Blood Circulation and Muscle Physiology Overview

What is the starting point of blood circulation in the body?

The left ventricle of the heart.

What are the two main types of circulation in the body?

Systemic circulation and pulmonary circulation.

What is the role of portal circulation?

It involves blood flow from the gastrointestinal tract to the liver for nutrient processing before entering systemic circulation.

What are the characteristics of arteries?

Arteries have thick, elastic walls to withstand high pressure.

How do arterioles regulate blood flow?

They regulate blood flow and pressure through vasoconstriction and vasodilation.

What is the function of capillaries?

Capillaries are thin-walled for efficient gas and nutrient exchange.

What prevents backflow in veins?

Valves in veins ensure unidirectional blood flow back to the heart.

What factors influence peripheral resistance in blood circulation?

Blood viscosity, vessel length, and diameter.

How does vessel diameter affect blood pressure?

Smaller diameters increase resistance, leading to higher blood pressure.

What are the three layers of the heart wall?

Epicardium (outer), myocardium (muscle layer), and endocardium (inner lining).

What is the function of the pericardium?

It is a protective sac surrounding the heart, preventing friction during heartbeats.

Describe the flow of blood through the heart starting from the body.

Blood flows from the body into the right atrium, through the tricuspid valve to the right ventricle, then to the lungs via the pulmonary arteries.

How does oxygenated blood return to the systemic circulation?

It returns to the left atrium, passes through the mitral valve to the left ventricle, and is pumped into systemic circulation through the aorta.

What is the relationship between heart size and heart rate in animals?

Larger animals typically have slower heart rates due to lower metabolic rates, while smaller animals have faster heart rates.

What are the components of blood?

Blood consists of red blood cells, white blood cells, platelets, and plasma.

What is the primary function of red blood cells?

They transport oxygen via hemoglobin.

What role do platelets play in the blood?

Platelets are crucial for clotting and wound healing.

What is erythropoiesis and what stimulates it?

Erythropoiesis is the production of red blood cells, stimulated by erythropoietin from the kidneys in response to low oxygen levels.

What factors influence hemoglobin's affinity for oxygen?

pH, temperature, and carbon dioxide levels (Bohr effect).

What are the three types of muscle tissue?

Skeletal muscle, cardiac muscle, and smooth muscle.

What is the role of actin and myosin in muscle contraction?

Actin and myosin interact during contraction, powered by ATP hydrolysis.

What initiates muscle contraction at the neuromuscular junction?

Neurotransmitter release, specifically acetylcholine, depolarizes the muscle fiber membrane.

What is the function of acetylcholinesterase?

It terminates the action of acetylcholine, allowing muscle relaxation.

What is the significance of satellite cells in muscle physiology?

Satellite cells are essential for muscle repair and regeneration after injury or stress.

How do peptide hormones affect muscle metabolism?

They regulate muscle metabolism and cardiovascular function, influencing heart rate and muscle growth.

What is the role of connective tissues in muscle function?

Connective tissues provide structural support and enable muscle attachment to bones.