Animal Physiology Exam Lecture Review

Flashcards created for key terms and concepts from the Animal Physiology Exam Lecture.

Sarcomere

The basic structural unit of a muscle fiber.

Z disc

Boundary of the sarcomere, characterized by a zigzag edge.

A band

The entire length of the thick myosin filament.

I band

Region beside Z disc containing only thin actin filaments.

H zone

Region in the A band containing only thick myosin filaments.

M line

The center of the sarcomere.

Actin

Protein that forms thin filaments in muscle cells.

Myosin

Protein that forms thick filaments in muscle cells.

Sarcolemma

The outer membrane of a muscle cell.

T Tubules

Inward extensions of the sarcolemma that help transmit signals.

Sarcoplasmic reticulum

Smooth endoplasmic reticulum in muscle cells that stores calcium ions.

Neuromuscular junction

The synapse between a motor neuron and a muscle fiber.

Cross-bridge cycle

The process where myosin heads bind to actin and produce muscle contraction.

Troponin

A protein that, when bound with calcium, allows muscle contraction to occur.

Calmodulin

A protein involved in smooth muscle contraction, activating MLCK.

Myofibril

Long, thread-like structures in muscle fibers composed of sarcomeres.

Plateau phase

Phase in cardiac muscle contraction caused by prolonged calcium entry.

Phototransduction

Process by which light is converted into electrical signals in the retina.

Exhalation

The process of breathing out, decreasing thoracic volume.

Filtration

The process of filtering blood in the kidney glomerulus.

Nephron

The functional unit of the kidney responsible for urine formation.

ADH (Antidiuretic hormone)

Hormone that promotes water reabsorption in the kidneys.

Vasoconstriction

The narrowing of blood vessels to increase blood pressure.

Vasodilation

The widening of blood vessels to decrease blood pressure.

Hemoglobin

Protein in red blood cells that carries oxygen.

Bohr Effect

The phenomenon where oxygen release from hemoglobin increases under conditions of low pH, high CO₂, and high temperature.