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Anatomy Class Notes Chapters 1-4

Introduction to Human Anatomy and Physiology

Gross anatomy - seen with the naked eye

Microscopic anatomy - needs a microscope

Physiology - the study of function

  • dictates the structure

Anatomy - the study of structure

  • form will follow function

Levels of Structural Organization

  • Chemical

    • atoms

  • Cellular

    • basic level of life

  • Tissue

    • multiple cells

  • Organ

    • multiple tissues

  • Organ System

    • multiple organs

  • Organism

    • organ systems working together

Organ Systems Examples

  • nervous

  • endocrine

  • integumentary

  • skeletal

  • muscular

  • circulatory

  • lymphatic/immune

  • respiratory

  • digestive

  • urinary

  • reproductive

Characteristics of Life

  • maintaining boundaries - mouth, skin

  • responsiveness - sense and respond to stimuli

  • adaptability - change with the environment

  • growth and reproduction - increase in size and number of organisms

  • movement - intended change in location or position

  • digestion - breakdown of food into simpler structures for absorption into the bloodstream

  • metabolism - chemical reactions of a cell

  • respiration - absorption and use of respiratory gases

  • circulation - fluid movement within the organism

  • excretion - removal of chemical waste

Requirements of Human Life

  • oxygen

  • nutrients

  • temperature range

  • atmospheric pressure

Homeostasis

  • a state of equilibrium or balance within the body

  • vital for survival

  • feedback mechanisms: receptors, control centers, effectors

    • negative - reduce the original stimulus

      • body temperature

    • positive - accelerates a process to competition by intensifying the original stimulus

      • blood clotting

Abdominopelvic Quadrants and Regions

  • Quadrants

    • RUQ

    • LUQ

    • RLQ

    • LLQ

  • Regions

    • right hypochondriac

    • epigastric

    • left hypochondriac

    • right lumbar

    • umbilical

    • left lumbar

    • right iliac

    • hypogastric

    • left iliac

Anatomical Terminology

  • Directional Terms

    • other parts of the body

  • Sectional Terms

    • planes

  • Regional Terms

  • Anatomical Position ****

    • always patient left and right

Body Cavities

  • Dorsal

    • cranial

    • vertebral

  • Ventral

    • thoracic

    • abdominopelvic

Medical Imaging Techniques

  • x-ray - uses electromagnetic radiation to create images of dense body structures

  • computed tomography scan (CT) - combines multiple x-ray images to create detailed cross-sectional views

  • magnetic resonance imaging (MRI) - uses magnetic fields and radio waves to produce detailed images of soft tissues

  • positron emission tomography scan (PET) - uses a short-lived radioactive contrast that will travel to areas with high metabolic activity such as cancer

  • ultrasound - uses high-frequency sounds waves to create real time images of internal structures

The Chemical Level of Organization

Atomic Structure

  • atom

    • smallest unit of an element

  • subatomic particles

    • protons, neutrons, electrons

  • atomic number

    • number of protons

    • identifies the element

    • isotopes = ±neutrons relative to base protons

Electron Behavior

  • electron shells - layers around the nucleus at distinct energy levels

    • first only holds 2 electrons

  • valence shell - outermost shell

    • determines chemical reactivity

  • octet rule - 8 electrons in the valence shell

    • most stable at completion

Ionic Bonds

  • Formation - atoms donate or accept electrons

    • become charged ions (electrolytes)

  • unstable

  • attraction - opposite charges of cations and anions create attraction

  • example - table salt: Na+ and Cl- ions strongly attract

  • positive charge when loses an electron

  • negative charge when accepts an electron

Covalent Bonds

  • Electron sharing - atoms share electrons in valence shell

  • types:

    • polar - equal sharing

    • non-polar - unequal sharing

  • Example:

    • water - polar covalent bonds between oxygen and hydrogen

    • carbon dioxide - non-polar

  • Stable

Hydrogen Bonds

  • weak attraction between polar molecules

  • formation: weakly positive hydrogen attracted to electronegative atom

  • water molecules

Energy in Chemical Reactions

  • Kinetic energy - energy of motion that powers chemical reactions

  • Potential energy - stored energy in chemical bonds

  • Exergonic (Catabolic) Reactions - release more energy than they absorb

  • Endergonic (Anabolic) Reactions - absorb more energy than they release

Types of Chemical Reactions

  • Synthesis - smaller components join to form larger molecules

    • requires energy, anabolic

    • A+B=AB

  • Decomposition - breakdown of larger molecules

    • released stored energy, catabolic

    • AB = A + B

  • Exchange - both synthesis and decomposition occur

    • bond are formed and broken

    • anabolic and catabolic

Factors Influencing Reactions

  • Temperature

    • higher temp = increase reaction rate from increased particle motion

  • Concentration

    • higher concentration of reactant increases collision frequency

  • Enzymes

    • catalysts that lower activation energy and speed up reactions

Water: The Universal Solvent

Makes up 70% of an adults body weight

  • Lubricant - joints and aids digestion

  • Cushion - protects organs from physical trauma

  • Heat sink - water absorbs heat without greatly increasing in temperature

Salts: Ionic Compounds

Salts dissociate into ions in water, crucial for nerve impulses and muscle contraction

  • NaCl = table salt

  • CaHCO3 = Calcium Carbonate (Tums)

Acids and Bases: pH Regulators

Acids release hydrogen ions (H+) in solution

Bases release hydroxyl ions (OH-) or accept H+

  • <7 acids

  • 7 neutral

  • >7 bases or alkaline

p - partiality

The Chemistry of Carbon

  • Carbon - four electrons in valence shell

  • Covalent Bonds - shared electrons between atoms

  • Functional Groups - atoms that function as a unit

Carbohydrates

  • Monosaccharides

    • single sugar units like glucose, fructose, and galactose

  • Disaccharides

    • pairs of monosaccharides like sucrose, lactose, and maltose

  • Polysaccharides

    • long chains of monosaccharides like starch, glycogen, and cellulose

Lipids

hydrophobic compounds made of mostly hydrocarbons

provide energy, cell membrane structure, and signaling molecules

  • triglycerides

    • major fuel source, composed of glycerol and fatty acids

  • phospholipids

    • cell membrane components with hydrophobic tails and hydrophilic hairs

  • steroids

    • four-ring structures like cholesterol, important for hormones

  • Prostaglandins

    • signaling molecules derived from unsaturated fatty acids

Amino Acids

  • structure

    • have a central carbon atom bonded to a hydrogen, an amino group, a carboxyl group, and a variable side chain

  • bond

    • amino acids join via dehydration synthesis to form peptide bonds, creating polypeptides and proteins

  • essential amino acids

    • nine essential

    • cannot be synthesized by the body and must be consumed in the diet

Protein Structure and Shape

  • primary structure

    • the sequence of amino acids in the polypeptide chain

  • secondary structure

    • folding patterns like alpha-helices and beta-pleated sheets, maintained by hydrogen bonds

  • tertiary structure

    • three-dimensional shape formed by further folding and bonding of a secondary structure

  • quaternary structure

    • interactions between two or more tertiary subunits, as in hemoglobin

Protein Functions in the Body

  • structural support

    • collagen

  • enzymes

    • catalyze chemical reactions

  • hormones

    • chemical messengers to regulated body functions

  • transport

    • substances across cell membranes and through the bloodstream

Nucleic Acids: DNA and RNA

DNA

  • contains deoxyribose sugar

    • missing an oxygen

  • forms a double helix structure

  • stores genetic information

  • bases: adenine, cytosine, guanine, and thymine

RNA

  • contains ribose sugar

  • single-stranded

  • helps manifest genetic code as protein (translation)

  • bases: adenine, cytosine, guanine, and uracil

Adenosine Triphosphate (ATP)

  • structure: composed of ribose sugar, adenine base, and three phosphate groups

  • function: high energy compound that fuels body activities

  • energy release: hydrolysis of ATP produces ADP and inorganic phosphate, releasing energy

The Cellular Level of Organization

Cell Membrane Structure:

  • phospholipid bilayer - selectively permeable barrier made of phospholipids

  • membrane proteins - integral and peripheral proteins embedded in membrane

    • cholesterol gives fluidity

Passive Transport:

Simple Diffusion - small non-polar molecules move down concentration gradient

  • molecules have no charge

Facilitated Diffusion - carrier proteins help move larger molecules

Osmosis - water diffuses through a semipermeable membrane

Active Transport:

  • Sodium-Potassium Pump - uses ATP to move ions against concentration gradient

    • always a high concentration of sodium outside the cell (at rest)

    • always a high concentration of potassium in the cell (at rest)

    • always pushing 3 sodium out and 2 potassium in

  • Endocytosis - cell engulfs material by forming vesicles

  • Exocytosis - cell releases material by fusing vesicles with membrane

Cytoplasm and Organelles:

  • Cytoplasm - cytosol and organelles inside of cell

    • cytosol

  • Endoplasmic reticulum - network of membranes for protein and lipid synthesis

    • rough - proteins

    • smooth - storage, create lipids

  • Golgi Apparatus - modifies, packages, and distributes cellular products

    • Golgi prime

    • cis - enter

    • trans - exit

  • Mitochondria - powerhouses of the cell, produce ATP through respiration

  • Peroxisomes - break down fatty acids and detoxify harmful substances

    • crystalline core - peroxide

  • Lysosomes - contains enzymes for breaking down cellular materials

    • pre-programmed cell death

  • Cytoskeleton - all structural components, cells would have no structure without them

    • microtubules - provide structure and assist in cell division

    • intermediate filaments - provide tensile strength to cells

    • microfilaments - actin filaments involved in cell movement and division

  • Nucleus

    • nuclear envelope - double membrane with pores surrounding genetic material

    • chromatin - DNA and proteins that make up chromosomes

      • spaghetti

    • nucleolus - site of ribosome production

DNA Structure:

  • double helix - two complementary strands of nucleotides

  • base pairs - adenine pairs with thymine, cytosine with guanine

    • at&t

    • cgi

  • who discovered DNA (bonus question)

DNA Replication:

  • initiation - DNA strands separate at origin of replication

    • helicase - unzips the DNA strand

  • elongation - new complementary strands synthesized by DNA polymerase

  • termination - replication complete, yielding two identical DNA molecules

Transcription:

  • initiation - RNA polymerase binds to DNA promoter region

  • elongation - RNA strand synthesized complementary to DNA template

  • termination - RNA polymerase reachers terminator sequence and detaches

Translation:

  • initiation - ribosome assembles on mRNA start codon

  • elongation - amino acids added to growing polypeptide chain

  • termination - ribosome reaches stop codon, polypeptide released

Cell Cycles:

  • G1 phase - cell growth and normal metabolic roles

  • S phase - dna replication occurs

  • G2 phase - cell prepares for division

    • protein synthesis

  • M phase - mitosis and cytokinesis

Mitosis:

  • prophase - chromosomes condense, nuclear envelope breaks down

  • metaphase - chromosomes align at cell equator

  • anaphase - sister chromatids separate to opposite poles

  • telophase - nuclear envelopes reform, chromosomes decondense

  • cytokinesis - cleavage furrow pinches cell in two

Cancer and the Cell Cycle:

  • uncontrolled cell division

    • cells divide excessively and invade other tissues

  • mutations

    • changes in genes controlling cell cycle regulation

  • loss of contact inhibition

    • cancer cells continue dividing when touching other cells

Stem Cells:

  • totipotent - can form all cell types

  • pluripotent - can form most cell types

  • multipotent - can form multiple cell types

  • unipotent - can form only one cell types

Cell Differentiation:

  • gene regulation - selective gene expression determine cell specialization

  • transcription factors - proteins that control which genes are expressed

  • epigenetic changes - modifications to DNA that affect gene expression

The Tissue Level of Organization

Introduction to Tissues:

  • cell types - at least 200 distinct cell types in body

  • organization - cells occur in organized layers called tissues

  • development - single fertilized egg gives rise to trillions of cells

Types of Tissues:

  • epithelial - covers surfaces, lines cavities, forms glands

  • connective - binds, supports, protects body parts

  • muscle - contracts to provide movement

  • nervous - transmits electrical signals

Tissue Membrane:

  • thin layers of cells covering surfaces

  • functions - protection, secretion, absorption

  • types - connective tissue and epithelial membranes

Connective Tissue Membranes:

  • composition

    • connective tissue

  • location

    • encapsulate organs

    • line movable joints

  • example

    • synovial joints

  • function

    • produce lubricating synovial fluid

Epithelial Membranes:

  • composition

    • epithelium attached to connective tissue

  • types

    • mucous, serous, cutaneous

  • functions

    • line cavities, protect, secrete

Epithelial Tissue Functions

  • protection

    • first line of defense against wear and tear

  • absorption

    • selective transfer of materials across barrier

  • secretion

    • release mucus and chemical compounds

  • sensation

    • contain sensory nerve endings

The Epithelial Cell

  • polarity

    • organelles distributed between basal and apical surfaces

  • specializations

    • microvilli, cilia on apical surface

  • function

    • adapted for protection, absorption, secretion

Cell-to-Cell Junctions:

  • tight junctions - form seal between adjacent cells

  • anchoring junctions - mechanically attach cells

    • desmosomes - side walls

    • hemidesomosomes - basal side to basement layer

  • gap junction - allow passage of materials between cells

Types of Epithelial Cells and Examples

  • simple squamous

    • lung

  • stratified squamous

    • esophagus

  • simple cuboidal

    • kidney

  • stratified cuboidal

    • sweat gland

  • simpler columnar

    • stomach

  • stratified columnar

    • salivary duct

  • pseudo-stratified columnar

    • trachea

  • transitional

    • bladder

Glandular epithelium:

  • endocrine - ductless glands secreting hormones into blood

  • exocrine - glands with cuts secreting substances externally

    • ducts can be tubular, bulbar, or combination

Connective Tissue Functions:

  • support - provides structural framework for body

  • protection - cushions and insulates organs

  • integration - binds organs and tissues together

  • storage — stores energy in form of fat

Connective Tissue Proper:

  • diverse group of tissues that connect, support, and protect other tissues and organs

  • composed of cells, fibers, and a ground substance

    • ground substance - a gel-like material that fills the spaces between cells and fibers

      • a medium for the exchange of nutrients and wastes

Cells of Connective Tissue Proper:

  • fibroblasts - produces the extracellular matrix, the structural framework of connective tissue

  • macrophages - cells that engulf and digest debris, pathogens, and foreign materials

  • mast cells - release histamine, causing inflammation and allergic reactions

  • adipocytes - fat cells store energy, insulate, and cushion organs

Fibers of Connective Tissue Proper:

  • provide strength, elasticity, and support

  • collagen - strong and flexible, providing tensile strength

  • elastic - stretchy and allow tissues to return to their original shape

  • reticular - thin and branching, forming delicate networks that support other tissues

Types of Connective Tissue:

  • loose - flexible, with space between fibers

    • adipose, areolar, reticular

  • dense - tightly packed fibers

    • tendons, ligaments

  • specialized - unique properties

    • cartilage, bone, fluid

Loose Connective Tissue:

  • areolar connective tissue - areolar tissue is a flexible, web-like tissue with a variety of cell types

  • adipose connective tissue - consists mainly of adipocytes, which store energy as fat

  • reticular connective tissue - forms a framework for organs like the spleen and lymph nodes

Dense Connective Tissue:

  • Dense regular - tightly packed, parallel collagen fibers, providing high tensile strength

    • tendons

    • ligaments

  • dense irregular - collagen fibers arranged in a more irregular pattern, provide strength in multiple directions

    • dermis of skin

    • capsules surround organs

  • elastic - more elastic fibers than collagen fibers, allowing it to stretch and recoil

    • walls of blood vessels

    • lungs

Cartilage Connective Tissue:

  • hyaline cartilage - most common, reduces friction in joints and provides support

    • joints

    • trachea

  • elastic cartilage - more flexible than hyaline cartilage due to elastic fibers

    • ear

    • nose

  • fibrocartilage - strongest type with a high density of collagen fibers

    • intervertebral discs

    • menisci

Specialized Connective Tissue:

  • bone tissue - provides support, protection, and movement

    • specialized cells produce a hard, mineralized matrix

  • blood and lymph - fluid connective tissues that transport gases, nutrients, and waste products throughout the body

Muscle Tissue:

  • skeletal - striated, voluntary

    • body movement

  • cardiac - striated, involuntary

    • heart contraction

  • smooth - non-striated, involuntary

    • organ movement

Nervous Tissue:

  • neurons - conduct electrical signals

  • glial cells - support and protect neurons

  • function - information processing and response

Tissue Aging:

  • skin changes

    • thinner, less elastic, wrinkles form

  • muscle loss

    • decreased mass and strength

  • bone weakening

    • lower mineral density, increased fracture risk

  • slower healing

    • reduced capacity for tissue repair