Human Anatomy & Physiology

Mrs. HodgesRoom A204Per 1, 2, 3

Anatomical DirectionsAnatomical position Illustrated at the left

Anatomical Directions-(for the biped) Anterior (ventral) vs. Posterior (dorsal) Medial vs. Lateral Superior (cranial) vs. Inferior (caudal) Superficial vs. Deep Proximal vs. Distal

Anatomical Planes Frontal = Coronal Transverse = Cross Section Sagittal

Cell ConnectionsCells are connected to neighboring cells via: Proteins – adjacent proteins in membranes fuse

to form:Cell Junctions

Tight Junctions - plasma membrane of adjacent cells fuse; impermeable

Desmosomes-adhesive spots on lateral sides

Gap junction-spot-like junction occurring anywhere, lets small molecules pass

Histology

Study of tissuesA tissue is a group of cells

with similar structure and embryonic origin working together to perform a particular function in the body.

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

Four types of tissueA. Epithelial = covering/liningB. Connective = supportC. Muscle = movementD. Nervous = control

Most organs contain all 4 types

A. EPITHELIAL TISSUE: sheets of cells that cover a surface or line a cavity

Functions Protection Secretion Absorption

How are epithelial tissues classified?

Shape Squamous Cuboidal Columnar

Number of Layers Simple: single layer

Stratified: many layers

8 Specific Epithelial Tissues

Simple Simple squamous Simple cuboidal Simple columnar Pseudostratified

8 Specific Epithelial Tissues

Simple Simple squamous Simple cuboidal Simple columnar Pseudostratified

Stratified Stratified squamous Stratified cuboidal Stratified columnar transitional

Can You Identify the Classes of Epithelium?

A B

C

D

E

Quiz!!

Structural Characteristics of EpitheliumCellularity Mostly composed of cell

Specialized Contacts Composed mostly of sheets

Polarity Has one free surface, the other is attached to an underlying

tissue

Avascular No blood vessels

Regenerative Replaces cells with like cells

Basement Membrane Is the foundation

B. CONNECTIVE TISSUE Structural CharacteristicsCells

Fibro- -blast = immature cell that secretes matrix Hemocyto- Chondro- -cyte = mature cell that maintains

matrix Osteo-

Extracellular matrixTissue component that is NOT the cells and is made up of:

ground substance = amorphous substance that fills space between cells and consists of interstitial fluid, proteins and polysaccharides. The more polysaccharides the stiffer the ground substance.

fibers = interspersed throughout the ground substance and provides strength to the matrix.

FIBER TYPESCollagen (aka white) –

Tough stronger than steel fibers of same size provide high tensile strength (resists longitudinal

stress).

Elastic (aka yellow) – Can be stretched to 1.5X its length recoil to original size found where great elasticity is needed

Reticular – Fine collagenous fibers that form a delicate branching

network within solid organs such as spleen and liver.

4 Types of Connective Tissue

1. Connective Tissue Proper

Made by fibroblasts

2. Cartilage Made by chondroblasts

3. Bone Tissue Made by osteoblasts

4. Blood Made by

hemocytoblasts

1) Connective Tissue ProperLOOSE• Areolar• Adipose• Reticular

DENSE• Regular• Irregular• Elastic

2) Cartilage

Chondroblasts produce cartilage tissueMore abundant in embryo than adultFirm, FlexibleResists compression (eg) trachea, meniscus

80% waterAvascular, NOT Innervated (that means no blood, no pain)

Cartilage in the Body

Three types: Hyaline

most abundant support via

flexibility/resilience found at limb joints, ribs, nose very fine collagen fibers

Elastic many elastic fibers in matrix great flexibility Found external ear, epiglottis

Fibrocartilage resists both compression and

tension found in menisci,

intervertebral discs

3) Bone Tissue

Compact• cells contained in spaces called lacuna• fine collagen fibers• ground substance contains minerals

Spongy (Cancellous)• Looks like a sponge• Spaces are filled with red bone marrow

which is hematopoietic tissue

4) BloodFormed by hemocytoblasts in red

bone marrow which is hematopoietic tissue

Functions: Transports waste, gases, nutrients,

hormones through cardiovascular system

Helps regulate body temperature Protects body by fighting infection

Cells erythrocytes leukocytes thrombocytes

Matrix = Plasma

C. MUSCLE TISSUE

Consists of cells that are specialized for generating a contraction.

Cells are elongated and can become shorter and thicker.

Three Types: Skeletal, Cardiac, Smooth

MUSCLE TISSUE FUNCTIONS

Produce movementGenerate heatMaintain postureStabilize joints

Characteristics common to ALL muscle tissue:

1. made of many cells close together2. well vascularized tissue3. elongated cells4. contain myofilaments ( contractile proteins

actin and myosin)

Skeletal Muscle Tissue(each gross skeletal muscle is an organ)

Cells Long and cylindrical, in

bundles Multinucleate Obvious Striations Voluntary

Attached to bones, fascia, skin

pg 235

Cardiac MuscleCells Found only in the heart Branching cells uninucleated Striations Connected by

Intercalated discs

Cardiac Muscle-Involuntary

Be Mine

Smooth Muscle Tissue

CellsSingle cells, uninucleateNo striations

Involuntary2 layers-opposite orientation (circular and longitudinal arrangement)

Found in hollow, muscular organs including blood vessels

D. Nervous Tissue

Neurons: specialized nerve cells Cell body, dendrite, axon

Brain, spinal cord, nerves

“May I please be excused? My brain is full!!”