PHYSIOLOGY Flashcards
WHAT IS NTS
NUCLEUS TRACTUS SOLARITIS
WHERE ARE SENSORS FOR REGULATING MAP LOCATED
CAROTID SINUS
AORTIC ARCH
WHAT TYPE OF RECEPTORS REGULATE MAP
BARORECEPTORS- SENSITIVE TO STRETCH
THE AORTIC BARORECEPTOR IS CONNECTED TO WHICH CRANIAL NERVE
10TH- VAGUS NERVE
CAROTID BARORECEPTOR IS CONNECTED TO WHICH CRANIAL NERVE
9TH- GLOSSOPHARYNGEAL
NORMAL RANGE OF MAP
70-105 mm Hg
minimum map of _______ is needed to perfuse vital organs
60 mm Hg
normal range of pulse pressure
30-50 mm Hg
value of Bp for hypertension
140/90 mm Hg
daytime avg: 135/85 mm Hg
neruotransmitter released by sympathetic division + receptor on which it acts
receptor acting on heart
noradrenaline- beta 1 adrene receptors
neurotransmitter released by parasympathetic division + receptor on which it acts
acetylcholine- m2 muscarinic receptors
parasympathetic division is linked to stimulation of which cranial nerve
10th- vagus nerve
slowed heart rate
bradycardia
fast heart rate
tachycardia
most anterior surface of heart
right ventricle
most posterior surface of heart
left atrium
neurotransmitter acting on vascular smooth muscle supplied by sympathetic nerve fibres
noradrenaline
noradrenaline acting on vascular smooth muscle supplied by sympathetic nerve fibres acts on which receptor
alpha receptor
Disadvantage of Anastomoses
Disadvantage = they bleed from both sides of a cut
external iliac artery supplies
lower limbs
internal iliac artery supplies
pelvis and perineum
where does lymph return to veins
root of the neck
what is an End artery
the ONLY arterial blood supply to a given area
what is Infarction
irreversible cell death due to hypoxia
what is hypoxia
inadequate oxygen supply
what does an Anastomosis/ collateral circulation around a tissue do
Provides alternative routes for blood to flow to supply the cells distal to an arterial occlusion (blockage)
aortic arch 3 branches:
brachiocephalic trunk
left common carotid artery
left subclavian artery
Lymph eventually drains into venous system at?
venous angles in root of neck
Venous blood flows assisted by :
3 things help it
Venous valves
(2) Muscular contraction
(3) Venae comitantes
Small veins run in pairs or more with an artery in a sheath
what is Venae comitantes
Small veins run in pairs or more with an artery in a sheath
Arterial pulsation pushes venous blood along
blood in veins flows in ___ direction
one/ unidirection
venous blood from GI tract and associated organs is drained to the
portal vein
Two main venous systems
hepatic/portal venous system
system venous system
lymph node can usually be palpated true or false?
false.
Normal lymph nodes cannot usually be palpated
Lymph nodes fighting infection or being taken over by a spreading cancer usually enlarge and can be palpated or seen on CT scan
what is vasomotor tone
Vascular smooth muscles partially constricted at rest - caused by tonic discharge of sympathetic nerves
what are the major components of a cell plasma membrane.
lipids:phospholipids, cholestrol
carbohydrates: glycoproteins and glycolipids-glycocalyx
protiens: membrane proteins
Pure phospholipid bilayer membranes are extremely impermeable to
almost any water-soluble substance/ polar/ hydrophilic substance
Pure phospholipid bilayer membranes are permeable to
small uncharged polar molecules can cross fairly freely
eg: O2, CO2, NH3, H2O
water is impermeable to the phospholipid bilayer due to hydrophobic tails
true or false
false
small uncharged polar molecules can cross fairly freely including H2O
Two types of membrane proteins are
peripheral or integral
Peripherally associated membrane proteins are not embedded within the membrane
true or false
true
they adhere tightly to the cytoplasmic or extracellular surfaces of the PM
what are transmembrane proteins?
integral proteins span the lipid bilayer once or several times
functions of integral membrane proteins
7 functions
Adhesion molecules
Ligand-binding receptors
Pumps
Carriers
Pores and channels
Enzymes
Intracellular signalling
what are Docking-marker acceptors? where are they located
Docking-marker acceptors interact with secretory vesicles leading to exocytosis of the vesicle contents.
they are located on the inner membrane surface
what is glycocalyx
Short carbohydrate chains bound to membrane proteins lipids form glycoproteins and glycolipids- which
together form glycocalyx
Membrane carbohydrates serve as self-identify markers
true or false
true
ensures:
Cells do not overgrow their own territory
cancer cells have a normal surface marker of membrane carbohydrates
true or false
false
cancer cell growth have abnormal surface markers
3 types of cell junctions
tight junctions
adhering junctions
gap junctions
connexons are hydro____ channel proteins present in gap junctions
hydrophilic
what is tonicity
effect a solution has on cell volume
what are the two properties that influence whether a particle can permeate the plasma membrane without assistance
lipid solubility
Size of the particle
passive transport is driven by which two gradients
concentration gradient
electrical gradient
5 factors on which Ficks law of diffusion depends on
Fick’s law of diffusion:
1.magnitude of the concentration gradient
2.surface area of the membrane across which diffusion is taking place
3.lipid solubility of the substance
4.molecular weight of the substance
5.distance through which diffusion must take place
in Ficks law of diffusion, which factors are directly proportional to net rate of diffusion
conc gradient,surface area,lipid solubility
in Fick’s law of diffusion, which factors are indirectly proportional to the net rate of diffusion
molecular weight, distance
what are the two types of ion-gated channel proteins?
leak: always open
gated: open and close in response to membrane potential or chemical stimuli (ligand-gated channels)
what is osmosis
Osmosis is the net diffusion of water down its own concentration gradient through a selectively permeable membrane
what are water channels ( membrane proteins) called
Aquaporins
unit of osmolarity
osmoles/litre
how does passive transport occur down a concentration gradient?
simple diffusion
how does passive transport occur along an electrical gradient?
ion channels
what is an electrochemical gradient
The net effect of simultaneous electrical and concentration gradients on an ion is called an electrochemical gradient
3 important characteristics determine amount of material transferred across a carrier-mediated membrane
1.Specificity
2.Saturation- Tm
3.Competition
1.Each carrier is specialised to transport a specific substance or a few
2.Transport Maximum
3.E.g. An amino acid carrier can transport both Gly and Ala. The presence of both diminishes the rate of transfer for either.
how does carrier-mediated transport work
Substances bind onto a specific carrier protein which undergoes a conformational change (shape change) that transports the substance
what are the two forms of active transport?
Primary active transport
Secondary active transport
what is primary active transport
when energy is directly required to move a substance against its concentration gradient- ATP is hydrolysed to give ADP+Pi
what is secondary active transport
when the carrier moves a molecule by using secondhand energy stored in the form of an ion concentration gradient (usually a Na+ gradient)
3 important roles for the Na+-K+ pump
1.Helps establish Na+ and K+ concentration gradients
2.regulates cell volume
3.energy source for secondary active transport
2.controls concentration of solutes inside the cell
3.energy used to drive the pump indirectly serves as the energy source for secondary active transport
Na+-K+ ATPase transports __ Na+ out for ___ K+ in
3, 2
what is secondary active transport
transfer of solute across the membrane coupled with the transfer of the ion that supplies the driving force (typically Na+)
what is Symport (co-transport)
The solute and Na+ move in the same direction.
solute gets into cell
what is Antiport (exchange or countertransport)
The solute and Na+ move in opposite directions (Na+ into, solute out of the cell)
vesicle transport requires energy for formation and movement within the cell
true or false
true
Normal Heart Rate/Pulse in adults
normal resting HR 60-100 beats/min
Normal Capillary refill time in adults
<2 seconds- less than 2 sec
Normal Oxygen Saturation in adults
≥96%.
Normal Respiratory Rate in adults
normal resting RR 12-20 breaths/min
“outer shell” of the human body consists of
skin and subcutaneous tissue
Core Body Temperature is:
The temperature of the blood and internal organs, 37.8 C
what is normothermia
Normal core body temperature is kept within a narrow range called normothermia
3 indirect estimates of core body temperature
infrared tympanic thermometer, infrared forehead and forehead strips
what is tympanic temperature? what is the normal range
Ear Drum (tympanic): normal range about 36 C-37.5 C:
what is the range for fever
38-40 C
what is the temp for hyperthermia
above 40 C
what is the temp for hypothermia
at or below 35 C
Direct estimates of core body temperature are taken by measuring temp in?
Rectal or Oesophageal
Nonshivering thermogenisis is by
Brown fat
Shivering increases heat production by increasing _________, hence metabolic heat production can be increased enormously
Muscle Activity
The BMR can be increased by hormones such as
3
adrenaline, noradrenaline, and thyroxine
what is Basal Metabolic Rate
minimum amount of energy required to sustain vital body functions- leads to the basic level of Heat Production
WHAT ARE THE SENSORS TO SENSE CHANGES IN CORE BODY TEMPERATURE
THERMORECEPTORS
where are the thermoreceptors located?
-Central thermoreceptors
hypothalmus, abdominal organs
-Peripheral thermoreceptors
skin
what is the control centre to maintain core body temp
hypothalamus
The Hypothalamus acts as the body’s thermostat (maintains the temperatur
what are the effectors to maintain core body temp
Skeletal Muscles
Skin Arterioles
Sweat Glands
The __________ hypothalamic centre is activated by cold
and
The __________ hypothalamic centre is activated by warmth
posterior ,anterior
The posterior hypothalamic centre is activated by ______
cold
The anterior hypothalamic centre is activated by _______
warmth
how do Skin Arterioles (effectors) help to warm the body during exposure to cold
Vasoconstriction
(contraction of the arterioles’ smooth muscles) - blood flow to the skin surface is reduced - heat conservation (Decreased heat loss)
how do Skeletal Muscles
help to warm the body during exposure to cold
Increased muscle tone
Shivering
Increased voluntary movement (behavioural)
increased heat production
how do Skin Arterioles (effectors) help to cool the body during exposure to warmth
Vasodilatation
(relaxation of the arterioles smooth muscles) - blood flow to the skin surface is increased (Increased heat loss)
how do Skeletal Muscles
help to cool the body during exposure to warmth
Decreased muscle tone
Decreased voluntary movement (behavioural)
who releases endogenous pyrogens
macrophages (certain type of phagocytic white blood cells)
what do endogenous pyrogens stimulate the release of?
Endogenous pyrogen (e.g. interleukins) stimulates the release of prostaglandins in the hypothalamus
what do prostaglandins do to the body’s normal hypothalamic set point?
prostaglandins act on the hypothalamic thermo-regulatory centre to “reset” the thermostat at a higher temperature
During fever, how would the hypothalamic set point return to normal?
The hypothalamic set point would be restored to normal if the pyrogen release is reduced/stopped or the prostaglandin synthesis is decreased/ceased
