Exam 2 Flashcards
Muscle Classifications
Skeletal Muscle
Smooth Muscle
Cardiac Muscle
Myocyte
Muscle Cell
Sarcomere
Individual contractile unit in skeletal muscle
Sarcolemna
Plasma membrane of skeletal muscle cells
Myrofibrils
Give structure to muscle cells through thin actin filaments and thick myosin filaments
Epimysium
Connective tissue sheath that encases the entire muscle (skeletal)
Perinmysium
Surrounds muscle bundle (skeletal)
Endomysium
Surrounds myoctes (skeletal)
What is skeletal muscle in between?
2 Z lines
sarcoplasmic reticulum
smooth ER (skeletal)
stores calcium
stores glycogen
Capacity of mitochondria in skeletal muscle
Contains many mitochondria
Misconception about contraction of muscle
A common misconception is that muscle shortens when contracted
How does contraction occur (simply)?
Through the sliding of thick Myosin filaments and thin Actin filaments
What is the result of bases in contraction?
Shortens Distance of Z-lines and all bands except for the A band
Tropomyesin
blocks the binding cite on actin for myosin and inhibit interaction when relaxed
Properties of Myosin
2 Heavy Chains and 4 Light chains
Troponins
Part of Actin
Troponin C
Troponin I
Troponin T
Troponin C
binds calcium
Troponin I
Binds Actin
Troponin T
Tropomyesin
Relaxation of Skeletal Muscle
Low Cytoplasmic Ca
Myosin head is energized through ADP + Pi bound to the head
Cross Bridge Cycle Purpose
Contraction of muscle
Steps of Cross Bridge Cycle
1.) Low Ca
2.) Energized myosin head (ADP + Pi)
3.) Releases Ca from sarcoplasmic reticulum(Goes from 10^-7 M to 10^-5 M)
4.) Ca binds to troponin C
5.) Open actin binding cites
6.) Myosin binds to actin
7.) ADP + Pi come off of myosin and allows for myosin to move
8.) ATP binds to myosin and allows for myosin to release from actin
9.) ATP goes back to ADP + Pi which then in turn renergizes myosin head
What triggers a new Cross Bridge Cycle
High amounts of Ca and the renewal of ATP in (ADP and Pi)
What receptor is part of the sarcoplasmic reticulum and what is it responsible for?
The ryadine receptor is a calcium channel that connects to a neuromuscular junction
Motor Unit
Motor neuron and skeletal muscle fibers it innervates
Motor neuron rates of connection
1 motor neuron innervates many muscle fibers however one muscle fiber is innervated by only one motor neuron
Within a whole muscle are there many motor units or few?
many
What is a neuromusclular junction
Its the interaction between the skeletal muscle and axon terminus
Motor end plate
Region of post synaptic membrane
Whats the ratio of neuromuscular cell to neuromuscular junction?
1:1
Traverse tublues
Contains the DHP receptor
DHP receptor
Part of the neuromuscular junction of the transverse tubules and it is a volted gated calcium channel that is connected to the Sarcoplasmic reticulum
What do neuromuscular vesicles contain?
Acetyl Choline
What is the relationship between the relative refractory period and the pumping of calcium
The speed of pumping calcium into the sarcoplasmic reticulum is slower than the refractory period
What happens as soon as calcium is released
it’s pumped back to SR
What does smooth muscle not have in comparison to skeletal?
Transverse tubules
Troponins
neuromuscular junction
What does smooth muscle have instead of troponins
varicosities
What are the two types of smooth muscle?
Multi unit and single unit
Multi Unit Smooth Muscle Loc.
In walls of large arteries and upper large airways in lung
Single Unit Smooth Muscle(loc)
In digestive tract, in walls of uterus, contains gap junctions
What is spontaneous activity known as as part of a neurotransmitter in smooth muscle?
Myogenic activity
How does contraction in smooth muscle
its a calcium mediated event that comes out of cell and binds to calmodulm instead of troponin C
What does calmodulm activate?
Activates myosin light chain kinase
How does calcium enter axon terminals?
Through voltage gated calcium channels (DHP receptors)
What does calcium trigger the release of from axon terminals?
Acetyl Choline
Where does acetyl choline diffuse in muscle fiber?
From axon terminals to moter end plates
Where does acetyl choline bind to and what does this then allow?
It binds to nicotonic receptors on the motor end plate which then increases the permeability of sodium and potassium
Where does end plate action potential travel along?
T-Tubules
What’s the purpose of calcium binding to troponin on thin filaments?
Causes tropomyesin to move away from its blocking position and thereby help start the crossbridge cycle
How does the action potential across T-tubules induce travel of calcium
DHP receptors pull open and allow the release of Calcium from the sarcoplasmic reticulum
What form of energy is used for thick filaments to bind to actin?
ADP
What breaks down the linkages between myosin and actin?
ATP
What energies the myosin crossbridge
ATP –> ADP
What does the cycle of the cross bridge cycle induce?
The sliding of actin and myosin
Where does calcium go after the cross bridge cycle is complete?
The sarcoplasmic reticulum
What happens as soon as calcium is removed from troponin?
Restores the blocking action of tropomyesin on actin and allows muscle fibers to relax
Cardiomyocytes physical components
Involuntary striated muscle
More stellated
branches
fibrous cards
How many nuclei are present in cardiomyocytes?
1 or two nuclei
Whats very similar between cardiomyocytes and skeletal muscle
The cross bridge cycle
Cell to Cell grouping in cardiomyoctyes
contain gap junctions and are intercalated discs
What determines the rate of depolarization in cardiomyocytes?
Population of cells with most unstable resting potential
Describe the refactory period of cardiomyocytes
It’s protracted and causes obigatory relaxation of cardiac muscle
What does the excitation/depolarization of skeletal muscle or cardiomyocytes allow for?
The opening of T-tubules and Calcium channels
Pericardium Structure
Contains serous fluid
Parietal (Outer)
Visceral(Inner)
Myocardium
True Heart Muscle
Endocardium
Endothelial cells continuous with blood cells
Atria
Receive Venous Blood
Ventricles
Much Thicker walls
pump blood throughout body
Atrio-ventricular Left and Right differences
Right AV is tricuspid, Left is bicuspid
Chordae Tendinae
Anchor free margin of valve
Papillory
Anchors chordae tendinae
Semi-lunar (Heart) Left and Right
Trans-cuspid
Separate ventricles and arteries
Right: Right ventricle and pulmonary artery
Left: Left ventricle and aorta
Sinoatrial node
Pacemaker (Responsible for heartbeat)
Atrioventricular Node
Promotes healthy conduction pathways in heart
Bundle of HIS
Branches from antrioventricular node
branches from left and right bundles
Purkenji Fibers
conduct electrical stimulus
SA node stabilization
acetyl choline via muscarnic receptors which then stabilizes the node
Norepenephrine via adrenergic receptors
increases contraction
Pathway of Circulation
Vena cava –> RA –> Tricuspid Valve –> RV –> Pulmonary Valve –> Pulmonary A –> Lungs –> Pulmonary Veins –> LA –> Mitral Valve –> LV –> Aortic Valve –> Aorta
Diastole
Ventricles are relaxed, fills blood
Systole
Ventricles are contracted, pushes out blood
Lubb
Closure of Atrioventricular valves (tricuspid/bicuspid)
Dupp
Closure of Semilunar valves (Aortic/pulmonary)
Types of Murmurs
Stenosis and Insufficieny
Stenosis
The valve is stiff, doesn’t totally open, in diastole its heard in the atrioventricular, during semilunar its systolic
Insufficiency
Not closing completely, back flow, AV = systolic, semilunar = diastolic
What changes in the heart during a contraction cycle
Pressure and Volume
What does cardiac output = to
Heart Rate * Stroke Volume
What’s normally the ratio of increasing heart rate or stroke volume?
Both will increase when increasing one
Steps of Regulation for the heart
Increase in atrial pressure –> Baroreceptors –> Afferent nerve endings –> medulla–> efferent nerve endings –> Heart
Baroreceptors
Sensory nerve endings, detects increase in pressure. Is felt through carotid sims and the left aorta that goes to the brain
Cardioinhibitory Center
In the medulla, Vagal output to SA node, reduces cardiac output
Vasomotor
In the medulla, increases cardiac output through speeding up the tachycardia with epinephrine
Starlings law of the heart
Strength of contraction during systole is proportional to ventricular distension at the end of the diastole
What neurotransmitters increase and decrease HR
Norep. inc.
Acetyl Choline dec.
What will happen if you increases the sympathetic output of norep
Increases the strength of contraction which will then increase stroke volume
Properties of Major Arteries
Fibrolastic Walls
Allows stretch and recoil
Less Neural Control
Arterioles Properities
Tunic Media
Less Stretch and Recoil
Sympathetic Output
Tunic Media
Smooth muscle layer in Arterioles
Sympathetic Output in Arterioles
Causes waves of constriction (made of endothelial cells)
Is blood pressure greater or lesser in the pulmonary in comparison to systemic?
Pulmonary Pressure is less than systemic circulation
In response to pulsation contraction of the heart:
Pulses of pressure move throughout the vasculature, decreasing in amplitutde with distance.
Tonic wave of constriction
A tone provided to constricted or non constricted valves
Major drop in systemic blood pressure occurs in ….
arteries
What regulates downstream pressures and flow rates?
Dynamic changes in vasodilation and vasoconstriction
Capillaries Properties
Lack smooth muscle
precapillary sphincters/shunts determine volume of blood capillaries receive
As cross sectional area increases what decreases?
velocity
Vasoconstriction
Increases blood pressure
vasodilation
decreases blood pressure with the widening of blood vessles
How do arterioles correlate with constriction and dialation?
With constriction, blood pressure decreases and is slightly reduced with dialation.
Starlings Law of Filtration: Forces favoring filtration
Hydrostatic Blood Pressure
Collolial/osmotic pressure of tissue
Starlings Law of Filtration: Forces opposing filtration
Colloidial/ osmotic pressure of blood
hydrostatic pressure in tissue
Veins/Venuoles Properties
Some Smooth muscle
some sympathetic N.S. control that’s much less than arterioles
Whats in veins walls
valves and flaps
What percent of blood is in the venous system
60%
What components lead to an increase of blood pushed back to the heart
Skeletal muscle tone
Abdominal Pump
Thoracic Pump
What changes blood pressure in the venous system?
Abdominal Pump and Thoracic Pump
What does vessel diameter determine?
Constriction increases pressure/resistance
What does strength of heart contraction determine
higher pressure
What does the Vessel length determine
longer the greater the resistance
Degree of branching, what changes when degree changes
decreases velocity and pressure
Blood visocisty
Resistance of fluids, higher viscosity means thicker blood
Baroreceptors signals to
carotid sinus
aoritic arch
left and right atria
left ventricle
Components of neural control
vasomoter center and cardioinhibitory
What is the neural control center mediated by
medulla
What ahppens when the sympathetic system is inhibited
parasympathetic is excited
This is produced by endothelial cells and nerve cells and is used as a vasodilator
Nitric Oxide
Vasopressin
An anti-diaharettic and vasoconstrictor
Anigotensin 2
circiulatory vasoconstrictor
Hemorrhages
cause decrease in arterial pressure
How do you fix hemorrhages
By increasing sympathetic output which my decrease P.S. output
Relationship between blood volume pressure and urine
as blood volume pressure goes down urinary loss increases
What’s in plasma?
Water
Ions
Proteins
Nutrients
Hormones
Wastes
What is a Hematocrit
Assess Red blood cell percentage in a given sample
Formed elements in blood
Euthrocytes(RBC)
Leukocytes(WBC)
Platelets
What are red blood cells also known as?
Euthrocytes
What are white blood cells also known as?
Leukocytes
How is O2 restored in the kidneys?
Through secretion of erythropoietin
Kinds of Leukocytes, and their percent appearance
Neutrophils (50%)
Eosinophils (1-4%)
Basophils(.1-.3%)
Where are formed elements formed?
Bone Marrow
Initial sympathetic output to cause vasoconstriction
Myogenic activity of smooth muscle
What does myogenic mean
can contract on its own
How long does the inital sympathetic output to cause vasoconstriction last?
20 minutes
The initial sympathetic output to cause vasoconstriction allows for what formation?
Platelet plug formation
What can plaetelets stick to?
exposed collagen fibers
Why does platelets secret ADP
to make platelets more stick
why do platelets secrete thromboxane A2
to transform more platelets
Why do platelets secrete serotonin?
To make platelets more sitcky
What is platelet factor 3?
It’s secreted by platelets and is involved in the clotting process
What 3 items are responsible for clot formation
thromboplastin, platelet factor 3 and calcium
What do clot formation items combine to form
prothrombin activator
Prothrombin
Plasma Protein
What is required to make prothrombin in liver
vitamin K
What does thrombin clear to form fibrin
fibrinogen
Threads of fibrin
will form loose clot
What does factor 13a do?
Cross-links fibrin threads to form firm clot
What does plasminogen do?
Formas PLasmin and breaks down fibrin
How do you fix hemorrhages
By increasing sympathetic output which may decrease P.S. output
Plasmin Inhibitors
Try to combat plasmin so it doesnt break down fibrin as fast
What kind of cells are lymphatic capillaries composed of?
Epithelial
How are lymphatic capillaries able to move around substances that normal capillaries could not?
By being packed less tightly
What structural component of lymphatic capillaries cause substances to go towards the cardiovascular system
Being “blind” at one end
What vein is in the right lymphatic duct?
Right Subclavien Vein
What vein is in the Thoracic Duct Left
Subclavian Vein
Function of the central lacteal
drain digestive system
Where is heumoral immunity present in
antibodies
Where do antibodies act as receptors
on cell surface
Lymph node components (2)
Macrophages and lympocytes
Immunogloblin
proteins that function as antibodies
How do lymphocytes become a T Cell or a B cell
through the bone marrow
T-Cells play in the immune system
Binds to cells or virus and tries to kill it
How do B cell play out in immune system
By becoming plasma cells when activated by antigens they produce antibodies
Helper t cell recpetors
interleukins
interferons
inner necrosis factor
What do helper t cells activated
B cells and the cytotoxic component on t cells
How are T cells helpers activated
by class 2 histocomabatability complex
What kind of cells can B cells be?
Plasma cells and memory cells
What kind of cells can B cells be?
Plasma cells and memory cells
Function of respiratory system
Provide Oxygen
Eliminate CO2
Regulates pH in relation to kidneys
Speech
Defends against microbes
dissolves blood clots in systemic veins
Influences artrial concentrations of chemical messengers
What are the two kinds of respiration
Internal and External
Function of external respiration
Moves O2 from lungs to blood and moves O2 from blood to tissues along with CO2 from cells into blood
What is considered the active form of breathing
Inspiration
How is maximal inspiration achieved?
Through external intercostals and the usage of muscles connected to the head and neck
Air passage pathway
Trachea–> Bronchi –> Bronchioles –> Terminal Bronchioles –> Respiratory Bronchioles –> Alveolar ducts –> alveolar sacs
What are the two zones in a lung?
Conducting and respiratory
Where is the intrepleural fluid
between the throacic wall and lung
What does the fluid inside and outside the pleural cavity function as?
Lubricant to reduce friction
Where is the parietal portion in the respiratory system
lining the thoracic wall
What does the visceral portion line in the respiratory system
Lungs
What is the charge of pressure in the pleural cavity relative to the atmospheric
It’s negative
During expiration what is the reduction of mercury?
-3 mm Hg
During quiet inspiration what is the reduction of mercury?
-10 mm Hg
During maximal inspiration what is the reduction of mercury?
-33 mm Hg
When does the thorax expand?
During inspiration
What happens after the lungs expand in inspiration?
Air in alveolar becomes compressed and alvelic pressure becomes greater than atmospheric
What is the number of alveolis proportional to?
metabolic rate
What is considered to be the passive form of breathing?
Expiration
When does maximal expiration occur?
During intercoastels
What happens when the chest wall recoils inward during expiration
Transpulmonary pressure moves back towards preinspiration value
When is the air in alveolis compressed
during expiration and after the recoil of lungs
What is the most abundant pnemocyte?
Type 1
What are type 1 pnemocytes
epithelial cells lining air facing surfaces
What are type 2 pnemocytes
THey are producers of surfactant
What is surfactant
A detergent like substance that prevents air sacs from collapsing
what would you provide to someone with respiratory distress syndrome
synthetic surfactant
What is k in the gas exchange equation
diffusibility constant
What happens to K as the surface area increases?
K increases
What happens to k as the thickness of diffusion barrier increases
K decreases
Pressure differential
The difference between circulating O2 and O2 going into blood and the difference between CO2 ciruclating and the CO2 leaving the blood
Ideally what would you want your PO2 to look like?
High range of O2
How is oxygen transported through the blood?
Hemoglobin
How many globins are there
4
what subsets are the 4 globins split in
2 alpha 2 beta
How many molecules of O2 can each hemoglobin carry?
4
How is the affinity of hemoglobin decreased?
Increased pH
Increased CO2
Increased temperature
Increased DPG concentration
How does hemoglobin bind to oxygen
through Fe^2+
What is Vital Capacity
Maximal inspiration + maximal expiration
What does Tidal Volume include
Inspiratory Reserve volume and expiratory reserve volume
Residual Volume
Air left over after maximal expiration
What is the primary controller for breathing?
Medulla
What are the two respiratory centers in the medulla
Inspiratory and expiratory centers
Phrenic Nerve(C2-C3)
They are spinal motor fibers that go to diaphragm
Where can spinal motor fibers branches go to
external intercostals
Function of lung stretch receptors
inhibition of phrenic nerve output in inspiratory for relaxation
What causes a stimulation for inspiration
Decreased PO2 increased pH or increased CO2
Erythropoeitin function
stimulation of red blood cell production
Gluconeurogenesis
generation of glucose from noncarbohydrate precursors
What hormones does the kidneys produce
erythropoeitin, renin and 125 Vitamin D
What does Vitamin D do in the kidneys
calcium balance
Function of renin
influences blood pressure and sodium
Basic renal functions
regulates water, removes metabolic wastes from blood and foreign chemicals that is then later excreted into urine
Where is transitional epithelium?
In the bladder, it helps with the expansion and contraction of the bladder
synonym for micturition
urination
What inhibits micturition in the bladder
smooth muscles sphincter
Is the bladder PNS or CNS
PNS
Apperance of renal cortex
granular
apperance of renal medulla
striated
function of renal pelvis
where urine is collected
What is a nephron
The functional unit of the kidney
What are the two types of nephrons?
Cortical and Juxtomedallory
Where does the initial filtration occur in the kidneys
Renal Corpuscle
Where is the gilomerculas?
In the kidneys
Gilomerulas function
Capilllary bed with afferent and efferent arterioles
What two componenets are in the renal corpuscle
Bowmans capsule and Giomerulas
Where in the kidneys is the bowmans capsule
They overlay glomerular capilaries
what do the slits on bowmans capusle allow for
filtration of blood from gilomerular
What main component is inside the Distal Conulted Tube
The Macula Densa
Function of Macula Densa
To sense osumularity of the tubule fluid
Juxtaglomecular Cells Function
Secrete renin
Renin function
In renal system, it cleans angiotensionogen into angiotensionogen 1
Drop in afferent arterial pressure or low plasma Na triggers what?
Triggers the mascula Densa due to low osmolarity and juxtoglomecular cells
Steps before micturition
Glomerular filtration
Tubular secretion
Tubular reabsorption
What favors glomerular capillary filtration?
Glomerular capillary blood pressure
What opposes glomerular capillary filtration
Fluid pressure in bowman’s space and osmotic force from protein in plasma
What is the colloidal pressure in bowman’s capsule
0 mm Hg
Reabsorption rates greatest to least
Glucose > Water > Na > Urea
What is mainly responsible for reabsorption?
Proximal Convoluted Tubule
How is glucose reabsorbed?
Through secondary active transport of SGLT2 as part of Na cotransport
What component in the brain stimulates calcium reabsorption
Parathyroid
What is the main anti-diuretic hormone?
Vasopressin
What percentage of water reabsorption occurs in collecting ducts?
Less than 15 percent
What is the primary driver of aldosterone secretion
Potassium concentration in blood
Atrial Naturietic Peptide (ANP)
Inhibits aldosterone
What happens when you inhibit aldosterone
Inhibits reabsorption of Na
Why is it important to excrete Na for high blood pressure?
To excrete water along with the Na
