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Anatomy-Physiology•Anatomy – “ana” (apart) “tomy” (to cut),

study of the structure and shape of the body and body parts and their relationships to one another.

•Physiology – “physio” (nature) “ology” (the study of)

study of how the body and its parts work or function.

THE CELL

Monina C. Montenegro, MD, DPSP

Antoni van Leeuwenhoek

• (1632-1723), Dutch, maker of first single lens microscope

• The first to document the structure of RBC & the nature of the circulatory system

• protozoans & bacteria, life cycles of many species of insects.

Micrometer = (µm) metric unit = 1/1000

Types of microscopes1. Compound or light microscopes

Principle: light source -- sunlight

Magnification = extent to which an image is enlarged

2. Electron microscopePrinciple: beam of electrons a. Transmission (magnification: 1Mx or greater)b. Scanning (3 – D image <250,000x)

Image under Compound microscope

Scanning EMTransmission EM

Ant Tissue Paper

Pollen Blood Cells

CELL

•Robert Hooke (1665) = study the cork & other plant materials many small partitions separatingcavities cells.

•Building block of all living things

•Carry out all chemical activities needed to sustain life

• carbon, oxygen, hydrogen, nitrogen• Iron, Na, K

3 Main Regions

1. Nucleus

•“headquarters” “control center”

•DNA ▫Genetic blueprint▫Building proteins▫Cell reproduction

3 Distinct Regions

•Nuclear envelope/membrane – encloses the nucleoplasm

•Nucleoli – 1 or more round bodies, where ribosomes are assembled

•Chromatin – DNA + protein (nondividing)▫Chromosome (dividing)

2. Plasma Membranesyn: plasma membrane, plasmalemma, cell

membrane- outer covering of the cell- surround each cell separate its

contents from external environment- composed of a bilipid layer

(proteins & carbohydrates float)- regulates what enters & leaves

the cell

Cell Membrane

rane

Plant cell

Membrane Junctions

1. Tight junction= formed from fusion of adjacent cell membrane= keep digestive juices & harmful substances from damaging the organs

2. Desmosomes= an area of contact between two adjacent cells= cell membrane thickened & fine fibers (tonofibrils) extend from the desmosome into the cytoplasm

e.g. skin

3. Gap junction= allow all materials to pass between cells

e.g. nervous system

3. Cytoplasm•semifluid, “factory area”

•3 Major Elements ▫Cytosol – semitransparent, largely water▫Organelles – “little organs”, specialized

compartments, specific functions▫Inclusions – nonfunctioning, stored nutrients or

cell products (pigment, mucus, fat, crystals, etc.)

1. Mitochondria•Tiny, threadlike

(mitos) or•Sausage-shaped•“powerhouse”

- ATP

2. Ribosomes•Tiny, round, dark

bodies•Proteins +

ribosomal RNA (rRNA)

•Actual site of protein production

3. Endoplasmic Reticulum (ER)• “network within the

cell”• Fluid-filled tubules or canals• Minicirculatory system• 2 Types

▫ Rough ER – w/ ribosomes, protein synthesis

▫ Smooth ER – cholesterol synthesis/breakdown, fat metabolism, drug detoxification

4. Golgi Apparatus•Stack of flattened membranous sacs

•Modify and package proteins

5. Lysosomes•“breakdown bodies”

•digestive enzymes

•demolition sites

▫WBC’s

6. Peroxisomes•Sacs containing oxidase

enzymes•Use oxygen to detoxify

harmful or poisonous substances (e.g. alcohol, formaldehyde)

•Disarm “free radicals”▫FR → H2O2→H2O▫ liver and kidney cells

7. Cytoskeleton•cell’s “bones and muscles”•cell shape•supports other organelles•intracellular transport•cellular movements

3 Types1. Microtubules -

cell shape, cell division

2. Intermediate filaments

3. Microfilaments

8. Centriole•Rod-shaped bodies•Direct the formation of mitotic spindle

1.Cilia – “eyelashes”, hair-like e.g. cells lining the respiratory system

2.Flagella – e.g. sperm

Cell Life Cycle•2 Major Periods1.Interphase – “metabolic phase”, cell

growth, longer phase, resting from division

- genetic material (DNA) - duplicated

2.Cell division – reproduces itself

DNA Replication

•DNA – building blocks “nucleotides”

▫Deoxyribose sugar▫Phosphate group ▫Nitrogen-containing

base

DNA Replication

2 Events of Cell Division

1. Mitosis – division of the nucleus

2 daughter nuclei

2. Cytokinesis – division of the cytoplasm

MitosisSTAGES:

• PROPHASE = chromatin coil and shorten chromosomes, barlike bodies

▫ Chromosome = 2 strands of chromatids, held together by a buttonlike body, centromere

MitosisSTAGES:• METAPHASE – chromosomes cluster and align at the center

MitosisSTAGES:• ANAPHASE – movement of chromosomes toward opposite ends of the cell

MitosisSTAGES:• TELOPHASE – chromosomes uncoil and become chromatin again, nuclear envelope forms around each chromatin mass

Cell Division

CELL PHYSIOLOGY

• Definition of terms:▫ Solution – homogenous mixture of 2 or more

components (e.g. air, seawater, alcohol)

▫ Solvent – (dissolving medium) substance present in the largest amount in a solution

▫ Solutes – components or substances present in smaller amounts

MOVEMENT of SUBSTANCES MOVEMENT of SUBSTANCES ACROSS CELL MEMBRANEACROSS CELL MEMBRANE

Definition of Terms:

•Intracellular fluid – (nucleoplasm and cytosol) ▫solution containing gases (O2, CO2),

nutrients and salts dissolved in H2O. •Interstitial fluid – fluid that bathes the

exterior of cells▫nutrients (amino acids, sugars, fatty acids,

vitamins), hormones, neurotransmitters, salts and waste products.

Definition of Terms:•Selective permeability – allows some

substances to pass through it while excluding others

•Passive transport – substances are transported across the membrane w/o energy input from the cell

•Active transport – use of ATP to drive the transport process

Passive Transport Processes

1. Diffusion – movement of molecules or ionsfrom a region of higher to lower concentration (concentration gradient).

Size of the molecules Temperature

Diffusion

Simple Diffusion

MOVEMENT of SUBSTANCES ACROSS CELL MEMBRANE

PHYSICAL PROCESSESPASSIVE PROCESS

2. Osmosis = movement of water from a lower to higher concentration

through a semi-permeable membrane

Osmosis

MOVEMENT of SUBSTANCES ACROSS CELL MEMBRANEPHYSICAL PROCESSES

PASSIVE PROCESS3. Facilitated diffusi0n = protein carrier

is needed as a transport vehicle (e.g. glucose)

MOVEMENT of SUBSTANCES ACROSS CELL MEMBRANE

PHYSICAL PROCESSESPASSIVE PROCESS

4. Filtration = process by w/c H2O and solutes are forced through a membrane (or capillary wall) by fluid or hydrostatic pressure (pressure gradient)

e.g. filtering capacity of the kidney

Active Transport Processes

1. ACTIVE TRANSPORT - “solute pumping”

- when a cell requires protein carriers that use ATP to move substances across the membrane

- move against concentration or electrical gradients

Active Transport

MOVEMENT of SUBSTANCES ACROSS CELL MEMBRANE

PHYSICAL PROCESSESREQUIRE CELL ENERGY2. BULK TRANSPORT

a) EXOCYTOSIS – “out of the cell”e.g. hormones, mucus,

wastes

Exocytosis

MOVEMENT of SUBSTANCES ACROSS CELL MEMBRANE

PHYSICAL PROCESSESREQUIRE CELL ENERGY

2. ENDOCYTOSIS – “into the cell”

Phagocytosis – “cell eating”, bacteria or dead body cells

MOVEMENT of SUBSTANCES ACROSS CELL MEMBRANEPHYSICAL

PROCESSESREQUIRE CELL ENERGY

3.PINOCYTOSIS - “cell drinking”

- bulk-phase endocytosis

- droplet or extracellular fluid containing dissolved proteins or fats- e.g. intestinal lining, kidney tubules

Table. 3.2

EFFECT of OSMOSIS in CELLS

ISOTONIC = same concentration as cell fluid = tissue fluids; blood plasma

0.9% NSS; 5% dextrose (glucose)

HYPOTONIC = lower concentration than cell fluid = cell swells

HYPERTONIC = higher concentration than cell fluid

= cell shrinks

Effects of osmosis

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