***********HEART:
Heart and Blood Vessels are the cardiovascular system
Closed circular system for blood
blood goes from heart -> arteries -> capillaries veins heart again
embryonic (baby) development of heart:
starts as tube receiving (venous) end and delivery (arteriel) end
20 days there are two endocardial tubes
21 days, they fuse into primitive heart tube
from top to bottom, truncus arteriosus, bulbus cordis, primitive ventricle, primitive atrium (22 days)
at the bottom we got sinus venosus (23) no more primitive
S shape in week 5. Left and right atrium. aortic arch arteries at the very top.
in week 7, 4 chambers (ventricles split). inter(atrial/ventricular) septum separate each.
FLOW OF BLOOD THROUGH HEART
right atrium gets blood from sup/inferior vena cava, they get their blood (deoxygenated) from upper and lower body each.
moves to right ventricle
pumps through pulmonary trunk into pulmonary arteries in lung (gets its oxygen boo)
blood is a new bitch with it's oxygen and comes back to the heart through the pulmonary veins to flex in the left atrium
to left ventricle
pumps blood into body through aorta, skips lungs though
COVERING OF HEART
heart enclosed by pericardium
outer layer has fibrous connective tissue attatched to base of great vessels
inner layer has serous membrane called parietal pericardium
pericardium reflects onto surface of heart as visceral pericardium (epicardium)
in between these bitches is pericardial space. is a whore i guess and needs serous fluid for lubrication
So from outer to inner: fibrous p, parietal p, p space, visceral/epi p, myocardium, endocardium
cardiac tamponade is a condition where fluid builds in pericardial space, blocking chambers (ejection from heart)
myocardium is the muscle of the heart. thiccer in ventricles especially left one
covered by epi p, wbk, inside by endocardium which is the endothelium and connective tissue .
rough appearance of ventricles is trabeculae carnae
striated bands of atria called pectinate muscle
Atria and Ventricles each contract together
HEART VALVES
four heart valves. two atrioventricular and two semilunar.
cusps of valves comprised of reflections of endocardium
atrioventricular valves in between atria and their ventricle
right has three cusps, tricuspid valve
left has two cusps, bicuspid or mitral valve
ventricles contract and the devil laughs by increasing pressure and flapping valves to approximate each other to close
the cusps have chordae tendinae attatched to papillary muscles which contract with ventricular wall and hold c. tendinae taught to prevent valve from prolapsing into atrium
during contraction blood is pumped into pulmonary trunk aorta
relaxation prevents the return by semilunar valves
pulmonary s. valve is in between right ventricle and pulmonary trunk
aortic s. valve is in between left ventricle and aorta
each have three cusps that approximate each other and form a seal when blood moves towards ventricles
systole- atrioventricular valves close and semilunar valves open
diastole- opposite
when this happen a "lub-dub" noise happens and can be heard with stethoscope lol, atrioventricular valves closing make lub and closing of semilunar makes dub.
CORONARY ARTERIES AND CARDIAC VEINS
right and left coronary artery rise from the base of the aorta, just above the aortic semilunar valve
they supply oxygenated blood to myocardium.
right coronary artery courses to the right (in atrioventricular sulcus) gives off the right marginal artery and travels back to heart to as the posterior interventricular artery.
left c. artery courses left (posterior to pulmonary trunk) before dividing into anterior i. artery and circumflex artery.
AIA descends on the front of the heart between ventricles
circumflex artery courses to the back of the heart (in a. sulcus) providing branches to left ventricle on the way
cardiac veins carry deoxygenated blood from the myocardium
a cardiac vein runes along each of the main branches of coronary arteries
a great cardiac vein runs with AIA, middle cardiac vein with PIA, small cardiac vein with marginal artery.
all veins empty into the coronary sinus , between left atrium and ventricle.
coronary sinus opens into right atrium
angina pectoris: chest pain
myocardial infarction: heart attack bc lack of blood in myocardium
heart murmur: weird sound in heart caused by faulty valve
cardiomegaly: enlargement of heart
atherosclerosis: narrowing of arteries
pericarditis: inflammation: of pericardium bc of bacteria or virus
atrial fibrillation: random electric activity in atria, poorly coordinated contractions leading to blood clots and strokes
ventricular fibrillation: same but in ventricles, leads to cardiac arrest
72 beats per minute and has autorhythmicity
special cardiac muscle cells spread impulses through myocardium
heartbeat initiated by group of specialized cells called sinoatrial (SA) node, near superior vena cava
SA node is the pacemaker of heart, spontaneously depolarizing about 72 beats per minute
from SA node, impulses spread through walls of the atria and collect at the atrioventricular node (AV) in the floor if right atrium
flow from AV node through atrioventricular bundle, enters interventricular septum and divides into right and left branch bundles
branch bundles conduct impulses to perkin heart and and extend up through the walls of the ventricle
CARDIAC MUSCLE TISSUE
striated and contracts by sliding filaments
short and branched, 1-2 centered nuclei
adjacent cells are joined by intercalated discs to form cellular networks
at junctions, sarcolemma (cell membrane) of adjacent cells interlock through fingerlike projections
discs got two regions, fascia adherens and gap junctions
fascia adherens help bind cells together and help transmit contractile force to adjacent cells
gap junctions, allow ions to pass between cells, allowing transmission of impulse to spread through cardiac muscle cells (helps whole ass chamber contract at once)
CARDIAC CYCLE
start of one heartbeat to another
1. Atrial Systole - contraction of atria initiated by SA node, filling ventricles
2. Early Ventricular Systole - atria relax and ventricles contract, causing AV valves to close and make that lub sound
3. Late Ventricular Systole - continued contraction cause semilunar valves to open and blood enters into arterial trunks
4. Early Ventricular Diastole - ventricles relax and semilunar valves close to prevent blood from coming back into ventricles (dub)
5. Late Ventricular Diastole - continued relaxation of ventricles causes atrioventricular valves to open and atrial contractions to fill ventricles
*************BLOOD VESSELS
consist of arteries, veins, and capillaries
arteries carry AWAY from heart
veins carry TOWARDS the heart
exchange of gases (O2 CO2), nutrients and waste products happen in capillaries
arteries and veins have 3 layers:
tunica intima: innermost layer of vessel, composed of endothelium (simple squamous epithelium and thin layer of connective tissue)
tunica media: middle layer, circular smooth muscle
tunica externa: (adventitia) outer layer connective tissue anchoring vessels to other structures
Elastic Arteries:
biggest arteries, also called conducting arteries
have lots of elastic fibers throughout all tunics (especially tunica media)
the elastic fibers let arteries stretch then recoil when blood is pumped through
aorta, pulmonary, brachiocephalic, common carotid, subclavian, common iliac arteries
branch into muscular arteries
Muscular Arteries
medium size arteries. distribute blood to organs and tissues
sandwich muscular layer with elastic fibers, internal and external elastic laminae
less elastic tissue makes them less extensible, allows for vasoconstriction and vasodilation
branch into arterioles
Arterioles
smallest of arteries
smallest of these (not all) don't have all tunics, have endothelium surrounded by single layer of smooth muscle
vasoconstriction reduces blood-flow
vasodilation increases blood flow
both do opposite in terms of pressure
CAPILLARIES:
smallest of ALL blood vessels
located in between arterioles and venules
slightly larger diameter then erythrocyte
has tunica intima (endothelium and basement membrane)
allows for diffusion of gases and nutrients
a capillary bed is fed by a metarteriole and drained by a thoroughfare channel
channel connects to a post-capillary venule
VENULES
Smallest veins
run with arterioles
thin layer of smooth muscle, little ability for vasoconstriction
merge to make big venules which merge to make veins
VEINS
Small/Medium veins run with muscular arteries
big ones run with elastic arteries
low pressure in veins mean valves must maintain one way flow
SKELETAL MUSCLE PUMP
skeletal muscle contraction and relaxation helps move venous blood
muscles squeeze the vein pushing venous blood towards heart
inactivity results in reduced muscle pump and greater risk of clot formation
RESPIRATORY PUMP
Inferior Vena Cava, ascends in abdomen and thorax, doesn't benefit from skeletal muscle pump
blood-flow is assisted by contraction and relaxation of the diaphragm
during inhalation- diaphragm is depressed, this results in increased abdominal pressure and decreased thoracic pressure. (blood moves from abdominal part of IVC into thoracic part)
during exhalation, diaphragm is elevated, opposite of above happens
SPECIAL ARTERIES
Branches off Aortic Arch:
right to left: brachiocephalic artery, left common carotid artery, and left subclavian artery
brachiocephalic artery divides into right common carotid and right subclavian artery
common carotid arteries give blood to head and neck
subclavian arteries give blood to upper extremities
Common Carotid Arteries
Branches into external and internal carotid arteries
internal carotid arteries pass through carotid canals to supply blood to brain
external carotid arteries branch into:
superior thyroid artery- blood for thyroid gland
lingual artery- supplies blood for tongue
facial artery- blood for face
occipital artery- Blood for back of head
maxillary artery- supplies blood to upper teeth and muscles of mastication
superficial temporal artery- supplies blood to scalp
Subclavian Arteries:
travel under 1st rib and clavicle to get to upper extremities
thyrocervical trunks provide blood to thyroid gland and deep neck
internal thoracic arteries descend along sternum, giving rise to anterior intercostal branches before dividing into musculophrenic (to diaphragm) and superior epigastric (upper abdominal wall) arteries
vertebral arteries ascend neck by coursing through transverse foramina of cervical vertebrae and then pass through foramen magnum to help supply blood to brain.
BLOOD SUPPLY TO BRAIN
internal carotid arteries each branch into a middle and anterior cerebral artery
anterior cerebral arteries connect through anterior communicating artery
the vertebral arteries unite to form basilar artery
basilar artery provides branches to the brainstem and cerebellum and split into the right and left posterior cerebral arteries
posterior cerebral arteries connect to internal carotid arteries through posterior communicating arteries.
circle of willis - an arterial circle formed by all the posterior/anterior/communicating/cerebral/internal carotid arteries. 5 in total
AXILLARY ARTERY
once the subclavian artery passes 1st rib it becomes axillary artery
gives blood to shoulder and lateral thorax
passes teres major muscle and enters arm to become brachial artery
BRACHIAL ARTERY
descends in arm medial to biceps brachii muscle
used to check blood pressure
deep brachial artery branches off the brachiala artery and moves to posterior arm
at anterior elbow, the brachial artery divides into the radial and ulnar arteries
RADIAL AND ULNAR ARTERIES
give blood to forearm and wrist and join in at palm to form superficial and deep palmar arch
palmar arches give blood to muscles in hand
THORACIC AORTA
descends into posterior thorax, slightly left of midline
gives posterior intercostal branches which anastomose with anterior intercostal branches from internal thoracic artery
passes thru diaphragm to become abdominal aorta
ABDOMINAL AORTA
descends in the posterior abdomen, giving off paired and unpaired branches
celiac artery is unpaired branch that gives blood to the stomach, duodenum , liver, gallbladder, spleen, and pancreas (foregut)
superior mesenteric artery is unpaired and gives blood (i assume) to jejunum, ileum, and the ascending colon and transverse colon (midgut)
inferior mesentric artery is unpaired and gives blood (i assume) to descending colon, sigmoid colon, and upper rectum. (hindgut)
renal arteries are paired and give blood (i assume) to the kidneys
gonadal arteries are paired and give blood (i assume) to gonads (testes and ovaries)
L5 vertebra has the abdominal aorta dividing into right and left common iliac arteries
ILIAC ARTERIES
common iliac arteries enter the pelvis and divide into internal and external iliac arteries
internal iliac arteries give blood to pelvic organs, muscles in gluteal region and external genitalia
external iliac artery leaves the pelvis and enters upper thigh as femoral arteries
FEMORAL ARTERIES
gives blood to muscles of anterior thigh
gives deep branch to posterior thigh
passes through adductor hiatus, to popliteal fossa (posterior knee), becomes popliteal artery
superior aspect of posterior leg shows popliteal artery makes anterior tibial artery, posterior tibial artery and fibular artery.
anterior tibial artery gives blood to anterior leg
posterior tibial artery gives blood to posterior leg and plantar foot
fibular artery gives blood to lateral leg
femoral artery can be used to access heart. opening is made and catheter passes through superiorly through external iliac artery, common iliac artery, abdominal aorta, thoracic aorta, aortic arch, then the heart.
SUPERIOR VENA CAVA
two brachiocephalic veins join to form superior vena cava
each vein receives deoxygenated blood from head and upper extremities by the internal jugular vein and subclavian vein respectively.
INTERNAL JUGULAR VEIN
is deep in sternocleidomastoid muscle
gets most of blood from brain (dural venous sinuses give it), orbit, face, tongue and thyroid gland.
EXTERNAL JUGULAR VEIN
superficial to sternocleidomastoid muscle
removes blood from neck and tissue external to skull
SUBCLAVIAN VEIN
travels with subclavian artery behind clavicle
joins the internal jugular vein to form brachiocephalic vein
AXILLARY VEIN
runs with axillary artery
gets blood from shoulder, lateral thoracic wall, and upper extremity (from brachial vein)
DEEP VEINS OF UPPER EXTREMITY
paired radial and ulnar veins run with same arteries
they drain blood from forearm and hand (palmar arches)
they empty into paired brachial veins that run with brachial arteries
brachial veins empty into axillary vein
SUPERFICIAL VEINS OF UPPER EXTREMITY
cutaneous veins
cephalic vein runs along lateral forearm and empties into subclavian vein
basilic vein runs along medial forearm and arm and drains into the axillary vein
median cubital vein runs between the cephalic and basilic veins
These veins are used for venipuncture.
AZYGOS VEIN
located on right side of posterior thorax and gets blood from intercostal veins, directly from right and indirectly from left
intercostal veins empty on the left into hemiazygos or accessory hemiazygos, then cross to the right and empty into the azygos.
INFERIOR VENA CAVA
receives blood from the liver, kidneys, gonads, pelvic organs, external genitalia, and lower extremities
doesn't get blood directly from digestive tract
renal veins drain blood into IVC
right gonadal veins go directly into IVC, but left gonadal veins go into left renal vein
IVC divides into right and left common iliac veins
ILIAC VEINS
internal and external for each common one
external iliac vein gets blood from lower extremity, the femoral vein
internal iliac vein gets blood from pelvic organs, external genitalia, and gluteal muscles
DEEP VEINS OF LOWER EXTREMITY
posterior tibial veins, run with posterior tibial artery, drain blood from foot and posterior leg
anterior tibial vein does same for anterior
fibular veins for lateral
all drain into popliteal vein
passes from posterior into anterior, through adducot hiatus, to anterior thigh as femoral vein
femoral vein collects blood from anterior thigh and from posterior thigh through deep femoral vein
femoral vein passes into pelvis, becomes external iliac vein
SUPERFICIAL VEINS OF THE LOWER EXTREMITY
great saphenous vein travels along medial leg and thigh collecting superficial blood of lower extremity, draining into femoral vein.
small saphenous vein courses along the posterior leg, collecting superficial blood, emptying into popliteal vein.
Hepatic Portal Vein
gets blood from digestive tract and other digestive organs so it can be filtered by the liver
hepatic portal vein receives blood from the superior mesentric, inferior mesentric, and splenic veins
blood collected here has nutrients and dangerous agents that need to be filtered from the blood
hepatic portal vein enters the liver and branches into small vessels (sinusoids) for filtration
once blood is filtered by the liver, it goes to hepatic veins for drainage into inferior vena cava
CAVAL VS PORTAL VENOUS DRAINAGE
Structures that empty directly into inferior vena cava have caval venous drainage
Structures that empty into hepatic portal vein have portal venous drainage
FETAL CIRCULATION
relatively inactive pulmonary circulation in fetus in terms of oxygen
umbilical arteries, branched from external iliac arteries, carry blood from fetus to the placenta
freshly oxygenated blood from placenta comes drains into inferior vena cava from umbilical vein
has nutrients from mother, emptied into right atrium
some of the blood goes through opening in interatrial septum, called foramen ovale, to the left atrium, to left ventricle, to aorta.
some blood goes into right ventricle then pulmonary trunk
no functional lungs in fetus, blood comes back to aorta through ductus arteriosus
birth, umbilical cord is cut, lungs expand, blood rushes to the lungs and back to the left atrium. foramen ovale and ductus arteriosus close
*****LYMPHATIC SYSTEM
LYMPH VESSELS
at arterial ends of capillaries, blood pressure forces fluid from blood to interstitial space
most fluid is reabsorbed by capillaries but not all
3 liters of fluid per day doesn't go back to venous return
lymph vessels reabsorb excess fluid and return it to venous circulation
poor reabsorption = edema
lymph vessels around GI tract transport dietary lipids = lacteals
lymphatic capillaries "trap" fluid with one-way valve system
lymphatic capillaries merge to form these vessels
lymphatic vessels. have 3 tunics and valves
afferent lymphatic vessels bring lymph to a node for filtering and efferent vessels take it away
lymph includes interstitial fluid and solutes that enter lymph bessels
Vessels - Trunks - Ducts
LYMPHATIC TRUNKS
formed by merging vessels
drain lymph from major regions
jugular trunks drain lymph from head and neck
subclavian trunks drain from upper extremities, breasts and thoracic wall
bronchomediastinal trunks drains lymph from deep thoracic structure
intestinal trunks drains from abdominal structures
lumbar trunks drain lower extremities and pelvis
LYMPHATIC DUCTS
largest of lymphatic vessels
right lymphatic duct drains lymph from right upper extremity, right side of head neck and thorax. empties into junction of the right subclavian vein and right internal jugular vein
thoracic duct drains from left, plus abdomen, pelvis, and lower extremities. empties into left shit.
crysterna chyli is a sac that receives milky lymphatic fluid, chyle, from small intestine
LYMPHATIC CELLS
lymphoid cells is another name
illicit immune response
include macrophages, dendritic cells and lymphocytes
MACROPHAGES
monocytes that come from bloodstream
cause phagocytosis in certain substances
DENDRITIC CELLS
in lymphatic nodules (cluster of lymphatic cells)
internalize antigens from lymph and give them to other lymphatic cells
LYMPHOCYTES
Most common
T or B-lymphocytes, and natural killer cells
T-Lymphocytes
T-cells
70-85% of all lymphocytes
surface receptors for specific antigens
helper T-lymphocytes begin defense against antigen and have CD4 coreceptor. activated by a type of antigen and releases cytokines to let other lymphatic cells know.
cytotoxic T-lymphatic cells have CD8 receptor and directly kill infected/foreign cells. they respond to a specific antigen.
memory T-lymphocytes form when normal T-cells meet a foreign antigen and provide an augmented response to exposure to the specific antigen
B-LYMPHOCYTES
15-30% of lymphocytes
surface receptor to specific antigen
activated by helper T-Cells, divide and differentiate into plasma and memory B-cells
plasma cells secrete immunoglobulins/antibodies that attach to antigen
antigen/antibody complex is eliminated
memory B-lymphocytes remember this shit
NATURAL KILLER CELLS (NK)
the rest. can kill a wide variety of infected cells
LYMPHOPOIESIS
lymphocyte development and maturation
all lymphocytes start in red bone marrow, maturation sites differ
B-lymphocytes and NK Cells mature in red bone marrow
T-lymphocytes mature in thymus during childhood
Lymphatic Nodules
Filter and Attack antigens
mucusa-associated lymphatic tissue (MALT) are large collections of lymphatic nodules in mucosa of digestive, respiratory, and urinary tracts.
tonsils are large clusters of lymphatic cells surrounded by connective tissue capsule (palatine tonsils, pharyngeal tonsils, and lingual tonsils)
LYMPHATIC ORGANS
lymphatic cells surrounded by connective tissue capsule
thymus is made of:
cortex with immature T-cells, nurse cells and macrophages
medulla with mature T-cells, and epithelial cells
thymic corpuscles are degenerated nurse cells in medulla
no thymus in adults.
spleen:
biggest lymphoid organ, surrounded by connective tissue capsule
made of red and white pulp
white pulp has circular clusters of lymphatic cells to monitor blood for foreign material, bacteria, and other antigens.
red pulp has extra erythrocytes and platelets if needed.
LYMPH NODES
ovoid structures along lymph vessels
have B/T-cells/macrophages surrounded by a capsule
filter antigens from lymph and initiate immune response
nodules consist of B-cells and macrophages and are surrounded by T-cells in the germinal center
*********RESPIRATORY SYSTEM
Gas Exchange, respiratory system brings oxygen into body and bloodstream and removes CO2
Adds warmth and moisture to air we breathe in
Larynx produces sound for speaking when air passes thru during exhalation
Olfaction tissue in nasal cavity carries smell information
Mucus protects fragile respiratory lining from drying out but traps dirt particles. Lymphoid tissue associated with respiratory tract monitors the air we breathe for unwanted shit.
UPPER RESPIRATORY TRACT: nasal cavity and pharynx
LOWER RESPIRATORY TRACT: larynx, trachea, bronchi, and lungs
NASAL CAVITY
Divided into right and left by nasal septum (cartilage and bone)
lined with mucous membrane
lateral walls display projections called concha (superior, middle, inferior)
superior and middle are part of ethmoid bone
under each concha is a groove called a meatus
outgrowths of nasal cavity form paranasal sinuses
can be found in maxillary, frontal, ethmoid, and sphenoid bones
tears drain into nasal cavity, under inferior concha, from nasolacrimal duct
Pharynx
located posterior to nasal and oral cavities and larynx
air goes through nasopharynx and oropharynx before entering larynx
food entering mouth enters oropharynx and laryngopharynx before esophagus
eustachian tube connect nasopharynx to middle ear and equalizes pressure
pharyngeal tonsil monitors air for shit
palatine and lingual tonsils monitor food for shit
immune responses from tonsils if necessary
breathe in=muscles opening larynx so air goes to trachea
swallow=different muscles open larynx and direct food to esophagus
LARYNX
Voice Box
cartilage and muscle and lined with mucous membrane
associated with hyoid bone above
thyroid cartilage: C-shaped and forms laryngeal prominence (adam's apple) in the front
cricoid cartilage: ring shaped/right below thyroid cartilage/articulates with its inferior horns
arytenoid cartilages: pyramidal that sits on top of cricoid cartilage, has apex, muscular process and vocal process (for vocal ligaments)
coriniculate cartilages: small cartilage fused into arytenoid cartilage
epiglottis-leaf like cartilage. stem attached to thyroid cartilage, closing over larynx while swallowing
Conus Elasticus: membrane that extends from vocal ligaments to the cricoid cartilage, leaving an opening between the vocal ligaments called rima glottidis.
MUSCLES OF LARYNX
posterior cricoarytenoid muscle run from the posteriofr aspect of cricoid cartilage to muscular process of arytenoid cartilage and rotates it outward, opening the rima glottidis
arytenoid muscle runs between it's cartilages and draws them and vocal ligaments together during speaking and swallowing
TRACHEA
flexible tube that extends inferiorly from larynx to thorax
supported by C-shaped cartilages
open ends of cartilage connected by trachealis muscle, forming the posterior wall of the trachea
lined with pseudostratified ciliated columnar epithelium with numerous goblet cells that make mucus
BRONCHI
at a sternal angle, trachea splits into right and left primary bronchi for each lung
supported by C-shaped cartilages
smooth muscle in between cartilage
lined with pseudostratified ciliated columnar epithelium with numerous goblet cells that make mucus
bronchi enters lung and branches into smaller bronchi
each primary bronchus divides into a secondary bronchus for each lobe of lung
secondary bronchi divide into tertiary bronchi and so on for 9-12 levels of branching
as they branch further, cartilage becomes more sparse till there's only smooth muscle in the wall
TERMINAL BRONCHIOLES AND ALVEOLI
terminal bronchioles are the smallest of the bronchial tree
give rise to respiratory bronchioles, which are associated with alveoli
alveoli can occur individually or as part of large cluster called alveolar sacs
spherical walls of alveoli are formed by simple squamous epithelium of basement membrane
pulmonary capillaries ss the respiratory membrane into the capillary while carbon dioxide moves from the capillary tosurround the alveoli
respiratory membrane consists of two layers of simple squamous epithelium, one from alveolus and one from capillary with fused basement membranes in between
oxygen in an alveolus moves across the respiratory membrane and into the capillary, while carbon dioxide moves from capillary to alveolus
squamous alveolar cells also called alveolar type 1 cells
alveolar type II cells are scattered through the alveoli and produce pulmonary surfactant
alveolar macrophages (dust cells) keep the alveoli clean of particulate matter
BEFORE BIRTH lungs don't work bc placenta and maternal blood do the gas exchange so the lungs remain collapsed in pleural cavities. First contraction of diaphragm and intercostal muscles at birth expand the thorax and lungs. they need surfactant in the lungs to do this. there's usually enough after 7 months in utero.
Tracheotomy: opening made in the trachea that's inferior to the larynx
Emphysema: merging and reduction of surface area of alveoli due to degeneration of lung tissue
Cystic Fibrosis: thick mucus build-up in the lungs with infections
Bronchitis: inflammation of the bronchi
Asthma: episodes of bronchoconstriction
LUNGS
begin to grow in 4th week of development as the respiratory diverticulum
lung buds grow into pleural cavities, lined with serous membrane called pleura
pleura covering lungs is called visceral pleura and pleura lining cavity is parietal pleura
pleural space has a bit of serous fluid
base of lungs rest on diaphragm with their apex leveled with the clavicle
right lung has 3 lobes (superior, middle, and inferior) and is divided by fissures.
left lung has 2 lobes (superior and inferior) divided by fissures, lingula extending from superior lobe
left lung has cardiac impression on medial surface and cardiac notch above lingula
blood vessels and bronchi enter each lung at the hilum
the lobes are divided into functional segments, called bronchopulmonary segments, each with its own tertiary bronchus, artery, and vein
BREATHING
primary muscle is the diaphragm
inhalation brings inferior flattening to diaphragm and creates vacuum in pleural cavities
exhalation brings relaxation to diaphragm along with superior doming, pushing air out of the lungs
with quiet breathing, the diaphragm and external intercostals alternately contract and relax
with physical activity, other muscles help with respiration
pectoralis minor-helps with inhalation
serratus posterior superior-helps with inhalation
serratus posterior inferior-helps with exhalation
abdominals and internal intercostals- help with exhalation
respiratory centers located in the pons and medulla oblongata send out rhythmic motor commands to the diaphragm through the phrenic nerves that are formed by the branches of spinal nerves C3,4, and 5. C3 4 and 5 KEEPS THE DIAPHRAGM ALIVE. The medulla oblongata is influenced by afferents from the aortic bodies, carotid body, and carotid sinus.
