Lab exam 2

Lab Exam Overview

  • Emphasis on overlap with lecture content.

  • Strong recommendation to follow lab PowerPoint presentations and videos for exam preparation, especially regarding terminology.

  • Importance of accurate terminology in written exams.

Terminology Caution

  • Warning against using colloquial terms in exams.

  • Clarification that lab PowerPoints may contain simplified terms for understanding, but precise scientific terminology is essential in written responses.

  • Reference to terms learned in lectures: anterior, posterior, proximal, distal.

  • Reminder for students to distinguish between colloquial and proper terminologies to avoid past mistakes.

Muscle Contraction Basics

  • Introduction to muscle contraction topics discussed in previous lab sessions.

  • Importance of reviewing key terms related to muscle functions.

Dialysis

  • Definition: A process used to purify blood when kidneys are not functioning properly.

  • Significance: Removes impurities from the blood, thus aiding patients who require this treatment.

  • Explanation of an experiment illustrating dialysis:

    • A beaker with glucose and albumin vs. a beaker with pure water.

    • A cell-like bag containing glucose and albumin demonstrating semipermeable membranes in the body.

  • Key Processes:

    • Movement of substances through membranes.

    • Role in homeostasis and elimination of excess substances.

Racks (Rafts) within Cell Membrane

  • Explanation of what 'racks' refer to in cellular biology:

    • Yellow protrusions visible under atomic force electron microscopy.

    • Structure: Composed of proteins embedded within the phospholipid bilayer of cell membranes.

    • Function: Provide cellular identity that distinguishes different cell types (e.g., stomach cells vs. brain cells).

  • Importance of racks in cellular communication:

    • Analogy: Cells communicate much like people texting – are identified by their unique proteins (address).

Muscle Contraction Types

  • Overview of threshold stimulus required for muscle contraction.

  • Explanation of different types of muscle contractions:

    1. Tonic Contraction: No movement involved; maintains posture.

    2. Isotonic Contractions: Includes:

      • Concentric Contraction: Muscle shortens; e.g., lifting a load.

      • Eccentric Contraction: Muscle lengthens; e.g., lowering a weight.

    3. Isometric Contraction: Generates tension without changing muscle length.

    • Importance of both isotonic contractions for daily movement and isometric contractions for strength training.

Practical Implications of Muscle Contraction

  • Relevance of contraction types in everyday activities (lifting, typing).

  • Feedback example: Picking up a backpack vs. typing on a keyboard illustrates varying threshold stimuli.

Effects of Training on Muscle

  • Atrophy vs. Hypertrophy explained:

    • Atrophy: Reduction in muscle size due to inactivity.

    • Hypertrophy: Increase in muscle size and strength due to regular exercise.

  • Clarification on muscle fibers and myofilament quantity:

    • Strength training increases myofilament count per muscle fiber, enhancing muscle force and tone without increasing the number of fibers.

Endurance vs. Strength Training

  • Distinction between endurance training (improves overall conditioning) and strength training (focuses on muscle size and force generation).

  • Physiological changes resulting from consistent physical activity:

    • Improved blood circulation benefits muscle cells by delivering nutrients and oxygen efficiently.

    • Importance of oxygen and ATP for muscle function.

Movement Types in Muscle Function

  • Description of muscle movements related to sports activities (e.g., basketball).

  • Specific movements discussed:

    • Flexion: Decreasing the angle at a joint (e.g., bending the elbow).

    • Extension: Increasing the angle at a joint (e.g., straightening the elbow).

    • Abduction: Movement away from the body’s midline.

    • Adduction: Movement toward the body’s midline.

    • Supination and Pronation: Movements of the hand; supination turns the palm up, while pronation turns it downward.

General Advice for Students

  • Review all notes and terms thoroughly for the upcoming exam.

  • Read exam questions with care and apply proper terminology in responses.

  • Encourage active engagement in physical activities to enhance understanding of body mechanics.

  • Any lingering questions should be addressed before the exam as preparation is key.