LAB EXAM! Flashcards
What is the function of goblet cells?
Produce and maintain the protective mucus blanket by synthesizing and secreting high MW glycoproteins known as mucins
Why so many goblet cells in colon?
Mucus is an important lubricant that protects the epithelium and also serves to bind the dehydrated ingesta to form feces
Epithelium classification:
1. mammalian skin
2. lumen surface of stomach
3. jejunum
4. outer covering (serosa) of jejunum
5. colon
6. around blood vessels
- stratified squamous
- simple columnar
- simple columnar
- simple squamous
- simple columnar
- simple squamous
Difference between erythrocytes and leucocytes?
Erythrocytes: no nucleus and concave (reason for white center)
Leucocytes: have nucleus (stained dark purple)
4 main functions of glial cells
- where are they located?
- surround neurons and hold them in place
- supply nutrients and oxygen to neurons
- insulate (by producing myelin) one neuron from another
- destroy and remove dead neurons (clean up)
*located in white and grey matter
Function of fibroblasts?
Produce extracellular matrix components! macrophages, elastic fibers, mast cells, GAG, collagen fibers
What are the 3 layers of muscle in stomach? Vs how many layers in rest of GI tract?
- Oblique layer (most on top)
- Circular layer (middle)
- Longitudinal layer (bottom
Rest of GI tract only circular and longitudinal
Rank order: muscularis, mucosa, serosa, submucosa, lumen
Lumen –> mucosa –> submucosa (connective tissue) –> muscularis –> serosa (simple squamous epithelial)
Pectic cells release what in stomach? (2)
Parietal cells release what?
- Pepsinogen and chymosin Pepsinogen activated into pepsin when acidic conditions
- HCl
Where do you find entrance to L and R coronary arteries?
Aortic sinus! In the aortic arch, before the brachiocephalic trunk
4 coverings of heart? + function
PERICARDIUM:
- fluid filled sac providing protection against friction not on specimen
EPICARDIUM:
- outer layer of heart wall (visceral layer)
MYOCARDIUM:
- muscle tissue of heart
ENDOCARDIUM:
- inner layer of heart wall
- trabeculae carnae muscle!!
What are the 2 chambers of heart + explain
+ extra? What muscle?
ATRIA:
- 2 superior chambers of heart, receiving blood
VENTRICLES:
- 2 lower chambers of heart, pumping chambers
AURICLES:
- earlike appendage of each atrium of the heart –> pectinate muscle
Which valves need _______ _______ and ______ muscles to close completely, to prevent regurgitation/back flow?
- tricuspid and bicuspid/mitral valves atrioventricular valves
- chordae tendinae (ligaments) that attach to papillary muscles
What carries part of the right branch of AV bundle from septum to anterior papillary muscle?
- only which part of the heart has it?
Trabecula septomarginalis
- only R ventricle has it
What is the role of valves of heart?
- 2 categories + 2 in each category
- Mechanical devices that permit flow of blood in one direction only
- Atrioventricular: tricuspid (3 cusps) and bicuspid/mitral (2 cusps)
- semilunar: half-moon shaped flaps growing out from lining of pulmonary artery (pulmonary semilunar valve) and of aorta (aortic semilunar valve)
Systemic blood circulation + pulmonary circulation
deox blood from superior and inferior vena cava right atrium tricuspid valve right ventricle pulmonary semi-lunar valve pulmonary trunk left and right pulmonary artery CO2-O2 exchange oxygenated blood in pulmonary vein left atrium bicuspid valve left ventricle aortic semi-lunar valve aorta whole body
Cross section of heart showing all 4 valves and arteries. How do you know which valve is the aortic vs pulmonary one?
Know it’s aortic because the coronary arteries leave it!
How is the heart supplied with blood?
When?
- by ways of right and left coronary arteries
- coronary arteries fill aorta when ventricles relax = diastole! Suring isovolumetric relaxation : aortic valve closes, blood fill coronary arteries
How is cardiac deox blood returned to heart? To which chamber?
via the great cardiac vein –> into the right atrium via the coronary sinus
What does right coronary artery supply?
What does left coronary artery supply?
Which one branches into 2?
- R –> right atrium and R ventricle
- L –> left atrium and L ventricle
- Left coronary artery leaves left sinus –> short branch splits into
1. circumflex artery: coronary groove
2. paraconal (anterior interventricular branch of the left coronary artery) along septal wall/beside cardiac vein
What are the 3 main parts of the conduction system + describe/location
- Sinoatrial node (SA node or pacemaker): hundreds of cells (autorythmic) located in right atrial wall near superior vena cava
- atrioventricular node: special cardiac tissue located in right atrium along the lower part of interatrial septum
- atrioventricular bundle (bundle of His) and purkinje fibers: special cardiac fibers originating in AV node, extend down septum, become purkinje fibers at lateral walls of ventricles and papillary muscles
Does SA node need signal from nervous system to contract heart?
Nope! Self-excitable cell!
What slows down the signal to the SA node?
AV node delay
Which sympathetic fibers (from which segments of the spinal cord) and which parasympathetic nerve increase/decrease heart rate?
- SNS –> T2 to T4 ganglia –> increase heart rate
- PSNS –> vagus nerve (nerve 10) –> decrease heart rate
Explain the conduction system of heart
- SA node –> sends depolarization to both auricles and atria (contract at same time) –> push blood into ventricles
- AV node slows down impulse (?)
- bundle of His make whole ventricles contract
- repolarization –> diastole for blood to fill back up
Are cardiac cells dependant or independent of one another? Explain
Dependant! They are connected through the intercalated disks (formed by desmosomes and gap junctions)
- desmosomes
What is ECG?
Electrocardiogram graphic record of the heart’s electrical activity (conduction impulse)
- impulse conduction generates electrical currents in the heart, spread to tissue and surface of body
- it is not a record of the heart’s contraction but the electrical events that precede them
Describe the different waves of the ECG + steps (7 steps)
- heart wall is completely relaxed, no change in electrical activity, so the ECG remains constant
- P wave –> when AV node (?) and atrial walls depolarize
- atrial walls completely depolarize and thus no change is recorded in ECG = atrial delay! atria contract filling of ventricles
4.QRS complex: atria repolarize (little downward Q) and ventricular walls depolarize - Atrial walls are completely repolarized + ventricular walls are now completely depolarized no change in ECG = ventricular contraction
- T wave: repolarization of ventricular walls
- back at baseline. TP line = diastole
Depolarization triggers ____A_____ in affected muscle tissue. Cardiac muscle _____A_____ occurs after/before __________ begins
A = contraction
- occurs after depolarization
What is isovolumetric contraction vs isovolumetric relaxation?
CONTRACTION:
- very short period of time when all ventricular blood volume remains the same because all 4 valves are closed due to blood pressure created in chambers (ventricles) during beginning of ventricles systole. Phase marks the beginning of systole
RELAXATION:
- when ventricular pressures drop below the diastolic aortic and pulmonary pressures, aortic and pulmonary valves close producing the second heart sound. This marks the beginning of diastole
How does smoking affect heart function?
Smoking vasoconstriction increase blood pressure
What does blood pressure represent?
Formula ish?
- pressure exerted by circulating blood on the walls of blood vessels
- Systolic/diastolic
- systolic: pressure as your heart beats and pushes blood through blood vessels
- diastolic: pressure when the vessels relax btw heartbeats
Suggested normal blood pressure?
Vs low vs normal high/limit for high
- men vs women
- normal: 120/80
- low: lower than 90/60
- normal high/limit: 140/90
- men have higher blood pressure than women
What foods affect blood pressure? Vs what foods are good for blood pressure?
“NO” FOODS:
- high salt, medium salt, hydrogenated oils, sat fat, protein
YES FOODS:
- high potassium and calcium
- apples, avocadoes, bananas, broccoli, fish, grapes, oats, orange juice, water
How to reduce blood pressure? (8)
- stop smoking
- reduce weight
- exercise
- low salt/protein
- no caffeine
- mild sedation
- sufficient rest
- don’t oversleep
when you exercise, which segment in the ECG will increase/last longer?
TP (diastole) will decrease because heart beats faster so less time between each heart beat
how does the stethoscope measure blood pressure?
- put on brachial artery
- pump to 160 mm Hg = no blood flowing
- then you release –> first sound = systolic, 2nd sound = diastole
what is keratin?
tough protective protein which prevents water loss + is resistant to friction + repels bacteria
what are the 3 types of fibers? + explain
- COLLAGEN FIBERS (white)
- extremely tough (stronger than steel fibers)
- can resist longitudinal stress - ELASTIC FIBERS (yellow)
- can be stretched to 1.5x length but recoil to initial length when released
- found where greater elasticity is neede (lungs, blood vessel walls) - RETICULAR FIBERS:
- fine collagenous fibers
- form delicate branching network supporting soft organs (liver and spleen)
what are the 4 classes of connective tissue?
- identified on the basis of which 3 criteria?
- connective tissue proper + cartilage + bone + blood
1. cells (fibroblast, hemocyblast, chondroblast, osteoblast)
2. fibers (collagen, elastic, reticular)
3. ground substance (ECM)
Explain coronary blood circulation.
when is heart supplied?
coronary artery fill from the aorta when ventricle relaxes. they are the only blood vessels in body to fill when the heart is in diastole.
- both arteries originated from the aortic sinus
- blood is returned to right atrium through the great cardiac vein, via the coronary sinus
