Biology Chapter: Maintaining Life and Homeostasis

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Questions and Answers

Which of the following is NOT considered a necessary life function?

Growth

Communication (correct)

Excretion

Reproduction

Passive processes in membrane transport do NOT require what?

Metabolic energy from the cell (correct)

Transport proteins

Gradients for diffusion

Nutrient concentration

What is NOT a survival need for the human body?

Oxygen

Nutrients

Water

Chemical reactions (correct)

Which type of tissue is responsible for covering and lining surfaces?

Epithelial tissue Signup and view all the answers

What is the primary type of energy used in active transport processes?

Chemical energy (ATP) Signup and view all the answers

Which function is NOT associated with epithelial tissue?

Transportation Signup and view all the answers

Which type of connective tissue is the least rigid?

Blood Signup and view all the answers

What form of energy is involved in moving objects?

Mechanical energy Signup and view all the answers

Which statement about the states of matter is incorrect?

Liquids have a definite shape but take the volume of their container. Signup and view all the answers

What element makes up the largest percentage of the human body mass?

Oxygen Signup and view all the answers

Which of the following factors does NOT increase the rate of chemical reactions?

Decreasing kinetic energy Signup and view all the answers

What type of energy is stored in the bonds of substances?

Chemical energy Signup and view all the answers

Which of the following is NOT a characteristic of connective tissue?

Covers body surfaces Signup and view all the answers

How does particle size affect the kinetic energy and movement of particles?

Smaller particles move faster and have more kinetic energy. Signup and view all the answers

What distinguishes inorganic compounds from organic compounds?

Inorganic compounds are generally small, simple molecules. Signup and view all the answers

Which joint type allows for the greatest range of motion?

Ball-and-socket joint Signup and view all the answers

Which of the following is NOT a basic type of muscle found in the body?

Striated muscle Signup and view all the answers

What role do catalysts play in chemical interactions?

They decrease the energy needed by holding reactants in proper positions. Signup and view all the answers

Which of the following joints is classified as a plane joint?

Wrist joint Signup and view all the answers

Which of these is an example of an inorganic compound?

Water Signup and view all the answers

What type of muscle is primarily responsible for rapid and involuntary contractions?

Cardiac muscle Signup and view all the answers

What occurs during depolarization of the muscle cell?

More sodium ions enter the cell than potassium ions leave. Signup and view all the answers

Which statement accurately describes the role of acetylcholinesterase (AChE) in muscle contraction?

AChE breaks down acetylcholine to end muscle contraction. Signup and view all the answers

What is the role of a synergist in muscle movement?

It aids the prime mover during the movement. Signup and view all the answers

Which rule is NOT a part of the five golden rules of skeletal muscle activity?

All skeletal muscles are contracted when a joint is extended. Signup and view all the answers

What happens after a single nerve impulse in muscle fibers?

It produces only one contraction of the muscle fiber. Signup and view all the answers

What structure is responsible for the contraction of smooth muscle?

Dense bodies. Signup and view all the answers

Which characteristic is unique to cardiac muscle compared to skeletal and smooth muscle?

Cardiac muscle has intercalated discs. Signup and view all the answers

What is a key factor that causes muscle relaxation after contraction?

Breakdown of acetylcholine by AChE. Signup and view all the answers

What occurs during the power stroke of the cross bridge cycle?

Myosin heads pull actin filaments toward the center of the sarcomere Signup and view all the answers

Which type of muscle contraction is characterized by muscle filaments attempting to slide but not shortening?

Isometric contraction Signup and view all the answers

How can graded responses in skeletal muscle be achieved?

By changing the frequency of stimulation and the number of stimulated muscle cells Signup and view all the answers

What is the main effect of aerobic exercise on muscles?

Enhances muscle flexibility and endurance Signup and view all the answers

What defines muscle tone?

Continuous partial contractions maintained by systematically stimulated motor units Signup and view all the answers

Which statement about the sodium-potassium pump is accurate?

It creates an imbalance of sodium and potassium ions across the cell membrane Signup and view all the answers

What happens to individual muscle fibers during resistance exercise?

They enlarge, thereby increasing muscle size and strength Signup and view all the answers

In the context of muscle contractions, what does the term 'graded response' imply?

Variation in strength and duration of muscle contractions Signup and view all the answers

Study Notes

Maintaining Life

Maintaining boundaries: The internal environment remains distinct from the external environment.
Movement: Includes both external and internal movement.
Responsiveness: Ability to react to stimuli.
Digestion: Breakdown of food substances.
Metabolism: All chemical reactions in the body.
Excretion: Elimination of waste products.
Reproduction: Production of new cells or organisms.
Growth: Increase in size.

Survival Needs

Nutrients: Used for energy and cell building.
Oxygen: Required for chemical reactions.
Water: Most abundant chemical in the body.
Normal body temperature: Essential for chemical reactions.
Atmospheric pressure: Needed for breathing.

Homeostasis

Homeostasis is the ability to maintain a relatively stable internal environment despite external changes.
It is important for maintaining normal body function.

Anatomical Position

Body erect, feet slightly apart, palms facing forward.
Important for directional terms, referring to the body.

Body Cavities

Dorsal Body Cavity: Contains the brain and spinal cord.
Ventral Body Cavity: Contains the thoracic and abdominopelvic cavities.

Plasma Membrane

Composed of a phospholipid bilayer with embedded proteins.
Controls what enters and exits the cell.

Cell Structure

Nucleus: Contains DNA, the cell's genetic material.
Cytoplasm: The fluid inside the cell, where the organelles reside.
Organelles: Specialized structures that perform specific functions within the cell.

Membrane Transport

Passive processes: Movement of substances across the membrane without cellular energy input.
Active processes: Movement of substances across the membrane requiring cellular energy input.

Sodium-Potassium Pump

An active transport mechanism that pumps sodium ions (Na+) out of the cell and potassium ions (K+) into the cell.
Important for maintaining cell membrane potential.

Body Tissues

Epithelial tissue: Covers surfaces, lines cavities, and forms glands.
Connective tissue: Supports and protects, binds together tissues.
Muscle tissue: Responsible for movement.
Nervous tissue: Transmits impulses.

Connective Tissue

Bone: Most rigid connective tissue.
Cartilage: Supporting tissue with a flexible matrix.
Dense connective tissue: Strong, fibrous tissue found in tendons and ligaments.
Loose connective tissue: Contains more cells with less dense matrix.
Blood: Fluid connective tissue.

Matter and Energy

Matter: Anything that takes up space and has mass.
Energy: The ability to do work.
Kinetic energy: Energy in motion.
Potential energy: Stored energy.

Forms of Energy

Chemical energy: Stored within bonds of molecules.
Electrical energy: Movement of charged particles.
Mechanical energy: Energy associated with movement.
Radiant energy: Energy that travels in waves.

Composition of Matter

Elements: Fundamental units of matter.
96% of the body is made from four elements: oxygen, carbon, hydrogen, and nitrogen.
Atoms: Smallest unit of an element.
Molecules: Two or more atoms joined together.
Compounds: Two or more different atoms joined together.

Inorganic Compounds

Lack carbon.
Tend to be small and simple molecules.
Include water, salts, and many acids and bases.

Organic Compounds

Contain carbon.
Large, covalent molecules.
Include carbohydrates, lipids, proteins, and nucleic acids.

Bone Markings

Surface features that serve as points of attachment for muscles, tendons, and ligaments, or mark the passage of blood vessels and nerves.

Synovial Joints

Freely movable joints that contain synovial fluid.
Types: plane, hinge, pivot, condylar, saddle, ball-and-socket.

Skeletal Muscles

Responsible for all types of body movement.
Types: skeletal, cardiac, and smooth.

Skeletal Muscle Activity

Five golden rules of skeletal muscle activity:
- All skeletal muscles cross at least one joint.
- The bulk of a skeletal muscle lies proximal to the joint crossed.
- All skeletal muscles have at least two attachments: the origin and the insertion.
- Skeletal muscles can only pull; they never push.
- During contraction, a skeletal muscle insertion moves toward the origin.

Interactions of Skeletal Muscles

Prime mover/agonist: The muscle primarily responsible for a movement.
Antagonist: The muscle that opposes or reverses a prime mover.
Synergist: The muscle that aids a prime mover in a movement or reduces undesirable movements.
Fixator: Specializes synergists that hold a bone still or stabilize the origin of a prime mover.

Motor Units

Consists of a motor neuron and all the muscle fibers it stimulates.

Events at the Neuromuscular Junction

Motor neuron releases acetylcholine (ACh), a neurotransmitter, which diffuse across the synaptic cleft and bind to receptors on the sarcolemma.
Sodium ions enter the muscle cell, causing depolarization and generating an action potential.
Acetylcholinesterase breaks down ACh, ending the muscle contraction.

The Cross Bridge Cycle

A series of events that allow muscle contraction to occur.
Steps: cross bridge formation, the power stroke, cross bridge detachment, reactivation of myosin head.

Contraction of a Skeletal Muscle as a Whole

Graded responses are different degrees of skeletal muscle shortening.
Muscle fiber contraction is “all-or-none.”
Graded responses can be produced by changing the frequency or number of muscle cells being stimulated.

Types of Muscle Contractions

Isotonic: Muscle shortens and movement occurs (“same tone”).
Isometric: Muscle tension increases without muscle shortening (“same measurement / length”).

Muscle Tone

State of continuous partial contractions.
Results from different motor units being stimulated in a systematic way.

Effect of Exercise on Muscles

Aerobic exercise: Strengthens, more flexible, and more resistant to fatigue.
Resistance exercise: Increases muscle size and strength - individual muscle fibers enlarge.

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Description

Test your knowledge on the essential processes that sustain life, including movement, metabolism, and homeostasis. This quiz covers key survival needs and anatomical position concepts in biology. Challenge yourself to see how well you understand these fundamental biological principles.