Human Anatomy(BIOL 1010)

E. Goffeeggoffe@ccri.eduOffice 1132F (Providence)

What is Anatomy?Anatomy (= morphology): study of body’s structurePhysiology: study of body’s functionStructure reflects Function!!! Structure reflects Function!!! Branches of Anatomy Gross: Large structures Surface: Landmarks Histology: Cells and Tissues Developmental: Structures change through life Embryology: Structures form and develop before birth

Hierarchy of the Body Moleculesmade of chemicals (4 macromolecules in body) carbohydrates, lipids, proteins, nucleic acids

Cellsmade of molecules cells and organelles

Tissuemade of cells epithelial, connective, muscular, nervous

Organsmade of tissues made of >1 type of tissue

Systemsmade of organs 11 systems in human body

Organismsmade of systems

Anatomical DirectionsAnatomical positionRegions Axial vs. Appendicular

Anatomical Directions-It’s all Relative! Anterior (ventral) vs. Posterior (dorsal) Medial vs. Lateral Superior (cranial) vs. Inferior (caudal) Superficial vs. Deep Proximal vs. Distal

Anatomical Planes Frontal = Coronal Transverse = Horizontal = Cross Section Sagittal

Embryology: growth and development

of the body before birth38 weeks from conception to birthPrenatal period Embryonic: weeks 1-8 Fetal: weeks 9-38

Basic adult body plan shows by 2nd month Skin = epidermis, dermis Outer body wall=muscle, vertebral column and

spinal cord Body cavity and digestive tubes Kidney and gonads Limbs=skin, muscle, bone

Weeks 5-8 and Fetal Period Second month, tadpole person Tail disappears Head enlarges Extremities form (day 28, limb buds appear) Eyes, nose, ears form Organs in placeFetal Period Rapid growth and maturation Organs grow and increase in complexity

& competence

4 Types of Tissue

1)Epithelium2)Connective3)Muscle4)Nervous

Tissues: groups of cells closely associated that have a similar structure and perform a related function

Four types of tissue Epithelial = covering/lining Connective = support Muscle = movement Nervous = controlMost organs contain all 4 typesTissue has non-living extracellular material between its cells

EPITHELIAL TISSUE: sheets of cells cover a surface or line a cavity (tissue type #1)

Functions Protection Secretion Absorption Ion Transport Slippery Surface

Characteristics of Epithelium

CellularitySpecialized ContactsPolarity Apical vs. Basal

Supported by Connective TissueAvascularInnervatedRegenerative

Classification of Epithelium-based on number of layers and cell shapeLayers Simple Stratified Psuedostratified

Stratified layers characterized by shape of apical layerShapes Squamous Cuboidal Columnar Transitional

Features of Apical Surface of Epithelium

Microvilli: (ex) in small intestine Finger-like extensions of the plasma

membrane of apical epithelial cell Increase surface area for absorptionCilia: (ex) respiratory tubes Whip-like, motile extension of plasma

membrane Moves mucus, etc. over epithelial surface

1-wayFlagella: (ex) spermatoza Extra long cilia Moves cell

Features of Lateral Surface of Epithelium

Cells are connected to neighboring cells via: Proteins-link cells together, interdigitate Contour of cells-wavy contour fits together Cell Junctions

Desmosomes-adhesive spots on lateral sides linked by proteins/filaments, holds tissues together

Tight Junctions-at apical area, plasma membrane of adjacent cells fuse, nothing passes

Gap junction- spot-like junction occurring anywhere made of hollow cylinders of protein, lets small molecules pass

Features of the Basal Surface of Epithelium

Basement membrane = Sheet between the epithelial and connective tissue layers Attaches epithelium to connective tissue below Basal lamina: thin, non-cellular, supportive sheet

Made of proteins Superficial layer Acts as a selective filter Assists epithelial cell regeneration by moving new cells

Reticular fiber layer Deeper layer Support

Glands: epithelial cells that make and secrete a water-based substance w/proteins

Exocrine Glands Secrete substance onto body surface or

into body cavity Have ducts (simple vs. compound) Unicellular (goblet cells) or Multicellular

(tubular, alveolar, tubuloalveolar) (ex) salivary, mammary, pancreas, liver

Glands: epithelial cells that make and secrete a water-based substance w/proteinsEndocrine Glands Secrete product into blood stream Either stored in secretory cells or in follicle

surrounded by secretory cells Hormones travel to target organ to

increase response (excitatory) No ducts (ex) pancreas, adrenal, pituitary, thyroid

4 Types of Connective Tissue

1) Connective Tissue Proper

2) Cartilage3) Bone Tissue4) Blood

Connective Tissue (CT): most abundant and diverse tissue

(tissue type #2)

Four Classes Functions include connecting, storing & carrying nutrients, protection, fight infection CT contains large amounts of non-living extracellular matrix Some types vascularized All CT originates from mesenchyme

1) Connective Tissue Proper

Two kinds: Loose CT & Dense CTPrototype: Loose Areolar Tissue Underneath epithelial tissue Functions

Support and bind to other tissue Hold body fluids Defends against infection Stores nutrients as fat

Each function performed by different kind of fiber in tissue

Fibers in Connective TissueFibers For Support Reticular: form networks for structure &

support (ex) cover capillaries Collagen: strongest, most numerous,

provide tensile strength (ex) dominant fiber in ligaments Elastic: long + thin, stretch and retain shape (ex) dominant fiber in elastic cartilage

In Connective Tissue ProperFibroblasts: cells that produce all fibers in CT, produce + secrete protein subunits to make them, produce ground matrixInterstitial (Tissue) Fluid: derived from blood in CT proper; medium for nutrients, waste + oxygen to travel to cells; found in ground matrixGround Matrix (substance): part of extra-cellular material that holds and absorbs interstitial fluid, jelly-like with sugar & protein molecules

Defense from Infection Areolar tissue below epithelium is body’s first defenseCells travel to CT in blood Macrophages-eat foreign particles Plasma cells-secrete antibodies, mark molecules

for destruction Mast cells-contain chemical mediators for

inflammation response White Blood Cells = neutrophils, lymphocytes,

eosinophils-fight infectionGround substance + cell fibers-slow invading microorganisms

Specialized Loose CT ProperAdipose tissue-loaded with adipocytes, highly vascularized, high metabolic activity Insulates, produces energy, supports

(eg) in hypodermis under skin

Reticular CT-contains only reticular fibers Forms caverns to hold free cells

(eg) bone marrow, holds blood cells Forms internal “skeleton” of some organs

(eg) lymph nodes, spleen

Dense/Fibrous Connective Tissue

Contains more collagen Can resist extremely strong pulling forcesRegular vs. Irregular Regular-fibers run same direction, parallel to pull

(eg) fascia, tendons, ligaments Irregular-fibers thicker, run in different directions

(eg) dermis, fibrous capsules at ends of bones

Components of CT Proper Summarized

Cells Matrix

Fibroblasts Gel-like ground substance

Defense cells-macrophages-white blood cells

Collagen fibersReticular fibersElastic fibers

Adipocytes

2) CartilageChondroblasts produce cartilageChondrocytes mature cartilage cellsMore abundant in embryo than adultFirm, FlexibleResists compression

(eg) trachea, meniscus80% waterAvascular (chondrocytes can function w/low oxygen)NOT InnervatedPerichondrium-dense, irregular connective tissue around cartilage

growth/repair of cartilage resists expansion during compression of cartilage

Cartilage in the Body

Three types: Hyaline

most abundant fibrils in matrix support via flexibility/resilience (eg) at limb joints, ribs, nose

Elastic many elastic fibers in matrix too great flexibility (eg) external ear, epiglottis

Fibrocartilage resists both compression and tension (eg) meniscus, annulus fibrosus

Components of Cartilage Summarized

Cells Matrix

Chondrocytes Gel-like ground substance

Chondroblasts(in growing cartilage)

Lots of water

Some have collagen and elastic fibers

3) Bone Tissue:(a bone is an organ)

Functions: support (eg) pelvic bowl, legs protect (eg) skull, vertebrae mineral storage (eg) calcium,

phosphate (inorganic component) movement (eg) walk, grasp objects blood-cell formation (eg) red bone

marrow

Components of Bone

Matrix Mineralized with hydroxyappetite

Cells Osteoblasts: secrete organic part of bone matrix Osteocytes: mature bone cells, maintain bone matrix

Connective Tissue Proper Periosteum: external layer of CT surrounds bone Endosteum: internal layer of CT lines cavities and covers

trabeculae Both contain osteoblasts and osteoclasts

Bone is well-vascularized, highly innervated

Compact bone: dense, external layerHaversian system = osteon long, cylindrical structures run parallel to long axis of

bone within each osteon, groups of concentric tubes (lamella) Lamella: layer of bone matrix all fibers run in same

direction fibers on each lamella runs in opposite directions to one near it

Haversian canal-runs through center of osteon, contain blood vessels and nerves

Interstitial Lamella- pieces of bone matrix between osteon

Osteocytes between osteons

Bone Anatomy: Compact bone

Spongy bone (cancellous bone): internal layer Trabeculae: small, needle-like pieces of bone

form honeycomb each made of several layers of lamellae + osteocytes no canal for vessels space filled with bone marrow not as dense, no direct stress at bone’s center

Bone Anatomy: Spongy bone

Shapes of BonesFlat = skull, sternum, clavicle

Irregular = pelvis, vertebrae

Short = carpals, patella

Long = femur, phalanges, metacarpals,

humerus

Anatomy of a Long BoneDiaphysis

Medullary Cavity Nutrient Art & Vein

2 Epiphyses Epiphyseal Plates Epiphyseal Art & Vein

Periosteum Outer: Dense irregular CT Inner: Osteoblasts, osteoclasts Does not cover epiphyses Attaches to bone matrix via

collagen fibersEndosteum

Osteoblasts, osteoclasts Covers trabeculae, lines medullary

cavity

2 Types of Bone FormationEndochondral Ossification: All other bones

Begins with a cartilaginous model Perichondrium becomes replaced by periosteum Cartilage calcifies Medullary cavity is formed by action of osteoclasts Epiphyses grow and eventually calcify

Epiphyseal plates remain cartilage for up to 20 years Intramembranous Ossification

Membrane bones: most skull bones and clavicle Osteoblasts in membrane secrete osteoid that mineralizes Trabeculae form between blood vessels, thickens to

become compact bone at periphery Osteocytes maintain new bone tissue Periosteum forms over it

Bone Growth & Remodeling

GROWTH Appositional Growth = widening of bone

Bone tissue added on surface by osteoblasts of periosteum

Medullary cavity maintained by osteoclasts Lengthening of Bone

Epiphyseal plates enlarge by chondroblasts Matrix calcifies (chondrocytes die and disintegrate) Bone tissue replaces cartilage on diaphysis side

REMODELING Due to mechanical stresses on bones, their

tissue needs to be replaced Osteoclasts-take up bone ( = breakdown) release Ca2+

+ , PO4 to body fluids from bone Osteoblasts-form new bone by secreting osteoid

Ideally osteoclasts and osteoblasts work at the same rate!

Components of Bone Tissue Summarized

Cells Matrix

Osteocytes Gel-like ground substance calcified with inorganic salts

Osteoblasts Collagen fibers

4) Blood: Atypical Connective Tissue

Function: Transports waste, gases, nutrients,

hormones through cardiovascular system Helps regulate body temperature Protects body by fighting infectionDerived from mesenchymeHematopoiesis: production of blood cells Occurs in red bone marrow In adults, axial skeleton, girdles, proximal

epiphyses of humerus and femur

Blood CellsErythrocytes: (RBC) small, oxygen-transporting

most abundant in bloodno organelles, filled w/hemoglobinpick up O2 at lungs, transport to rest of body

Platelets = Thrombocytes: fragments of cytoplasmplug small tears in vessel walls, initiates clotting

Leukocytes: (WBC) complete cells , 5 typesfight against infectious microorganisms stored in bone marrow for emergencies

Components of Blood SummarizedCells Matrix

Erythrocytes (red blood cells)

Plasma (liquid matrix)

Leukocytes(white blood cells)

NO fibers

Platelets

Muscle Tissue (tissue type #3)

Muscle cells/fibers Elongated Contain many myofilaments: Actin & Myosin FUNCTION Movement Maintenance of posture Joint Stabilization Heat Generation Three types: Skeletal, Cardiac, Smooth

Skeletal Muscle Tissue(each skeletal muscle is an organ)

Cells Long and cylindrical, in bundles Multinucleate Obvious Striations

Skeletal Muscles-VoluntaryConnective Tissue Components: Endomysium-surrounds fibers Perimysium-surrounds bundles Epimysium-surrounds the muscle

Attached to bones, fascia, skinOrigin & Insertion

Cardiac MuscleCells Branching, chains of cells Single or Binucleated Striations Connected by Intercalated

discsCardiac Muscle-InvoluntaryMyocardium-heart muscle Pumps blood through vessels

Connective Tissue Component Endomysium: surrounding cells

Smooth Muscle Tissue

CellsSingle cells, uninucleateNo striations

Smooth Muscle-Involuntary2 layers-opposite orientation (peristalsis)

Lines hollow organs, blood vesselsConnective Tissue Component

Endomysium: surrounds cells

Nervous TissueNeurons: specialized nerve cells conduct impulses Cell body, dendrite, axon

Interneuron: between motor & sensory neuron in CNSCharacterized by: No mitosis (cell replication) Longevity High metabolic rate

Nervous Tissue: control

Support cells (= Glial): nourishment, insulation, protection Satellite cells-surround cell bodies

within ganglia Schwann cells-surround axons Microglia-phagocytes Oligodendrocytes-produce myelin

sheaths around axons Ependymal cells-line brain/spinal cord,

ciliated,help circulate CSFBrain, spinal cord, nerves

Neuronal Anatomy

Synapse: cell junction where neurons communicateOne direction: presynaptic neuron, postsynaptic neuronPresynaptic neuron

Synaptic vesicles fuses w/presynaptic membrane

Neurotransmitters released, diffuse across synaptic cleft, bind to postsynaptic membrane ٠Creates impulse (action potential) in that neuron

٠Cycle repeats

Integumentary System

Skin Epidermis = epithelium Dermis = connective tissue Hypodermis = connective tissueSkin Appendages = outgrowths of epidermis Hair follicles Sweat and Sebaceous glands Nails

Integumentary System

Functions Protection

Mechanical, thermal, chemical, UV Cushions & insulates deeper organs Prevention of water loss Thermoregulation Excretion

Salts, urea, water Sensory reception

Layers of the Epidermis Stratum corneum

Dead keratinocytes

Stratum lucidumDead keratinocytes

Stratum granulosumKeratinocytesTonofilamentsLamellated & keratohyaline granules

Stratum spinosumKeratinocytesTonofilamentsLangerhans cells

Stratum basaleKeratinocytesMelanocytesMerkel receptors

Dermis Highly innervated

Highly vascularizedCollagen & Elastic fibersMany cell types

FibroblastsMacrophagesMast cellsWhite blood cells

Papillary layer (20%) Areolar CT Hair follicles

Reticular layer (80%) Dense Irregular CT Glands

Sebaceous glands Sweat glands

Smooth muscle fibers

HypodermisAlso called superficial fasciaAreolar & Adipose Connective TissueFunctions Store fat Anchor skin to muscle, etc. Insulation