14-some of 29 lectures Flashcards
1
Q
what are the 3 main things that the respiratory do?
A
moisten, warms and cleans the air
2
Q
what does the respiratory need to be effective?
A
a surface for gas exchange
3
Q
what happens at the surface of gas exchange?
A
where blood and air are brought close together
4
Q
what does URT mean?
A
upper respiratory tract
5
Q
what does LRT mean?
A
lower respiratory tract
6
Q
what does the respiratory zone consist of?
A
bronchioles to alveoli
7
Q
what happens at the respiratory zone?
A
where gas exchange occurs
8
Q
what does the conduction zone consist of?
A
nose to the bronchioles
9
Q
what does the conduction zone do?
A
ensures warm, clean and moisten the air
10
Q
what happens at the oral cavity?
A
passage for food and air
11
Q
what happens in the nasal cavity?
A
where officiation happens
12
Q
what epithelia lines the respiratory tract?
A
mucosa that is attached to the basement membrane to lamina propria
13
Q
what epithelium is in most of the conducting region?
A
respiratory epithelium
14
Q
what is the epithelium where air and food travels?
A
stratified squamous cells
15
Q
what cells line the sites of the gas exchange?
A
simple squamous cells
16
Q
what epithelium lines areas of olfaction?
A
olfactory mucosa
17
Q
what does the mucosa of the reparatory tract do?
A
clean, warms and moistens the air
18
Q
what is the lamina propria?
A
connective tissue and may contain glands
19
Q
what is below the lamina propria?
A
the submucosal layer
20
Q
what is the submucosa layer?
A
connective tissue and depending on the region it may contain glands
21
Q
what is respiratory epithelium known as?
A
pseudostratified ciliated columnar epithelium
22
Q
what does respiratory epithelium contain?
A
goblet cells
23
Q
where is respiratory epithelium found?
A
nasal cavity, part of the pharynx, larynx, trachea and bronchi
24
Q
what do goblet cells do?
A
produce mucus to trap debris and moistens the air
25
what are ciliated cells?
a patterned movement that pushes the mucus towards the pharynx to be swallowed and digested in the stomach acid
26
what are some components of the URT?
nose, nasal cavity, paranasal sinuses, pharynx
27
what is the noses job?
primary passageway for air
28
what does the cartilage of the nose do?
maintains patent which keeps it open
29
what are nosetrils?
the external nares
30
what are the vestibule?
line the skin and has sebaceous and sweat glands as well as hair follicles
31
what are vibrissae?
hairs that line the nasal cavity which filter the air
32
what is the nasal septum?
the bone down the midline that separates the nostrils
33
what forms the roof cavity?
ethmoid and sphenoid bones
34
what forms the floor cavity?
the hard and soft palates
35
what are the conchae?
the lateral walls of the nasal cavity
36
what are the 3 projections of the conchae?
superior, middle and inferior conchae
37
what do the conchae do?
spin the air around (turbinate)
38
what covers the conchae?
respiratory epithelium
39
what does spinning the air in the conchae do?
gives it more time to clean, warm and moisten the air
40
where is nasal epithelium?
in the nasal cavity
41
what is another name for smell receptors?
olfactory receptors
42
where are smell receptors found?
on the roof of the nasal cavity
43
what is the vascular plexus?
a thin wall that has nasal epithelium sitting on the lamina propria
44
what does the vascular plexus do?
when cold air enters the nasal cavity it dilates and brings the air closer to the blood to warm it up more
45
what is a sinus?
a cavity in the bone
46
what does paranasal mean?
surrounding the nose
47
where are the paranasal sinuses found?
the frontal sphenoid, ethmoid and the maxillary bones
48
what lines the paranasal sinuses?
respiratory muscosa
49
what do the paranasal sinuses drain into?
the pharynx
50
what does clearing the paranasal sinuses do?
stops the blockage with interferes with the resonance so we sound different
51
what is the pharynx?
a muscular funnel-shaped tube shared by the respiratory and digestive system
52
what are the 3 regions of the pharynx?
nasopharynx, oropharynx, laryngopharynx
53
what is the nasopharynx?
air passage only
54
what blocks the nasopharynx during swallowing?
the soft palate and the uvala
55
what does blocking the nasopharynx?
prevents food from entering the nasal cavity
56
what does the oropharynx do?
allows food and air and enters
57
what does the laryngopharynx do?
allows food and air to pass but has a food has right of way during swallowing
58
what are the components of LRT?
larynx, trachea, bronchi, bronchioles and alveoli
59
what does the LRT do?
conducts air to the site of gas exchange and completes cleaning, warming, and humidifying the air
60
what is the only passage that sits Infront of the esophagus?
the larynx
61
what does the cartilage of the larynx do?
protects it and keeps the airway open
62
what is the thyroid cartilage?
the biggest piece of cartilage of the throat
63
what is the laryngeal prominance?
the medial part of the thyroid cartilage ad is also referred to as the apples apple
64
what is the cricoid cartilage?
a solid peice of cartilage that wraps the larynx
65
what is the epiglottis?
a piece of cartilage that closes over the airway when swallowing so no food goes down the larynx
66
what does Epi mean?
ontop of
67
what does Glottis mean?
voice box
68
what are the true vocal cords?
passing air causes vibrations which makes sound waves
69
what causes a deeper voice?
testosterone which affects the cartilage and muscle
70
what are vestibular folds called?
false vocal cords
71
what are vocal folds called?
true vocal cords
72
where is the trachea?
anterior to the esophagus and is between the larynx and primary bronchi
73
how are sounds produced?
air plucks the strings and makes vibrations
74
what is the function of the trachea?
to keep the throat patent
75
what is the structure of the trachea?
C-shaped cartilage rings that end are connected by a band of muscles called the trachealis
76
what are the trachealis?
the muscle that connects the c shaped cartilage
77
what happens when the trachealis contracts?
causes a cough
78
what epithelium lines the the trachea?
respiratory epithelium
79
are there goblet cells in the trachea?
yes
80
what is the mucosillary escalator do?
has cilia that beat in unicen to move the mucus with the debris up the trachea to the pharynx
81
how many lobes are in the right side of the lung?
3
82
how many lobes are in the left side of the lung?
2
83
why does the left side of the lungs have 1 less lobe?
to accommodate for the heart
84
what is the top of the lung called?
the apex
85
what is the bottom of the lung?
base
86
what does the base of the lungs sit ontop?
the diaphragm
87
what is the hilum?
where the bronchi and the blood vessels enter
88
what is the costal surface of the lungs touch?
the ribs
89
explain the bronchial tree?
the trachea branches into 2 primary bronchi, which split into the lobar branches and go in different lobes.
once in the lobes, they separate into the segmental bronchi within the lobes
these continue to split into the terminal bronchioles
90
is the trachealis muscle posterior or anterior?
posterior
91
structure of the primary bronchi?
respiratory epithelium, cartilage and smooth muscle rings are complete
92
structure of the secondary and tertiary bronchi?
respiratory epithelium starts to decrease in height, goblet cell numbers are reduced and cartilage is not in plates
93
what is the structure of the bronchioles?
cuboidal epithelium, no cartilage but thicker smooth muscles
94
what is the function of the terminal bronchioles?
each supplies a pulmonary lobule
95
what are pulmonary lobules?
many alveoli arranged in bunches like grapes
96
structure of the alveoli?
thins walls of simple squamous epithelium on a thin basement membrane
the external surface is covered in a fine network of pulmonary capillaries
97
what is the alveolus?
pocket like open at one side covered by a dense capillary network
98
what is the name for lung epithelium called?
pneumocytes
99
what is the respiratory membrane?
a wall of the capillary and the alveoli that share the same basement membrane
100
how does oxygen get into our blood?
O2 travels through the alveoli wall, across the basement membrane and pass the capillary wall
101
how does C02 get into our lungs?
CO2 travels through the capillary wall, across the basement membrane and pass the alveoli wall
102
what is the gas exchange?
O2 goes into the blood and CO2 goes into the lungs
103
what is the mediastinum?
the region that contains the heart, vessels, pericardium
104
whats in the pleural cavity?
contains the lungs
105
what does the pleural cavity do?
keeps the lungs separate so if one stops functioning you can have another stop the spread of infections between the two lungs
106
what are the 2 layers of the pleural cavity?
the visceral and parietal layer
107
where is the visceral layer of the pleural cavity?
closer to the lungs
108
where is the parietal layer of the pleural cavity?
the layer further from the lungs
109
what happens to the volume if the pressure increases?
the volume decreases
110
what happens to the volume if the pressure decreases?
the volume increases
111
what happens if we change the volume of the thorax?
we change the pressure of the thorax
112
how do we measure pressure?
collisions
113
what does smaller spaces have in relation to pressure?
more collisions
increased pressure
114
what does larger space have in relation to pressure?
less collisions
decreased pressure
115
what is Boyles law mean when it comes to breathing?
we need to establish a pressure gradient to make air move
116
what binds ribs to ribs?
costal cartilage
117
what are the joints of the ribs?
they are all synovial except the first sternocostal are cartilaginous joints
118
what is the coastal chondral?
is the cartilage binding to the ribs via cartilaginous joints
119
what are interchondral?
where the cartilage is attached to help allow more individual movement yet keeps the structure whole
120
how many points are there between the ribs and the vertebrae?
2
121
what is the costotransverse mean?
between the rib and the transverse process of the vertebrae
122
what is costalvertebral mean?
between ribs and the body of vertebrae
these help lift the ribcage up
123
what are the primary muscles required in respiratory?
diaphragm and intercoastal
124
what are accessory muscles?
only active when they are needed
125
what is the diaphragm?
a sheet of skeletal muscle that separates the thorax from the abdomen?
It has a dome shape when relaxed and flattens when contracted
126
what are the 3 openings in the diaphragm that contraction expands?
the aorta, inferior vena cava and the esophagus
127
where are intercoastal muscles?
attached diagonally between neighbouring ribs
128
what does the external intercoastals do?
lift the ribcage and expands the cavity
129
what does the internal intercostals do?
depress the ribcage and decrease the cavity
130
where are accessory muscles?
many muscles that attach to the thoratic cage
some increase and some decrease cavity volume
131
what is inspiration?
diaphragm contracts and external intercostals contract in 'quiet'
accessory muscles contract to further expand the thoracic cavity in 'forced'
132
what is expiration?
passive process, diaphragm relaxes and external intercoastal relax in 'quiet'
internal intercoastal contract and accessory muscles contract to further decrease cavity volume in 'forced'
133
what is good about lung tissue being elastic?
allows lungs to take up air and recoil afterwards
134
what does plueral do?
makes the lungs stick to the thoracic wall
135
why do we want the lungs to stick to the thoracic wall
so when the wall expands the lungs expand and vise versa
136
where does the parietal pleura stick?
to the wall
137
where is the pleural fluid?
between the visceral pleura and the parietal pleura and allows frictionless movement
138
what is respiratory?
taking the air from the atmosphere into the lungs to be used in cell around the bopdy
139
what is needed to get oxygen into the lungs?
a pressure gradient to move air from the atmosphere to the lungs
140
what happens if we expand the lungs?
we decrease the pressure of the lungs and draws the air from the environment
141
how much of a change in pressure is sufficient for taking in and out air between 0.5- 3 liter of air from the enviroment.
1 mmhg
142
what are the 2 forces that must be overcome to take a breath?
stiffness of the lungs
resistance of the airways to the lungs
143
what determines stiffness?
relationship of pressure and volume
144
what happens to people with pulmonary fibrosis?
they struggle to breath as there is less compliance so high pressure is needed to take up a small volume compared to a normal lung
145
what lines the alveoli?
fluid that exerts surface tension
the thin wall of the alveoli enhances this effect
146
why do we need to overcome surface tension?
to expand the lung
147
what does sufactant do?
reduces surface tension in alveoli which makes it easier to expand the lungs
148
what produces surfactant?
type 2 pneumocytes in the alveoli
149
what is the result of lack of surfactant?
stiff lungs
150
what is resistance of the airways?
is like friction of the airways must be overcome to help compliance
151
what is important for resistance?
vessel diameter
152
where does most of the resistance airflow arises from?
the bronchi
153
what is the spirometry test?
how we can measure volume inspired/exhaled and also how fast you can breathe
154
what is the symbol for tidal volume?
Vt
155
what is the tidal volume?
volume of air moved in and out during normal quiet breath
156
what is the symbol for expiratory reserve volume?
ERV
157
what is expiratory reserve volume?
extra volume that can be exhaled voluntarily after completion of a normal, quiet respiratory cycle
158
what is the symbol for inspiratory reserve volume?
IRV
159
what is inspiratory reserve volume?
extra volume that can be inhaled over and above the tidal volume
160
what is the symbol for residual volume?
Rv
161
what is residual volume?
volume remaining in lungs after maximal exhalation
161
what is the symbol for minimal volume?
Mv
161
what is minimal volume?
volume remaining in the lungs if they have collapsed
161
what is the small amount of air that is always in the lungs called?
the residual volume
161
what is an indication of our lung resistance?
depends on our breathing rate
161
what is obstructive breathing?
resistance to airways
162
what is restrictive breathing?
reduced lung capacity
162
what is the dead space?
some of the inhaled air that never gets to the alveoli so it cant gas exchange
162
how do we calculate how much we breathe in and out?
respiratory minute volume = tidal volume (times) respiratory rate
162
what is alveolar ventilation?
the volume of gas per unit time that reaches the alveoli
162
how do we calculate alveolar ventilation?
(tidal volume - dead space) (times) respiratory rate
162
symbol for dead space?
Vd
162
symbol for respiratory rate?
f
163
what is partial pressure?
each gas exerts its own individual pressure in a gas mixture (air)
163
what is the pressure of a mixture of gases?
the sum total of the pressures of each individual gas
163
what happens to air as we breathe it in?
it becomes saturated so now we have nitrogen, oxygen and water vapour
163
what happens to the partial pressure of the air when it reaches the alveoli?
it drops from 160 to 100
163
what does oxygen do when it reaches the alveoli?
it dissolves into a solution until the pressure of the air and solution are in equilibrium
163
what is ficks law?
the rate of diffusion is determined by the surface area of which a gas is diffused across
163
what determines ficks law?
the soluablity of gas as well as a pressure gradient
164
what is the diffusion constant?
the solubility of gas
164
how do we calculate the diffusion?
surface area/thickness (times) diffusion constant (times) pressure difference
165
what is the partial pressure when the haemoglobin is 50% saturated?
p50
165
what pressure does the sigmoidal curve starts to platue?
p60
165
what can cause a large desaturation of oxygen of the haemoglobin?
a small drop in partial pressure
165
can nitrogen be dissolved?
no, because the diffusion constant is so low
165
what happens to oxygen if the curve shifts to the right?
the oxygen is released as a higher amount of partial pressure is required
165
what helps the rate of diffusion in the lungs?
the high surface area of the alveoli
165
how much faster does carbon dioxide diffuse compared to oxygen?
20 times because CO2 has a higher solubility
166
what drives the gas across the membrane?
the pressure gradient
166
what is the thickness of the membranes that gas has to cross?
3 microns thick
166
why does oxygen move down the gradient when crossing the membrane?
because the partial pressure in the capillaries is higher
166
what is the partial pressure of the alveoli and the capillary?
150 mmhg
166
what determines the rate of oxygen in our venous blood which comes back to the lungs?
metabolism
166
what happens to the partial pressure of the air and oxygen in the alveoli?
mixes with water vapour so the partial pressure decreases
166
what lowers the level of oxygen in the venous blood?
exercise as we use more oxygen in the blood
167
how many oxygens can bind to the haemoglobin?
4
167
what happens to the oxygen as soon as it enters the blood?
it is taken up by the haemoglobin
167
what binding to haemoglobin is the hardest?
the first binding
167
what does the first binding of haemoglobin do?
unmasks the other binding sites to make it easier to bind to more oxygen
167
what happens to the haemoglobin as the partial pressure increases?
the haemoglobin becomes more saturated oxygen
168
what does a decrease in partial pressure do to the saturation of haemoglobin?
the saturation of the haemoglobin decreases
168
what happens to oxygen if the curve shifts to the left?
the oxygen is loaded to the haemoglobin as less pressure is required to bind to the oxygen
168
what happens during metabolism to do with respiration?
CO2 is produced, O2 is needed
168
what are the 3 forms the carbon dioxide is transported in?
dissolved in plasma 7%
dicarbonate 70%
combined with proteins as carbamino compounds 23%
169
what carbonic anhydrase?
an enzyme in the RBC which converts 70% of the carbon dioxide into carbonic acid
170
what happens to carbonic acid?
it dissosiates into a hydrogen ion and bicarbonate ion
171
how does haemoglobin transport C02?
binds to the hydrogen ion formed by carbonic acid
172
what forces the C02 across the membrane?
a decrease of CO2 in the plasma which increases the pressure
173
where is respiratory controlled?
in the brainstem
173
how do the chemical chemoreceptors in the medulla pick up on PCO2?
CO2 diffuses out of the cerebral capillaries which changes the pH of the cerebrospinal fluid
173
what does the respiratory rhythmicity center do?
generates cycles of contraction and relaxations in the diaphragm
it also establishes a pace of respiration
modifies activity in response to chemical and pressure signals
173
what do central chemoreceptors respond to?
pH change
173
what is the purpose of the GI tract?
to injest food and break it up
173
what do peripheral chemoreceptors respond to?
changes in the arterial PO2
173
where are the peripheral chemoreceptors located?
in the carotid and aortic bodies
174
what re the 4 main ways that nutrients /water are brought into the internal enviroment to be used by the body?
motility, secretion, digestion, absorbtion
175
what is motility?
transport food into and through the body, mixing luminal contents and transport waste out
175
what is secretions?
synthesised and released enzymes, mucus and serous fluids into the lumen
175
what is digestion?
breaking of nutrients into smaller peices
175
what is absorbtion?
bring nutrients/water from the lumen to internal enviroment
175
what is the entire GI tract lined with?
epithelium
175
what do sphincters do?
close off ends and separate sections of a tube
separates the enviroments of the tube
175
what are sphicters made of?
thick rings of muscles that when contract it closes and when it dilates it lets things pass
175
what epithelium lines the mouth, pharynx and esophagus?
stratified squamous epithilium to protect it from abrasion
175
what epithelium lines the stomach and the intestines?
simple columnar to help with secretions and absorbtion
176
what epithelium lines the anus?
stratified squamous to protect it from abrasion
176
what are unicellular glands?
goblet cells which are columinar and goblet shaped
176
what do goblet cells have?
they have apical mucus granules and a basal nucleus
177
what are multicellular glands?
they have epithelium that can invaginate to form glands
177
what are simple glands?
glands with a single duct
178
what are the 4 layers of the gut from inner most to outer?
mucosa, submucosa, muscularis and adventitia
178
what are compound glands?
have 2 or more ducts
178
what does the mucosa consist of?
epithelium, basement membrane, lamina propria and mucularis mucosae
178
what is the muscularis mucosae?
a small muscle to help move the mucosa a little bit
178
does the mucosa have glands?
sometimes
178
what does the submucosa plexus do?
regulates the secretions and is part of the enteric nervous system
178
what are the 2 layers of the muscularis?
inner circular
outer longitudinal
178
where is the submucosa?
below the mucosa
178
what does the submucosa consist of?
FCT, glands and blood vessels
178
what does the adventitia consist of?
FCT
178
what is the muscularis made up of?
smooth muscle
178
what is the lumen?
the middle of the tube where everything happens
178
why is the mouth and oral cavity lined with stratified squamous epithelium?
as food may be rigid and hard so the epithelium protects against abrasion
179
what are the 3 pairs of the salivary glands?
paratoid glands
sublingual glands
submandibular glands
179
what do salivary glands secrete?
mucus and enzymes to help lubricate our food
179
what do the paratoid glands do?
secretes serous fluid with amylase to help with the break down of carbohydrates
179
what do sublingual glands do?
secretes from multiple ducts from under the tounge and secretes a mixture of mucus and serous fluids
179
what type of glands are salivary glands?
copound glands
180
what is the job of the esophagous?
to bring food to the stomach
180
why is the mucosa and submucosa highly folded in the esophagus?
to expand to have the capacity for the passage of the food bolus
180
what do acinar cells do?
secrete a number of things such as bicarbonate to be used as a pH buffer
180
explain the muscles in the esophagus?
the first third is skeletal muscle, the last third is smooth muscle and the middle third is a mixture of both
180
what do the muscles in the esophagus do?
helps to move the food bolus to the stomach
180
what is the peritoneum?
a serous membrane that consist of 2 layers
180
what does the parietal layer of the peritoneum line?
it lines the body wall
181
what is between the 2 layers of the peritoneum?
serous fluid
181
what does the visceral wall of the peritoneum line?
covers and lines the organs
181
What is the retroperitoneal?
posterior to the peritoneum
181
what are the areas that are tethered to the visceral wall to the parietal layer?
mesentary
181
what are organs that sit outside the peritonuem cavity called?
retroperitoneal organs
181
what is the mesentary?
a double layer of visceral peritonium that connects organs to the body wall
181
what is another name for an omenta?
a 'sing'
181
what shape is the stomach?
'J' shaped
181
What is the omenta?
a double layer of visceral peritonium that connects organ to organ
181
what is the main function of the stomach?
holds food and has chemicals that break it down
181
what are the 4 main parts of the stomach?
cardia, fundus, body and pylorus
181
what does the omenta do?
keeps the organs in place aswell as lets then expand and have a little movement
181
what is the area that the esophagus passes through the diaphragm called?
the esophageal hiatus
181
where is the stomach located?
at the base of the esophagus
181
what does the LES do?
prevents reflux from the stomach
181
what does the fundus do?
where gases collect during the digestion process at the superior end of the stomach
182
what is the sphincter at the base of the esophagus called?
the lower esophageal sphincter (LES)
182
what does the cardia do?
passes food into the stomach
182
what does the body of the stomach do?
where the main functions of the stomach happen
182
what does the pylorus do?
allows small bits of food called chyme to pass through into the instestine
182
where is the greater omentum?
goes from the stomach to the trasverse colon
182
what is chyme?
small digested food that is allowed to pass into the intestine from the stomach
182
where is the lesser omentum?
between the stomach and liver
183
what is the job of the greater omentum?
to keep the intestinal tract clean
184
what are the 3 layers to the muscularis?
oblique (inner)
circular (middle)
longitudinal (outer)
184
what are rugae?
temporary folds that allow for expansion of the stomach which doesnt stretch the tissue
185
what is a modification of the submucosa?
rugae
186
what is the core of submucosa do?
used for structure and support
187
what are modifications in the mucosa?
simple columinar epithelium
188
what does the stomach need?
acid and enzymes for digestion
mucus for protection
hormones for regulation
188
what do gastric glands do?
secrete mucus for protection
these are also called goblet cells which are around the surface of the glands
188
are gastric glands temporary or not temporary?
not temporary
188
what are the 3 glands that are deeper within the gastric glands?
G cells, cheif cells and parietal cells
188
what do G-cells secretes?
hormones
188
what do cheif cells secrete?
pepsinogen
189
what does pepsinogen do?
inactive form of pepsin ad helps with digestions
189
what do parietal cells secrete?
acid and intrincic factors
189
cheif cells consist of alot of what?
rough ER
they also have a nucleus
190
how do parietal cells produce acid?
they pump hydrogen across the gradient
190
what do parietal cells consist of?
alot of mitochondria to make energy to pump hydrogen across the gradient
it also has a central nucleus
191
what are canaliculi?
channels between the microvilli
192
what is the sphincter that connects the stomach to the small intestine?
the pyloric sphincter
193
what does the pyloric sphicter do?
controls the release of chyme into the small intestine
194
what is the duodenum?
the entrance of the small intestine
195
is the pancreas retroperitoneal?
yes
196
what shape is the pancreas?
C-shaped
196
where is the pancreas located?
posterior to the stomach
196
what is the duct called that the pancreas secretes into the duodenum?
pancreatic duct
197
what is the endocrine functions of the pancreas?
pancreatic islet alpha cells secrete glycagon
pancreatic islet beta cells secrete insulin
197
what are the exocrine functions of the pancreas?
acinar cells secrete digesive enzymes
duct cells secrete bicarbonate
197
what does the pancreatic acinar cells consists of?
apical zymogen granules and a basal nucleus with an abundant of rough ER
197
why do the pancreatic cells have so much rough ER?
to secrete enzymes
198
where does the bile duct meet the pancreatic duct?
at the entrance of the hepatopancreatic ampulla
198
what does the hepatopancreatic ampulla do?
collects and mixes the secretions of the pancrease and live/gallbladder
198
what does the duodenal papilla do?
projects into the duodenal lumen and mixes with the chyme of the stomach
199
what controls the release from the hepatopancreatic ampulla?
the hepatopancreatic sphincter
200
how do we protect the small intestines from the acid chyme when it enters the duodenum?
we have goblet cells that produce mucus
200
how do we neutralize the acidic chyme when it enters the duodenum?
we secrete bicarbonate which comes from the pancreas through a duct
201
what are the 3 areas of the intestine called?
the duodenum
jejunum
ileum
201
what does the duodenum recieve?
the chyme from the stomach
bicarbonate from the pancreas
bile from the liver
202
what is the main function of the jejunum and ileum?
to digest and absorb
203
what keeps our intestines from tangling?
mesentery which anchors the intestines in place
203
is the jejunum retro or intro peritoneal?
intro
203
is the ileum retro or intro peritoneal?
intro
203
is the duodenum retro or intro peritoneal?
retro
203
what does the mesentary protect between the 2 layers?
arteries, veins, nerves and lymphatics
203
what parts of the intestinal tract require mesentary?
jejunum and ileum
203
what do the mesenteric arteries and veins do?
bypass the muscularis and can go to the mucosa layer and is important for carrying away nutrients absorbed into the small intestine
204
what is the blood that leaves the small intestines?
deoxygenated but full of nutrients
204
where do the mesentary veins go?
to the hepatic portal vein
205
where does fats from the small intestines go?
to the lymphatic lacteals which breaks it down
it then goes through the lymph into the cisterna chyli, into the thoracic duct and into the subclavian vein.
206
what happens to the blood in the hepatic portal vein?
goes to the liver to be detoxified
206
why do we want the small intestine to have alot of surface area?
for efficient absorbtion
207
what is plicae circularis?
permanent folding of the submucosa of the intestinal wall
207
what are villi?
on the surface of the plicae circularis
made of mucosa
208
what does muscularis mucosa do to villi?
allow it to wiggle back and forth to allow contact digestion and allows chyme to come in contact with the villi
209
what is inside each villi?
a singular lymph lacteal for digestion of fats
A capillary network wraps around the lacteals to take nutrients into the bloodstream
210
what are enterocytes of the small intestine?
epithelium simple columnar cells which can fit goblet cells with each one touching the basement membrane
they have microvilli on the apical surface of the enterocytes to form a brush border
211
what do glycocalyx do?
tether localized enzymes to the surface of a cell
these help with contact digestion which involves enzymes that are attached to the brush border
211
what is glycocalyx?
a meshwork of glycoproteins which are a bit sticky and form a branchy network and are good at anchoring things in place
211
what is the plasma membrane?
a semi-permeable barrier that is selective to lipid soluables
212
what are 5 things that the epithelial of the small intestines consist of?
enterocytes
goblet cells
paneth cells
endocrine cells
stem cells
212
what controls paracellular pathway?
tight junctions
213
what are intestinal crypts?
in the mucosa but dip down and kept away from the outer most surface for protection
213
what are in the intestinal crypts?
endocrine cells, paneth cells, stem cells
214
what do paneth cells do?
protects us from anything that does damage such asbacteria getting out of control an paneth secrete antibacterial enzymes
215
where are paneth cells located?
usually at the base of the intestinal crypts
215
what is the ileocecal valve do?
connects the ileum to the cecum and acts as a sphincter
215
what can stem cells do?
they can become any sort of cell to replicate and replace damaged cells
215
what areas of the large intestine are introperitoneal?
transverse and sigmoid colon
215
what areas of the large intestine are retroperitoneal?
ascending and decending colon
215
why do we have an intestine?
so we do not have to go to the bathroom all the time and to have regulatory absorption of sodium and waters
215
what are the 4 parts of the large intestine?
ascending, transverse, descending and sigmoidal
216
what is the cecum?
a blind-end pouch which means it doesnt continue on
it is the beginning of the large intestine
217
where is the appendix found?
in the cecum
217
what happens in appendicitis?
when the appendix ruptures and bacteria floods the body
217
what are some modifications of the large intestine?
stores faeces, expells faeces during defication, be lubricated and allows absorption of water
217
what is the appendix?
a worm shaped structure that is an important location of bacteria for the large intestine
217
what does the bumpy appearance of the large intestinal wall do?
help stores faeces
218
what are the haustra?
a series of pouches to allow more area for storage
218
what are tenia coli?
bands of longitudinal muscles that holds the haustras together
218
what are the omental appendices?
sacs of fats that attach to the outer layer of the large intestine
219
what is the gallbladder?
a hollow sac below the liver and concetrates the bile
219
how are gall stones made?
if the gallbladder concetrates the bile too much
219
what percentage of caridac output does the liver recieve cardiac?
25%
219
how does 2/3 of the blood supply get to the liver?
the hepatic vein
219
how does 1/3 of the blood supply to the liver get there?
through the hepatic artery
219
what are hepatocytes?
cells that process anything toxic that enters our blood such as alcohol or drugs
220
what does the lesser omentum contain?
hepatic portal vein, hepatic artery and the bile duct
220
what are the sinusoids?
they run between rows of the liver cells
220
what is the structure of the liver?
the liver is made of lobules
221
what runs between the cells in the liver?
the bile canaliculi
222
what produces the bile?
rows of hepatocytes
223
what do hepatic portal veins do?
they take the blood for the GI tract to the liver to be cleaned
223
how many sphincters control defication?
2
223
what are the 2 main types of cells in the large intestine?
absorptive cells for water and salts
goblet cells to produce mucus for protection and lubrication
223
what happens in the anal canal?
where the epithelium switches simple columinar and stratified squamous epithelium
223
what is the internal anal sphincter?
the inner anal sphincter made of smooth muscles and is involuntary control
224
what is the portal traid of the liver?
branch of hepatic artery
branch of hepatic portal vein
a bile duct
224
what does the anal canal connect?
the anus to the colon
224
what are the 2 anal sphincters?
internal anal sphincter
external anal sphincter
225
what sends a signal to the brain before defication?
stretch receptors in the anus of the internal sphincters
225
how do we relax the external anal sphincter?
sends a signal to the brain to relax the skeletal muscles
225
what is the external anal sphincter?
the outer anal sphincter made of skeletal muscles and is voluntary control
226
where is the liver located?
superior right quadrant of abdominopelvic cavity and is attached to the stomach by the the lesser omentum
227
what is the shape of the liver?
a wedged shape organ
228
what are the main functions of the liver?
metabolic processes
detoxifies blood
produce bile
229
what is the central nervous system?
long distance controller and is good for external inputs
230
what is the parasympathetic nervous system?
the rest and digest system which wakes the GI tract while the rest of the body is still asleep
230
what is the sympathetic nervous system?
the fight and flight system which puts of GI tract to sleep
230
what is the submucosa plexus?
regulates secretions
230
what does the enteric nervous system have?
submucosa plexus and myenteric plexus
230
what are paracrine effect?
effects the next-door endocrine cells
230
what is the myentric plexus?
controls motility
230
what is tonic contractions?
sustain contractions for minutes to hours
230
what is the point of the enteric nervous system?
to respond to internal stimuli with receptors to detect conditions in the GI tract
231
what do enteroendocrine cells do?
secrete hormones and detect luminal contents
231
what is phasic contractions?
waves of contractions and relaxation, each wave lasting seconds (peristalsis)
231
what is motility/motility patterns?
any pattern of contraction or relaxation of GI tract smooth muscle
231
what is movement/propulsion?
motility patterns that specifically move/propel GI contents along the tract
232
what does the intestine work on its own?
uses pace maker cells just like the ones in the heart
slows down for absorption
speeds up for mixing with digestive enzymes
233
what is the peristalsis?
the propulsion of food bolus along the intestinal tract
234
what happens in peristalsis?
muscles relax ahead of the food bolus and contracts behind the food bolus forward in a propulsion muscle
235
what happens in the stomach when the stretch receptors are activated?
the rugae unfold to not change the pressure of the stomach
235
what is segmentation?
circular muscle that pinches and makes unturnatives segments and exposes the food to alternative segments as well as mixes the food with the serous fluids and enzymes to help breakdown
235
what does chewing do?
breaks large food boluses with mechanical breakdown and reduces the size of the food before its swallowed aswell as mixes it with saliva and enzymes
235
what is swallowing?
a complex reflex when the tounge pushes the food to the back of the mouth and the epiglottis closes as the food bolus travels done to the stomach
235
how is chyme forced through the pylorus sphincter?
the chyme is forced and slowly builds up pressure until it gets through the sphincter
236
what salivary gland contributes the most to saliva secretion?
submandibular glands
236
what does the intrinsic factor do?
stabilizes vitamin B12 and facilitates its absorbtion in the small intestine
236
what is the motility patterns between meals?
migrating motor complexes
236
what happens when the pylorus sphincter is closed?
retropulsion happens and the chyme is mixed around in the acid and enzymes of the stomach
236
what does saliva contain?
lubrication, dilute solution of NaHCO3/NaCl and digestive enzymes such as lingual lipase and a-amylase
236
what is the motility patterns after meals?
segmentation and some peristalsis
236
what is secretions?
the movements of solutes and water from the body to the lumen across an epithelial layer
236
what is absorption?
movements of solutes and water from the lumen into the body across the epithelial layer
236
why do we need to irrigate our mouths?
it can lead to dental issues
236
what does basal secretions do?
helps with talking aswell a respiratory tract moistening
236
what are stimulated secretions?
when we stimulate the glands ourselves
236
what does pepsin do?
digests proteins
236
how much does the gastric system secrete per day?
2-3 liters
236
how do we activate pepsinogen?
comes in contact with the acids
237
what amount of secretions happen in the cephalic phase (head phase)
20% of secretions
237
what do gastric acids do?
dilute food, denature protein, activates pepsinogen, protection and is also a good antimicrobial protection
237
what are carbonic-anhydrase do?
takes CO2 and water to make bicarbonate and hydrogen
so its catalyses the reaction
237
where does the chloride come from in the production of the HCl?
a bicarbonate chloride exchanger
the chlorides are channeled out and binds to the hydrogen
237
what does bicarbonate dissociate into?
H+ and HCO3-
237
what are the 3 phases of regulation?
head phase
stomach phase
intestinal phase
237
what signals does the head send to the stomach when the food enters the mouth?
signals to start making pepsinogen
237
what percentage of the secretions happens in the gastric phase?
70% of secretions
237
what percentage of secretions are in the intestinal phase?
10% of secretions
237
what hormones are secreted in response to nutrients in the chyme?
GIP, CCK and secretin
237
what do GIP and CCK do?
travel through the bloodstream to the chief and parietal cells to stimulate the production of acid within the stomach
238
what does secretin do?
diffuses into the chief and parietal cells and is the hormone that decreases pH
238
what makes lipolytic?
lipase and phospholipase
238
what is amylytic?
pancreatic amylase which digests starches
238
what is proteolytic?
trypsin
238
what digestive enzymes does the pancreas secrete?
lipolytic, amylytic, protoelytic, chymotrypsin, carboxypeptidase, nucleolytoic and deoxyribonuclease
239
what is nucleolytic?
ribonuclease
239
what secretes pancreatic enzymes?
acinar cells
239
what is CCK?
and what does it do?
cholestokinin
a hormone that gets released by nutrients getting released into the duodenum which tells the pancreas to secrete enzymes to digest the food to make nutrients
240
what does trypsin do?
is on the brush border and enzymes activated
240
what do bile salts do?
stablize lipids
240
what is enterokinase?
bound to the duodenal membrane and converts trypsinogen into trypsin
240
what is enterohepatic circulation?
big release of CCK which releases alot of bile salt
240
how much bile is reabsorbed?
around 90%
240
how are the bile salts reabsorbed into the liver?
the liver recognises the bile in the blood stream and reabsorbs it
240
what is our main source of energy?
carbohydrates
240
what hormone forces bile into the intestinal tract?
CCK
241
what are carbohydrates?
a long complex chains tht are monosaccharides such as glucose
242
what bonds glucose together?
glycosidic bonds
243
what is an example of disaccharides that we ingest?
sugars such as sucrose
243
what do proteins require?
amino acids
243
how many amino acids can be synthesised?
12
244
what links long chains of amino acids together?
peptide bonds
244
why do we need chemical digetion?
to dijest food into monosaccharides and amino acids
245
what is mechanical digestion?
breaks food up to increases surface area available for chemical digestion
246
what do organic catalysts do?
enzymes which take substrates and makes a ES complex and then it seperates to return back to the enzymes but the substrate goes to a product
246
what is contact digestion?
the border enzymes absorb into the body
246
whjat are 2 types of chemical digestion?
luminal and contact digestion
246
what is luminal digestion?
enzymes that are secreted into our GI tract and are free floating
247
what does amylase break?
alpha bonds of the poly saccharides into disaccharides
247
what do the brush border enzymes do?
takes disaccharides and breaks them into monosaccharides
248
what enzymes break the peptide bonds in the small intestine?
trypsin and chymotrypsin
249
what enzymes chops the amino acids off in the peptides in the small intestine?
carboxypeptidase
250
what does peptidase do?
converts polypeptides into amino acids onn the brush border
251
what digestion does lipids go through?
luminal not contact digestion
252
what is emulsifaction?
the first stage of lipid digestion
retroplusion breaking lipids into smaller droplets to increase surface area
253
what is stabilization?
the second step of lipid digestion
bile salts stabilize the emusion in the small intestine
254
what is hydrolysis?
the third stage of lipid digestion
lipase is secreted from the pancreas and breaks the lipids into smaller lipid molecules
255
what is the formation of michelles?
the fourth stage of lipid digestion
michelles allow enzymes to get close to the hydrophillic lipid molecules so that they can be absorbed easier into the body
256
how do we maximise absorption into the blood stream in the small intestines?
villi which have a brush border of micro villi to maximise surface area
257
what is transcellular pathway?
passing the epithelium through the cell through transporters and cytoplasm
258
how do we get solutes through transcellular pathway if it has a bilayer that is impermeable to solutes?
we can use protein transporters to change shape and allow solutes to pass
259
what do we need to help move solutes across the celles membrane?
ATP synthesis to occur
260
how much water are we meant to drink a day to keep up with how much we have lost?
1.5 liters
261
how do we lose water?
sweat, urine, faeces and as we breathe out
262
what are sodium potassium channels?
pumps sodium out of a cell and potassium in with the help of ATP
this is active transport
263
what does the active absorbtion of carbohydrates involve?
a co-transport of sodium
264
how do amino acids diffuse through the epithelial?
through the paracellular pathway
265
what does sodium ATPase do?
move sodium against to gradient and the amino acids are moved out of the cell
266
what does the amino acids pass through to leave the cell?
basolateral membrane through an amino acids carrier
267
what pulls tripeptides into the cell?
the hydrogen going into the cell through a co-transporter due to the sodium exchange being a negative potential
268
what happens to the tripeptides in the cell?
they are broken down into amino acids and are pushed out of the cell
269
what are chylomicrons?
small vesicles that package the lipids which then get exocytosis
269
what removes the lipids?
lacteals
270
what stabilises the fats?
bile salts
271
what happens to majority of the bile salts when they have been used?
they get reabsorbed
271
what do intrinsic factors do?
binds to the vitamins which protects them from being absorbed until they reach the ileum where there are receptors that the factor binds to and allows the vitamin to be internalized through an endocytosis process
271
what helps the absorbtion of vitamins?
intrinsic factors
272
how are fat soluable vitamins tended to be absorbed into cells?
they are carried by lipid droplets and michelles to diffuse across the cell membrane for fat soluable vitamins
272
what do they do in weight loss surgery?
they get rid of theintrinsic factor so there needs to be injections of B12 to get in the blood stream
273
how are water soluable vitamins tended to be absorbed into cells?
similar to amino acid absorbtion and are absorbed by a sodium dependant driving force to move into the cell
273
what happens to the vitamins that we dont absorb?
it is expelled through the elimination process of defication
274
how much water is women (%)?
55%
274
how much of males are water (%)?
60%
275
why are men more water than women?
because men are more muscle and women are more fat
276
what amount of the TBW is extracellular fluid?
1/3
276
what is TBW??
total body water
276
what is ECF?
extracellular fluid
277
what amount of TBW is intracellular fluid?
2/3
278
wat is ICF?
intracellular fluids
279
what is the main function of the urinary system?
maintain the balance in blood by filtering and expelling things like excess water, salts, wastes and many toxins and drugs
280
what is urine?
a waste product which is excreted from the body to maintain waste
281
what does urine consist of normally?
water, salts, urea, metabolites, hormones and small proteins
282
what is different about the pH in urine?
it is not tightly regulated and is influenced by what was excreted
283
what does abnormal urine consist of?
large proteins, red blood cells and glucose
284
what are the main components of the urinary system?
2 kidneys, 2 ureters, urinary bladder and a urethra
285
what are the structure of the kidneys?
allows the blood to be brought into close proximity of the nephrons for filtering
286
where are the kidneys located on the body?
between the T12-L3 vertebrae
287
what superiorly protects the kidneys?
the 11th and 12th ribs
288
where is the convex side of the kidney facing?
laterally
289
what si the medial side of the kidney?
the concave side and is called the hilum
290
are the kidneys peritoneal or retroperitoneal?
retroperitoneal
291
what are the 3 regions of the kidney called?
the cortex, medulla and the pelvis
292
what are the regions o0f the kidneys surrounded in?
a fibourus capsule
293
what is the inner medullary divided into?
medullary pyramids with papilla at the ends
294
what is the outer cortex?
a continuos layer that has renal columns
295
how many functional lobes are in each kidney?
between 5-11
296
what defines a kidney lobe?
one medullary pyramid surrounded by a cortex
297
what are nephrons?
tiny tubes that filter blood and produce urine in each lobe of the kidney
297
what does the urine drain from and where does it go?
it drains through the papilla and collects in the caylx
calyces join to form a renal pelvis
the pelvis narrows and exits the hilum through the ureter
297
what does the afferent arterioles do?
deliovers blood from the arteries to the glomerlus
297
where does filtration occur in the lobe?
in the cortex
297
where does the renal artery arise from?
the abdominal artery
branching arteries get smaller and smaller until they reach the cortex
298
what dio veins do in the renal area of the body?
return filtered blood from the cortex to the renal vein and then to the inferior vena cava
298
what ios the globmerlus made of?
glomerular cappillaries and is where the filtration occurs
299
what does the efferent arterioles do?
carries blood from the glomerlus to the peritubule capillaries
299
what does the peritubules capillaries do?
carries blood to the veins
300
what percentage of our nephrons are cortical?
85%
300
where does the nerve supply to the kidneys come from?
a network of autonomic nerves and ganglia called the renal pelvis
300
what do sympathetic nerves of the renal system do?
acts to adjust diameter of renal arterioles and thus regulate blood flow
301
what percentage of our nephrons are juxtamedullary?
15%
301
what are nephrons?
short and long loops that extend down into the medulla and are responsible for urine formation
301
what are the 2 types of nephrons?
cortical and juxtamedullary
302
what nephrons are shorter?
cortical
303
what nephrons are longer?
juxtamedullary
303
how fa do the longer nephron loops extend to?
almost the papilla
