Human Physiology Flashcards
Define anatomy
Deals with structure of human body parts
Define Physiology
Considers the functions of those body parts
What is homeostasis
The process by which the body substances and characteristics are maintained at their optimal level
Where is auto-regulation
Cell, tissue, organ adjusts activity itself
What is extrinsic regulation
nervous system
endocrine system
What is th ebasic process of homeostasis
Imbalance - detect - respond
Afferent pathway vs efferent pathway
a = input
e= output
Describe the reflex arc
receptor, sensory neuron (afferent response), integrating neuron, motor neuron(efferent response)
Describe the withdrawal reflex
uses inter neurons which pass signals between sensory and motor neurons ultimately creating synaptic connections
Describe the gross organisation of the nervous system
cranial nerves, brain, spinal cord, spinal nerves
Describe the structure and function of sensory receptors
Transduction= convert,
convert stimuli into electrical potentials in neurons
Describe the structure and function of neuron
dendrites, axons, myelin sheath, node of ranvier, axon terminals, nucleus
Describe the role of the action potential in the CNS
depolarization so Na + inflows - na channceles open
repolarisation so K+ outflow k channels open and na channels close
k+ leaves cell causing membrane to return to a resting level and k channels close
hyperpolarization
what is the structure of the chemical + electrical synapse and function
c= a gap between 2 neurons where info passes chemically via neurotransmitters
electrically= a gap w channel proteins connecting 2 neurons so it travels directly over the synapse
what are the sequence of events that lead to the chemical synapse
action potential reaches pre-synaptic terminal
depolarisation of presynaptic terminal
opens ion channels allowing Ca2+ into cell
Ca2+ triggers release neurotransmitters from vesicles
What are the physiological responses mediated by the parasympathetic nervous system
rest and digest
decrease in heart rate
What are the physiological responses mediated by the sympathetic nervous system
fight or flight
increase heart rate, inhibitoin of digestion, widen bronchial passages
What hormones increase heart rate?
Adrenaline, NAd , thyroid hormones
how does the autonomic nervous system regulate the heart rate
Sympathetic increases
cardiac reflexes
What affects stroke volume
end diastolic volume
- higher preload = higher sv
-preload= amount of myocardial stretching
Endsystolic volume
-higher force contraction lower esv
-sympathetic increase force and low edv
what are the factors affecting cardiac output
autonomic innervation and hormones
what factors affect peripheral resistance
Vasuclar resistance, viscosity, turbulence
REGULATION :
- auto-regulation, local vasodilators
-autonomic innervation of blood vessel
-endocrine
What should blood pressure be
in vein - 16mmHg
in artery- 120 / 70 mmHg
What is the cardiac output
blood pumped per min is around 6L
What is stroke volume
80ml/min volume of blood pumped from one ventricle with each beat
Where is adh releases from
posterior lobe pituitary
what is angiotensin 2
Stimulus= decrease renal BP causes increase in angiotensin 2
Angiotensin 2 increases BP by
- vasoconstriction
-NaCl reabsorption in kidney
- stimulates thirst and release of aldosterone and adh reabsorbs water in kidney
what is pulmonary ventilation
the mechanical process that moves air into and out of the lungs
What is external respiration
the exchange of gases between alveoli and lung capillaries
what is the internal respiration
the exchange gases between blood and tissue cells
what is the pulmonary ventillation process
inspiration and expriation
moves air into and out of the lungs
Define respiration
Interchange of gases that supply tissue cells w o2 and removes co2
what so the respiratory tract
mouth,nose
pharynx
larynx
trachea
lungs- bronchi- alveoli
what do cillated epithelium cells do in the trachea
waft mucus up the throat so you can swallow i instead of inahling it
What si the epiglottis
flexible flap at the superior end of the laryn int the thorat that acts as a switch between the larynx and the esophagus to permit air to enter the airway to the lungs and food to pass
What is the functions of the respiratory tract
catilage keeps passageway open mucous secretion
mucous secretion removes dirt
warm and moisten incoming air
adjust volume and speed of flow into passage way
protect against infection via macropahges
function of pharynx
channels the air down the airways
function of pleural membrane
keeps the lungs flexible
Function of intercostal muscles
moves ribs during breathing
what is the structure of the lungs
- right lung has 3 lobes and left one has 2 lobes
plueral membranes - visceral pleura = membrane covering each lung, parietal pleura= covering the thoracic cavity
Lung surfactant= prevents alveoli from colla[sing and sticking together
describe respiratory reflexes
chemo receptor reflexes = monitor pco2 and p02 and ph in the blood
Baroreceptor = monitor blood pressure
hering- beuruer reflexes = prevent overexpansion or too much deflation of the lungs
protective reflexes= coughing sneezing and laryngeal spasms
describe stretch receptors
located in the bronchi, increases in activity in stretch receptors decreases activity in inspiratory areas
Describe the herring brewer reflex
limits degree of inspiration and prevents the inflation of the lungs, lungs deflate and decrease activity in the lung stretch receptors which then increases activity in the inspiratory area
what is daltons low of partial pressure
each gas in a mixture tends to diffues independently of of all other gases
what are the factors affecting diffusion of gases across the membrane
Maintaining partial pressure gradient, coordinating blood flow and ventillation, respiratory membranes- thin w large surface area
describe the transport of oxygen in blood
98% in Hb - 4 subunits carry 402
Hb has a high affinity w o2 to create oxyhaemoglobin
o2 + Hb –> HbO2
describe the bohr effect on a graph
when increase in temperature = shift to the right
decrease in the ph shifts to the right
What are the factors effecting the release of oxygen
increase in temo - cell metabolism
increased h+ ions
2,3 - diphosphoglycerat
Describe the transport of co2 in blood
waste product of respiratoion within the mitochondria. 7% dissolved in the blood, 70 biocarbonate ion, 23% carbaminohaemoglobin
co2 joins w amino group in globin
describe the biocarbonate ion preocess in co2 transport
CO2 = H20 -> H2CO3 -> HCO3 - + H+
catalysed by carbonic anhydrase
C
describe the respiratory center in the brain
PONS MEDULLA
pneumotaxic center, apneustic center, expiratory center, inspiratory center
What is the role of the apneustic area
activates the inspiratory area and prolongs inspiration, transmits stimulatory impulses to the inspiratory area to activate it and prolong and promote inspiration
what does the pneumotaxic area (pons)
Inhibits inspratory area and limits inspiration
transmits inhibitory impulses to the inspiratory area of the mra to switch of at 2 seconds
what are the factors affecting pulmonary ventilation
chemical stimuli, co2
Describe the role of hormoneones
a chemical messenger from one cell to another group of cells
Describe the principle functions of the endocrine system
- maintenance of the internal environment in the body (biochemical environment)
-integration and regulation of growth and development - control, maintenance and istigation of sexual reproduction
-secretion of hormones regulated by a negative feedback system
-number of receptors for a specific hormone can be altered to meet the bodys demand
Describe the gross organisation of the endocrine system
endocrine cells and glands = synthesize and store glands, sensing and signalling system regulating duration + magnitude of hormone release
hormones = carry messages through the body through blood
target cells = respond to a hormone because it bears receptors for the hormone
Describe the structure and function of the endocrine glands
sensing and signaling
Describe the differences between steroid and non steroid hormones
Nonsteroid hormones attach to receptors in the cytoplasm; steroid hormones attach to membrane-bound receptors. Steroid hormones inactivate genes; nonsteroid hormones directly activate genes. Steroid hormones are produced by endocrine glands; nonsteroid hormones are produced by nervous tissue.
compare the endocrine system to the nervous system
Nervous is
electrical neurotransmitter
rate of signal is fast
duration of action is short
How do endocrine hormones travel
classic- blood stream
neurohormones - via synapses and blood stream
paracrine- adjacent cells
autocrine- act on cell secreted ing it
describe what the pineal gland is and what it releases
glandular tissue, produces melatonin regulating circadian rhythm, inhibited by stimulation form the photo receptors of the retina, only produced at low light
describe the hypothalamus, function and its hormone
direct control of endocrine organs,
neuro-secretory cells
regulate : Oxycontin, antidiuretic hormone, trh, ghrh
describe the pituitary gland and its hormones
controlled by hypothalamus,
oxytocin, antidiuretic hormone
describe the thymus gland and its hormones
produces thymosins to help train and develop T-lymphocytes during foetal development and childhood
describe the islets of langerhans and its hormones
alpha cells = insulin
beta= insulin
delta= somatostatin
pp cells= pancreatic polypeptide
What are erythrocytes
red blood cells, oxygen transport i blood
what are leukocytes
body defense systems, 5 classes w# different functions
what are thrombocytes
membrane bound cell fragments involved in clotting
which side of the heart has oxygenated blood
left
describe the histology of the heart
epicardium- outer layer of connective tissues
myocardium- bulk of the heart, straited and branched, connected via intercalated discs
endocardium- thin layer of connective tissue producing smooth lining for the heart, endothelial lining and rest of system
overview of digestive system
mechanical and chemical breaking down of food into smaller components, to a form that can be used by the body.
how is food digested
mix food with digestive juices, large molecules to smaller molecules
function of the mouth
salivary galnds activated, secrete saliva amylase begins starch digestion, moistens food, bacteria killing
order of digestive system
salivary glands, mouth and glands, oesphagus, stomach, small intestine, large intestine, rectum
function and structure of oesophagus
skeletal muscle upper third, lower 2 smooth, ends closed by sphincters, carries food to the stomach by peristalsis, les- opens to let food pass
function and structure of stomach
storage and digestion, fundus, body, antrum, muscles in wall cause mechanical digestion, chemical digestion- enzymes and acid
fundus- upper curvature of organ, cardia- contents of esophagus empty. body- main. pylorus- contents into small intestine
function and structure of small intestine
chemical digestion, sugars and proteins are absorbed into inner lining, fatty acids and glycerol go to lymphatic system
duodenum= most digestion, jejunum = absoprtion of nutrients and water, ileum = same
weak peristalsis
function and structure of large intestine
absorption of water and certain electrolytes, systhesis of vitamins, temporary storage of feces, elimination of waste through the body
acseing transending descending
