Introduction to anatomy power point presentation.

1. INTRODUCTION TO HUMAN
ANATOMY
HUMAN ANATOMY
MR. F.C. UDEH
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2. INTRODUCTION
ANATOMY AND ITS BRANCHES
• Anatomy: ‘anatome’ – to cut up: study of body structure (size,
shape, composition, colour)
• Branches: Gross Anatomy, Developmental Anatomy
(Embryology), Microscopic Anatomy (Cytology, Histology),
Gerontology, Comparative Anatomy, Pathological Anatomy
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3. BRIEF HISTORY OF ANATOMY
• EGYPTIAN: mummification of the royalty and wealthy, way before 3400 B.C.
• CHINESE: great herbalists; acupuncture; JAPANESE.
• GREEKS: Hippocrates (460-377 B.C.) - father of medicine; Herophilus (325-255 B.C.) -
a great teacher of anatomy in Alexandria; the first physician to prosect; Erasistratus
(about 300B.C.) sometimes called the father of physiology
• ROMANS: Cornelius Celsus (30 B.C.–A.D. 30), Roman encyclopedist; Claudius Galen
(A.D. 130–201); most influential writer of all times on medical subjects
• MIDDLE AGES (Dark Ages, 5th-15th century) – fall of Rome to the Goths
• RENAISSANCE (14th -16th century) – rebirth of science: Leonardo da Vinci (Italian,
1452–1519); Andreas Vesalius (Belgian, 1514-64), father of modern anatomy.
• MODERN AGE (17th century till date)
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5. APPROACHES TO THE STUDY OF ANATOMY
• Regional approach – head, neck, thorax, abdomen, upper
limbs, lower limbs, pelvis and perineum
• Systemic approach – skeletal; integumentary; muscular;
respiratory; circulatory (cardiovascular and lymphatic );
endocrine; digestive; urinary; reproductive; nervous.
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6. BODY CAVITIES AND PLANES, ABDOMINAL
QUADRANTS AND ANATOMICAL POSITION.
• Cavities – cranial, spinal, thoracic, mediastinum, abdominal, orbital, nasal, oral
(buccal), pelvic,
• Planes – sagittal, mid-sagittal, coronal (frontal), transverse (horizontal)
• Body regions -
• Abdominal quadrants – right upper, left upper, right lower, left lower
• Anatomical position - stand erect, feet parallel to each other, face and eyes
point forward, arms are straight beside the body; palms turned forward
• Directional terms – superior, inferior, anterior, posterior, medial, lateral etc.
• Terms related to movement – flexion, extension, abduction, adduction etc.
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8. INTRODUCTION
• Cell is the structural and functional unit of the living body
• Unicellular, multicellular (human - 100 trillion cells.)
• Body organization: Cells tissues  organs  system  human body
• Cell theories (Matthias Schleiden and Theodor Schwann )
a. All living things are made of one or more cells
b. Cell is the basic unit of life
c. Cells come from pre-existing cells
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9. A
TYPICAL
CELL
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10. CELL/PLASMA MEMBRANE/PLASMALEMMA
• ≈7.5nm in thickness; envelops the cell
• Functions –
• Envelop; structural and functional integrity; permeability; recognition;
potential difference maintenance
• Made of lipid bilayer, protein and glycocalyx
• Lipid bilayer – phospholipids, cholesterol and glycolipids
• Phospholipids - pin-like (polar hydrophilic head & 2 nonpolar hydrophobic
tail); in two layers; permit only small lipid-soluble substances (O2, CO2,
alcohol) across
• Cholesterols - in between phospholipid molecules; responsible for the
structural integrity of cell membrane
• Glycolipids – carbohydrates that are attached to the outer surface of the lipid
bilayer, form part of the glycocalyx, and they can act as receptors.
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11. Cell membrane fluidity
• The fluid-like state of the
membrane is very important, it
allows membrane biogenesis,
endocytosis, exocytosis,
membrane trafficking
• ↑ temp. and ↓ saturation of
the tail - ↑ fluidity
• ↑ cholesterol content - ↓
fluidity
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12. Proteins
• ≈50% of membrane composition; mobile or immobile along the cell
membrane
• Integral/transmembrane proteins
• project across the cell membrane;
• allow the passage of water-soluble substances (such as electrolytes, glucose,
urea) as they can act as receptors, transport proteins, enzymes, & pumps.
• most are Glycoproteins (with carbohydrate attached to them) and multipass
proteins (moveable along the membrane)
• Peripheral proteins
• Mostly on the cytoplasmic surface of the phospholipids
• Held to the membrane or integral proteins by noncovalent bond
• Transport ions
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13. Glucocalyx
• This is the cell coat found on the extracellular side
• ≈50 nm in thickness
• Made of glycoproteins and glycolipids
• Functions –
• Adherence of some cells such fibroblasts to extracellular matrix (except
epithelial cells)
• Attaches enzymes and antigen to the surface of a cell
• Protects cells
• Allows cell-cell recognition and interaction
• It assists T cells and antigen-presenting cells to align properly
• Preventing inappropriate enzymatic cleavage of receptors and ligands
• It lines the endothelium to reduce friction as blood flows and it reduces fluid
loss in blood vessels 11/17/2022 13

14. TRANSPORT ACROSS CELL MEMBRANE
• Movement of molecule(s) across the cell membrane
• Uniport (movement of a molecule)
• Cotransport (movement of 2 different molecules)
• Symport (movement of molecules in the same direction)
• Antiport (movement of molecules in opposite direction)
• Passive transport
• Active transport
• Facilitated diffusion of ions
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15. PASSIVE TRANSPORT
• Movement down concentration gradient without the need of energy.
• Simple diffusion
• small uncharged polar molecules (H2O, steroid, glycerol) and small nonpolar
molecules (N2, CO2, O2)
• speed is dependent on conc. gradient
• Facilitated diffusion
• ions, large polar molecules and water-soluble molecules (e.g., glucose and amino
acids)
• transport is via integral proteins (channels) that are specific to molecules, number
specific; transport maximum
• Ion channel protein for small water-soluble molecules and ions
• Carrier proteins for specific molecules; they are multipass proteins; also functions in
active transport.
• Aquaporins for the transport of water 11/17/2022 15

16. CLINICAL CORRELATE
Cystinuria
• hereditary metabolic condition
• abnormal carrier proteins are unable to remove cystine (amino acid) from
the urine,
• Excess cystine in urine thus cause crystals and stone (calculi) formation in the
kidney, urinary bladder and/or ureter - kidney stones
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17. ACTIVE TRANSPORT
• Movement up concentration gradient through carrier proteins; requires ATP (energy).
• Sodium-potassium (Na+-K+) pump :
• functions to maintain cell volume and assist in maintain a resting membrane
potential (potential difference), by transporting sodium and potassium ions.
• 3 Na+ are moved out and 2 K+ are moved in as the pump uses 1 ATP molecule for
the 5 ions.
• Glucose transport – transport glucose
• ATP-binding cassette (ABC) transporters – export drugs and toxins from cytoplasm
into extracellular space
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18. CLINICAL CORRELATE
Multidrug-resistant proteins (MDR proteins)
• These are ABC-transporters found in certain cancer cells
• Once cancerous cells develop MDR proteins, treatment will be impaired
because the cells will become resistant to the drugs used.
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19. FACILITATED DIFFUSION OF IONS via ion channel proteins or
ionophores
• Ion channel proteins allow specific ions.
• K+ leak channels - most common; ungated; establish potential difference across the
cell membrane
• Gated ion channels – closed most times, open only in response to stimuli.
• Voltage-gated channels – changes in potential difference (e.g., Na+ influx in action
potential)
• Mechanically gated channels - mechanical stimulus
• Ligand-gated channels - binding of a signaling molecule (e.g., neurotransmitter or ion).
Anesthetic agents here block action potentials spread.
• Ionophores - lipid-soluble molecules that transport specific ions across cell membrane.
They inhibit the functionality of bacteria; fed to cattle and poultry. 11/17/2022 19

20. CYTOPLASM
Cytoplasm - contains cytosol
Cytosol - jellylike fluid; made of water, ions and enzymes;
~50% of the cytoplasm; cell organelles float
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21. CELL ORGANELLES
Nucleus
• largest organelle;
• controls all cell activities
• stores hereditary information in genes
• synthesis of RNA
• sending genetic instruction for protein synthesis
• wrapped by a double-layered nuclear envelope
• contains nucleolus responsible for ribosomal RNA synthesis
Mitochondria
• sausage-shaped
• energy production organelle, initiate apoptosis (programmed cell death)
• More in very active cells 11/17/2022
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22. CELL ORGANELLES
Endoplasmic reticulum (ER)
• interconnecting membranous compartments; continues from the outer layer of
nuclear envelop
• Rough ER: synthesis of proteins; degradation of worn-out organelles
• Smooth ER: catabolism and detoxification of toxic substances and some drugs;
synthesis of steroid hormones; cellular metabolism
Peroxisomes
• tiny sacs
• β-Oxidation/breakdown fatty acids, amino acids and hydrogen peroxide
• Impairment or absence of peroxisomes has been implicated in some genetic
diseases: Zellweger (cerebrohepatorenal) syndrome (peroxisome biogenesis
disorder, PBD) and Leukodystrophies like Neonatal adrenoleukodystrophy
[NALD] and Infantile Refsum disease. 11/17/2022
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23. CELL ORGANELLES CONT.
Golgi apparatus/body/complex
• Like a flattened sac in all cells except RBCs
• Packaging and labeling of proteins and lipids into vesicles
• Further modification of carbohydrate section of glycoproteins to produce hybrid
oligosaccharide chains. A breakdown in this process due to failure of particular
enzyme causes:
• Hyperproinsulinemia – (failure of peptidase) high blood proinsulin level,
clinical findings are similar NIDDM
• I-cell disease – (failure of N-acetylglucosamine-phosphotransferase) results in
skeletal abnormalities, restrictive joint movements and psychomotor retardation.
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24. CELL ORGANELLES CONT.
Lysosomes (tiny sacs)- made of hydrolytic enzymes that breakdown foreign
materials and worn-out organelles (intracellular digestive system). Pinched
off from golgi apparatus.
Vesicles (tiny sacs) - temporarily house molecules to be transported within
the cell or exported out.
Ribosomes (small & dot-like)- protein synthesis; protein factories
Cytoskeleton - complex network of protein fibers that determines cell
shape, supporting framework, cell movement
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25. CYTOSKELETON
Centrosome and centrioles: Centrosome (microtubule-organizing center, MTOC);
Centrioles are active during cell division
Cell fibers
Microfilaments – twisted; smallest fibers,
Intermediate filament – twisted; thicker than microfilaments: improve structural
strength
Microtubules – thickest; spiral appearance; form spindle fibers; organelle or vesicle
transport. Defect in microtubules arrangement causes Chédiak-Higashi syndrome
Cell extensions – microvilli, cilia, flagella
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Chédiak-Higashi syndrome – delayed fusion of
phagosomes with lysosomes in white blood cells
(impaired phagocytosis); increased fusion of
melanosomes in melanocytes (albinism); granular
defect in natural killer cells and platelets

26. CELL CONNECTIONS
• Desmosomes - outer connecting fibers are interlocked.
Hemidesmosomes anchor a cell to basement membrane;
skin.
• Disruption of desmosomes connecting keratinocytes
causes Pemphigus, epidermal cells are separated.
• Pemphigus is an autoimmune disease that causes
blistering of the skin
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• Gap junctions – membrane channels connection allowing small
molecules and ions to pass; cells of myocardium
• Tight junctions – form permeability barrier or greatly limit
exchange of molecules between adjacent cells; epithelial cells
lining the intestines and other regions with simple epithelium

27. CELL-TO-CELL SIGNALLING
• Signaling molecules (e.g., neurotransmitters, hormones)
• Lipid-soluble signalling molecules bind to receptors within the
cytoplasm or inside the nucleus; steroid hormones and thyroid
hormones.
• Water-soluble signalling molecules bind to receptors on the cell surface;
neurotransmitters and numerous hormones (e.g., peptide hormones and
catecholamines).
• Membrane receptors – glycoprotein with 3 domains (extracellular,
transmembrane, intracellular). Functions (control the entry of molecules into
the cell and may allow pathogens that mimic normal molecules)
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28. CLINICAL CORRELATES
Non-Insulin Dependent Diabetes mellitus (NIDDM) / Type 2
Diabetes Mellitus
• Insulin receptors on the cell membrane of the target cells become
insensitive to insulin leading to cells starving of energy-rich
glucose.
• Obesity is mostly the predisposing condition to NIDDM
Autoimmune diseases may lead to the production of antibodies that
specifically bind to and activate certain plasma membrane
receptors making the concerned cells become hyperactive. An
example is Graves disease (hyperthyroidism) 11/17/2022 28

29. CLINICAL CORRELATES CONT.
• Venoms
• Many poisonous snake venoms
inactivate postsynaptic
acetylcholine receptors on the
sarcolemma of skeletal muscles at
neuromuscular junctions causing
paralysis.
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30. PLASMALEMMA–CYTOSKELETON ASSOCIATION
(erythrocytes)
• Achieved by Integrins in the cell membrane
• This association determines and maintains the shape of the cell
• Red blood cells have :
i. Integrins called band 3 proteins
ii. Cytoskeleton made of actin, spectrin, band 4.1 protein and ankyrin
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Actin binds to double-chained
flexible spectrin.
Band 4.1 protein stabilizes the
spectrin-actin complexes
Ankyrin attaches the
complexes to band 3 proteins

31. PLASMALEMMA–CYTOSKELETON ASSOCIATION
(nonerythroid cells).
• Nonerythroid cells’ cytoskeleton is
made of actin, α-actinin and vinculin.
• α-Actinin cross-links actin filaments
• Vinculin binds to α-actinin
• Talin binds to the integrin of the cell
membrane.
• In skeletal and cardiac muscle fibres,
dystrophin (a protein) is also a vital
part of the plasmalemma-cytoskeleton
association
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32. CLINICAL CORRELATES
HEREDITARY SPHEROCYTOSIS
Occurs when spectrin becomes
defective and poorly binds to
band 4.1 protein.
RBCs become fragile and
deformed (spherocytes).
Destruction of the spherocytes in
the spleen leads to anaemia.
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High-speed car accidents and often
shaken baby syndrome
These cause damage to axons, especially
at the interface between white mater and
grey mater resulting in diffuse axonal
injury.
Examination of the affected tissue
displays irreparable cleavage of
spectrin and damage to the neuronal
cytoskeleton that eventually causes cell
death

33. • DUCHENNE MUSCULAR DYSTROPHY (DMD),
• X-linked recessive disorder caused by frameshift or
nonsense mutation causing dystrophin to be missing or
truncated.
• Dystrophin connects the cytoskeleton (actin) to the
transmembrane proteins α- and β-dystroglycan, and then
connected to the extracellular matrix (ECM).
• Contractions of muscles thus pull at the weakened
connections of the sarcolemma to create a leaky hole through
which extracellular Ca2+ flood the muscle fibre causing cell
damage and eventual cell death.
• DMD causes muscle weakness from the pelvis upward
(respiratory and cardiac muscles)
• It’s evident at age 2-5 years and victims rarely live past 30
years. 11/17/2022 33