Anatomy and Physiology Defined

Anatomy

• Concerned with bodily structure of humans and animals

• Involves studying body parts, their structure, shape, and relationships

• Types of Anatomy: Systemic (by systems), Regional (by areas), Surface (external features)

Physiology

• Deals with normal functions of living organisms and their parts

• Focuses on processes and functions of living things

• Major Goals: Understand body's responses to stimuli, maintain conditions within a narrow range

Structural and Functional Organization

Levels of Structural Organization (CCTOOO)

• Chemical level involves interactions among atoms and molecules

• Cells are basic units, with organelles made up of molecules

• Tissues are groups of similar cells with specific functions

• Four primary tissue types: Epithelial, Connective, Muscle, Nervous

• Organs composed of multiple tissue types performing common functions

• Organ Systems are groups of organs with related functions

• Organism is a living thing composed of organ systems

Organ Systems of the Human Body

1. Skeletal System

2. Muscular System

3. Respiratory System

4. Digestive System

5. Nervous System

6. Endocrine System

7. Cardiovascular System

8. Lymphatic System

9. Integumentary System

10. Urinary System

11. Reproductive System

Characteristics of Life/Living Organism (OMRGRD)

Key Characteristics

• Organization: Parts interact to perform specific functions

• Metabolism: Ability to use energy for vital functions

• Responsiveness: Ability to sense and adjust to environmental changes

• Growth: Increase in size of organism or its parts

• Reproduction: Formation of new cells or organisms

• Development: Changes an organism undergoes over time

Homeostasis (BALANCE)

Definition and Importance

• Maintenance of a constant internal environment

• Self-regulating process for survival

• Diseases disrupt homeostasis and can lead to death

Feedback Mechanisms

Negative Feedback Mechanism (HOMEOSTATIC)

• Regulates body systems to maintain homeostasis

• Components: Receptor, Control Center, Effector

Positive Feedback Mechanism (NOT HOMEOSTATIC)

• Amplifies deviations from normal values

• Can lead away from homeostasis and sometimes result in death

Terminology and Body Plan

Body Positions

• Anatomic position: Standing erect, face forward, palms facing forward

• Supine position: Lying face upward

• Prone position: Lying face downward

Directional Terms

• Describe body parts relative to each other

• DIRECTIONAL TERMS FOR HUMAN

Right= towards the body’s right side

Left= towards the body’s left side

Inferior= below

Superior= above

Anterior= towards the front of body

Posterior= towards the back of body

Dorsal= back

Ventral= front

Proximal= Closer to a point of attachment

Distal= farther form a point of attachment

Lateral= away from midline

Medial=towards midline

Superficial= towards or on the surface

Deep= away form the muscle, internal

Body Parts and Regions

• Identify and describe different body parts and regions

Planes

• Sagittal, Median, Transverse, Frontal planes divide the body for observation

• Longitudinal, Transverse, Oblique sections provide different views of organs

• PLANES

Sagittal= vertically divides left and right

Median= divides body left and right equally

Frontal/Coronal= divides front and back

Transverse= divide top and bottom

Longitudinal section= Long axis at organ

Cross section= cut right angle- 90 degrees

Oblique= anything other than 90 degrees

• Body Cavities: Thoracic, Abdominal, Pelvic cavities protect internal organs

Serous Membranes (covering-organs)

• Cover and line trunk cavities and organs

• Function to reduce friction between organs

• Thoracic cavity contains 3 serous membrane-lined cavities

Serous Membranes and Body Cavities

Serous Membranes in Thoracic Cavity

• The thoracic cavity contains 3 serous membrane-lined cavities:

• Pericardial Membrane (HEART): Surrounds the heart, with the visceral pericardium covering the heart within a connective tissue sac lined by the parietal pericardium. It contains pericardial fluid.

• Pleural Membrane (LUNGS): Surrounds each lung, covered by visceral pleura, while the parietal pleura lines the thoracic wall, mediastinum, and diaphragm. It contains pleural fluid.

• Abdominopelvic Membrane (PERITONEUM-STOMACH…): Contains the peritoneal cavity lined by serous membranes.

• Visceral Peritoneum (IN) covers organs, while Parietal Peritoneum (OUT) lines the cavity wall and diaphragm. The Peritoneal Cavity contains Peritoneal Fluid.

Mesenteries and Retroperitoneal Organs

• Mesenteries anchor intraperitoneal organs to the body wall and provide pathways for nerves and blood vessels.

• Retroperitoneal Organs are closely attached to the body wall and lack mesenteries. Examples include kidneys, adrenal glands, pancreas, parts of the intestines, and the urinary bladder.

Cell Structures and Functions

The Cell and Modern Cell Theory

• A cell is the smallest unit of life responsible for all life processes and is the basic living unit of organisms.

• Cells replicate independently and are considered the building blocks of life.

• The Modern Cell Theory states that all living things are made up of cells, cells come from pre-existing cells, and organisms can be unicellular or multicellular.

Major Groups of Cells

• Prokaryotes lack a nucleus and membrane-bound organelles, while Eukaryotes have both.

• Both groups have DNA, cytoplasm, ribosomes, and a cell membrane, but only eukaryotes have a nucleus and membrane-bound organelles.

Eukaryotic Cell Structure

• Cell/Plasma Membrane: Encloses cytoplasm.

• Cytoplasm: Contains organelles and cytosol.

• Organelles: Specialized structures within cells for specific functions.

• Nucleus: Contains genetic material.

Cell Membrane and Cytoplasm

• The Cell Membrane encloses the cytoplasm, serving as a boundary for extracellular and intracellular substances.

• It is composed of phospholipids, proteins, cholesterol, carbohydrates, water, and ions.

• Movement Through Cell Membrane occurs via direct diffusion, membrane channels, carrier molecules, and vesicles.

• Cytoplasm is the cellular material outside the nucleus, consisting of cytosol, cytoskeleton, and cytoplasmic inclusions.

Organelles in Cytoplasm

• Ribosomes produce proteins and can be free or attached to the endoplasmic reticulum.

• Endoplasmic Reticulum includes rough ER for protein synthesis and smooth ER for lipid synthesis and detoxification.

• Golgi Apparatus modifies, packages, and distributes proteins and lipids.

• Secretory Vesicles transport materials within cells, originating from the Golgi Apparatus.

• Lysosomes (DIGESTS ANYTHING) and Peroxisomes (SELECTIVE DIGESTION) are membrane-bound vesicles with digestive enzymes and detoxification functions.

Mitochondria and Cytoskeleton

• Mitochondria are sites of ATP production, with more in cells with higher energy requirements.

• Cytoskeleton consists of proteins supporting the cell, holding organelles in place, and enabling shape changes.

• It includes Microtubules for support and cell division, Microfilaments for structural support and movement, and Intermediate Filaments for mechanical support.

Centrioles and Cell Structure

Centrioles

• Small, cylindrical structures composed of nine triplets of microtubules.

• Play a crucial role in cell division by facilitating the movement of chromosomes.

• Found in the centrosome, which is a specialized zone of cytoplasm near the nucleus.

• Each centrosome typically contains two centrioles oriented perpendicular to each other.

Cilia

• Project from the cell surface and are capable of movement.

• Vary in number, ranging from 1 to thousands per cell.

• Composed of specialized microtubules and enclosed by the cell membrane.

• Example: Surface cells lining the respiratory tract.

Flagella and Microvilli

• Flagella are longer structures similar in composition to cilia, usually occurring singly per cell (e.g., sperm cells).

• Microvilli are extensions of the cell membrane supported by microfilaments, increasing the cell's surface area.

• Microvilli do not exhibit active movement like cilia and flagella.

• Example: Microvilli are numerous on cells lining the intestine and kidney, enhancing absorption.

Nucleus and Protein Synthesis

Nucleus

• Largest organelle in the cell, usually located near the center.

• Contains genetic material in the form of DNA organized into chromosomes.

• Nucleus is surrounded by a nuclear envelope with pores for material exchange.

• Nucleoplasm is a gel-like substance where nuclear structures like chromatin and nucleolus are suspended.

Nucleoli

• Rounded, dense nuclear bodies without a surrounding membrane, typically 1-4 per nucleus.

• Site where ribosomal subunits are formed, involving ribosomal ribonucleic acid (rRNA).

Protein Synthesis

• Process involving amino acid synthesis, transcription, translation, and post-translational events.

• DNA, found mainly in the nucleus, serves as the template for protein synthesis.

• Chromosomes contain DNA and associated proteins, organizing genetic material.

• Example: Osteoclasts and skeletal muscle cells may contain multiple nuclei.

Movement Through Cell Membrane

Plasma Membrane Permeability

• Plasma membranes selectively allow substances to pass in and out of cells.

• Intracellular and extracellular fluids have different compositions crucial for cell survival.

• Intracellular substances include enzymes, glycogen, and potassium, while extracellular substances include sodium, calcium, and chlorine.

Cell Membrane Transport

• Cells maintain proper ion and molecule concentrations through membrane permeability and transport processes.

• Disruption of membrane integrity or transport mechanisms can lead to cell death.

• Ions and molecules move across membranes via diffusion, osmosis, filtration, mediated transport, and vesicular transport.

Diffusion

• Process where ions and molecules move from areas of high concentration to low concentration.

• Lipid-soluble molecules like oxygen and carbon dioxide readily diffuse through the phospholipid bilayer.

• Terms to understand diffusion include solutions, solutes, and equilibrium.

Osmosis

• Movement of water across a selectively permeable membrane from high to low water concentration.

• Selectively permeable membranes allow water but not all solutes to pass through.

• Osmotic pressure, hydrostatic pressure, and tonicity are crucial concepts in understanding osmosis.

Cell Membrane Transport

Hypotonic, Isotonic, and Hypertonic Solutions

• Isotonic Solution: Retains water content to normal water volume. (UNCHANGED)

• Hypotonic Solution: Has low solute concentration and high water concentration compared to body fluids, leading to water moving into the body. (BURSTING)

• Hypertonic Solution: Has high solute concentration and low water concentration compared to body fluids, causing water to move out of the body. (SHRINKING)

• Cell Response: Cells can swell, remain unchanged, or shrink based on the type of solution.

Movement Through Cell Membrane

• Filtration: Involves the movement of fluid through a partition with small holes, allowing small substances to pass through.

• Mediated Transport Mechanisms: Transport proteins assist in moving non-lipid-soluble molecules and ions across the plasma membrane.

• Characteristics of Mediated Transport: Specificity, competition, and saturation affect the rate and selectivity of substance movement.

• Types of Transport Proteins: Channel proteins, carrier proteins (facilitated diffusion), and ATP-powered pumps (active transport).

Three Types of Transport Protein

• Channel Protein: Simple tubes; specific with who enters.

• Carrier Protein: Transporters; change shape; carry

• ATP Powered Pump: Needs energy to work; like pumps-out

Facilitated Diffusion and Active Transport

• Facilitated Diffusion: Moves substances from higher to lower concentration without requiring ATP.

• Active Transport: Moves substances against the concentration gradient, requiring ATP for energy.

• Examples: Sodium-potassium pump is a vital active transport mechanism.

Secondary Active Transport and Vesicular Transport

• Secondary Active Transport: Involves establishing a concentration gradient to transport substances using energy from diffusion.

• Vesicular Transport: Involves the movement of materials by vesicles into, out of, or within cells.

• Endocytosis: Uptake of materials through vesicle formation; includes phagocytosis and pinocytosis.

• Exocytosis: Release of materials from the cell via secretory vesicles.

Cell Division: Mitosis vs. Meiosis

General Overview

• Purpose: Both processes, along with cytokinesis, are involved in creating new cells.

• Mitosis: Results in body cells, maintaining the same chromosome number.

• Meiosis: Results in gametes (sperm and egg cells) with half the chromosome number.

Chromosome Distribution

• Human Chromosomes: Two sets of 23 chromosomes each, totaling 46 chromosomes.

• Stages: Both mitosis and meiosis go through PMAT stages, but meiosis repeats them.

• Cytokinesis: Follows to complete cell division by splitting the cytoplasm.

Outcome of Mitosis and Meiosis

• Mitosis Result: Two identical diploid cells with 46 chromosomes each, crucial for growth and cell replacement.

• Meiosis Result: Four non-identical haploid gametes with 23 chromosomes each, essential for sexual reproduction.

• Fertilization: Combination of sperm and egg cells forms a diploid zygote, initiating a new organism's development.