Muscle Tissue and Molecular Mechanisms Quiz

Histology smooth muscle tissue is characterized by its involuntary nature, scattered arrangement of myosin and actin, lack of striations, and presence of a single nucleus. This tissue type differs from voluntary skeletal muscle with aligned myosin and actin in sarcomeres, striations, and multiple nuclei, as well as cardiac muscle with intercalated discs, striations, and a single nucleus.

Skeletal muscle tissue is characterized by being under voluntary control, containing multiple nuclei, and having striations which refer to the organized arrangement of myosin and actin filaments.

Cardiac muscle tissue is characterized by having a single nucleus in each cell, striations (striped appearance), intercalated discs for cell-to-cell connections, and branching structures to create a network for coordinated heart contractions.

A sacromere is specifically defined as the smallest functional unit of a muscle that plays a crucial role in muscle contraction.

In muscle fibers, myosin is known as the thick filament responsible for muscle contraction, while actin serves as the thin filament, working together in a sliding filament mechanism during muscle contraction.

Depolarization refers to the loss of negative membrane potential where cell membranes have a negative charge and the outside has a positive charge. It is a crucial process in the functioning of neurons and muscle cells.

Repolarization is the phase of an action potential when the membrane potential returns to its resting state after depolarization. This involves the movement of ions across the cell membrane to restore the negative charge inside the cell and positive charge outside.

In skeletal muscle contraction, acetylcholine (ACH) is the neurotransmitter that plays a key role in initiating the process by binding to voltage gated channels and allowing for the depolarization of the muscle cell.

Aerobic respiration consists of glycolysis with O2 in the cytoplasm producing 2 ATP, Krebs cycle in the mitochondrial cristae producing 2 ATP, and Electron Transport Chain (ETC) in the Mitochondrial matrix producing 32 ATP + 2 ATP + 2 ATP = 36 ATP in total.

Anaerobic respiration, which occurs in the absence of oxygen, involves glycolysis to produce a small amount of ATP, along with the buildup of lactic acid and the creation of O2 debt. This process is different from photosynthesis, Krebs cycle, and oxidative phosphorylation which all require oxygen as part of aerobic respiration.

The structure mentioned in the correct answer is unique to compact bone, providing strength and support to bones.

Spongy bone is actually stronger than compact bone as it can accept more stress due to its unique structure. It lacks osteons, giving it a more porous or sponge-like appearance.

Bone marrow is primarily responsible for storing lipids (calcium and phosphate) in yellow bone marrow, and producing red and white blood cells in red bone marrow.

The axial skeleton includes the skull (cranium), face, vertebral column, and rib cage (thorax) which are essential for protecting vital organs and providing structure and support to the body.

The appendicular skeleton includes the bones of the upper and lower limbs along with the pectoral girdle. It does not include the skull, spine, ribs, or other parts mentioned in the incorrect answers.

Synovial joints allow for a wide range of movement compared to fibrous and cartilaginous joints. Fibrous joints are immovable or slightly movable, while cartilaginous joints are slightly movable. Fixed joints, such as the pelvis bones, are not found in the classification of synovial joints.

The correct answer provides a comprehensive list of the 4 main types of bones, including their defining characteristics and examples. The incorrect answers either describe non-existent types of bones or misinterpret the characteristics of bones, thereby differentiating them from the correct answer.

Osteoporosis is characterized by decreased bone density and strength due to a gradual decrease in the rate of bone formation, making bones more brittle and prone to fractures. It is commonly seen in elderly individuals as a result of aging and hormonal changes.

Fractures can be classified based on the position of bone alignment. Displaced fractures have bone alignment that is off, while nondisplaced fractures have bone alignment that is okay. The incorrect answers provide alternative classifications of fractures based on different characteristics such as bone exposure, break pattern, and alignment angles.

Fractures can be categorized based on completeness as complete (broken into 2 or more pieces) or incomplete (simple break).

Fracture orientations are categorized based on the direction of the crack in relation to the longitudinal axis of the bone. Linear fractures run parallel to the bone's axis, transverse fractures run perpendicular to the axis. Oblique, spiral, and comminuted fractures refer to different patterns of fracture lines.

Fractures can be categorized as open fractures when the bone is broken through the skin and closed fractures when the skin is not affected. The incorrect answers provided do not accurately depict the two distinct types of fractures involving the skin.

The bone repair process involves specific steps that include the rush of blood, cartilage formation, bony callus formation, and bone remodeling to ultimately restore the bone's integrity and strength.

Foramen is a key anatomical term referring to openings in bones or between body cavities. The largest foramen, known as the obturator foramen, is located in the pelvis between the ischium and pubis bones. The incorrect answers provided aim to mislead by presenting other foramina and unrelated definitions, highlighting the importance of clear understanding of anatomical terminology.

Sella turcia is a depression in the sphenoid bone that forms a saddle-like shape where the pituitary gland is located.

The list of paired bones in the head includes parietal, temporal, maxillary, palatine, zygomatic, nasal, and lacrimal. Each pair works together to form the structure of the head and face.

Understanding the rules of origin and insertion in muscle movement helps in identifying the specific roles muscles play in specific movements. Flexors are responsible for decreasing the angle at a joint, while extensors increase the angle. Abductors move a structure away from the midline of the body. Origins are the stable attachment points of the muscles while insertions are the points where the muscles exert force to create movement.

Isometric contractions involve muscle tension without movement, while isotonic contractions result in movement as muscles work together. Understanding this difference is crucial in explaining muscle physiology.

O2 debt is the term used to describe the amount of oxygen required to metabolize the lactic acid produced during anaerobic respiration, leading to an oxygen debt to be repaid after exercise.