Module 5 - Topic 1 - 2A: The Respiratory System and The Digestive System Flashcards
Conducting Region
a system of tubes that provide passage for air to enter and leave lungs
Respiratory Region
site of exchange of oxygen and carbon dioxide between blood stream and atmosphere
Conducting Region - place
begins with nose and extends down into lungs
Structures that air passes to
nasal or oral cavity pharynx larynx trachea primary bronchi secondary bronchi tertiary bronchi bronchioles terminal bronchioles
Function of conducting region
pathway for gases to enter and leave body
trap and expel most particulate matter
How particles are trapped
by mucus produced by goblet cells
Cilia function
produce currents that sweep mucus and particles towards oesophagus where it is spat out or swallowed and digested
Epithelium of upper respiratory tract
multiple layers of squamous epithelial that resists wear and tear and assists food transportation
Mucus function
traps particles and moistens and warms incoming air, prevents airways from drying out
branching of airways - structure
gradual change in structure
epithelium becomes flatter and cilia and goblet cells disappear as you move down bronchial tree
smooth muscle function
enables diameter of airways and regulates air flow
broncho - constricition
contraction of smooth muscle
causes narrowing of airways
broncho-dilation
relaxation of smooth muscle
causes opening of airways
Respiration region - function
gas exchange of oxygen and carbon dioxide
Respiration region - structures
respiratory bronchioles
Alveolar ducts
Alveolar sacs
Alveoli
Alveoli - function
site of gas exchange
Respiratory bronchioles and alveolar ducts - function
passage for gas to enter and leave alveoli
Alveolar sacs
bunches of alveoli
Respiratory membrane
barrier in each alveolus through which gas diffuses
Respiratory membrane - make up
alveolar Type 1 cell
endothelial cell
collagen fibres
Alveolar type 1 cells
single flattened alveolar epithelial cell
Endothelial cell
single flattened blood capillary epithelial cell
type 2 cells
produce surfactant
Surfactant
reduces surface tension of watery fluid that coats the surface of alveolus
SIDS
decreased surfactant production
Macrophages in alveoli
maintain sterility of alveoli
alveolar pores
allows air pressure throughout lungs to be equalised and provide alternate routes for air to pass to any alveoli
Intercostal muscles
skeletal muscles that surround the thoracic cavity
What surrounds thoracic cavity
ribcage
skeletal muscles
diaphragm
inspiration
breathing in
expiration
breathing out
how contraction occur
coordinated contraction of intercostal and diaphragm muscles
thoracic cavity - volume increase
pull ribcage upwards and outwards
Increase in thoracic cavity volujme
decrease in pressure causing negative pressure
negative pressure
causes atmospheric air to be sucked into lungs
decrease in thoracic cavity volume
ribcage is pressed inwards, pressure in cavity decreases, and air is pushed out
pleural cavities
surrounds each lung
pleural cavity - makeup
thin cavities formed of serous membrane
pleura
serous membrane covering lungs
visceral pleura
covers each lung
parietal pleura
lines thoracic wall
decreases in pressure in thoracic cavity
pull on pleural cavities, promotes expansion of lungs
increase in pressure in thoracic cavity
exerts pressure on pleural cavities which causes lungs to expel air
intrapleural pressure
always slightly less than atmospheric pressure within alveoli
imbalance in pressure
prevents collapse of alveoli and lungs
pleurisy
inflammation of pleurae, as a result of pneumonia, hinders breathing
atelectasis
lung collapse
air enters the pleural cavity through chest wound or rupture of visceral pleura
pneumothorax
presence of air within intrapleural space
movement of oxygen and carbon dioxide
simple diffusion
concentration of gases
referred to as partial pressure
Atmospheric pressure
composite of all partial pressures
one atmosphere
760 mmHg
what regulates diffusion of gases
relative solubility and difference in partial pressure
carbon dioxide water solubility
20 times more soluble in water that oxygen
oxygen solubility
poorly soluble in water and plasma
majority of oxygen - transport
carried by haemoglobin
higher the concentration of oxygen
better chance of oxygen being bound to haemoglobin
oxyhaemoglobin
haemoglobin and oxygen combination
HbO2
deoxyhaemoglobin
haemoglobin that has released attached oxygen
fully saturated
when all four heme groups are bound to oxygen
allosteric binding
the chances of the first molecule enhances the binding of the second heme group
rate at which haemoglobin binds or releases oxygen - factors
concentration of oxygen temp blood Ph concentration of carbon dioxide concentration of organic molecules
rate at which haemoglobin binds or releases oxygen -
concentration of oxygen
produces an oxygen haemoglobin dissociation curve
rate at which haemoglobin binds or releases oxygen - temp
increasing temp aids oxygen unloading
rate at which haemoglobin binds or releases oxygen - blood pH
if blood is too acidic, unloading is accelrated
rate at which haemoglobin binds or releases oxygen - concentration of carbon dioxide
increasing concentration produces acidic pH therefore oxygen unloading is increased
rate at which haemoglobin binds or releases oxygen - concentration of organic chemicals
high levels of BPG (produced by red blood cells) aids oxygen unloading
loading and unloading of oxygen equation
lung –>
HHb + o2 –> Hb-O2 + H+
tissues
when blood travels through lungs - oxygen concentration
enhances the binding of oxygen
carbon dioxide reacts with water
forms carbonic acid which disscoiates into bicarbonate ions
carbonic anhydrase
increases bicarbonate formation
carbonic acid - bicarbonate buffer
resists shifts in blood pH and aids maintains homeostasis
chloride shift
chloride ions move from plasma to red blood cells to counterbalance the quick diffusion of bicarbonate ions
carbon dioxide binding
binds to amino acids within globin protein chains of haemoglobin molecule
control of respiration
activity of nerves in hypothalamus, medulla oblongata and pons
stimulation of chemoreceptors
Hypothalamus control
strong emotions and pain activate sympathetic nerve centres
sends signals to respiratory centres that modify the rate and depth of respiration
Medulla Oblongata control
by 2 neurons
dorsal respiratory group
ventral respiratory group
dorsal respiratory group
inspiratory centre controls basic pace and rhythm
Ventral respiratory group
expiratory centre role in forced breathing when strenous breathing is required
The pons control
pnemotaxic centre and apneustic centre
pnemotaxic centre
fine tunes the breathing rhythm and prevents lung over inflation
Apnuestic centre
prolongs inspiration and causes breath holding in inspriatory phase
The chemoreceptors control
respond to changing levels of CO2, H+ and O2 and found in two location
locations of chemoreceptors
central ( in CNS)
peripheral ( in carotid arteries of neck and aorta)
digestive system
long winding tube with several specialised organs attached at various points along its length
Main tube like part of digestive system
gastrointestinal tract
digestive system - function
acquire nutrients and water from the external environment and removes wastes
Ingestion
takes place within mouth and oesphagus
Propulsion
continually occurs throughout GI tract
Digestion
takes place in mouth, stomach and small intestine
Nutreint and water absorption
takes place in small and large intestine
Defecation
removal of wastes
Makeup of GI tract
epithelial lining changes throughout but begins and ends with multiple layers of flattened cells in mouth and anus
in between mouth and anus epithelium varies in accordance with activites
Mucosa
inner most layer of GI tract
secretes mucus, digestive enzymes and hormones
absorbs nutrients
protects against infection by possessing mucosa associated lymphiod tissue
Muscularis Mucosae
thin layer of smooth muscle that produces twitching contractions of overlying epithelium and prevents material from building up and clogging GI tract
folds the epithelium of small intestine into villi
Submucosa
rich supply of blood vessels, nerves, lymph nodes and lymph vessels
Muscularis
inner circular and outer longitudinal layers of smooth muscle
propels contents of GI tract forward and assists digestion
Segmentation
mixing of contents
peristalsis
propulsion of contents
serosa
protective outer layer composed of connective tissue
Oral cavity
contains salivary ducts, teeth, tongue and taste buds
initial site of chemical and mechanical digestion
Oropharynx
back of throat, below nasopharynx
contains tonsils and epiglottis
Oesophagus
muscular tube
goes through diaphragm and joins to stomach
gastro oesphogael sphincter
band of circular smooth muscle that stops food from the stomach reentering the oesophagus
sphincter
rubber band like valve
gastric reflux and oesophageal ulcers
weakening of gastro-oesophageal
Stomach
storage tank where chemical digestion of proteins begins
walls contain 3 layers of smooth muscle - allows churning and mixing of food
in stomach epithelium, deep gastric pits lead down into gastric glands
Chyme
creamy paste of digested food made in stomach
rugae
mucosal surface that contains large longitudinal folds which allow expansion of stomach
pyloric sphincter
joins stomach to small intestine
Parietal cells
gastric gland - secrete digestive acid
Chief cells
gastric glands - produce pepsinogen
pepsinogen
is converted into active pepsin that digests proteins in the presence of HCL
Enteroendocrine cells
gastric glands - release substances like gastrin and other hormones
gastrin
stimulates parietal cells to secrete HCl
Intrinsic factor
produced by stomach
must be present for B12 to be absorbed
small intestine
main site of nutrient absorption
divided into 3 sections
duodenum, jejunum and ileum
duodenum
first section, bile duct from liver and pancreatic duct from pancreas
jejunum
middle part of small intestine
ileum
last part of small intestine
brush border cells
individual intestinal epithelial absorptive cells comprising each villi
contain disaccharidases
disaccharidases
enzymes which aid in digestion of carbs and sugars
lipase
enzyme that digests lipids
proteinases
enzyme that aids digestion of proteins
Villus structure
contains a blood capillary system and lymphatic vessel
blood capillary system
absorbs amino acids from proteins and simple sugars
Lymphatic vessel
absorbs fats into lympathic system
crypts
small intestinal mucosa pits that secrete intestinal juices
Duodenal glands
in duodenum submucosa secrete alkaline bicarbonate rich mucus that helps neutralise the acid entering from stomach
goblet cells
produce mucus and protect epithelium from HCL
Large intestine
main site of water absorption
no villi
many goblet cells
contains bacterial flora
bacterial flora
bacteria that colonises the large intestine and ferment some of the indigestible carbs
synthesises B complex vitamins and vitamin K
teniae coli
3 ribbons that reduce the longitudinal muscle in wall of large intestine
causes large intestine to pucker up into pocket like sacs
haustra
pocket like sacs in large intestine
large intestine - division
4 parts cecum colon rectum anal canal
cecum
pouch like section that is just after ileocaecal valve that contains appendix
colon
ascending colon (upwards) transverse colon (across) descending colon (down) sigmoid colon (s shaped)
rectum
straight out
anal canal
contains internal and external anal sphincters
Epiglottis
covers hole in trachea
stops food from entering lungs
elastic cartilage
Larynx
patent open airway
switches mechanism to route air and food
made of cartilage
voice production
pitch of voice box
length and tension of folds
Voice box
loudness depends on force of air stream
slow vibrate = deep voice
Defacation
mass movement makes sensory receptors signal involuntary sphincters
Diverticulitis
associated with aging
pressure causes bulging pockets
Why we vomit
sensory impulses to brain
abdominal skeletal muscles and diaphragm contract
oesophagus sphincter releases
gamma cells
reduces appetite
releases pancreatic polypeptide
epsilon cells
secretes ghrelin
hunger hormone
secreted into stomach before meals
uvula
flap that stop food from going up into back of nose
pleurae
serous sac encasing each lung
inhaling
muscles contract and pleural and thoracic pressure is less than atmospheric pressure
exhaling
muscles relax and pleural and thoracic pressure is bigger than atmospheric