Introduction and TissuesHuman Anatomy

BIOL 1010

Liston Campus

What is Anatomy?Anatomy (= morphology): study of body’s structurePhysiology: study of body’s function

Structure 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 Structural Organization

Each of these build upon one another to make up the next level:Chemical level CellularTissueOrganOrgan systemOrganism

Hierarchy of Structural Organization

Chemical level Atoms combine to make molecules 4 macromolecules in the body

Carbohydrates Lipids Proteins Nucleic acids

Hierarchy of Structural Organization

Cellular Made up of cells and cellular

organelles (molecules) Cells can be eukaryotic or prokaryotic Organelles are structures within cells that

perform dedicated functions (“small organs”)

http://cmweb.pvschools.net/~bbecke/newell/Cells.html

Hierarchy of Structural Organization

Tissue Collection of cells that work together

to perform a specialized function 4 basic types of tissue in the human

body: Epithelium Connective tissue Muscle tissue Nervous tissue

www.emc.maricopa.edu

Hierarchy of Structural Organization

Organ Made up of tissue

Heart Brain Liver Pancreas, etc……

Pg 181

Hierarchy of Structural OrganizationOrgan system (11) Made up of a group of related organs

that work together Integumentary Skeletal Muscular Nervous Endocrine Cardiovascular Lymphatic Respiratory Digestive Urinary Reproductive

Circulatory

Pg 341

Urinary System

Hierarchy of Structural Organization

Organism An individual human, animal, plant,

etc…… Made up all of the organ systems Work together to sustain life

Anatomical Directions

Anatomical 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 Pg 5

Anterior – (ventral)

Closer to the front surface of the body

Posterior – (dorsal)

Closer to the rear surface of the body

Frontal Plane

Medial –

Lying closer to the midline

Lateral –

Lying further away from the midline

Sagittal Plane

Superior – (cranial)

Closer to the head in relation to the entire body

(More General)

Inferior – (caudal)

Away from the head or towards the lower part of the body

Horizontal Plane

Superficial –

Towards the surface

Deep –

Away from the surface

Surface of body or organ

Proximal –

Closer to the origin of a body part

(More Specific)

Distal –

Further away from the origin of a body part

Origin of a structure

Reference Point

4 Types of Tissue

1)Epithelium

2)Connective

3)Muscle

4)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 = control

Most 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

Functions Protection Secretion Absorption Ion Transport

Characteristics of Epithelium

Cellularity Composed of cells

Specialized contacts Joined by cell junctions

Polarity Apical vs. Basal surfaces differ

Supported by connective tissueAvascularInnervatedHighly regenerative

Classification of Epithelium-based on number of layers and cell shape

Layers Simple Stratified

Stratified layers characterized by shape of apical layer

Psuedostratified

Shapes Squamous Cuboidal Columnar Transitional

Types of Epithelium

Simple squamous (1 layer) Lungs, blood vessels, ventral body cavity

Simple cuboidal Kidney tubules, glands

Simple columnar Stomach, intestines

Pseudostratified columnar Respiratory passages (ciliated version)

Stratified squamous (>1 layer) Epidermis, mouth, esophagus, vagina Named so according to apical cell shape Regenerate from below Deep layers cuboidal and columnar

Transitional (not shown) Thins when stretches Hollow urinary organs

All histology pictures property of BIOL 1010 Lab

Special Epithelium

Endothelium Simple squamous epithelium that lines

vessels e.g. lymphatic & blood vessel

Mesothelium Simple squamous epithelium that forms the

lining of body cavities e.g. pleura, pericardium, peritoneum

Features of Apical Surface of EpitheliumMicrovilli: (ex) in small intestine

Finger-like extensions of the plasma membrane of apical epithelial cell

Increase surface area for absorption

Cilia: (ex) respiratory tubes

Whip-like, motile extension of plasma membrane

Moves mucus, etc. over epithelial surface 1-way

Features of Lateral Surface of Epithelium

Cells are connected to neighboring cells via: Contour of cells-wavy contour fits together Cell Junctions (3 common)

Desmosomes Proteins hold cells together to maintain integrity of tissue

Tight Junctions Plasma membrane of adjacent cells fuse, nothing passes

Gap junction Proteins allow small molecules to pass through

Features of the Basal Surface of Epithelium

Basement membrane Sheet between the epithelial and connective

tissue layers Attaches epithelium to connective tissue below Made up of:

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 productProducts are water-based and usually contain proteinsClassified as: Unicellular vs. multicellular Exocrine vs. Endocrine

Page 138

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

Exocrine Glands Secrete substance onto body surface

or into body cavity Activity is local Have ducts Unicellular or Multicellular (ex) goblet cells, salivary, mammary,

pancreas, liver

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

Endocrine 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 Tissue

1)Epithelium

2)Connective

3)Muscle

4)Nervous

4 Types of Connective Tissue

1) Connective Tissue Proper

2) Cartilage3) Bone Tissue4) Blood

Connective Tissue (CT): most abundant and diverse

tissue

Four Classes Functions include connecting, storing & carrying nutrients, protection, fight infection CT contains large amounts of non-living extracellular matrixContains a variety of cells and fibers Some types vascularized All CT originates from mesenchyme Embryonic connective tissue

Fibers in Connective Tissue

Fibers 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

Components of Connective Tissue

Fibroblasts: cells that produce all fibers in CT produce + secrete protein subunits to make them produce ground matrix

Interstitial (Tissue) Fluid derived from blood in CT proper medium for nutrients, waste + oxygen to travel to

cells found in ground matrix

Ground Matrix (substance): part of extra-cellular material that holds and absorbs

interstitial fluid Made and secreted by fibroblasts jelly-like with sugar & protein molecules

1) Connective Tissue Proper Two kinds: Loose CT & Dense CT Functions

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

Each function performed by different kind of fibers and cells in specific tissue

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

Loose CT Proper

Areolar CT All types of fibers present All typical cell types present Surrounds blood vessels and nerves

Specialized Loose CT Proper

Adipose tissue Loaded with adipocytes, highly vascularized,

high metabolic activity Insulates, produces energy, supports Found in hypodermis under skin

Reticular CT Contains only reticular fibers Forms caverns to hold free cells, forms

internal “skeleton” of some organs Found in bone marrow, holds blood cells,

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

Dense regular

Dense irregular

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 cells

Reside in lacunae

More abundant in embryo than adultFirm, FlexibleResists compression

(eg) trachea, meniscus

Avascular (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 fibers 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

Fibroblasts Some have collagen and elastic fibers

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

Well-vascularized Function: 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

Bone TissueOsteoblasts

Secrete organic part of bone matrixOsteocytes

Mature bone cells Sit in lacunae Maintain bone matrix

Osteoclasts Degrade and reabsorb bone

Periosteum External layer of CT that surrounds bone

Outer: Dense irregular CT Inner: Osteoblasts, osteoclasts

Endosteum Internal layer of CT that lines cavities and covers trabeculae Contains osteoblasts and osteoclasts

academic.kellogg.cc.mi.us/.../skeletal.htm

Compact Bone

External layerOsteon (Haversian system)

Parallel to the long axis of the bone Groups of concentric tubules (lamella) Lamella = layer of bone matrix where all fibers run in

the same direction Adjacent lamella fibers run in opposite directions

Haversian Canal runs through center of osteon Contains blood vessels and nerves Connected to each other by perforating (Volkman) canals

Interstitial lamellae fills spaces and forms periphery

www.mc.vanderbilt.edu/.../CartilageandBone03.htm

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 Bone

Diaphysis Medullary Cavity Nutrient Artery & Vein

2 Epiphyses Epiphyseal Plates Epiphyseal Artery & Vein

Periosteum Does not cover epiphyses

Endosteum Covers trabeculae of spongy bone Lines medullary cavity of long bones

training.seer.cancer.gov/.../illu_long_bone.jpg

2 Types of Bone Formation

Intramembranous Ossification Membrane bones: most skull bones and clavicle Osteoblasts in membrane secrete osteoid that

mineralizes

Endochondral Ossification: All other bones Begins with a cartilaginous model Cartilage calcifies Medullary cavity is formed by action of osteoclasts Epiphyses grow and eventually calcify

Epiphyseal plates remain cartilage for up to 20 years

Bone Growth & RemodelingGROWTH 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 & osteoblasts work at the same rate!

Components of Bone Tissue Summarized

Cells Matrix

Osteblasts Gel-like ground substance calcified with inorganic salts

Fibroblasts Collagen fibers

Osteocytes

Osteoclasts

4) Blood: Atypical Connective Tissue

Function: Transports waste, gases, nutrients,

hormones through cardiovascular system Helps regulate body temperature Protects body by fighting infection

Derived from mesenchymeHematopoiesis: production of blood cells Occurs in red bone marrow In adults, axial skeleton, girdles, proximal

epiphyses of humerus and femur

Blood Cells Erythrocytes: (RBC) small, oxygen-transporting

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

Leukocytes: (WBC) complete cells , 5 types

fight against infectious microorganisms

stored in bone marrow for emergencies

*Platelets = Thrombocytes:

fragments of cytoplasm

plug small tears in vessel walls, initiates clotting

Components of Blood Summarized

Cells Matrix

Erythrocytes (red blood cells)

Plasma (liquid matrix)

Leukocytes(white blood cells)

NO fibers

*Platelets(cell fragments)

4 Types of Tissue

1)Epithelium

2)Connective

3)Muscle

4)Nervous

Muscle Tissue

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

academic.kellogg.cc.mi.us/.../muscular.htm

Cardiac Muscle

Cells Branching, chains of cells Single or Binucleated Striations Connected by Intercalated discs

Cardiac Muscle-InvoluntaryMyocardium-heart muscle Pumps blood through vessels

Connective Tissue Component Endomysium: surrounding cells www.answers.co

m

Smooth Muscle Tissue

CellsSingle cells, uninucleateNo striations

Smooth Muscle-Involuntary2 layers-opposite orientation (peristalsis)

Found in hollow organs, blood vesselsConnective Tissue Component

Endomysium: surrounds cells

4 Types of Tissue

1)Epithelium

2)Connective

3)Muscle

4)Nervous

Nervous Tissue

Neurons: specialized nerve cells conduct impulses Cell body, dendrite, axon

Characterized by: No mitosis (cell replication) Longevity High metabolic rate

www.morphonix.com

Nervous Tissue: control

Support cells (= Neuroglial): nourishment, insulation, protection Satellite cells-surround cell bodies within ganglia Schwann cells-surround axons (PNS) Microglia-phagocytes Oligodendrocytes-produce myelin sheaths

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

help circulate CSF

Brain, spinal cord, nerves

Integumentary System

Functions Protection

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

Salts, urea, water Sensory reception

Microanatomy - Layers of the Skin

Epidermis Epithelium

Dermis Connective tissue

Hypodermis / subcutis Loose connective tissue Anchors skin to bone or muscle

Skin Appendages = outgrowths of epidermis Hair follicles Sweat and Sebaceous glands Nails

www.uptodate.com/.../Melanoma_anatomy.jpg

Cell Layers of the Epidermis

Stratum corneum Dead keratinocytes

Stratum lucidum Only in “thick” skin Dead keratinocytes

Stratum granulosum Water proofing

Stratum spinosum Resists tears and tension

Stratum basale Sensory receptors Melanocytes Keratinocytes (in all layers) 15minbeauty.blogspot.com

Layers of the DermisHighly innervatedHighly vascularizedCollagen & Elastic fibers2 layers:

Papillary layer (20%) Areolar CT Collagen & Elastic fibers Innervation Hair follicles

Reticular layer (80%) Dense irregular CT Glands

sebum 2.5 million sweat glands!!

Smooth muscle fibers Innervation

www.uptodate.com/.../Melanoma_anatomy.jpg

Hypodermis

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

Structure of Tubular Organs

LUMENTunica Mucosa

Lamina epithelialis Lamina propria Lamina muscularis mucosa

Tunica SubmucosaTunica Muscularis

Inner circular Outer longitudinal

Tunica Adventitia / Serosa Adventitia – covers organ directly Serosa – suspends organ in the peritoneal cavity