Ch19: The Heart (Pt1)

Flashcards reviewing key concepts from Chapter 19 on cardiac muscle cell anatomy, coronary circulation, intercalated discs, and the cardiac conduction system.

If an individual has type A blood, what specific antibodies are present?

Anti-B antibodies

What are three alternate names or nicknames used for a cardiac muscle cell?

Cardiocyte, cardiomyocyte, or cardiac muscle cell

What organelle uses oxygen and fuel (sugar, lipid, or amino acid protein) to produce ATP efficiently?

Mitochondria

Which main arteries start the coronary circulatory system that feeds the heart muscle?

Left and right coronary arteries

Where do the middle cardiac, posterior cardiac, great cardiac, and small cardiac veins pool their blood before it enters the right atrium?

The coronary sinus

What dark bands are found exclusively on cardiac muscle tissue and link neighboring muscle cells together?

Intercalated discs

What two cellular features make up intercalated discs?

Desmosomes and gap junctions

Why is smooth muscle tissue named 'smooth' compared to skeletal and cardiac muscle?

Because it lacks a visible striation pattern (stripes)

How does the nuclear count of a cardiac muscle cell compare to that of a skeletal muscle cell?

A cardiac muscle cell generally has one nucleus, whereas a skeletal muscle cell is multinucleated

How frequently does the heart perform physical labor according to the lecture?

Every $0.8$ milliseconds

Why do cardiac muscle cells depend heavily on extracellular calcium for contraction?

Because their sarcoplasmic reticulum is chintzy and has limited internal calcium storage space

What three hormones are involved in balancing blood calcium levels?

Calcitonin, parathyroid hormone, and calcitriol (or vitamin D)

What is myoglobin?

An oxygen-binding red pigment protein found inside muscle cells

What type of cells form the heart's conduction system?

Modified cardiocytes (muscle cells that self-stimulate and act like neurons)

What structural characteristic enables spontaneous depolarization in the cells of the heart's conduction system?

An abundance of leaky channels on their cell membranes

What is the resting membrane potential mentioned for fat cells versus regular/muscle cells?

Fat cells have a resting potential around $-40$, while regular and muscle cells sit around $-65$

How many sodium and potassium ions are moved across the membrane by the sodium-potassium exchange pump?

It sends $3$ sodium ions out of the cell and brings $2$ potassium ions into the cell