Biology Chapter on Metabolism and Body Systems

Anatomy & Physiology

• Physiology is the study of bodily functions.
• Anatomy is the study of body structures.
• Tissue is a group of similar cells and cell products working together for a specific function.
• Organ is composed of two or more tissues working together to perform a specific function.
• Molecule is a group of at least two atoms.
• Organism is a complete individual.

Levels of Organization

• Atoms are the smallest chemical units.
• Molecules are groups of atoms working together.
• Cells are groups of atoms, molecules, and organelles.
• Tissues are groups of similar cells working together.
• Organs are groups of different tissues working together for a specific function.
• Organ systems are groups of related organs working together with a common function.
• Organism is a complete individual composed of multiple organ systems.

Cellular Level

• Organelles are small, specialized structures within a cell's cytoplasm.
• Mitochondria are the "powerhouse" of the cell, responsible for energy production.
• Golgi apparatus packages and modifies proteins.
• Endoplasmic reticulum is a network of transport channels in the cell.
• Cells are the smallest structural unit of an organism.
• Each cell type has specialized functions:
  • Fat cells (adipose) store lipids.
  • Cardiac cells contract to enable the heart's pumping action.

Tissue Level

• Tissues are composed of cells with similar structure and function.
• There are four major tissue types:
  • Epithelial tissue covers body surfaces and lines cavities (e.g., skin).
  • Connective tissue supports and binds other tissues (e.g., bone, blood).
  • Muscle tissue allows for movement (e.g., skeletal, cardiac, smooth).
  • Nervous tissue transmits signals (e.g., neurons, glial cells).

Nervous Tissue

• Neurons transmit nerve impulses.
• Glial cells support and protect neurons.

Organ Level

• Organs are composed of different tissue types working together to perform a specific function.
• Example: The heart, composed of muscle and connective tissue, enables blood circulation.

Organ Systems

• An organ system consists of related organs with a common function.
• There are 11 organ systems in the human body.

Types of Glands

• Exocrine glands secrete substances through ducts (e.g., sweat glands).
• Endocrine glands release hormones into the bloodstream (e.g., thyroid gland).

Organ Systems in Detail

• Integumentary System

  • Major organs: Skin, hair, sweat glands, nails.
  • Functions: Protection from environmental hazards, temperature regulation, sensory information.

• Skeletal System

  • Major organs: Bones, cartilages, ligaments, bone marrow.
  • Functions: Support, protection, mineral storage, blood cell formation.

• Muscular System

  • Major organs: Skeletal muscles and tendons.
  • Functions: Movement, protection, heat generation.

• Nervous System

  • Major organs: Brain, spinal cord, peripheral nerves, sense organs.
  • Functions: Directs immediate responses to stimuli, coordinates organ system activities, sensory information processing.

• Endocrine System

  • Major organs: Pituitary, thyroid, pancreas, adrenal glands, gonads.
  • Functions: Long-term regulation of organ system activity, metabolic control, developmental changes.

• Cardiovascular System

  • Major organs: Heart, blood, blood vessels.
  • Functions: Distribution of blood cells, nutrients, waste products, oxygen, carbon dioxide, heat regulation.

• Lymphatic System

  • Major organs: Spleen, thymus, lymphatic vessels, lymph nodes, tonsils.
  • Functions: Immune defense, return of tissue fluid to bloodstream.

• Respiratory System

  • Major organs: Nasal cavities, larynx, trachea, bronchi, lungs, alveoli.
  • Functions: Air delivery to alveoli, oxygen uptake, carbon dioxide removal, sound production.

• Digestive System

  • Major organs: Teeth, tongue, pharynx, esophagus, stomach, small intestine, large intestine, liver, gallbladder, pancreas.
  • Functions: Food processing and digestion, water absorption, nutrient absorption, energy storage.

• Urinary System

  • Major organs: Kidneys, ureters, urinary bladder, urethra.
  • Functions: Waste excretion, water balance, blood ion and pH regulation.

• Male Reproductive System

  • Major organs: Testes, epididymides, ductus deferentia, seminal vesicles, prostate gland, penis, scrotum.
  • Functions: Production of sperm and male hormones, sexual intercourse.

• Female Reproductive System

  • Major organs: Ovaries, uterine tubes, uterus, vagina, labia, clitoris, mammary glands.
  • Functions: Production of oocytes and female hormones, support of developing embryo, milk production, sexual intercourse.

Organismal Level

• An organism is a complete individual composed of multiple organ systems.

Homeostasis

• Homeostasis is the ability of the body to maintain stable internal conditions despite external changes.

Metabolism

• Metabolism is the sum of all chemical processes in the body.
  • Catabolism is the energy-releasing breakdown of substances (e.g., digestion).
  • Anabolism is the energy-requiring synthesis of complex molecules (e.g., growth).

Responsiveness

• Responsiveness is the ability to detect and respond to changes in the environment.

Movement

• Movement encompasses a range of motions from tiny subcellular structures to movement within cells and organs.

Growth

• Growth is an increase in body size due to an increase in existing cells, number of cells, or both.

Differentiation

• Differentiation is the development of specialized cells from unspecialized precursor cells.

Reproduction

• Reproduction refers to the formation of new cells for growth, repair, or replacement, and can also encompass the production of a new individual.

Feedback Systems

• Feedback systems monitor and regulate controlled conditions in the body.

Components of a Feedback System

• Receptor: Detects changes in a controlled condition.
• Control center: Sets the range for the controlled condition and receives input from the receptor.
• Effector: Receives output from the control center and produces a response to change the controlled condition.

Negative Feedback Systems

• Negative feedback systems reverse a change in a controlled condition.
• Example: Regulating blood pressure.

Positive Feedback Systems

• Positive feedback systems strengthen or reinforce a change in a controlled condition.
• Example: Normal childbirth.

Anatomical Terminology

• Surface anatomy refers to the location of structures near the body surface.

Anatomical Position

• Anatomical position: Standing upright, arms at sides, palms facing forward.
• Supine: Lying on back, face up.
• Prone: Lying on stomach, face down.

Directional Terms

• Superior: Towards the head (e.g., the skull is superior to the chest).
• Inferior: Towards the feet (e.g., the feet are inferior to the head).
• Anterior (ventral): Front of the body.
• Posterior (dorsal): Back of the body.
• Medial: Towards the midline.
• Lateral: Away from the midline.
• Proximal: Nearest to the point of reference.
• Distal: Farthest from the point of reference.
• Superficial: Towards the surface.
• Deep: Away from the surface.
• Ipsilateral: Same side of the body.
• Contralateral: Opposite side of the body.

Descriptive Terms

• Visceral: Pertaining to a covering of an organ.
• Parietal: Pertaining to a covering against a cavity wall.

Body Planes

• Sagittal Plane: Divides the body into left and right sections.
• Coronal (frontal) Plane: Divides the body into anterior and posterior sections.
• Transverse (horizontal) Plane: Divides the body into superior and inferior sections.

Body Cavities

• Dorsal Cavity:

  • Cranial Cavity: Contains the brain.
  • Spinal Cavity: Contains the spinal cord.

• Ventral Cavity:

  • Thoracic Cavity: Contains heart and lungs.
  • Abdominal Cavity: Contains digestive organs.

The Chemical Level of Organization

• There are 26 elements in the human body, with 11 being major elements.
• The top four major elements, comprising 96% of the body, are Carbon, Hydrogen, Oxygen, and Nitrogen.

Structure of an Atom

• Nucleus: Contains protons and neutrons.
  • Protons: Positively charged.
  • Neutrons: No charge.
• Atomic Number: Number of protons in the nucleus.
• Mass Number: Total number of protons and neutrons.
• Electrons: Negatively charged particles that orbit the nucleus. The number of electrons in an atom equals the number of protons.

Enzymes

• Enzymes are proteins that act as catalysts, speeding up chemical reactions.

Isotopes

• Isotopes are atoms of the same element but with different mass numbers due to varying numbers of neutrons.

Chemical Bonds

• Ionic bonds form when electrons are transferred between atoms, creating charged ions.
• Covalent bonds form when electrons are shared between atoms.
  • Polar covalent bonds: Electrons are shared unequally.
  • Nonpolar covalent bonds: Electrons are shared equally.

Valence

• Valence refers to the number of electrons in an atom's outer shell, which determines its chemical properties.

Octet Rule

• The Octet Rule states that atoms tend to gain, lose, or share electrons to achieve a stable outer shell containing eight electrons.

Electrolytes

• Electrolytes are inorganic compounds, including acids, bases, and salts, that conduct electricity when dissolved in water.

Organic Compounds

• Proteins: Composed of amino acids and perform various functions (e.g., enzymes, structural support, transport, signaling).
• Carbohydrates: Composed of carbon, hydrogen, and oxygen (usually in a 1:2:1 ratio), providing quick energy and structural support.
  • Monosaccharides: Simple sugars.
  • Disaccharides: Two monosaccharides linked together.
  • Polysaccharides: Long chains of monosaccharides.
• Lipids: Composed of carbon, hydrogen, and oxygen, primarily used for energy storage, insulation, and cell membranes.
  • Fatty Acids: Long hydrocarbon chains.
  • Triglycerides: Composed of glycerol and three fatty acids.
  • Phospholipids: Contain two fatty acids, glycerol, and a phosphate group, forming cell membranes.
  • Steroids: Characterized by a four-ring structure.
• Nucleic Acids: Large molecules that store and process genetic information.
  • DNA (deoxyribonucleic acid)
  • RNA (ribonucleic acid)

Protein Structure

• Primary Structure: The sequence of amino acids in a protein chain.
• Secondary Structure: Folding of the protein chain into alpha helices or beta pleated sheets.
• Tertiary Structure: The three-dimensional shape of a single polypeptide chain.

Cells

• Prokaryotic Cells: Simple cells without a nucleus.
• Eukaryotic Cells: Complex cells with a nucleus and other membrane-bound organelles.

Cell Structures

• Plasma Membrane: The outer boundary of the cell, controlling the passage of substances.
• Cytoplasm: The substance within the cell, including organelles.
• Nucleus: Contains DNA, the genetic material of the cell.

Membrane Permeability

• Selectively permeable: Allows some substances to pass through while blocking others.

Membranes

• Serous Membranes: Thin membranes lining closed body cavities, producing serous fluid.
• Pleural Membranes: Serous membranes surrounding the lungs.

Solutions

• Hypotonic Solution: Has a lower solute concentration than the cell, causing the cell to gain water and swell.
• Hypertonic Solution: Has a higher solute concentration than the cell, causing the cell to lose water and shrink.
• Isotonic Solution: Has the same solute concentration as the cell, causing no change in cell volume.

Transport Mechanisms

• Endocytosis: Brings material into the cell.
• Exocytosis: Releases material from the cell.

Membrane Transport

• Simple Diffusion: Movement of small, nonpolar molecules directly through the membrane.
• Facilitated Diffusion: Movement of larger or polar molecules through protein channels.
• Osmosis: Diffusion of water across a semipermeable membrane.

Organelles

• Endoplasmic Reticulum (ER): A network of interconnected membranous channels called cisternae.
  • Rough ER: Covered with ribosomes, synthesizes proteins.
  • Smooth ER: Lacking ribosomes, synthesizes lipids.
• Nucleus: Contains genetic material.
• Mitochondria: Energy production (ATP).
• Ribosomes: Protein synthesis.
• Golgi Apparatus: Modifies and packages proteins.
• Lysosomes: Digestion of waste products.

Body Fluids

• Intracellular Fluid (ICF): Fluid within cells.
• Extracellular Fluid (ECF): Fluid outside cells.