Histology 2: Cardiac muscle

gap junctions

specialized proteins that form channels; intercalated discs are these.

collagenous scar tissue

healing from an MI results in large deposits of __________ that will continue to impede the heart's ability to pump

aerobic respiration

lipid droplets are converted into usable energy for the heart via ____________

lysosomal

lipofuscin pigment granules represent undigested material left over from _______ digestion. predominant in older ppl

heart fuel

lipoproteins and fatty acids are like the ______

may or may not recover

marginal area of a necrotic core due to myocardial infarction _______

~15 um

mature cardiac muscle cell diameter

irreversible

myocardial infarction is ________ damage to the heart muscle due to prolonged hypoxia

tissue perfusion

passage of fluid (e.g., blood) through a specific organ or body part

intercalated disks

primary distinguishing characteristics b/w skeletal and cardiac muscles are dark staining lines that bisect the individual cardiac cells

AV node function

receives impulse from SA node and delays relay of the impulse to the bundle of His, allowing time for the atria to empty their contents into the ventricles before the onset of ventricular contraction

cardiac muscle

responsible for producing the continuous, rhythmic contractions of the heart

cardiac atrophy

results due to MI caused by ischemic heart disease

glucagon

the hormone __________ signals the release of lipase which breaks down the fatty acids into useful form for the heart

never

the necrotic core in a myocardial infarction can ____ recover

1-2 centrally located

unlike the skeletal muscles, cardiac muscles contain __________ nuclei

pacemaker cells

-specialized types of cardiac cells which have the ability to depolarize themselves through a slow leak of potassium -Following depolarization the pacemaker cells rapidly polarize again to prepare for the next contraction -This slow leak followed by rapid re-polarization results in the regular rhythmic contraction of the heart

cardiac muscle cell

Striated, involuntary cell that has centrally located 1-2 nuclei per cell.

cardiac muscle

The muscle tissue of the heart Cardiac muscle is striated, uninucleate, and under involuntary control (controlled by teh autonomic nervous system). Note also that cardiac muscle is self-stimulatory, and autonomic control serves only to modify the intrinsic rate of contraction.

intercalated disk

A specialized junction between adjacent heart muscle cells that contains gap junctions, allowing electrical signals to pass between the cells.

striated in appearance

cardiac muscle is ________ but should not be referred to as striated

identical to skeletal muscles

cardiac muscles exhibit cross-striated banding pattern that is ____________

mitochondria

cardiac muscles require large amounts of energy to maintain continuous contractions therefore the cardiac cells are abundant in __________

myocardial infarction

destruction of heart tissue resulting from obstruction of the blood supply to the heart muscle

ischemic heart disease

disease in which insufficient amounts of oxygen are delivered to the heart

triglycerides and lipid droplets

fatty acids are stored as _________and ______ within the cardiac muscles

lipofuscin pigment granules

yellow brown pigmentation found in the cardiac muscles generally located near the nuclei