insulin, Haemoglobin, Ion Channels, Ion Pumps
Give a broad definition of lipids
Small, amphiphillic molecules.
Triglycerides. 3 fatty acids + glycerol (propane -1,2,3 - triol)
Define a steroid.
Four linked cyclocarbons. Three 6C rings joined to a 5C ring
A monoglyceride is..
One fatty acid joined to glycerol
Give four uses of lipids in the body.
Lipid bilayers, electrical insulation (myelin), hormone production, energy storage, thermal insulation
The lock and key hypothesis states that..
The substrate must fit exactly into the enzyme's active site
The induced fit model for an enzyme states that..
The substrate induces an exact fit at the active site and the reaction takes place (explains why competitors fit but don't react)
Enzymes provide an alternative transition state with..
Reaction rate in the context of enzymes depends on..
Temperature and pH (enzymes have ideal ranges for both), enzyme concentration, substrate concentration
Small organic molecules, often containing a vitamin in their structure, which bind to enzymes for the duration of a reaction. E.g. NAD
Name three types of Cofactors
coenzymes, metal ions and inhibitors
What are non-competitive reversible inhibitors?
Inhibitor cofactors that bind to an enzyme (not at the active site) and change its shape, slowing down the reaction.
What are reversible inhibitors?
Inhibitor cofactors that bind temporarily to the active site of an enzyme, slowing down the reaction.
What are irreversible inhibitors?
Bind permanently (covalently) with the enzyme at the active site, effectively reducing enzyme concentration.
What are the advantages of having a double circulation?
It allows increased pressure and flow rate to systemic circ
What are the average lumen diameter and wall thickness of the aorta?
lumen diameter = 25 mm
wall thickness = 2 mm
How are arteries adapted to their role?
Muscular and elastic to smooth out pressure pulsations.
Muscular arteries can constrict to prevent blood loss.
Wall thickness reflects the high pressure of the blood they carry (compared to veins)
The endothelium lines all..
blood contacting surfaces
Give a typical value for the lumen d. and wall thickness of an arteriole
lumen d. = 30 um
wall thickness = 20 um
What is the function of arterioles?
Control the direction of blood flow priority by changing their resistance (vasoconstriction, vasodilation)
Arterioles change their resistance in response to..
Autonomic Nervous System
Most of the vascular resistance is accounted for by..
Give the lumen d. and wall thickness for a typical capillary.
lumen d. = 5 um
wall thickness = 1 um
Give the equation governing fluid flux through capillaries.
Jv = [ (Pc-Pi) -σ(Пp - Пi) ]
Give typical values for the lumen diameter and wall thickness of venules.
lumen diameter = 20 um
wall thickness = 2 um
Give the sequence of blood vessel type in the body.
Aorta -> Arteries -> Arterioles -> Capillaries -> Venules -> Veins -> Vena Cava
Hematocrit = ..
Give normal values for H in males and females.
H = vol of RBCs / total blood vol
Give three adaptations of RBCs.
Large s.a. to volume ratio from bioconcave shape
Flexible membrane to squeeze through capillaries
Lack of organelles & nucleus -> more space for Hb
Give the proportions of blood volume in different vessels.
Veins -> 60% Arteries -> 15% Capillaries -> 10%
Heart -> 7% Pulmonary -> 8%
Why is blood velocity the slowest in the capillaries?
Lowest pressure (except for veins) and the largest total cross-sectional area means that the flow rate is low in a single capillary.
What purpose does the slow flow rate in capillaries serve?
Allows time for the exchange of nutrients and gases
Do RBCs slow down blood in capillaries?
Yes. They are squeezing through (hence friction) so are slower than the blood would be otherwise. They are a large obstruction (to scale).
Why does blood leaving the capillaries to the venules speed up?
The pumping of the right side of the heart leads to suction and increased blood velocity
The biggest drop in pressure in the systemic circulation is across the..
Arterioles (arterioles to capillary transition)
Two blood vessels, A and B, have diameters of 3 cm and 1.5 cm, respectively. They each have the same volume of blood flowing through them. Which has the higher pressure?
Give Poiseuille's Law
ΔP = 8μLQ / ∏R^4 (ΔP ∝ Q / R^4)
Q = ΔP∏ R^4 / 8μL (Q ∝ ΔP R^4 / L)
Why is Poiseuille's Law not usually valid in vivo?
Under what conditions is Poiseuille's Law valid?
Large L, small D (e.g. less than aorta d.), STEADY STATE, Laminar Flow.
FAILS in the limit of low viscosity (e.g. high flow & shear rates in aorta).
Flow through a capillary is 12 mL/s. What would be the flow if the length was tripled?
Flow through a capillary is 32 mL/s. What would be the flow if the radius was halved?
What is the main reason why Poiseuille's Law is not valid for flow in the Heart?
The heart beats periodically (so no steady state).
Give a typical value for the lumen diameter and wall thickness of venules..
lumen diameter = 20 um
wall thickness = 2 um
Do veins and venules have smooth muscle?
Yes, but it is poorly developed.
Give a typical value for the lumen diameter and wall thickness of veins.
Lumen diameter = 5 mm
wall thickness = 0.5 mm
The Vena Cava has a l. diameter of ... and a wall thickness of ...
The right AV valve is called the..
The left AV valve is called the ..
Name the 5 stages of the heart cycle.
Mid diastole, atrial contraction, isovolumetric ventricular contraction, ventricular ejection, isovolumetric ventricular relaxation
The first heart sound is caused by..
Mitral valve slamming shut
The second heart sound is caused by..
The aortic valve slamming shut
Most organs are connected in parallel. Why?
Give an exception where organs are in series.
So that they have the same pressure across them.
Spleen and gut are in series with the liver.
What distinguishes Leukocytes (WBCs) with RBCs?
White blood cells have a spherical/irregular shape, are much larger than RBCs and they have a nucleus.
How would you differentiate between Basophils and Monocytes?
Basophils have a granular cytoplasm, Monocytes do not
Name the Agranulocytes and Granulocytes.
Agranulocytes -> Monocytes and Lymphocytes
Granulocytes -> Neutrophils, Eosinophils, Basophils, Mast cells, Megakaryocyte.
How would distinguish Monocytes from Lymphocytes?
Monocytes -> notched/kidney shaped nucleus
Lymphocytes -> round nucleus
What WBC count would be particularly high in a bacterial infection?
Give the main features of Monocytes
Phagocytic against antibody coated bacteria and viruses, and fungi.
Kidney shaped/notched/single lobe nucleus.
Differentiate into Macrophages.
Give the main features of a Lymphocyte
Identify cells infected by viruses
Give the main features of a Neutrophil
Break down ingested bacteria with lysosomes
Lobed nucleus, 1-4 lobes
High count indicates bacterial infection
Give the main features of Eosinophils
Fight parasitic infections
Work against allergens by making antihistamines in their granules
Give the main features of Basophils
Involved in allergic reactions
Create/start the immune response
Produce anti-/histamines, heparin and seratonin
The latter makes caps leaky so phagocytes can leave blood to fight infection
What is meant by antibody-mediated immunity?
Activation of B cells and production of plasma cells and memory B cells. Antibody production followed by the clearing of antigen-antibody complexes on invaders by the complement system, the liver or the spleen.
What is meant by cell-mediated immunity?
Activation of T cells -> production of memory T cells and Tc cells -> maturation and migration of Tc cells to fight invaders.
What role do Helper T cells play?
They are involved in the activation of B cells and T cells and the differentiation of B cells.
Release cytokines which are involved in the above and in attracting more macrophages and neutrophils as well as directing the troops when they arrive.
What are the main functions of B cells?
Millions made everyday performing Immune Surveillance
Unique protein that binds only one antigen.
Can differentiate into memory B cells and plasma (B) cells.
What do plasma B cells do?
What is the function of memory B cells?
They allow the response to successive exposures to an antigen to be more rapid and effective (no processing). They can differentiate into plasma cells -> hence more antibodies produced.
Innate Immunity is..
Set of non-specific defenses that come into play immediately or within hours of an antigen's appearance.
Includes the complement system, liver, spleen, skin, mucosa and some leukocytes.
Adaptive Immunity is...
An antigen-specific immune response. Antigen must be processed which takes time. The specific response is cell-mediated and antibody-mediated.
Possesses memory which allows successive exposure to be dealt with rapidly and effectively.
What happens in the early stages of bacterial infection before antigen processing?
NK cells and Macrophages migrate to the infected area to fight the infection. (Innate immunity, non-specific defenses)
What are the two main tissue types for transport in plants and what do they transport?
Xylem -> transports water and minerals
Phloem -> transports organic molecules
Describe Xylem vessels
Made of dead, hollow cells. They are long, with a large lumen and many perforations.
Describe movement of water in the Xylem.
Transpiration through stomata and mesophyll cells emptying water out of top of xylem lower Ptop. Active transport of minerals into the root draws in more water by osmosis -> increase in root pressure. Proot > Ptop so water flows up.
Root hair cells have a high..
surface area, osmolarity (hypertonic)
Describe the structure & function of the Phloem.
Transports sap. Two way flow. Takes water and sugar from leaves to other parts. Sieve Tube Elements are tubular cells connected end to end. Ends are perforated -> sieve plates. Lack nucleus + organelles -> more room for water and solutes (organic) to move.
Describe the location and function of Companion Cells.
Next to each sieve tube element. Connected cytoplasms. Provide ATP to STEs and control movement of solutes in STEs.
Support (through turgidity) to STEs
Transport of organic molecules such as sucrose in the Phloem is from the ... to the ...
leaves, roots (or other parts)
Sucrose is loaded into the phloem by..
H+/sucrose pump (driven by a [H+] gradient)
[H+] gradient maintained by ATP/H+ pump.
What effect does the active transport of sucrose (or other molecule) have on transport in the Phloem?
It increases the tonicity which causes water to flow in from the Xylem, increasing the pressure and driving flow.
Define Heterotrophic Nutrition.
Organisms that feed on others that have made their own food. They have to convert solid food into soluble compounds capable of being absorbed.
Give the sequence of structures in the human GI tract.
Esophagus -> Stomach -> Duodenum -> Jejenum -> Ileum -> Cecum -> Colon -> Rectum -> Anus
How long is the human GI tract?
Where does most chemical digestion take place?
In the duodenum.
Besides the stomach, what empties into the duodenum?
Common bile duct (union of common hepatic + cystic duct from gall bladder) and the Pancreatic duct.
Where are most nutrients such as sugars, amino acids and fatty acids absorbed?
In the Jejenum
What is absorbed in the Ileum?
Mainly B12 but also remaining nutrients.
In what parts of the GI tract are villi located?
Duodenum, Jejenum and Ileum (small intestine)
The small intestine consists of..
Duodenum -> Jejenum -> Ileum
The large intestine consists of..
Cecum (+appendix) -> Colon (ascending, transverse, descending) -> Rectum -> Anus
The function of the large intestine is to..
Absorb water and pass waste material from the body.
Also stores waste.
Absorb remaining nutrients.
Describe the initial form of digestion which takes place in the mouth.
Chewing + saliva -> breakdown and increase surface area
Saliva contains amylase for the breakdown of polysaccharides.
What role does HCL play in the stomach?
Optimum pH for enzymes
Name a protein present in the stomach which degrades proteins.
When chyme passes the pyloric sphincter into the duodenum it is mixed with which three fluids?
Briefly describe the function of each.
Bile -> emulsifies fat and neutralises chyme
Pancreatic Juice -> amylase, lipase, tripsinogen, etc
Intestinal Juice -> enteropeptide, maltase, lactase, sucrase, etc
Bile is made in the ... and stored in the ...
Liver, gall bladder
What vessel carries absorbed nutrients from the duodenum to the liver?
Hepatic portal vein
Peristalsis is driven by ... muscles and ... muscles which are antagonistic.
Protein breakdown occurs in the..
stomach and duodenum
Name two enzymes that breakdown proteins into polypeptides.
Pepsin and trypsin
What organ secretes the enzymes responsible for the breakdown of DNA & RNA?
What purpose does emulsifying fats serve?
They are present as a 'bolus' in the GI tract. Emulsification allows them to be mixed with water and breaks up the bolus. It removes the hydrophobicity.
Give the overall reaction of photosynthesis.
6CO2 + 6H2O -> C6H12O6 + 6O2
The main photosynthetic pigment is..
List three environmental factors affecting the rate of photosynthesis.
Temperature -> higher is better but only up to optimum
The LD reactions in photosynthesis provide ... and ... to the Calvin Cycle for the production of sugars.
Summarize the LDR reactions of photosynthesis in terms of light, electrons and gradients.
light -> excitation -> electron "capture" -> electron transport -> energy drives conc gradient of H+ -> gradient drives ATP synthesis
What is meant by non-cyclic phosphorylation?
Electrons passed to NADP instead of ETC which results in no ATP being produced
Cyclic phophorylation produces ATP. This occurs in the presence of plenty of ...
NADPH2 (NADPH + H+)
What is the net result of spermatogenesis in terms of the number of spermatozoa produced?
1 spermatogonium -> 4 spermatozoa
Define diploid and haploid.
Diploid -> 2 sets of each chromosome (mother and father) 2n
Haploid -> 1 of each of the 23 chromosomes n
In the testes, sperm is produced in the ...
Cells involved in the process are ... and ...
Leydig cells, Sertoli cells
Outline the processes involved in the production of spermatozoa from a single spermatogonium.
Mitosis -> Meiosis I -> Meiosis II -> Spermination
Name three hormones involved in spermatogenesis.
LH, FSH, Testosterone
What is meant by a Graafian Follicle?
A Secondary Oocyte surrounded by follicle cells.
The release of a 2dary Oocyte from the Graafian Follicle is termed..
What is left behind?
Describe the Graafian Follicle
Thick wall of follicle cells (Theca) surrounding the 2dary Oocyte like a capsule. Filled with fluid.
Are the 2 mitotic divisions that produce Oogonia part of Oogenesis?
The menstrual cycle can be described as two cycles, the ... and the ...
What are the two phases of the Ovarian Cycle?
Follicular (1-14) and Luteal (14-28)
Describe the Follicular phase of the Ovarian cycle.
Follicular -> FSH stimulates ovarian follicles to compete
All but one stop growing. Dominant follicle matures into Graafian Follicle.
FSH rises then declines.
estradiol is supressing LH
Describe the events that lead to ovulation.
estradiol begins to stimulate LH
Large, rapid LH surge weakens Graafian follicle wall releasing 2dary oocyte which then matures into Ovum.
Left over -> corpus luteum
Ovum swept to fallopian tube.
Describe the Luteal phase of the Ovarian cycle.
Corpus Luteum produces progesterone which rises.
Increased progesterone -> increased oestrogen
Both supress LH & FSH
Later, falling progesterone causes uterine lining breakdown and menstruation
What are the three phases of the Uterine cycle?
Menses, Proliferative, Secretory
Give the duration, and describe the events of the menses phase of the Uterine cycle.
2-7 days considered normal.
Breakdown of uterine lining due to falling progesterone
Describe the proliferative phase of the Uterine cycle.
Oestrogen rises causing uterine lining to grow
As ovarian follicles mature they secrete oestrogen and estradiol which increase causing LH surge and ovulation
Describe the secretory phase of the Uterine cycle.
Corpus luteum produces progesterone which makes endometrium receptive to implantation, increases uterine secertions and reduces contractility of uterine sm. muscle
(preparation for possible pregnancy)
Interphase, Prophase, Prometaphase, Metaphase, Anaphase, Telophase
Describe Interphase (mitosis)
G1 -> growth by producing proteins and organelles
S -> chromosomes replicated
G2 -> grows again and prepares for division
Describe Prophase (mitosis)
Chromatin condenses into chromosomes
Centrosomes move to either side of cell
Formation of spindle attached to centrosomes
Spindle microtubules attach to centromeres
Chromosomes align along metaphase plate
(Meet in Middle) X1 aligned with X1 (duplicated)
Chromatids separate and move to opposite sides of cell
Organelles also at the sides -> empty space in middle
New nuclear envelopes form around each group of DNA
Chromosomes unfold back into chromatin
Citokinesis -> daughter cells divide
Give the sequence of phases in Meiosis.
Meiosis I : Prophase, Metaphase, Anaphase, Telophase
Meiosis II : Prophase, Metaphase, Anaphase, Telophase
What is the key difference in Prohase I in Meiosis compared to Mitosis?
Synapsis -> Cross over or swapping of genes between sister chromatids on homologous chromosomes. This leads to variation.
What is the key difference in Metaphase I in Meiosis compared to Mitosis?
Each duplicate pair can be on the left or on the right of the metaphase plate. Total 2^pairs combinations. VARIATION
What is the key difference in Meiosis II compared to Mitosis?
The process is the same except that the chromosomes have NOT been duplicated. This produces 4 (2each) haploid gametes.
Glycolysis is the metabolic pathway that converts ... into ...
The overall reaction for glycolysis is..
D-Glucose + NAD+ + 2ADP + 2[Pi] ->
2Pyruvate + 2NADH + 2H+ + 2ATP + 2H2O
The net gain in Glycolysis in terms of energy and reducing power is..
2 ATP, 2 NADH per glucose molecule
What are the rate limiting steps in Glycolysis?
Those that require ATP
The net gain in the oxidation of pyruvate is..
2 NADH (1 per pyruvate)
The net gain in the Kreb's Cycle in terms of energy and reducing power is..
2 ATP, 6 NADH, 2FADH (for 2 acetylCoA)
What is the net ATP gain for 1 glucose?
(10x3 + 2x2 -2 +4 = 36)
In the ETC & OP 1 NADH results in ... ATP, and 1 FADH2 results in ... ATP.
Without oxygen, what cannot be re-made which causes glycolysis to stop?
The last electron acceptor in the ETC is...
What is the key mechanism in anaerobic respiration?
The pyruvate is reduced to lactate which regenerates NAD+ allowing glycolysis to continue
Give the sequence of structures leading from the pharynx to the alveoli.
Pharynx -> Larynx -> Trachea -> Bronchi (L&R)
-> Bronchioles -> Terminal Bronchioles
-> Respiratory Bronchioles -> Alveolar Ducts -> Alveoli
Give the formula for the Respiratory Quotient.
RQ = CO2 eliminated / O2 consumed
The Kidneys are responsible for the homeostatic control of..
Blood H2O, Blood pH, salt & iron levels, elimination of uera & other wastes
Give three examples of homeostatic control.
Temperature, Blood H2O, Blood glucose
Name sources of heat loss from the body.
Radiation, conduction, convection, evaporation
Temperature control is performed by the..
Give the body's response to a hot environment.
Sweat, hairs lie flat
Arteriolar vasodilation increases blood flow to skin -> increased heat loss by convection, conduction and radiation
Give the body's response to a cold environment
No sweat, hairs stand on end -> less loss via convection
Arteriolar vasoconstriction -> blood away from skin & towards hot int. organs -> reducing heat loss
Shivering -> icreased resp. in muscles -> more heat prod
Mitochondria can convert fat into heat energy
Define Hyperglycemia and Hypoglycemia.
Hyper- persistenly high level of blood glucose
Hypo- persistently low level of blood glucose
What are the normal levels of blood glucose in a fasting state and 2 hours after eating?
2 hours after eating x<140
What is glycogenolysis? Where does it occur?
The breakdown of glycogen into glucose-1-phosphate
Hepatocytes and muscle cells
What is Gluconeogenesis? Where does it occur?
Synthesis of glucose from non-carbohydrate substrates.
Primarily in the liver.
Give an overview of the body's response to high blood glucose.
Beta cells release insulin -> increased uptake of glucose, increased rate of glycogenesis, decreased rate of glycogenolysis, increased rate of respiration
Give an overview of the body's response to low blood glucose.
Alpha cells release glucagon -> promotes glycogenolysis (liver), promotes gluconeogenesis (liver), reduces glucose uptake in liver, inhibits glycolysis
The Ornithine/Urea Cycle serves to convert ... into ... It requires ... molecules of ATP per NH3
Ammonia, Urea, 3
Excess protein intake is dealt with by ... (reaction/process) which produces ... which is then converted to Urea in the ... (organ)
Deamination, Ammonia, Liver
What is extracted from the blood during Ultrafiltration (glomerulus -> B capsule)?
H2O, urea, NaCl, glucose
What is reabsorbed, and how, during Selective Reabsorption in the Proximal Tubule (Kidney)?
Na+, Cl-, glucose, amino acids & vitamins.
They diffuse out into surrounding cells & are then actively transported back into the blood.
Describe what happens in the acending and descending limbs of the Loop of Henle.
Ascending limb: Na, Cl actively pumped out -> creates high NaCl in medulla. Impermeable to water. ∴ fluid gets diluted.
Descending limb: H2O flows out (since medulla salty) and collected by blood stream. Na & Cl diffuse in. ∴ fluid gets concentrated.
What hormone controls the permeability of collecting ducts in the kidneys? Where is it secreted?
ADH. Secreted in pituitary.
Give the response to concentrated blood (low H2O).
Osmoreceptors sense -> increased firing to pituitary
-> increased secretion of ADH -> increased permeability to H2O of coll. duct -> increased H2O reabsorption
What is meant by diuresis?
Increased or excessive production of urine.
What is Natriuresis?
The process of secreting Na in the urine. Na+ takes water with it because of osmotic forces. This lowers blood volume. Diuretics take advantage of this to treat hypertension.
The CNS consists of..
Brain and Spinal Chord
White matter consists of..
Axons and Olygodendrocytes (provide myelin sheath insulation and support to axons)
The PNS consists of..
Neuron cell bodies & ganglia
Somatic & Autonomic Nervous systems.
Ganglia are neuron cell body clusters outside of CNS.
The Autonomic Nervous system is..
Control system that acts below the level of conciousness
Controls HR, digestion, respiratory rate, salivation, perspiration, breathing, arousal, pupillary dilation/contraction, etc
The functions of the ANS can be divide into..
Sensory (afferent) & Motor (efferent)
The Enteric Nervous System (ENS) governs the funnctions of what system?
The SNS is responsible for the "..." response.
Fight or Flight
The PSNS can be described by which phrases, in contrast to the SNS?
"Rest & Digest", "Feed & Breed"
The SNS, PSNS and ENS are part of which nervous system?
Describe sensory and motor neurons.
Sensory -> respond to stimuli from sensory organs. afferent.
Motor -> receive signals from CNS & cause muscle contractions, affect glandular output, HR regulation, vasoconstriction/dilation, etc. efferent.
Dendrites extend from the ...
Axons are ..
Responsible for transmitting action potentials. One per neuron. Can be up to one metre long in humans.
Name examples of molecular machinery which contribute to the function of neurons.
Ion channels, voltage gated ion channels, ion pumps, chemically gated channels
Myelin sheaths are responsible for what aspect of conduction in neurons?
Name two types of synapses
Chemical and Electrical
Give a typical value for the resting potential of a neuron.
Give the Intracellular and Extracellular concentrations of Na+ and K+, as well as their respective equilibrium potentials.
Intracellular Extracellular Eq. Potential
K+ 140 5 -94 mV
Na+ 12 140 +54 mV
Cl- lower higher -65 mV
Give the formula for the Nernst Equation.
E = RT/zF ln( [Ion outside] / [Ion inside] )
If the K+ equilibrium potential is -90 mV and the membrane potential is -70 mV, in what direction will K+ move through open K+ channels?
Out of the cell.
Given that the Na+ equilibrium potential is +60 mV and the membrane potential moves from its resting level to 0 mV, in what direction will Na+ now move through any open Na+ channels?
Into the cell (as it usually does, but now even easier since only conc gradient matters)
Given that the membrane potential is -70 mV, in what direction will the electrical potential difference make K+ move through open K+ channels?
Into the cell
Describe the generation of a graded potential.
Opening of ligand gated channels -> influx of Na+, outflux of K+ -> influx of Na > outflux of K (since potential favors Na influx) -> leads to depolarisation (graded potential)
What is required for an Action Potential to occur
Graded pontential stimulus must reach the hillock of the axon and depolarise it to the threshold potential. This can be achieved by a large graded potential or several gr. pot. inputs to the soma adding up. Inputs closer to hillock more likely to generate AP
Describe Action Potentials.
Graded potential at hillock raises Vm to threshold (-55mV) -> VG Na+ channels open fast -> depolarization to +30mV -> causes neighbouring VG Na+ to open ->AP propagation -> (meanwhile) VG K+ open slow and close slow -> repolarization -> overshoot -> back to resting pontential
The neurotransmitter of the SNS is ...
Noradrenaline / Norepinephrine
The neurotransmitter of the PSNS is ...
A neurotransmitter found in the brain and related to Shizophrenia is ...
Glycogenolysis decreases after midnight because..
Glycogen is being depleted since we need glucose ergo we slow down the breakdown of glycogen
What provides the early morning (fasting) blood glucose supply?
Glycogenolysis and Gluconeogenesis
Thirty minutes after eating a large sweet meal including cake and candy, what levels of Glucose and Insulin would be expected?
High Glucose, High Insulin
(sufficient time for response and insulin secretion but not that long that blood glucose has gone down)
A person with blood type O+ can donate blood to all blood groups except ... Because ...
Rh-, because Rh- blood has antibodies against Rh antigens and hence this would destroy O+ blood and because O blood has no A or B antigens.
A patient with blood type A+ can receive blood of types ... because ...
A+, A-, O-, O+
no foreign antigens
A patient with blood type B- can receive blood of types ... because
no foreign antigens
A person with blood type AB has genotype ...
Ia Ib (codominance)
The Rh factor is inherited in ... fashion.
A person with blood type O has genotype ...
ii (homozygous recessive)
Give the Hardy-Weinberg Equation.
p^2 + 2pq + q^2 = 1
What is X linked inheritance?
A gene passed only through the X chromosomes. Hence fathers cannot pass to sons, etc
The hemophilia gene is and example of X-linked recessive inheritance. What are the genotypes of a female sufferer, a male sufferer and a female carrier?
Female sufferer -> Xh Xh
Male sufferer -> Xh Y
Female carrier -> XH Xh
Complete these lung volume equations.
IC = TV + IRV
FRC = RV + ERV
VC = IC + ERV
TLC = VC + RV = IC + FRV
The average TLC of an adult male is ... and the average resting TV of adults is ...
6.0 L, 0.5 L
Describe the trend in O2 binding to Hb which accounts for the sigmoid shape of the O2-Hb dissociation curve.
Binding the first molecule of O2 is hard. Successive O2 molecules are easier to bind due to conformational changes in Hb. Each Hb can bind up to 4 O2.
In the ... the affinity of Hb for O2 is higher than in the ...
lungs, tissues (systemic)
Normal Pa (O2) is ... and the corresponding SATs are ...
110 mmHg, 95-98 %
A right shift of the O2-Hb curve can be caused by ... and a left shift can be caused by ...
Increased CO2, decreased pH, increased T
opposite of the above
P50 is ... and its normal value is ...
The p(O2) at which Hb is 50% saturated
Normal value = 26.8 mmHg
The cells involved in Adaptive Immunity are ..
T cells and B cells
The cells involved in Innate Immunity are ..
NK cells, mast, eosinophils, basophils, monocytes/macrophages, neutrophils, dendritic
Which three cells are termed Lymphocytes?
T cells, B cells and NK cells
An example of APCs (antigen presenting cells) are ...
In a fungal infection we would see an elevated ... count.
In a parasitic infection we would see an elevated ... count.
In a bacterial infection we would see an elevated ... count.
The 1st and 2nd most abundant types of leukocytes are..
T cells mature in the ...
Give the equation for the osmotic component of water potential (osmotic pressure).
Ψ = -iCRT
A cell placed in pure water has, after a time..
equal osmotic and hydrostatic pressure (in magnitude)
Define cytolysis and plasmolysis.
Cytolysis: A cell gaining water in a hypotonic solution
Plasmolysis: A cell losing water in a hypertonic solution
During mitosis the number of (distinct) chromosomes ... whilst the amount of DNA ... because of division.
stays the same (2n), halves
During meiosis the number of (distinct) chromosomes ... during meiosis I and ... during meiosis II. The amount of DNA ... during meiosis I and ... during meiosis II.
halves (n), remains the same (n) (haploid),
halves (2d), halves again (d).
Genetic linkage is ... and is measure in ...
the tendency of genes located on the same chromosome to be inherited together, centimorgans (cM)
Give the equation for measuring 'map distance' and therefore genetic linkage.
Map d = # of recombinant offspring / total offspring *100
i.e. the % of recombinant offspring
A recombinant genotype is the result of ...
For two given genes with a given map distance between them, if the chromosomal arrangement of alleles is changed, what remains constant?
The percentages of recombinant and parental genotypes in the offspring. NB, the phenotypes of these may be different.
In the Hardy-Weinberg equation, what do each of the terms represent?
p^2 -> % of homozygous dominant individuals
2pq -> % of heterozygous individuals
q^2 -> % of homozygous recessive individuals
In a population of 100, 64 individuals show the Wild phenotype (complete dominance). Calculate the number of heterozygous individuals.
q^2 = 100 - 64 = 36% q = 0.6
p = 0.4 -> 2pq = 48% -> # heterozygous = 48