Midterm Flashcards
force that occurs as the result of lungs and body wall (ribs and intercostal muscles) constantly trying to pull away from one another
intrapleural pressure - ALWAYS negative
alveolar pressure starts out as equal to atmospheric (0 cm H2) and as the lungs increase in size, what happens to alveolar pressure?
decreases (to about -1 cm H2O) allowing air to flow into the lungs
amount of air you inhale and exhale at rest is referred to as what (~500 mL)
tidal volume
places where the airway does not contain alveoli (thus blood cannot pick up oxygen here)
anatomic dead space
what is the equation for alveolar ventilation
VdotA= (Vt-Vds) * f = (tidal volume- dead space) * frequency
how much air is inhaled every minute
minute ventilation
what is the name for the protective covering of the lungs
pleura (visceral and parietal)
what is the intrapleural pressure of the lungs relative to atmospheric pressure
below atmospheric pressure
what is the intrapleural pressure of the lungs relative to atmospheric pressure while the lungs are at rest
below atmospheric pressure (about -5 cm H2O)
as the thorax increases in volume during inspiration what happens to intrapleural pressure
decreases (to -8 cm H2O)
what muscles are involved in forceful exhalation
abdominals, internal intercostals
what muscles do we use to exhale when we are breathing normally
NONE- expiration is passive
what muscles do we use to exhale when we are breathing normally
NONE- expiration is passive
what happens to alveoli when alveolar pressure drops below atmospheric pressure
air flows into the lungs
how do you calculate minute ventilation? (Vdot)
Vdot= Vt * freq
When is alveolar pressure equal to atmospheric pressure in the respiratory cycle?
In between inhalation and exhalation
When is alveolar pressure at its maximum in the respiratory cycle?
Mid-exhalation
When is alveolar pressure at its minimum in the respiratory cycle?
Mid-inhalation
When is intrapleural pressure at its minimum in the respiratory cycle?
After inhalation
When is intrapleural pressure at its maximum in the respiratory cycle?
After exhalation
what are the boundaries of the thorax
ribs, vertebra, superior thoracic aperture (thoracic inlet), diaphragm
we can divide the thorax into what 3 compartments
2 pulmonary cavities and 1 mediastinum
what are the 3 parts of the sternum
manubrium, body of sternum, typhoid process
how many costal notches do you find on the sternum
7
what do you ALWAYS find attaching rib to sternum
costal cartilage
which rib articulates with the articulation between manubrium and body of sternum
rib 2
which rib articulates with the articulation between body of sternum and xiphoid process
rib 7
synonym for “true ribs”? Which ribs are “true ribs”?
vertebrocostal ribs, (1-7)
synonym for “false ribs”? Which ribs are “false ribs”?
vertebrochondral ribs, 8-10
synonym for “floating ribs”? Which ribs are “floating ribs”?
vertebral ribs, 11-12
which ribs are atypical
1-2, 10-12
what are the components of a typical rib
head, neck, tubercle, body
the head of a rib articulates with what? The tubercle of a rib articulates with what?
rib head- vertebral body
rib tubercle- transverse process of vertebra
where do ribs tend to break most frequently?
near the costal angle
what makes rib 1 atypical?
it has 2 grooves (for subclavian vein and subclavian artery) and a tubercle = attachment site for superior scalene muscle
what is the “atypical” feature of rib 2
roughened area (tuberosity) on the body where serratus anterior attaches
what makes ribs 10-12 atypical?
they meet up with only 1 (instead of 2) vertebra so they only have 1 facet
ribs 11-12 also have no tubercle and no neck
what is a primary cartilaginous joint and examples?
synchondrosis (xiphosternal joint, first sternocostal joint)
what is a secondary cartilaginous joint and examples?
symphysis (manubriosternal joint)
while the first sternocostal joint is considered synchondrosis, what are the rest classified as?
planar synovial joint
what ligaments help to anchor the sternocostal joints
anterior radiate sternocostal L
what type of joint is the vertebrocostal
planar synovial joint
what ligaments help to anchor the vertebrocostal joints
radiate ligament, intra-articular ligament
rib 6 head articulates with which 2 vertebra
T5 and T6
the tubercle of rib 6 articulates with what
transverse process of T6 vertebra
costotransverse joint is what type of joint
planar synovial
what ligaments help to anchor the costotransverse joints
superior costotransverse ligament
lateral costotransverse ligament
lateral rib movement increases space in thorax and is classified how
bucket handle
anterior rib movement increases space in thorax and is classified how
pump handle
costochondral joints are what type of joint
synchondrosis
where does rib separation occur
between rib and costal cartilage (costochondral joint)
where does rib dislocation occur
between costal cartilage and sternum (sternocostal joint)
Except for where ribs 9 and 10 meet, how do we classify the joints of our false ribs
planar synovial
how do we classify the joint where ribs 9-10 meet up
fibrous joint
how do we classify intervertebral joints
symphysis
how do we classify zygopophyseal joints (between superior and inferior articulating facets of vertebra)
planar synovial
what are the 3 layers of intercostal mm?
external, internal, innermost
what is the function of external intercostal mm?
elevate ribs
what innervates intercostal mm?
intercostal nn
anteriorly, the external intercostal mm become what named structure
anterior (external) intercostal membrane
whats the job of internal intercostal mm
depress ribs
how many lobes are there in the left lung
2
how many lobes are there in the right lung
3
what is the term describing distinct lines in between lobes of the lung? What are the 2 types?
fissure (can be oblique or horizontal)
what major feature of the lung is found on the mediastinal surface
the hilum
what structure of the left lung is homologous to the middle lobe of the right lung
lingula of the left lung
what are the 4 parts of parietal pleura surrounding the lungs
cervical, costal, diaphragmatic, mediastinal
when you get air into the pleural cavity
pneumothorax
when you get blood into the pleural cavity
hemothorax
when you get water into the pleural cavity
hydrothorax (pleural effusion)
why does a pneumothorax cause lung collapse
it breaks the surface tension in the pleura which is normally used to keep the lung expanded
describe the path air takes as it enters the mouth and then travels to the lungs
trachea–> main bronchi–> lobar bronchi–> segmental bronchi–> conducting bronchiole–> terminal bronchiole–> respiratory bronchiole–> alveolus
you can find cartilage in which areas of the airway
trachea, primary, secondary, and tertiary bronchi
abnormal narrowing of the airway causes difficulty breathing in what pathological condition
asthma
1 tertiary bronchus supplies 1 ___ in the lung (there are 10 total)
bronchopulmonary segments
what are the two types of smooth muscle and what is the difference in their primary activation?
unitary (single unit): hormonal control
multi unit: single nerve ending
smooth muscle composed of separate smooth muscle fibers each operating independently and innervated by a single nerve ending
multi-unit smooth muscle
where in the body do we find multi unit smooth muscle
ciliary muscle of eye, iris muscle, piloerector muscle cause erection of hairs (sympathetic innervation)
unitary/visceral/syncytial smooth muscle contracts together as a single unit because ions can flow freely through what structures
gap junctions
where in the body do we find unitary smooth muscle
GI, bile duct, ureters, uterus, blood vessels
smooth muscle does not have the troponin complex so what controls contraction here?
calcium binds calmodulin and this complex initiates phosphorylation of myosin and then contraction can occur
these smooth muscle structures are found attached to cell membrane creating intercellular bridges AND dispersed throughout the cell and act like the Z disc acts in skeletal muscle
dense bodies
dense bodies in smooth muscle are analogous to what skeletal muscle feature
z disc
smooth muscle contraction is initiated by an influx of Ca++ into the cytosol. what mechanisms can control this influx?
hormone stimulation, nerve stimulation, stretch of fiber, or random change in chemical environment
what in smooth muscle is analogous to troponin in skeletal muscle
calmodulin
describe the 4 steps in smooth muscle contraction
- Intracellular Ca++ increase (from extracellular fluid or release from SR)
- Ca++ binds to calmodulin
- Ca/calmodulin complex binds and activates myosin light chain kinase
- myosin light chain gets phosphorylated and binds actin and pulls to contract
what structure found in smooth muscle is analogous to T tubules in skeletal muscle (help to conduct action potential along the SR for uniform contraction)
caveolae
the force of smooth muscle contraction is highly dependent on what
extracellular calcium ion concentration
what happens after calcium/calmodulin is released from the actin/myosin complex (at the end of contraction)
myosin phosphatase removes phosphate from myosin light chain so myosin and actin can release to allow relaxation
as skeletal muscle is stretched, what happens to the tension generated ? smooth muscle?
decreases in skeletal m
maintains tension when stretched in smooth muscle
is skeletal or smooth muscle more energy efficient?
smooth
smooth muscle neural control can be both intrinsic and extrinsic: what does this mean
intrinsic control: enteric nervous system (independent of CNS and PNS)
extrinsic control: autonomics
what neurotransmitters help control smooth muscle function
acetylcholine (muscarinic receptors: contract OR relax)
norepinephrine (contract vascular, inhibit gut)
NO (inhibit SM via cGMP)
whats the term for: swellings in axon near smooth muscle that releases neurotransmitter
varicosities
what type of receptor is required on smooth muscle to bind norepinephrine
andrenergic (alpha and beta types)
which neurotransmitter acts on smooth muscle by diffusing through the membrane and acting on cGMP system
NO
what structure in the smooth muscle is analogous to NMJ of skeletal muscle
varicosities (no motor end plate in smooth muscle)
hormones that can elicit smooth muscle contraction
epinephrine, CCK, oxytocin
where does NO come from?
its secreted by endothelial cells
to start a new cycle of contraction, a phosphate must be removed from the myosin light chain of smooth muscle. when does this happen?
can happen ANY time (high ca++ helps)
what creates active tension in muscle contraction? passive tension?
active- cross bridges
passive- stretching
why don’t we get a tension “plateau” in smooth muscle when we stretch it?
myosin and actin fibers can rearrange and continue to create active tension
What hangs out in the middle mediastinum and determines where posterior, superior, middle, and anterior medastinums are?
heart
From superficial to deep what are all the layers of the heart
fibrous pericardium parietal serous pericardium visceral serous pericardium (epicardium) myocardium endocardium
What provides a barrier to electrical impulses in the heart so it all doesn’t beat at once ineffectively?
fibrous skeleton
If you removed the sternum what surface of the heart are you looking at?
sternocostal surface
What surface of the heart makes the cardiac impression?
pulmonary surface
What view do you have to look at the heart for the borders to make sense?
sternocostal
If I’m looking at the right external surface of the heart what two main features will I see?
right AV groove
anterior inter ventricular groove
If I’m looking at the left external surface of the heart what two main features will I see?
left AV groove
posterior inter ventricular groove
What does the sulcus terminals on the external surface correspond to inside the heart?
crista terminalis
What does the ductus arteriosus become?What runs underneath it?
ligamentum arteriosum
left recurrent laryngeal nerve from vagus n
What doe we call the smooth and rough wall in the right atrium?
smooth- sinus venarum
rough- pectinate muscle
What separates the smooth and rough walls in the right atrium?
crista terminalis
What makes up the interatrial septum? What is the opening in it called?
sinus venarum (smooth wall) fossa ovalis
Where can yo find the opening to the coronary sinus?
right atrium
what is the valve between the right atrium and ventricle? What are the parts of it called?
tricuspid valve: septal, anterior, posterior cusps
What connects the cusps to the ___ muscle?
chordae tendineae
papillary m
What is the big trabeculae that goes from the anterior ventricular septum to the right margin of the heart?
septomarginal trabeculum
dead space that includes anatomic AND alveolar
physiologic dead space
What is the valve that the blood must get through to enter the lungs?
pulmonary valve
What is the space behind a cusp in the pulmonary valve’?
pulmonary sinus
What do we call the valve between the left atrium and ventricle? What are the parts of ti called?
bicuspid/mitral
anterior or posterior cusps
What do you call the smooth wall in the left ventricle before it goes into the aorta?
aortic vestibule
What do you call the rough wall in the left ventricle?
trabecula carnae
what is the space behind an aortic valve cusp?
aortic sinus
What node is found in the superior part of the right atrium?
sinuatrial node
What node sends the impulse to the ventricles?
atrioventricular node
What are other names for purkinje fibers?
septomarginal trabecula
moderator band
What do we call it when there’s fluid in the pericardial sack? What does it lead to? How do we treat it?
pericardial effusion —> cardiac tamponade
pericardiocentesis
What is the pericardial cavity between?
visceral serous (epicardium) and parietal serous pericardium
If we get fluid into the pericardial sack where will it pool?
pericardial sinuses: transverse and oblique
What do we call it when there’s fluid in the pericardial sack? What does it lead to? How do we treat it?
pericardial effusion —> cardiac tamponade
pericardiocentesis
amount of air inspired in a single breath
tidal volume (Vt)
normal resting tidal volume
500 mL
volume of air you can breathe in after Vt
inspiratory reserve volume (IRV)
volume of air you can breathe out after vt
expiratory reserve volume (ERV)
when you blow out your ERV it requires what?
activation of expiratory muscles
no matter how hard you try you cannot voluntarily force this air out of the lungs
residual volume (RV)
which lung volume cannot be measured using a spirometer
residual volume
IRV + VT + ERV
VC (vital capacity)
total volume of air you can inhale from a normal resting point
inspiratory capacity
IRV + VT
IC (inspiratory capacity)
ERV + RV
FRC (functional residual capacity)
all the air that remains in your lungs at the end of normal (passive) respiration
FRC (functional residual capacity)
If you have an area of lung getting a lot of air flow what chemical will you release to get blood over there? What actually makes it?
nitric oxide
endothelium
which capacities CANNOT be measured using spirometry and why
TLC and FRC because they include RV which cannot be measured
regions of the lung which receive air but not blood
dead space
dead space in conducting airways (where no gas exchange occurs)
anatomic dead space
dead space in alveoli that get air but no blood (no gas exchange)
alveolar dead space
dead space that includes anatomic AND alveolar
physiologic dead space
how can we estimate anatomic dead space in a patient?
weight in pounds in mL
50 lb patient has ~ 50 mL of anatomic dead space
how do you calculate alveolar ventilation
VdotA= (tidal volume-dead space)*frequency
how do you calculate minute ventilation
Vdot= tidal volume*frequency
Autonomic nervous system is activated by centers located where
Spinal cord, brain stem, hypothalamus
Sympathetic nerve fibers originate in the spinal cord with spinal nerves between cord segments T1-L2 but must pass through what before reaching the organs that they innervate
They synapse in the Sympathetic chain (paravertebral)
The cell body of each preganglionic sympathetic neuron lies where within the spinal cord
Intermediolateral horn
What type of postganglionic sympathetic fiber passes back from sympathetic chain through gray rami to spinal nerves
Small type C fibers (to blood vessels, sweat glands, piloerector hair muscle)
Sympathetic fiber pattern: from cord segment T1 usually terminate where
Head
Sympathetic fiber pattern: from cord segment T2 usually terminate where
Neck
Sympathetic fiber pattern: from cord segment T3-6 usually terminate where
Thorax
Sympathetic fiber pattern: from cord segment T7-11 usually terminate where
Abdomen
Sympathetic fiber pattern: from cord segment T12-L2 usually terminate where
Legs
Preganglionic sympathetic fiber can pass without synapsing through sympathetic chain, through splanchnic nerves, and into adrenal medullae where they end on what kind of modified neuronal cells
Chromaffin cell (secretes norepinephrine)
Which cranial nerves have parasympathetic fibers
3, 7, 9, 10
75% of all parasympathetic fibers travel in what named nerve
Vagus (CN X)
Vagus nerve supplies what structures
Heart, lung, esophagus, stomach, small intestine, proximal half of colon, liver, gallbladder, pancreas, kidney, upper ureter
Parasympathetics from CN III go where
Pupillary sphincter, ciliary muscle of eye
Parasympathetics from CN VII go where
Lacrimal, nasal, submandibular glands
Parasympathetics from CN IX go where
Parotid gland
Where do parasympathetics arise that supply descending colon, rectum, urinary bladder, lower ureter? (They also cause erection)
S2-3
Which autonomic division has a long presynaptic neuron and a short postsynaptic neuron (often located within the wall of the organ being innervated)
Parasympathetics
Which autonomic division has a short presynaptic neuron and a long postsynaptic neuron
Sympathetics
All autonomic preganglionic neurons are what
Cholinergic (release Ach)
Nearly all postganglionic neurons of the parasympathetic system are ___ compared to ___ for most postganglionic in the sympathetic system
Para- Cholinergic
Symp- Andrenergic (release norepinephrine)
There are a few cholinergic postganglionic sympathetic fibers which go to what structures
Sweat glands (and maybe a few blood vessels)
Autonomic neurotransmitter release at target tissue occurs at varicosities which are rich in what two things that are necessary to synthesize and store NT
Mitochondria, ATP
What is the process for making norepinephrine?
Tyrosine –> dopa –> dopamine –> into a vesicle –> norepinephrine –> (only in adrenal medulla) methylation to epinephrine
3 ways norepinephrine can be removed form secretory site
- Reuptake via active transport
- Diffusion into surrounding fluids
- Destruction by tissue enzymes
Because norepinephrine binds this kind of receptor it can have. Different functions. On different cells
GPCR
What type of receptor is a muscarinic Ach receptor? Nicotinic?
Muscarinic- GPCR (excitatory or inhibitory)
Nicotinic- ligand gated ion channel (excitatory only)
Contraction of the left ventricles closes what valves and opens what valves?
closes mitral
opens aortic
Even though they do so at different pressures, the left and right ventricles do what?!?!
pump the same volume of blood over the course of a minute
What is the blood pressure in the right ventricle forcing blood to the lungs?
25/15
Where do extra-alveolar capillaries arise from? What are their functions?
left ventricle
deliver o2 and co2 to the tissues the lungs
How do extra alveolar capillaries return to the heart?What do they cause?
pulmonary veins
venous admixture
Compare blood gases between alveolar capillary and extra-alveolar capillary
alveolar- high O2 low CO2
extra- low O2 high CO2
What is cardiac output comparable to in the lungs?
minute ventilation
What is the equation for blood pressure?
CoxTPR
cardiac output x total peripheral resistance
How can the right ventricle have such smaller pressure compared to left ventricle yet move the same amount of blood?
pulmonary vascular resistance is 1/4 of systemic
What causes pulmonary vascular resistance to be so low?
high number of capillaries
less sympathetic tone
Why does PVR drop during exercise?
more pulmonary capillaries open up to accommodate increased CO
What’s going on as far as size and blood flow in the apex (zone I) of the lungs? Why is blood flow the way it is?
alveoli are expanded
less blood flow
above level of heart- low BP
What’s going on in zone II of the lungs for blood flow and alveoli size?
both are average
What is the alveolar size and blood flow in zone III of lungs? Why?
alveoli-small
blood flow- high, below heart
So when we go from the top of the lungs to the base of the lungs what happens to alveolar pressure?
high to low
What does NO do?
smooth muscle relaxation and vasodilation
What can be used to constrict blood vessels so we don’t send blood to plays with low oxygenation? Where is it made and when do we see it?
endothelin 1 made in lungs
pathologic conditions
What is another vasoconstrictor in lungs that is found in conditions following injury
thromboxane
Why must we keep the alveoli dry?
oxygen is not water soluble so it wouldn’t be able to cross over to blood
What do we call the pressure generated from fluid pushing against the tissue or walls of the capillary?
hydrostatic pressure
the sympathetic “fight or flight” system functions when our body is under what conditions
needs oxygen, O2 to muscle, heart pumps fast and hard, no digestion
Where is tissue hydrostatic pressure trying to push fluid? How do we write it?
into capillary
Pt
Where is the plasma (capillary) oncotic pressure pull fluid? How do we write it?
pull water into capillary
pi c
sympathetic innervation to the ciliary muscle of the lens leads to what
relaxation (flattening) increasing far sight
So what are the two forces moving water into alveolus?
Pc and pi tissue
capillary hydrostatic and tissue oncotic pressure
What are forces trying to move water into capillary?
Ptissue and pi c
tissue hydrostatic pressure and capillary hydrostatic pressure
What its the greatest single starling force in the lungs?
Pc
hydrostatic pressure in capillary
The forces that cause a negative intrapleural pressure also cause what?
NEGATIVE hydrostatic pressure in the tissue
Even though the starling forces favor net filtration of fluid into the alveoli what do we do?
lymphatics remove filters fluid from alveoli
Where is angiotensinogen converted to angiotensin 1 and by what enzyme?
liver
renin
bronchial smooth muscle has what type of andrenergic receptor
beta 2 (makes sense because albuterol is a beta 2 agonist)
sympathetic innervation to the bronchial smooth muscle leads to what
bronchodilation (get more air in)
what type of andrenergic receptors do we have in bronchial glands? what do they do?
alpha1 - decrease secretion
beta2 - increase secretion (humidify dat air)
What are produced by immune system activation in the lungs?
leukotrienes and prostaglandins/thromboxane A2`
what type of sensory receptor activates a withdrawal reflex arc
nociceptor (pain)
unlike the withdrawal reflex, most autonomic reflexes occur where?
brain (lower levels than cortex like brainstem/hypothalamus)
the withdrawal reflex stimulates an alpha motor neuron to produce motion whereas visceral reflexes activate what
autonomic neurons
the parasympathetic “rest and digest” system functions when our body is under what conditions
plenty of oxygen, heart beat slow, BP low, blood to intestine for digestion
the sympathetic “fight or flight” system functions when our body is under what conditions
needs oxygen, O2 to muscle, heart pumps fast and hard, no digestion
whats the rule of thumb for andrenergic receptors in vasculature
alpha receptors : vasoconstrict
beta receptors : vasodilate
sympathetic innervation to the radial m. of the iris leads to what
alpha receptor : contraction (dilation, light comes in)
sympathetic innervation to the ciliary muscle of the lens leads to what
relaxation (flattening) increasing far sight
what class of andrenergic receptor do we find in radial m of iris
alpha
what class of andrenergic receptor do we find in ciliary m of lens
beta 2
what class of andrenergic receptor do we find in heart
beta 1 and beta 2
sympathetic innervation to the heart leads to what
increased HR and contraction strength
what type of andrenergic receptor do we find in vessels
BOTH! (alpha constricts, beta dilates)
what is the purpose of andrenergic receptors in vessels
direct blood flow to skeletal muscle mostly (also to heart, lung, abdominal organs, kidney)
bronchial smooth muscle has what type of andrenergic receptor
beta 2 (makes sense because albuterol is a beta 2 agonist)
sympathetic innervation to the bronchial smooth muscle leads to what
bronchodilation
what type of andrenergic receptors do we have in bronchial glands? what do they do?
alpha1 - decrease secretion
beta2 - increase secretion
what type of andrenergic receptors do we have in GI? what do they do?
alpha1 - decrease motility AND contract sphincter
alpha2 - decrease secretion
beta - decrease motility
what type of andrenergic receptors do we have in liver? what do they do?
alpha1 and beta2 (release glycogen)
what type of andrenergic receptors do we have in adipose? what do they do?
alpha1, beta1, beta3 (increase lipolysis)
What are the three layers of the endocardium starting at most proximal to lumen to distal
endothelium
sub endothelium
subendocardium
The endothelium of endocardium is continuous with what?
endothelium of blood vessels
What does the sub endothelium in endocardium contain?
collagen, elastin, some smooth muscle fibers
What does the subendocardium of endocardium contain?
thicker layer of CT
small blood vessels and subendocardial branches
What is thicker in the atrium and what is thicker in the ventricles?
atrium- endocardium
ventricles- myocardium
What do subendocardial branches (purkinje) stain like and why?
pale central area due to having a lot of glycogen
What are subendochardial branches modified versions of? How are they different?
cardiocytes
larger
fewer myofibrils
Overall what is the thickest layer of the heart?
myocardium
What does the myocardium consist of?
striated cardiac muscle fibers (contractile) specialized cardiocytes (nodal) myoendocrine cardiocytes (hormonal)
What are the two types of granules found in myocardium?
lipofuscin atrial (myoendocrine)
What cause striations in cardiocytes?
sarcomeres lined up
What two things are found in the transverse region of an intercalated disc?
fasciae adherentes (zonula adherents) macula adherentes (desmosomes)
What is the function of the zonula adherents?
anchoring site for actin filaments of terminal sarcomeres to the plasma membrane
What is the function of the maculae adherentes?
hold contractile cardiocytes tightly together
What is found in the lateral region? What is its relationship to myofibrils?
gap junctions
parallel
less mechanical stress
What is the t-tubule system in the cardiac cells? What makes up the system?
did
one t-tubule and one SR cisterna
Where is the diad t-tubule system found?
z-lines (AI junction in skeleton muscle)
What exactly is a transverse tubule?
fingerlike invaginations of the sarcolemma (plasma membrane)
What make up lipofuscin granules and in what cells do we find them?
contain material derived from residual bodies after lysosomal digestion
accumulate with age in stable non-dividing cells
What do we find in atrial granules? Where in the heart do we mostly find them?
precursor to atrial natriuretic factor (ANF)
right atrium
What does the epicardium consist of?
mesothelium
subepicardium
What makes the mesothelium in epicardium?
lining of simple squamous cells (visceral layer of pericardium)
What makes up the subepicardium?
layer of loose CT
collagen, elastin, adipocytes, nerves, coronary vessels
What is thefunctio of the epicardium?
protect the coronary arteries
What is also known as the heart’s pacemaker?
sinoatrial node
What is the path of an electrical impulse starting at SA node?
SA node internal atrial pathways AV node AV bundle (of His) R/L bundle branch subendocardial branches to ventricular contractile cardiocytes
where does the atrioventricular bundle (of His) travel?
in inter ventricular septum
Where is the SA node located?
along sulcus terminals at junction of the superior vena cava with right atrium
What are the cardiocytes of the SA node centered around?
sinoatrial nodal artery
What are the cells of the SA node connected by? What are they connected by? How do they stain?
pale
connected by gap junctions and desmosomes
NOT intercalated discs
where is the atrioventricular node located?
base of intertribal septum at the junction of the right atrium and ventricle
What are the atrioventricular node cardiocytes situated around?
atrioventricular nodal artery
How do the sells of the AV node look different from the cells of the SA node?
irregularly arranged
What are three functions of the fibrous skeleton?
- structural framework
- attachment for valves and myocardium
- electrical insulation
What are the three layers of the heart valves?
central- fibrosa
spongiosa sandwiches fibrous
outermost is endothelium
What is the cartilage that makes up heart valves continuous with?
annuli fibrous of the fibrocollagenous skeleton
What is the myocardium doing in relation to the heart valves?
myocardium extends into the valve, but stops before end of valve
If we’re piercing a blood vessel what are the layers we will encounter as we go deep?
tunica adventitia external elastic lamina tunica media internal elastic lamina tunica intima
What are the parts of the tunica intima from closest to the lumen to farther away?
endothelium
sub endothelium
basal lamina
What makes up the tunica media?
smooth muscle (CT)
What makes up the tunica adventitia?
fibroblasts
collagen
vasovasorum
nerves
In what layer do you find the vasovasorum?
tunica adventitia
What is the internal elastic lamina indistinguishable from?
basal lamina of tunica intimate
What kind of collagen is found in the basal lamina of the tunica intima?
type 4
In what layer of a blood vessel do you find the sensory fibers and motor innervation?
tunica media
What kind of sense is picked up in the tunica media? Who innervates it?
baroreceptors
autonomic nervous- sympathetic
What is the functions of the tunica adventitia?
anchors to surrounding connective tissue
What type of fibers are found in the tunica adventitia?
longitudinal type I and elastic
What is unique about the layers of arteries?
tunica adventitia is not that thick
tunica media is very thick
What is unique about the layers of capillaries?
there is only endothelium layer of tunica intima
What is unique about the layers of veins?
thin tunica media
thick tunica adventitia
What type of artery is the aorta?
elastic
How can we differentiate between muscular artery and elastic artery under a slide?
muscular- tiny tunica adventitia
elastic- big adventitia with lots of elastic fibers
What type of artery has vasovasorum?
elastic
What is another name for muscular arteries? What are some examples?
distributing
femoral, subclavian, etc
What is noteworthy of muscular arteries?
big tunica media
What makes up a capillary?
thin tube of endothelium surrounded by basal lamina
What are the three types of capillaries?
continuous
fenestrated
discontinuous
Where do you find continuous capillaries? What’s another name for these capillaries?
muscle, brain, peripheral nerves, exocrine glands
somatic
Why is a continuous capillary continuous?
endothelium bound tightly
zonula occludens
What’s another name for fenestrated capillaries? Where do you find them?
visceral
kidneys, intestine, exocrine glands (rapid exchange between tissue and blood)
How big are the pores in fenestrated capillaries?
size of a macromolecule
Where do you find discontinuous capillaries? What cells are usually interspersed along the walls?
hematopoietic organs
phagocytic cells
What is another name for discontinuous capillaries?
sinusoidal capillaries
What are the three types of veins?
large veins
medium-sized veins
venules
What type of collagen is found in the tunica media of large veins?
2
In large veins what is difficult to distinguish?
tunica adventitia from tunica media
What is sparse in tunica adventitia of large veins?
elastin
In what type of veins do we usually see valves?
medium-sized veins
What is the best developed tunic in medium-sized veins?
adventitia
What are valves projections of? What are they lined by? What supports them?
tunica intima
endothelial cells
elastic and collagen fibers
What is the best developed tunic in venules?
tunica adventitia
How does the lymphatic system terminate?
dumps into venous circulation via right lymphatic and thoracic ducts
What are the 3 parts of the aorta
Ascending, aortic arch, descending
What are the branches that come off of the ascending aorta
Left and right coronary artery
What are the anterior branches of the. Right coronary artery
Sinuatrial nodal Conus branch Atrial branch Right coronary Posterior interventricular a Right marginal a
What are the posterior branches of the right coronary artery?
Atrioventricular nodal a
Right posterolateral a
Posterior interventricular a
Normal range for arterial CO2
35- 45 mmHg
Normal range for arterial bicarb
22-26 mEq/L
What does the left vagus nerve become super low on the esophagus before it goes through diaphragm?
anterior vagal trunk
What does the right vagus nerve become super low on esophagus before it goes through diaphragm?
posterior vagal trunk
What are the roots for the vagus nerve
C3,4,5
What does the phrenic nerve travel through?
mediastinal parietal pleura and fibrous pericardium
What innervates all the muscles of the thoracic cage?
muscular branches from intercostal nerves
What are the three branches of the intercostal nerve?
lateral cutaneous
muscular
anterior cutaneous
Which intercostal nerves are typical?
3-6
Which intercostal nerves are atypical?
1-2
7-11
What is the anterior rams of the 1st thoracic spinal nerve doing?
joining brachial plexus
What makes 2nd thoracic spinal nerve atypical?
branch can go to brachial plexus
lateral cutaneous branch goes to skin and body wall
Why are intercostal nerves 7-11 atypical?
start thoracic
end abdomen
thoracoabdominal nerves
What do we call the sympathetic division of the ANS according to location?
thoracolumbar
What are the two divisions of the ANS?
sympathetic
parasympathetic
Which division of the ANS is limited?
parasympathetic
What division of ANS is in charge of vasoconstriction? glandular production?
sympathetic
parasympathetic
Where is the presynaptic cell of the sympathetic division?
lateral horn
What part of the spinal cord do you see the lateral horn?
thoracic and lumbar
What are the guys called that connect us from paravertebral to pre vertebral?
greater, lesser, least splanchnic nerves
what are the synaptic options for sympathetic division?
- synapse in same level paravertebral ganglion
- synapse in different level paravertebral ganglion
- synapse in pre vertebral ganglion
Why do we have a sympathetic trunk
to let the little presynaptics travel to different levels of ganglion
What are the four pre vertebral ganglion?
celiac
superior mesenteric
inferior mesenteric
aorticorenal
What are the guys called that connect us from paravertebral to pre vertebral?
splanchnic nerves
What makes up all the cardiopulmonary splanchnic nerves? Why?
post synaptic fibers
synapse in paravertebral ganglion (either same or different level)
What makes up all the abdomenpelvic splanchnic nerves?
pre synaptic fibers
synapse in prevertebral
Who is the parasympathetic guy from the cranium that we care about at this point?
vagus (CNX)
Where do we find the sacral part of the spinal cord?
up by conus medullaris so L1-2
Where is the postsynaptic cell body of parasympathetic division
in the cell body
What do we call the presynaptic fibers in the sacral part of parasympathetic?
`pelvic splanchnic nerves
What do we find in the autonomic plexus?
sympathetic and parasympathetic POSTsynaptic fibers
What contributes to the pulmonary autonomic plexus?
pulmonary splanchnic (sympathetic) pulmonary branches of vagus (parasympathetic)
What contributes to the superficial cardiac plexus?
cardiac splanchnic (sympathetic) superior, middle, inferior cardiac branches of vagus n (parasympathetic)
What contributes to deep cardiac plexus?
cardiac splanchnic nerves
so strictly sympathetic
What contributes to the aortic plexus?
continuation of superficial cardiac plexus
What contributes to the esophageal plexus?
great splanchnic (presynaptic, sympathetic) esophageal branches of vagus n (parasympathetic)
the left coronary artery splits into what two branches
circumflex a
anterior interventricular a (LAD)
the circumflex artery (after coming off of left coronary a) gives off what major branch inferiorly
left marginal a
what is the major branch from the anterior inter ventricular artery (LAD)
AV nodal a
AV bundle branches
where do they place the new vessel during coronary artery bypass
one end on aorta, other end on the occluded artery distal to occlusion
what branch of subclavian a is the major arterial supply to the anterior thorax
internal thoracic a
gives off anterior intercostal aa and pericardiacophrenic a and musculophrenic a
if we see a branch coming off the internal thoracic a and diving medially what do we call them
medial mammary a
where does lateral mammary a come from?
off of lateral thoracic a (which comes from axillary a)
OR from lateral cutaneous branch of posterior intercostal a
what are the unpaired visceral branches of the thoracic aorta
mediastinal
esophageal
pericardial
what are the paired lateral visceral branches of the thoracic aorta
bronchial a
what are the paired segmental parietal branches of the thoracic aorta
posterior intercostal a
subcostal a
what are the 2 possible branches that can come from posterior intercostal aa
lateral cutaneous a
collateral branch
what are the blood supplies to the diaphragm
musculophrenic (from internal thoracic) pericardiacophrenic (from internal thoracic) superior phrenic (from descending thoracic aorta)
how can we distinguish arteries and veins that supply/ drain the alveoli
arteries follow the airway and veins are intersegmental running between airways
whats it called if a blood clot travels to the lungs and causes major issues
pulmonary embolism
how many pulmonary veins drain into the posterior heart
4 (L superior pulmonary, L inferior pulmonary, R superior pulmonary, R inferior Pulmonary)
which cardiac veins empty directly into atrium
anterior cardiac veins
great cardiac vein, small cardiac v, and middle cardiac v all drain into what structure
coronary sinus
what v runs with right marginal a
small cardiac v
what a runs with great cardiac v
anterior interventricular a
what a runs with middle cardiac v
posterior interventricular a
what do posterior intercostal vv drain into on the left side? right side?
right- azygos v
left- hemiazygos or accessory hemiazygos v
behind the esophagus we see a vessel running superiorly without any branches. what is it?
thoracic duct
what are the 2 ways oxygen travels in the blood
bound to hemoglobin or dissolved
who has greater solubility in water: oxygen or CO2?
CO2 (6 mL / dL blood / 100 mmHg)– 20x more soluble
O2 (0.3 mL / dL blood / 100 mmHg)
when we refer to PaO2 levels (partial pressure of O2 in arterial blood) we are referring to what population of oxygen?
dissolved!!!
what is the range of O2 partial pressures in the blood that allow hemoglobin to be “fully” (>85%) saturated?
60-100 mmHg
what is the normal oxygen content of blood that is 85% Hb saturated
17 mL O2 / dL blood
an increase in Hb’s affinity for O2 would shift the Hb/PO2 curve to which direction? What can cause this?
left shift!
low CO2, high pH,
a decrease in Hb’s affinity for O2 would shift the Hb/PO2 curve to which direction? What can cause this?
right shift
High CO2, low pH, increase temperature, 23BPG
where in the body do we see increase in CO2, H+, temp, and 23BPG? Why is this a good thing
in the TISSUE
it shifts Hb/O2 dissociation RIGHT and we release O2 at the tissue
normal venous PO2
40 mmHg (=75% saturation = 15.2 mL O2/ dL blood)
what is the difference in arterial and venous O2
4.6 mL O2 / dL blood
this is how much O2 is USED by tissue being perfused
there is a consistent ratio of O2 used to CO2 produced in the tissue: what is that ratio if the fuel is carbs? fats? mixed fuels?
carb- 1:1 ratio
fat- 7 CO2 produced: 10 O2 consumed
mix: 8 CO2 produced: 10 O2 consumed
what is respiratory quotient? How do we find it?
its the ratio between volume of CO2 produced and O2 consumed
RQ= V(dot)CO2/V(dot)O2
whats the RQ if we are metabolizing mixed fuels?
RQ= V CO2 produced / V O2 consumed = 8/10 = 0.8
what are the 3 ways we transport CO2 in the blood
dissolved carbamino compounds (bound nonspecifically to proteins) as HCO3 (bicarb-- this accounts for MOST CO2 transport)
what is the haldane shift
presence of O2 bound to heme reduces heme affinity for CO2
what enzyme helps CO2 and water become H+ and bicarb
carbonic anhydrase – in RBCs
we pump bicarb out of RBCs by bringing in what ion? (an electroneutral exchange)
Cl-
this is why we have lower chloride in venous blood: The Chloride Effect
how do we calculate [O2] in the alveoli? (alveolar gas equation)
PAO2= PIO2 - (PaCO2/R)
PIO2: inspired PO2 (account for water vapor: PiO2=(760-47)*O2% at sea level)
PaCO2: arterial CO2
R: 0.8 for mixed fuel, 1 for carbs
A-a O2 gradient is normally what?
an increase in A-a O2 gradient means what?
less than 20 mmHg
diffusion impairment of alveoli
When anion gap is calculated to be greater than 12, what must be present and unmeasured (contributing to the metabolic acidosis)
MUDPILES
Methanol, uremia, diabetic (or starvation or alcoholic) ketoacidosis, paraldehyde, isoniazid, iron, lactic acidosis, ethanol or ethylene glycol, salicylate
