final exam cumulative review slides
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Final Exam Cumulative Review Slides. Lectures 1-17. Anatomical Terminology. Anatomical Position – body standing erect, facing forward, upper limbs at the sides, palms facing forward. Terms of Relative Position Superior versus Inferior Anterior versus Posterior Medial versus Lateral - PowerPoint PPT PresentationTRANSCRIPT
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Final Exam Cumulative Review Slides
Lectures 1-17
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Anatomical Position – body standing erect, facing forward, upper limbs at the sides, palms facing forward
Terms of Relative Position• Superior versus Inferior•Anterior versus Posterior•Medial versus Lateral•Ipsilateral versus Contralateral•Proximal versus Distal•Superficial versus Deep
Anatomical Terminology
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Body Regions
Fig 1.1 in Lab Manual, Figure 1.7 in Textbook
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Body’s maintenance of a stable internal environment**Absence of homeostasis = DISEASE
Homeostatic Mechanisms – monitor aspects of the internal environment and corrects any changes
•Receptors - provide information about environment•Control center - tells what a particular value should be•Effectors - causes responses to change internal environment
HomeostasisA CRITICAL (and very testable) concept in physiology
Negative feedback – deviation from set point progressively lessens
Positive feedback – deviation from set point gets progressively greater
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Homeostasis
• Remember that homeostasis does NOT mean constant!– Continual variations occur in body systems– Gives rise to ‘normal ranges’ (See Appendix B)
• Examples of negative feedback– Temperature regulation, blood pressure, blood
glucose levels• Examples of positive feedback
– Blood clotting, milk production, uterine contraction
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Chemical Bond SummaryTYPE OF BOND DEFINITION DESCRIPTION EXAMPLE
IONIC when atoms lose or gain electrons becoming ions, and then oppositely charged ions are attracted to one another
bond is broken by water salts, NaCl
COVALENT when 1 or more pair(s) of electrons is/are shared by atoms
(single, double, triple)
strong bond the bonds holding a molecule of H20 together, CO2
HYDROGEN when a (slightly positive) hydrogen atom that is already covalently bonded to a molecule is attracted to a slightly negative atom.
(typically with O, N)
Very weak bond; in molecules whose purpose is to easily break and then come back together
reactions between water molecules (i.e. ice to water to gas);
DNA chains
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Acids, Bases, and Salts
Electrolytes – soluble inorganic substances that release ions in water (aqueous) and will conduct an electrical current
Acids – substances that release hydrogen ions (protons) in waterHCl H+ + Cl-
Bases – substances that release OH- (or other negative) ions in water that can combine with, and remove, H+ from solution
NaOH Na+ + OH-
Salts – electrolytes formed by the reaction between an acid and a base (anions/cations EXCEPT H+ or OH-)
NaCl Na+ + Cl-
HCl + NaOH H2O + NaCl
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pH (H+ concentration)
*pH of human blood plasma = 7.35 – 7.45 (AVG = 7.4)
pH scale - indicates the concentration of FREE hydrogen ions insolution (think: “power of Hydrogen”)
*Notice: [H+], pH, [OH-] *Notice: [H+], pH, [OH-]
Acids – substances that release hydrogen ions (protons) in water
Bases – substances that release OH- (or other negative) ions in water that can combine with, and remove, H+ from solution
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Organic Molecule Carbohy-drates (sugars)
Lipids (Fats) Proteins NucleicAcids
Composed of what atoms?
C, H, O C, H, O C, H, O, N, S C, H, O, N, P
Building Blocks (monomers)
Monosaccharides, e.g. hexoses
Triglycerides: glycerol and 3 fatty acids
Phospholipid: glycerol, 2 FA, phosphate
amino acids nucleotides: pentose sugar, phosphate, nitrogen base
Specific types & functions of monomers
Mono-; glucose, fructose, galactose
Glucose = body’s energy source
TG: energyPhospholipid: cell
membrane component
Steroid: cell membrane component and chemical messenger (i.e. cholesterol)
20 different amino acids; each differs from the others because of its unique R group
N/A
Specific types and functions of polymers
Disaccharides:sucrose, lactose,
maltose; energy_____________PolysaccharidesStarch (plant);Glycogen (animal);
energy storage.
N/A proteins (>100 amino acids);
Many functions:ENZYMES,antibodies, structure,
transport, chemical messengers,
storage
DNA: deoxy-ribonucleic acid; genetic material; RNA:
ribonucleic acid; aids DNA in protein synthesis.
OtherInformation
Saturated (only single bonds between C’s in fa chain) vs. Unsaturated (at least 1 double bond in fa chain)
Amino acids are joined together by peptide bonds
Dipeptide = two aaTripeptide = three aa
DNA controls cellular activity by instructing our cells what proteins to make (i.e. Enzymes through protein synthesis).
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Summary of Transport ProcessesTRANSPORTPROCESS
ISENERGYNEEDED?
CONCEN-TRATIONGRADIENT
GENERALDESCRIPTION
EXAMPLEIN HUMANS
SIGNIFICANCE
SIMPLEDIFFUSION
NO [HIGH]TO[LOW]
spreading out of molecules to equilibrium
O2 into cells; CO2 out of cells.
Cellular Respiration
FACILITATED DIFFUSION
NO [HIGH]TO[LOW]
Using a special cm carrier protein to move something through the cell membrane (cm)
Process by which glucose enters cells
OSMOSIS NO [HIGH]TO[LOW]
water moving through the cm to dilute a solute
maintenance of osmotic pressure of 0.9%.
Same
FILTRATION NO [HIGH]TO[LOW]
using pressure to push something through a cm (sprinkler hose)
manner in which the kidney filters things from blood
removal of metabolic wastes
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Summary of Transport ProcessesTRANSPORTPROCESS
ISENERGYNEEDED?
CONCEN-TRATIONGRADIENT
GENERALDESCRIPTION
EXAMPLEIN HUMANS
SIGNIFICANCE
ACTIVE TRANSPORT
YES [LOW]TO[HIGH]
opposite of diffusion at the expense of energy
K+-Na+-ATPase pump
maintenance of the resting membrane potential
ENDOCYTOSIS YES [LOW]TO[HIGH]
bringing a substance into the cell that is too large to enter by any of the above ways;
Phagocytosi: cell eating;
Pinocytosis: cell drinking.
Phagocytosed (foreign) particles fuse with lysosomes to be destroyed
help fight infection
EXOCYTOSIS YES [LOW]TO[HIGH]
expelling a substance from the cell into ECF
Exporting proteins; dumping waste
Same
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Osmolarity and Tonicity
• Osmolarity of a solution is a measure of a solution’s attraction for water and depends on the number of particles ‘trapped’ in that solution– Higher the osmolarity, the higher the solute concentration– Higher the osmolarity, more strongly water is attracted
• Tonicity is a comparison of the osmolarity between two solutions– Equal osmolarity, no net water movement– Unequal osmolarity, water will always move into the
more concentrated solution (from hypotonic to hypertonic)
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Osmotic Pressure/Tonicity
Osmotic Pressure (Osmolarity) – ability of solute to generate enough pressure to move a volume of water by osmosis
*Osmotic pressure increases as the number of nonpermeable solutes particles increases
• isotonic – same osmotic pressure as a second solution
• hypertonic – higher osmotic pressure
• hypOtonic – lower osmotic pressure
0.9% NaCl5.0% Glucose
Crenation
The O in
hypotonic
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Passage of Materials through the Cell Membrane
oxygen, carbon dioxide and other lipid-soluble substances diffuse freely through the membrane
Carrier/channel proteins required for all but fat-soluble molecules and small uncharged molecules
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Cellular Organelles
CELL COMPONENT DESCRIPTION/STRUCTURE
FUNCTION(S)
CELL MEMBRANE Bilayer of phospholipids with proteins dispersed throughout
cell boundary; selectively permeable (i.e. controls what enters and leaves the cell; membrane transport)
CYTOPLASM jelly-like fluid (70% water) suspends organelles in cell
NUCLEUS Central control center of cell; bound by lipid bilayer membrane; contains chromatin (loosely colied DNA and proteins)
controls all cellular activity by directing protein synthesis (i.e. instructing the cell what proteins/enzymes to make.
NUCLEOLUS dense spherical body(ies) within nucleus; RNA & protein
Ribosome synthesis
RIBOSOMES RNA & protein; dispersed throughout cytoplasm or studded on ER
protein synthesis
ROUGH ER Membranous network studded with ribosomes
protein synthesis
SMOOTH ER Membranous network lacking ribosomes
lipid & cholesterol synthesis
GOLGI “Stack of Pancakes”; cisternae modification, transport, and packaging of proteins
Table 1 of 2
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Cellular Organelles
CELL COMPONENT DESCRIPTION/STRUCTURE
FUNCTION(S)
LYSOSOMES Membranous sac of digestive enzymes destruction of worn cell parts (“autolysis) and foreign particles
PEROXISOMES Membranous sacs filled with oxidase enzymes (catalase)
detoxification of harmful substances (i.e. ethanol, drugs, etc.)
MITOCHONDRIA Kidney shaped organelles whose inner membrane is folded into “cristae”.
Site of Cellular Respiration; “Powerhouse of Cell”
FLAGELLA long, tail-like extension; human sperm locomotion
CILIA short, eyelash extensions;human trachea & fallopian tube
to allow for passage of substances through passageways
MICROVILLI microscopic ruffling of cell membrane increase surface area
CENTRIOLES paired cylinders of microtubules at right angles near nucleus
aid in chromosome movement during mitosis
Table 2 of 2
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Some Definitions…
Gene – segment of DNA that codes for a protein or RNA- About 30,000 protein-encoding genes in humans- DNA’s instructions are ultimately responsible for the ability of the cell to make ALL its components
*Chromatin – combination of DNA plus histone proteins used to pack DNA in the cell nucleus
Genome – complete set of genes of an organism- Human Genome Project was complete in 2001- Genomes of other organisms are important also
Genetic Code – method used to translate a sequence of nucleotides of DNA into a sequence of amino acids
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Cell Death• Two mechanisms of cell death
– Necrosis– Programmed cell death (PCD or apoptosis)
• Necrosis– Tissue degeneration following suddent,
unexpected cellular injury or destruction– Cellular contents released into the environment
causing an inflammatory response• Programmed Cell Death (Apoptosis)
– Orderly, intentional cell death– Cellular contents are contained and cell is
immediately phagocytosed ; no inflammation
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Transcription/Translation• Transcription
– generates mRNA from DNA– Occurs in nucleus of the cell– Uses ribonucleotides to synthesize mRNA
• Translation – generates polypeptides (proteins) from mRNA– Occurs in the cytoplasm of the cell – Uses 3 components:
1. mRNA – carries copy of genetic instructions from DNA; has codons
2. tRNA w/aa; function as adapters in protein synthesis; has anticodons
3. Ribosomes; provide scaffold for protein synthesis and has enzymes that link adjacent amino acids
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The Genetic Code
1. Codon – group of three ribonucleotides found in mRNA that specifies an aa
2. Anticodon – group of three ribonucleotides found in tRNA that allows specific hydrogen bonding with mRNA
3. AUG is a start codon and also codes for MET. UAA, UAG, and UGA are stop codons that terminate the translation of the mRNA strand.
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Find the AMINO ACID SEQUENCE that corresponds to the following gene region on the DNA:
Template -> G G T C T C A T T
Coding -> C C A G A G T A A
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Enzymes
• Enzymes are proteins– They are biological catalysts
• Speed up reactions• Are not consumed during reaction
– Highly specific for their substrate
– Work by lowering the activation energy needed to start a reaction
– May require cofactors/coenzymes
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ATP – An Activated Carrier Molecule• each ATP molecule has three parts:
• an adenine molecule• a ribose molecule• three phosphate molecules in a chain
• ATP carries its energy in the form or P (phosphate)
• ATP is a readily interchangeable form of energy for cellular reactions (“common currency”)
These two components together are called a ?
High-energy bonds
ATP ADP + PReversible reaction of ATP breakdown and regeneration
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GLYCOLYSIS TCA ETC
Where it takes place
Cytoplasm Mitochondria Mitochondria
Products Produced ATPNADH
Pyruvate
ATPNADH,FADH2
CO2
ATPNAD+,FAD
H2OPurpose Breakdown of glucose
(6 carbons) to 2 molecules of pyruvate
(3 carbons)
Generation of energy intermediates (NADH, FADH2, ATP) and CO2
Generation of ATP and reduction of O2 to H2O (Recall that reduction is the addition of
electrons)What goes on 1. Glucose is
converted to pyruvate, which is enters the TCA cycle.
2. If O2 is not present, pyruvate is converted to lactic acid so glycolysis can continue to make ATP
1. The energy in acetyl CoA is trapped in activated carriers of electrons (NADH, FADH2) and activated carriers of phosphate groups (ATP). 2. The carries of electrons that trap the energy from acetyl CoA bring their high energy electrons to the electron transport chain.
1. Chemiosmosis (oxidative phosphorylation) uses the electrons donated by NADH and FADH2 to eject H+ from the matrix of the mitochondria to the intermembrane space. 2. These H+ then flow down their concentration gradient through a protein (ATP synthase) that makes ATP from ADP and phosphate.3. During this process, the H+
that come through the channel in ATP synthase are combined with O2 to make H2O.
Summary Table of Cell Respiration
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Cell Nucleus
• control center of cell
• nuclear envelope (membrane)
• porous double membrane• separates nucleoplasm from cytoplasm (*eukaryotes only)
• nucleolus• dense collection of RNA and proteins• site of ribosome production
• chromatin• fibers of DNA and proteins• stores information for synthesis of proteins Figure From: Marieb & Hoehn, Human Anatomy & Physiology, 9th ed., Pearson
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The Cell Cycle
• series of changes a cell undergoes from the time it forms until the time it divides
• stages • interphase (G1, S, G2)• mitosis• cytoplasmic division (cytokinesis)
Differentiated cells may spend all their time in ‘G0’ (neurons, skeletal muscle, red blood cells). Stem cells may never enter G0
Figure From: Marieb & Hoehn, Human Anatomy & Physiology, 9th ed., Pearson
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Mitosis and MeiosisFigures from: Martini, Anatomy & Physiology, Prentice Hall, 2001
Mitosis – production of two identical diploid daughter cells
Meiosis – production of four genetically varied, haploid gametes
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Characteristics of Epithelial Tissue
• Specialized contacts with other cells• Polarity (different ends of cell do different
things)• Avascularity (no blood supply)• Regeneration (can divide to make new
cells) • Cellularity (lots of cells in close contact)
Remember: Epithelial tissues always have a free surface and a basement membrane
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Membranes
Serous• line body cavities that lack openings to outside• reduce friction• inner lining of thorax and abdomen• cover organs of thorax and abdomen (pleura, pericardium, peritoneum)• secrete serous fluid
Mucous• line tubes and organs that open to outside world• lining of mouth, nose, throat, digestive tract, etc.• secrete mucus
Cutaneous• covers body• skin
A membrane is a combination of epithelium and connective tissue that covers and protects other structures and tissues. Technically, then, a membrane is an organ.
Synovial• surround joint cavities
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Introduction to InflammationFigure from: Martini, Anatomy & Physiology, Prentice Hall, 2001
Restoration of homeostasis after tissue injury or infections involves two processes: 1) inflammation and 2) repair.
Major signs (hallmarks) of inflammation: Redness, heat, pain, swelling, loss of function
(Inflammation = ‘-itis’)
Histamine
HistamineHeparin
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Glandular Epithelium
Composed of cells that are specialized to produce and secrete substances
Endocrine glands are ductless – secrete directly into the bloodExocrine glands have ducts – secrete into a duct or on to a surface
Unicellular exocrine gland • composed of one cell • Example: goblet cell
Multicellular exocrine gland • composed of many cells• Examples: sweat glands, sebaceous glands, salivary glands, etc.
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Name of CT
Different types of this CT
Main types of cells present
Main types of fibers present
Consistency of matrix Examples of Locations
CT Proper1) Areolar (Loose)2) Dense regular3) Dense irregular4) Adipose5) Reticular6) Elastic
1) Fibroblasts2) Fibroblasts3) Fibroblasts4) Adipocytes5) Fibroblasts6) Fibroblasts
1) Collagen, Elastic2) Collagen3) Collagen4) Reticular5) Reticular6) Elastic
Semi-liquid1) Skin, between muscles2) Tendons, ligaments3) Dermis 4) Body fat areas5) Stroma of liver, spleen6) Lungs, airways, arteries/heart
Cartilage 1) Hyaline2) Fibrocartilage3) Elastic
(All) Chondrocytes1) Collagen (sparse)2) Collagen (dense)3) Elastic
All types: Semi-solid, gelatinous;
rubbery
1) Ribs, ends of bones2) Intervertebral disks3) Pinna of ear, epiglottis
Bone 1) Dense2) Spongy
(All) Osteocytes Collagen Solid (hydroxyapatite)
1) Outer portions of bone2) Inner portions of bone
Blood--
1) RBCs2) WBCs3) Platelets (cell fragments)
Fibrinogen (soluble) Liquid Blood vessels, heart
Lymph -- Lymphocytes Reticular (in stroma of lymphoid organs)
Liquid Lymph vessels
Connective Tissue (CT) Summary Table
Three main components of ALL CT: cell, fibers, ground substance
-cyte = fully differentiated; -blast = young, actively synthesizing cell
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Components of Connective Tissue
Ground substance - Exists between the fibers and cells - Varies from semisolid to liquid - Composed of large molecules, many of which are complex combinations of polysaccharides and proteins
Table from: Hole’s Human A&P, 12th edition, 2010
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Skin Color/Thermoregulation
Diaphoresis - sweating with visible wetnessHyperthermia – higher than normal body temp; corrected by dilation of dermal blood vessels, sweating.
Physiological Factors affecting skin color
• dilation of dermal blood vessels (erythema – reddening of skin)
• constriction of dermal blood vessels (less pink, pale = pallor)
• level of oxygenation of blood * normal = pink (fair-skinned) * low = bluish (cyanosis)
Hypothermia – lower than normal body temp; corrected by constriction of dermal blood vessels, shivering.
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Structures of the Integument
Acc
esso
ry S
truc
ture
s
Figure from: Martini, Anatomy & Physiology, Prentice Hall, 2001
SKIN
Epidermis = protection; Dermis = nourishment of epidermis; SubQ = insulation
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Functions of Integument• The Integumentary System has numerous
functions that are related to its composition and structure– Protection – Temperature regulation (sweat, blood vessels)– Excretion– Vitamin D production– Sensation (touch, pressure)
• The epidermis – the outer, protective layer– S. basale, s. spinosum, s. granulosum, s. lucidum
(thick skin only), s. corneum
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Dermis and Hypodermis
• The dermis – the lower, nutritive layer– Papillary dermis (areolar CT)– Reticular dermis (dense irregular CT)– Dermis contains accessory organs of skin
• The hypodermis (subcutaneous, superficial fascia)
– Insulates (areolar CT with abundant fat)– Reservoir of blood– Stabilizes dermis– NOT part of the skin
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Hail, Nails, Glands of Integument• Accessory structures of the integumentary
system– Hair – warmth, protection– Nails – defense; picking up objects– Sweat glands
• Apocrine (merocrine) - odoriferous• Eccrine (merocrine) - thermoregulation• Modified (mammary, ceruminous)
– Sebaceous glands• Secrete sebum (waxy, fatty substance)• Lubricate/protect hair and skin• Sebum is antibacterial
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Compact and Spongy BoneEach bone in the skeleton contains two forms of osseous tissue - Compact bone (cortical) – solid (with osteons as structural units); found on outer parts of bone - Spongy (cancellous, trabecular) bone – network of struts and plates (trabeculae); found within the inner parts of bone
Figure from: Hole’s Human A&P, 12th edition, 2010
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Epiphyseal Plates
Epiphyseal cartilage = epiphyseal plate; allows long bones to grow in length
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Homeostasis of Bone Tissue
1) Bone Resorption – action of osteoclasts and parathyroid hormone (PTH)2) Bone Deposition – action of osteoblasts and calcitonin
Bone remodeling is a process that continues throughout life, and is accomplished by two processes:
• FACTORS AFFECTING REMODELING, GROWTH AND REPAIR OF BONE•Mineral salts, especially Calcium and Phosphorus
• Deficiencies of vitamins A, C, and D• Deficiency of Vitamin A – retards bone development• Deficiency of Vitamin C – results in fragile (brittle) bones • Deficiency of Vitamin D – rickets, osteomalacia
• Growth factors and Hormones• Sex Hormones – promote bone formation; stimulate ossification (closure) of epiphyseal plates• Insulin-like growth factors (IGFs) – stim. by hGH• Insufficient Growth Hormone – pituitary dwarfism• Excessive Growth Hormone – gigantism, acromegaly • Insufficient Thyroid Hormone – delays bone growth
• Physical Stress (exercise) – stimulates bone growth
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Axial Skeleton - Thoracic Cage
• True = 7 pairs• False = 3 pairs• Floating = 2 pairs
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Synovial Joints
* Diarthrotic (freely movable)
Structural features of diarthrotic joints
- joint cavity* - articular cartilage - synovial membrane - synovial fluid - reinforcing ligaments, bursae and tendons
Synovial fluid: Lubricates, distributes nutrients, and absorbs shock
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Divisions of the Pelvis
(Greater)
(Lesser)
Pelvic brim = (sacral promontory, sacral ala, arcuate line, pectineal line, pubic crest) x 2
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Joint ClassificationStructural Classification of Joints
Fibrous Synovial (D)Cartilaginous
Suture (S)
Syndesmosis (A)
Gomphosis (S)
Synchondrosis (S)
Symphysis (A)
Gliding (N)
Hinge (M)
Pivot (M)Condyloid (B)Saddle (B)
Ball/Socket (P)
This would be a really good chart to know for the exam!
(S) = Synarthrosis(A) = Amphiarthrosis(D) = Diarthrosis
(N) = Nonaxial(M) = Monaxial(B) = Biaxial(P) = Polyaxial
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Synovial Joint Movements Summary• Flexion – decrease in angle between bones• Extension – increase in angle between bones• ABduction – movement away from midline• ADduction – movement toward midline• Circumduction – Movement of the distal end of a limb in a
circle• Supination – palm facing anteriorly• Pronation – palm facing posteriorly• Protraction – anterior movement in transverse plane• Retraction – posterior movement in transverse plane• Dorsiflexion – Superior surface of foot moves superiorly• Plantar flexion – Inferior surface of foot moves inferiorly
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Muscles/ActionsMuscle Name Location Action Origin Insertion
Masseter Cheek in front of ear Elevates mandible (raises lower jaw)
Zygomatic arch Lateral surface of mandibular ramus
Trapezius Upper shoulder Elevates clavicle; Extends neck
Occipital bone; spinous processes of thoracic vertebrae Clavicle and Scapula
Sternocleidomastoid Side of neck Rotates head; Flexes head toward shoulder Clavicle and Manubrium
Mastoid process of temporal bone
Deltoid Shoulder Abduction at shoulder Clavicle and scapula Deltoid tuberosity of humerus
Biceps brachii Front of upper arm Flexion at elbow and shoulder Short head: coracoid process of scapula
Long head: glenoid tubercle of scapula
Tuberosity of radius
Triceps brachii Back of upper arm Extension at elbow Lateral head: humerusMedial head: humerus
Long head: glenoidOlecranon process of ulna
(elbow)
Abdominal muscles External oblique Internal oblique Rectus abdominis
Front and side of abdomen Flex trunk (vertebral column); depress ribs (as in forced
exhalation)
Superior surface of pubis around symphysis
Inferior surfaces of costal cartilages and xiphoid process
Pectoralis major Front of upper chest Flexion, adduction, and medial rotation of shoulder
Cartilage of ribs 2-6, body of sternum, inferomedial clavicle
Humerus (crest of greater tubercle and lateral lip of
intertubercular groove
Latissimus dorsi Upper back Extension, adduction, and rotation of shoulder
Spinous proc. of thoracic and lumbar vert. Humerus
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Muscles/ActionsMuscle Name Location Action Origin InsertionOrbicularis Oris Around mouth Compresses, purses lips Maxillary bone and
mandible LipsOrbicularis Oculi Around eye Closes eye Medial margin of orbit Skin around eyelids
Temporalis Side of head (skull) Elevates mandible Along upper temporal bone
Coronoid process of mandible
Gluteus maximus Buttocks Extension and lateral rotation at hip
Iliac crest, lateral surface of ilium, sacrum, coccyx
Iliotibial band (fascia on side of leg) and tuberosity
of femur
Hamstring group Biceps femoris Semitendinosus Semimembranosus
Back of thigh Lateral part of thigh Medial part of thigh Medial part of thigh
Flexes knee/extend thigh (all muscles in group)
IschiumIschium
Fibula; lat. condyle tibiaTibia
Quadriceps group Rectus femoris Vastus lateralis Vastus medials Vastus intermedius
Front of thigh Middle Lateral Medial Deep
Extends knee (all muscles in group) Iliac spine, acetabulum
Gr. Trochanter of femurAnt/lat surface of femur
All insert at the patella via the patellar tendon and the tibial tuberosity
Tibialis Anterior Shin (lower leg) Flexion at ankle; inversion of foot
Lateral condyle and proximal shaft of tibia
Base of first metatarsal and medial cuneiform
Gastrocnemius Calf (lower leg) Extension at ankle; inversion of foot;
flexion at kneeFemoral condyles Calcaneus via calcaneal
(Achilles) tendon
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Organization of Skeletal Muscle
• epimysium (around muscle)
• perimysium (around fascicles)
• endomysium (around fibers, or cells)
Alphabetical order largest to smallest: fascicle, fiber, fibril, and filament
Gross: Muscle (and fascia/epimysium), fascicle (and perimysium) Histological: Fiber (cell), endomysium Molecular: Myofibrils, sarcomere structure, actin/myosin arrangement
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Skeletal Muscle Fiber (Cell)
Transverse tubules contain extracellular fluid ( [Na+], [K+])
Sarcoplasmic reticulum is like the ER of other cells; but it contains [Ca2+ ]
Fully differentiated, specialized cell – its structures are given special names
Figure from: Saladin, Anatomy & Physiology, McGraw Hill, 2007
• sarcolemma (plasma membrane)• sarcoplasm (cytoplasm)• sarcoplasmic reticulum (ER)
• transverse tubule• triad
• cisternae of sarcoplasmic reticulum (2)• transverse tubule
• myofibril (1-2 µm diam.)
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Structure of the Sarcomere
‘A’ in A band stands for Anisotropic (dArk)
‘I’ in I band stands for Isotropic (LIght)
Zones of non-overlap: I band (thin filaments), and H zone (thick filaments)
A sarcomere runs from Z line (disk) to Z line (disk)
Figure from: Saladin, Anatomy & Physiology, McGraw Hill, 2007
52Latent period – time between motor nerve stimulation and contraction of skeletal muscle
Summary of Skeletal Muscle Contraction
Contraction Relaxation
- Bind (Ca, myosin) - Move- Detach- Reset
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Modes of ATP Synthesis During Exercise
Continual shift from one energy source to another rather than an abrupt change
Muscle stores enough ATP for about 4-6 seconds worth of contraction, but is the only energy source used directly by muscle. So, how is energy provided for prolonged contraction?
Figures From: Marieb & Hoehn, Human Anatomy & Physiology, 9th ed., Pearson, 2013
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Types of Contractions
• isotonic – muscle contracts and changes length
• concentric – shortening contraction
• isometric – muscle “contracts” but does not change length
• eccentric – lengthening contraction
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Motor Unit and Muscle Tone• Motor unit - single motor neuron plus all muscle fibers controlled by that motor neuron
• recruitment - increase in the number of motor units activated to perform a task
• whole muscle composed of many motor units
• as intensity of stimulation increases, recruitment of motor units continues until all motor units are activated
• smaller motor units recruited first• larger motor units recruited later• produces smooth movements• muscle tone – continuous state of partial contraction
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Table from: Martini & Ober, Visual A&P, 2011
*
*
**
*
*
*
*
**
*
*
*
*
*
*
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Skeletal Muscle Actions
• origin – immovable* end• insertion – movable end
• agonist (prime mover ) – primarily responsible for movement• synergists – assist prime mover• antagonist – resist prime mover’s action and cause movement in the opposite direction
Understand these terms
Figure from: Saladin, Anatomy & Physiology, McGraw Hill, 2007