Muscle and Cardiovascular System Quiz

Muscular System

• The muscular system provides motor power for all body part movements.
• Muscles are specialized tissues that contract and relax to produce force for movement.
• Muscles possess properties like excitability (responding to stimulation), contractility (shortening actively), extensibility (contracting over a range of lengths), and elasticity (rebounding to original length).
• Muscles are categorized by function (skeletal, visceral, or cardiac), activation method (voluntary or involuntary), and physiology (smooth, striated, or unstrained).

Types of Muscle

• Skeletal Muscle: Striated, voluntary, attached to the skeleton, responsible for major body movements.

  • Skeletal muscle cells are long, cylindrical, and multinucleated (multiple nuclei per cell).
  • Skeletal muscles can be divided into flexors, extensors, abductors, and adductors, which describe their movement function.

• Smooth Muscle: Non-striated, involuntary, found in soft organs (stomach, intestines, blood vessels) responsible for processes like digestion.

  • Individual smooth muscle cells are spindle-shaped.
  • Smooth muscle contractions are slow and wave-like.

• Cardiac Muscle: Striated, involuntary, found exclusively in the heart; responsible for pumping action.

  • Cardiac muscle cells are branching and typically have one or two nuclei per cell
  • Contractions are involuntary and rhythmic.

Muscle Function and Movement

• Skeletal muscles work in pairs, such as flexors and extensors (antagonistic).
• Synergistic muscles work together to perform a specific movement.
• Flexor muscles decrease the angle between two bones.
• Extensor muscles increase the angle between two bones.
• Abductor muscles move limbs away from the median plane.
• Adductor muscles move limbs towards the median plane.

Muscle Attachment

• Most skeletal muscles attach to two different bones, an origin (stable bone), and an insertion (movable bone).

Muscle Structure

• Skeletal muscles consist of bundles of fibers (cells) that connect to tendons.
• Fibers run parallel to each other within the muscle sheath, creating a striped or striated appearance.
• Each fiber bundle consists of individual cells with multiple nuclei.
• Individual fibers are made up of bundles of myofibrils.
• Myofibrils contain thick filaments of myosin and thin filaments of actin.

Muscle Contraction

• Muscle contraction occurs via sliding filament action, where actin and myosin filaments slide over each other.
• Energy for contraction primarily comes from ATP, glycogen, and body fats.

Cardiovascular System

• The circulatory system transports blood around the body, consisting of the heart and a system of vessels, for the distribution of blood.
• The cardiovascular system carries oxygen from the lungs to the body tissues and removes carbon dioxide from tissues to the lungs.
• The Cardiovascular system removes waste products of metabolism.
• The Cardiovascular system carries hormones from one part of the body to another part.
• The Cardiovascular system maintains water equilibrium
• The Cardiovascular system maintains the body's temperature
• The Cardiovascular system helps in overcoming disease by the antibodies contained in the blood.

The Heart

• The heart is located in the mediastinal space of the thorax.
• The heart is cone-shaped, hollow organ.
• The heart has four chambers: two atria (right and left) and two ventricles (right and left).

Heart Valves

• Atrioventricular (AV) valves (tricuspid and mitral) prevent backflow from ventricles to atria.
• Semilunar valves (aortic and pulmonary) prevent blood from flowing back into the ventricles from the aorta and pulmonary artery, respectively.

Heart Sounds

• Two sounds are typically heard through a stethoscope during the heart's operation: the "lubb" sound, caused by the closing of the mitral and tricuspid valves; and the "dub" sound, caused by the closing of the aortic and pulmonary valves.

Blood Vessels

• Five types of blood vessels exist in the body: arteries, arterioles, veins, venules, and capillaries.
• Arteries carry blood away from the heart.
• Arterioles are small branches of arteries that lead to capillaries.
• Veins carry blood back to the heart.
• Venules collect blood from capillaries and drain into veins.
• Capillaries are the smallest, thin-walled vessels involved in gas exchange and nutrient transport.
• Blood vessels become gradually smaller as they migrate away from the heart.

Blood Circulation

• Systemic circulation carries blood around the body and back to the heart.
• Coronary circulation supplies blood to the heart itself.
• Hepatic circulation supplies blood to the liver.
• Cerebral circulation supplies arterial blood to the brain.
• Renal circulation supplies arterial blood to the kidneys.
• Splanchnic circulation supplies arterial blood to the digestive tract.
• Pulmonary circulation carries blood from the heart to the lungs and back to the heart.

Blood Composition

• Blood is a fluid connective tissue made up of plasma (liquid portion) and blood cells (solid portion).
  • Plasma is primarily water and contains dissolved substances like proteins, electrolytes, hormones, nutrients, and wastes.
  • Blood cells include erythrocytes (red blood cells), leukocytes (white blood cells), and thrombocytes (platelets).

Blood Functions

• Transport: Blood carries oxygen to tissues, transports nutrients, removes metabolic wastes, and transports hormones.
• Regulation: Blood regulates body fluid volumes, temperature, acid-base balance, and helps protect against infection.

Lymphatic System

• The lymphatic system is made up of lymph vessels, lymph nodes, lymph organs, and lymphatic tissue, helping maintain fluid balance and immune responses.
• Lymphatic organs include bone marrow, tonsils, thymus, and spleen.
• Lymph vessels carry lymph (fluid) toward the heart.
• Lymph nodes filter lymph and contain immune cells.
• The lymphatic system assists in combating foreign bodies, such as bacteria, viruses and other infective agents.

Endocrine System

• The endocrine system is a regulatory system composed of glands that release hormones into the circulatory system.
• Hormones are chemical messengers that regulate the activity of other cells.
• The Hypothalamus and Pituitary glands regulate much of the endocrine system.
• There are three primary classes of hormones: steroids, peptides, and amines
• Hormones are secreted from a gland and act on a target cell in another part of the body.
  • Target cells have specific receptors for the hormone triggering a reaction.

Hormones

• Hormones play important roles in growth, fattening, reproduction, lactation, and egg-laying.
• Specific hormone examples include Growth, Adrenocorticotropic, Thyroid-Stimulating, Gonadotropic and Prolactin, from the anterior pituitary.
• The posterior pituitary releases antidiuretic hormone (ADH) and oxytocin.
• Adrenal hormones include glucocorticoids (e.g., cortisol) and mineralocorticoids (e.g., aldosterone).

Hypothalamus & Pituitary

• The hypothalamus controls the pituitary, releasing hormones that stimulate or inhibit other endocrine glands.
• The anterior pituitary releases hormones that regulate growth, stress, thyroid, and reproductive functions.
• The posterior pituitary stores and releases hormones made in the hypothalamus (oxytocin and ADH).

Thyroid Gland

• Located in the neck, the thyroid gland produces hormones (T3 and T4) that regulate metabolism.

Pancreas

• The pancreas is part of the digestive system and endocrine system.
• It has exocrine functions (producing digestive enzymes) and endocrine functions, including regulating blood sugar.
• Hormones released by the pancreas are insulin and glucagon.
• Insulin lowers blood glucose levels, while glucagon increases them.

Adrenal Glands

• Situated near the kidneys, the adrenal glands produce hormones that regulate stress response (epinephrine, norepinephrine) and control electrolytes.

Ovaries

• Ovaries produce estrogen and progesterone, which regulate the reproductive system and estrous cycle.

Testes

• Testes (in males) produce testosterone and estrogen, which regulate reproductive functions and male sexual characteristics