Lecture 8 Flashcards
what is the dia derived from? innervated by what? how is it shaped?
•Derived from hypaxial musculature of cervical
segments.
•So motor innervation is from cervical
segmental nerves: right and left phrenic nerves
(C3,4,5).
•Diaphragm is a muscular dome-shaped
structure.
what are the connective tissue structures of the diaphragm?
Three TYPES of ligaments, (five total). Called ARCUATE LIGAMENTS. (1) Median ligament. (2) (Right and Left) Medial Ligaments (2) (Right and Left) Lateral Ligaments
what are the muscular structures of the diaphragm
right and left crura- muscular columns that help attach diaphragm
describe all the parts of the respiratory tree?
-branches of it all?
Trachea - 2 Primary Bronchi (right and left)
Each Primary Bronchus - to many Secondary Bronchi
Each Secondary Bronchus - to many Tertiary Bronchi
Tertiary bronchi - to many Bronchioles
Bronchioles - to “Alveoli”
is the lung highly vascularlized?
ya
vessels derived from
arteries in lungs?
mesoderm, veins more variable in pattern.
arteries tend to run ventral to branches of
bronchial tree
where do bronchi and vessels disappear into tissue
of lung
root of the lung
why pleura in the lungs? hint describe chaffing/ where does it expand to?
Lung does not expand up into cupola.
Expands downward toward pleural recess (the
inferior space between ribs and diaphragm.
Pleura secretes coelomic fluid (for lubrication and to
pull lungs when body wall moves).
“Pleurisy” is the painful chaffing between visceral
and parietal pleura.
what is the mediastinum?
What is in the mediastinum?
The “MEDIASTINUM” is the partition between the right and left pleura and the enclosed lungs. \_\_\_\_\_\_\_\_\_\_\_?
why smooth muscle in the lung? \
nervous supply? constiction by what?
Smooth muscle can constrict or open respiratory tree. CONSTICTION: Parasympathetic nervous control is by VAGUS NERVE (X). Ganglia between pre- and post-ganglionic neurons right on target organ.
opening of lungs by what?
Sympathetic fibers.
• Pre- and postganglionic sympathetic fibers
synapse in thoracic region of sympathetic trunk.
• Then, they go up into the neck (cervical
sympathetic trunk) and back down to lungs.
• WHY?
BECAUSE! Remember: Lungs started out in the neck, and
then moved down. The nerves were simply following!
how do we thoracic breathe? explain the process?
Based on RIB MOVEMENTS:
• Scalene muscles pull cranially (up) on 1st and 2nd
ribs.
• Ribs move like bucket handles.
• Each successive rib pulls on the next via
intercostal muscles.
• When ribs/bucket handles move up and out,
VOLUME OF THORACIC CAVITY
INCREASES.
Each successive rib pulls on the next via
intercostal muscles
So what happens when volume
increases? in the lungs
pressure decreases
scalene muscles- innervated by what? located where?
(Scalenes are segmentally innervated: C2-7.)
cranially (up) on 1st and 2nd ribs.
When PRESSURE DECREASES…
Air gets SUCKED IN. All amniotes do this. In other words, amniotes (including humans as mammals)... …SUCK.
how do we abdomen breathe? use what
dia
ABDOMINAL BREATHING? explain contration? does what to do with thoracic
Diaphragm is “dome-shaped.”
• When it contracts, the dome flattens out.
• This INCREASES THORACIC VOLUME.
abd. So, when diaphragm contracts,
So what happens when volume
increases?
VOLUME OF THORACIC
CAVITY INCREASES.
PRESSURE DECREASES
abd. WhenPRESSURE
DECREASES…
Air gets SUCKED IN.
Only mammals (including
humans) have a diaphragm.
So, humans SUCK really well.
FORCED BREATHING describe/ process of inhalation?
Forced exhalation?
Inhalation can be increased by increasing
the amplitude of the movements we just
discussed.
• Forced Exhalation – facilitated by all the
muscles of the ribcage, pressurizing coelom,
and contracting limb muscles around the
axial body wall.
what is forced exhalation?
Muscles of the ribcage (bucket handles move
down).
Pressurizing coelom (pushes diaphragm back
up into dome-shape)** – decreases thoracic
volume to push air out.
Contracting limb muscles around the axial body
wall can help compress thoracic cavity
Pressurizing coelom (pushes diaphragm back up into dome-shape)** then decreases?
decreases thoracic volume
to push air out
In other words, mammals (including humans)
also
blow
humans ____ and _____
suck and blow
how much is in normal breathing volume
about half a liter per breath
normal breathing is called what
tidal volume
equation for inspiratory
capacity
Inspiratory reserve +
tidal volume
slide 43
innervations of the respiratory system? dia, scalenes?
Diaphragm: PHRENIC NERVES (right and
left)
• Scalenes: C2-7
breathing is a ________________________________.
Breathing is “involuntary behavior powered
by voluntary muscles.”
what is the placement of the phrenic nerve? where they at tho
Phrenic nerves pierce diaphragm near apex; send branches across inferior (abdominal) surface of diaphragm.
describe the chemicalness in breathing-what needs to happen
CO2 in blood dissociates into CARBONIC ACID.
• More carbonic acid means lower pH.
• CAROTID BODIES (at junction of internal and
external carotid): Sense pH and communicate with
medulla.
• AORTIC BODY (on arch of aorta): Sense pH and
communicate with medulla.
CAROTID BODIES
(at junction of internal and
external carotid): Sense pH and communicate with
medulla.
AORTIC BODY (on arch of aorta):
Sense pH and
communicate with medulla.
some facts about the RHYMICITY CENTERS OF
MEDULLA OBLONGATA what happens to CO2.. what happens with the carotid/arotic body? increases activity of what? increased co2-increase activity of apneustic area
Increased CO2 (in form of carbonic acid) or increased blood pressure signals from carotid and aortic bodies. • Carotid bodies and arotic body tell medullary rhymicity centers. • Medullary rhymicity centers can then increase activity of apneustic area (deeper breathing.)
some facts about the RHYMICITY CENTERS OF
MEDULLA OBLONGATA what is it called when CO2 is decreased? decreased co2-increase activity of pneumotaxic area
RESPIRATORY ALKALOSIS (higher pH)
Medullary rhymicity centers can then
increase activity of pneumotaxic area
(shallower breathing.)
what are alveoli? describe?
Terminal “Grape-like Lobes of Respiratory Tree.
Microscopic airsacs, thin enough for gas to pass
across.
Note! Only at this microscopic level is lung “hollow.”
Each alveolus is surrounded by _________
capillary plexus
(deoxygenated blood from pulmonary artery,
oxygenated blood returned via pulmonary vein).
how does gas exchange work, what structures does it involve? what does it mean?
Alveolar and capillary membranes: extremely thin.
(Capillaries only one red blood cell wide.)
Thus, hemoglobin in RBCs maximally exposed to
fresh oxygen.
Carbon dioxide dumped.
oxygen BINDS TO _____ in
regions of ____ oxygen concentration.
hemoglobin
high
Carbon dioxide dumped.
what is the job of a surfcant? reduces and prevents what?
Specialized cells of alveolar lining secrete thse
chemicals.
They reduce “surface tension” – prevents fluid
from beading up on alveolar surface.
Prevents collapse of alveoli due to concentrated
fluid weight.
Thinner layer of fluid makes gas diffusion easier
more defenses- Alveoli contain lots of phagocytic cells called
ALVEOLAR MACROPHAGES.
•Ingest and destroy microorganisms and other
foreign substances (from breathing them in…)
other types of defenses of lung
Cilia can transport small bits of foreign material and
mucous back up.
Coughing
Foreign material can be carried into lymphatic
system.
Smooth Muscle and Nervous Supply:
Bronchial segments include smooth muscle—can expand or
constrict tree.
PARASYMPATHETIC:
•Vagus Nerve – signals cause smooth muscle to contract and
constrict bronchioles.
•Ganglia between pre- and postganglionic neurons right on
target organ (on bronchioles themselves).
SYMPATHETIC:
•Pre- and post-ganglionic neurons synapse in thoracic part of
sympathetic chain.
•Go up to cervical region, then go back down sympathetic chain
to lungs.
•Why? Because lungs started out in neck.
•Cause dilation of bronchi.
