Flashcards in Physiology Deck (62):
Define the term tissue
A group of cells which have similar structures and a specialised function
Define the term Organ
Two or more types of primary tissues that work together to perform a particular function
Define a body system
A group of organs that perform related functions to achieve a common goal
What is Homeostasis?
The maintenance of steady states within our bodies by co-ordinated physiological mechanisms
When does the response occur in a feedforward mechanism?
In anticipation to a change
When does the response occur in a feedback system?
After a change has happened
What is a phospholipid?
A glycerol backbone with two fatty acid chains
What is the function of the lipid bilayer?
Structure, hydrophobic end acts as a barrier and gives membrane fluidity
Give examples of integral membrane proteins
Pores and channels
Give an example of a ligand binding receptor
Where do pumps get their energy from?
Use energy released from ATP hydrolysis
What is the function of cholesterol?
Gives the membrane structure and stability
Fick's law of diffusion - factors which effect the rate of diffusion
Magnitude of conc gradient
SA of membrane
Lipid solubility of substance
Distance for diffusion to take place
What are the units of osmolarity?
Osmoles of solute per litre
The effect a solution has on cell volume - has no units
Name the two types of carrier mediated transport and whether they require energy
Facillitated diffusion - no energy
Active transport - energy from ATP
Give an example of primary active transport
What is secondary active transport?
When energy is required but isn't used directly it is second hand energy - e.g. coupled with Na+
What is primary active transport?
When energy is required and used directly
Define membrane potential
The separation go opposing charges across a membrane
Is the membrane itself charged?
No - it is the the regions of intra and extracellular fluid which creates a charge across it
When is the resting membrane potential constant?
In non-excitable cells and excitable cells at rest
Where is the highest conc. of potassium?
Inside the cell
Where is the highest conc. of sodium and chlorine?
Outside the cell
Which direction is the conc. gradient for K+?
Which direction is the conc. gradient for Na+?
Which direction is the electrical gradient for K+?
What is the membrane potential at Ek?
What is the membrane potential at Ena?
At rest which ion is the membrane more permeable to?
What is the resting membrane potential, Em?
What does the nernst equation calculate?
The equilibrium potential taking into account a single ion
What does the goldman-Hodgkin-Katz equation calculate?
The membrane potential taking into account contributions made by more than one ion
What is the charge aside a cell at rest?
Which hormones control glucose conc. in the absorptive and post-absorptive states?
Insulin and glucagon
Which hormones control glucose conc. in emergencies?
Which hormones control glucose conc. during starvation?
Cortisol and growth hormone
What does each type of cell in the islets of Langerhan secrete?
Alpha - glucagon
Beta - Insulin, c peptide, amylin
Delta - somatostation
F cells - pancreatic polypeptide
Which hormone is the the hormone of the fed state?
Which hormone is the hormone of the hungry state?
What does insulin do?
Convert glucose into glycogen
What does glucagon do?
Converts glycogen into glucose
What does the sympathetic stimulation do to insulin secretion?
What does parasympathetic stimulation do to insulin secretion?
Name three types of incretins
CCK, GLP-1 and GIP
which reactions does glucagon stimulate?
Glycogenolysis, gluconeogenesis and ketogenesis
What is released from the adrenal gland in response to stress?
Adrenaline and cortisol
Which lobe is growth hormone secreted from?
Anterior pituitary gland
What is meant by mean arterial blood pressure?
The average arterial blood pressure during a single cardiac cycle which involves contraction and relaxation of the heart
What is the formula for MAP?
MAP = [(2xdiastolic) + systolic]/3 or MAP = diastolic blood pressure + 1/3(systolic - diastolic)
Which cranial nerve is involved in the carotid baroreceptor signalling?
IXth - glossopharyngeal
Which cranial nerve is involved in the aortic baroreceptor signalling?
Xth - Vagus
What relationship is CO and TPR to MAP?
MAP = CO x TPR
What is cardiac output?
The volume of blood pumped by each ventricle of the heart per minute
What is the relationship between SV, HR and CO?
CO = SV x HR
What is stroke volume?
The volume of blood pumped by each ventricle of the heart per heart beat
What is the normal core body temperature?
How can the body gain heat?
Through metabolic heat, radiation, convection and conduction
How does heat loss occur?
Through convection, conduction, radiation and evaporation
Where is the control centre for body temperature?
Which part of the hypothalamus is activated by the cold?