Integumentary System PDF

Integumentary system Karyne N. Rabey, Ph.D. (she/her) Division of Anatomy, Department of Surgery [email protected]  Objectives Explore the organization & functions of this system. Describe the histological organization of the layers of epider...

Integumentary system Karyne N. Rabey, Ph.D. (she/her) Division of Anatomy, Department of Surgery [email protected]  Objectives Explore the organization & functions of this system. Describe the histological organization of the layers of epidermis and the layers of the dermis. Explore the different types of cells throughout the system. Explore the accessory structures: hair, glands, & nails.  Membranes Composed of epithelium (epidermis) & connective tissues Mucous membrane (dermis) ↳ dermal = Skin Serous membrane Cutaneous membrane (skin) Synovial membrane  Major components Integument covers & protects the entire body Skin Accessory structures (cutaneous membrane) Epidermis Dermis Exocrine Hair Nails (epithelium) (connective tissues) glands ↳ ducts , into releasing Skin: membrane Largest organ system of the body (represents about 15% of total body mass) Ranges in thickness (from thin eyelids to thick skin between scapulae) visual appearance Most accessible system = best indicator of general health ] temperature et). Responds directly to local influences (calluses & scar tissue) ↳ ↳ environment protection from environmental Stress  Major functions of skin 1. Skin as a barrier: physical & immunological protection Bears the brunt of most injuries but resists & recovers better than any other organ system (wound healing) not loosing muchwatera le : too Protects body of harmful penetration & I excretion: however, some are essential (UV, sweat) which can make chemicals capable of doing the ⑮ same (transdermal absorption) important ↳ absorption through for Vit D sunthesis the skin 2. Thermoregulation. Constriction of vessels (keeps heat in) ↳ blood o the core Dilation & sweating (releases heat) ↳ close to surface ↳) generated by muscles 3. Sensation (varies throughout body: touch, pressure, vibration, tickle, temperature, pain) 4. Metabolic functions Vitamin D synthesis Stores energy as subcutaneous fat 5. Social functions Identity for all animals  Structure of the skin All four tissue types are represented: 3. Muscle tissue (smooth muscle) ² Controls the diameter of blood vessels 1. Epithelial tissue Lepidermis) ² Adjusts hair position ↳ goosebumps ! ² Covers the surface ² Forms boundary from outside world 4. Nervous tissue ↑ ² Controls the smooth muscle in the connective 2. Connective tissue tissue ² Supports epithelial tissue ² Generates sensation (tactile, pressure, ² Provides strength & elasticity temperature, pain) ² Important for thermoregulation ² Stimulates exocrine glands ↳ full of Vasculature m innervated  Structure of epidermis (5 layers) Superficial Stratum corneum Keratonized stratified squamous ↑ extrotection epithelial cells Stratum lucidum* (in non-hairy skin only) producing keratin Stratum granulosum neepalized Stratum spinosum (dark) Stratum basale (germinativum) mu layer basal Come, Let’s Get Sun Burnt Dermal papilla (dermis – papillary layer) Dermis (reticular layer) Deep "Come let's sun burnt " get  Stratum germinativum (basal layer) Deepest layer = large basal stem cells, Merkel cells, and melanocytes - Stem cells constantly divide to give rise to new keratinocytes (most abundant S epithelial cells in epidermis – synthesize daughter keratin: tough fibrous protein) to replace cells from mitosis the dead ones that flake off ↳ ex : nails Forms basal lamina: this makes sure that the epithelium is firmly attached to the dermis Stratum basale Dermis Basal lamina  Merkel (tactile) cells Least common cell type, but more abundant where skin has no hair (fingertips, lips) ↳ more sensitive to touch Important role for touch sensation (sensory touch receptor - tactile) With dermal sensory nerve fibre collectively called Tactile (Merkel) disc * covered more In sensory lectures  Melanocytes -2ndAnt About 8% of epithelial cells - synthesizes melanin pigment Tronection (transfer melanin granules to keratinocytes) from UV rays Contain long and slender processes Melanin granules are phagocytized by keratinocytes – form “umbrella” over nucleus to protect DNA from UV radiation ↳ BD U # of melanocyte cells depend by region of the body (ex. palm ↳ of hand) but NOT by people less ! ↳ we all have the same # of melanocytes I ACTIVITY is what is different Activity (granules produced & how they spread out in keratinocytes) determine skin tone  Stratum spinosum (spiny layer) ↳ all holding hands a Composed of several layers (8-10) of daughter living keratinocytes & Langerhans cells Stratum spinosum Protein filaments attach keratinocytes together (like people holding hands) Adjacent cell junctions provides strength & gives the spiny appearance of the layer  Langerhans (dendritic) cells Type of macrophage that originate from bone marrow & migrates to epidermis raise ↳ vacuums Phagocytic capabilities (engulf foreign microbes, destroys them, presents their antigens to the immune system for further action) Important role for immune response if pathogens penetrated the superficial layer (found in great numbers in the oral cavity, esophagus, anal canal, & vaginal canal)  Stratum granulosum (granular layer) 3-5 layers of mature keratinocytes (produce 2 types of granules) - change in cell shape ↳ similar to squamous Stratum Keratohyalin granules: surround keratin granulosum ↳ (important for cornification) ) makes it harder Lamellar granules: water-resistant glycolipids, ↳ fatty which stick cells together (responsible for waterproof properties of skin) Keratinization = accumulation of keratin from deep to superficial layers as cells mature ↓ Cells start to die (away from nutrient source - dermis) Too much of both granules due to abrasion = um calluses  Stratum lucidum (clear layer) Large amounts of keratin & thickened plasma Stratum membranes (no nutrients or oxygen at this level) lucidum Cells have no nucleus or organelles (3-5 layers) Only found in volar/thick hairless skin (palmar & plantar skin)  Stratum corneum Stratum Corne (hoof-like or hard); most superficial layer corneum * dead cells Multiple layers of flattened, dead, interlocking keratinocytes (up to 30 layers), no more organelles, fully keratinized Cells continuously shed (dander) - dandruff is clumps of dander stuck together with oil (sebum) from the scalp Protection against abrasion & microbial invasion nummmmmmmmmm From basal to corneum = 30-40 days (mitosis active at night, shedding occurs during the day), injury or mechanical stress accelerates division and can result in more keratin (therefore calluses)  Interface between dermis & epidermis 1 2 1 2 1: Epidermal ridge 2: Dermal papilla Peak-and-valley interface between dermis & epidermis allows for a tight bond between different layers of skin (can resist shearing stresses) Sensitive areas (lips, genitals) dermal mu papillae are tall allowing nerve fibres & capillaries near the surface ↳ Why they red (vasculature close surface) are to Interface is very developed & unique to each individual in the fingertips  Papillary layer of dermis Dermis Papillary layer (P) - always assoc. wl epithelium Connection to the epidermis Areolar connective tissue (loose CT) containing nerve endings (Meissner’s corpuscles: touch & vibrations) & many capillaries (oxygen, nutrients, WBC & other immune defenses) Dermal papillae increase area of contact with epidermis (differs with areas of the body)  Reticular layer of dermis Dermis Reticular layer (R) ↓ bulk of Dense irregular connective tissue (thicker layer: 80%) dermis Many collagen bundles & elastic fibres (provides extensibility & elasticity to skin) - ↳ tough Blood vessels, nerves, lymphatics, hair follicles, glands, adipocytes between fibre bundles Skeletal muscles of the face attach here for facial expressions  Lines of cleavage Collagen fibre bundles in dermis align differently in different regions of body (due to natural tension like bony projections, joint movements, orientation of skeletal muscles) Collagen fibre bundles align along these lines of tension (resist stretching) in the reticular layer of the dermis and form lines of cleavage Clinically significant: surgeons will try to cut parallel to line of cleavage so wounds close & heal nicely (a cut perpendicular can - remain open or not heal properly and form large scars also known as keloid – raised skin) * collagen can come in same orientation back ↳ going against line keloid of cleavage Stretch marks: scarring due to internal damage of collagen bundles & stretching of vasculature (pregnancy, weight-lifters). From red streaks (tearing of vessels) to white streaks (lack of vasculature after tearing)  Structure of hypodermis Also known as superficial fascia or subcutaneous tissue; stabilizes position of skin relative to underlying tissues Loose connective tissue that stores fat Hypodermis (adipose), pads the body, serves as energy reservoir, provides thermal insulation (also has blood vessels & sensory receptors) - Distribution of subcutaneous fat can differ between biological sexes - Influences shape & contours of the body - People with less adipose are more sensitive to temperatures (elderly) Anatomy of skin tone Varies throughout body due to thickness of skin & dermal papillae 3 pigments are responsible for skin tone Melanin – yellow/tan/brown/black from melanocytes in stratum basale (protects from UV radiation) Genetics & light exposure (UV stimulates melanin synthesis) Freckles/moles: accumulation of melanin/outgrowth of melanocytes Albinism – lack of melanin ↳ melanocytes are NOT active Hemoglobin – red pigment in dermal blood vessels Oxygenated hemoglobin (blood vessel dilation & increase blood flow) = pink hue of skin Nail body, around the lips (useful for health detection) ↳ should be able to see change in colour when pressed Carotene – yellow/orange in stratum corneum & hypodermis (precursor to vitamin A) From vegetables & egg yolk (apparent in calluses) Sunburn Skin tone can be diagnostic: cyanosis (lack of O2), erythema ↳ (pooling of RBC), jaundice (bilirubin), pallor (pale - low blood flow), ↳ problems w/ liver i hematoma (bruising – clotted blood)  Skin tissue damage Excessive UV radiation, heat, electricity, chemicals Destroys skin’s important contribution to homeostasis: homeostasis protection against microbial invasion, dehydration, regulation of body temperature, alters composition of dermis & forms premature wrinkling le : Sunburn # 1st degree: epidermis, mild pain, erythema (flaking after 3-6 mmmu ↳due to ↳ days) newepidermal endings nerve layers 2nd degree: epidermis & some dermis (most structures still function), blister formation, edema, redness, pain Find pooling (scarring after 3-4 weeks) ↳ interdigitation painful] # most a nerve damage 3rd degree: through to hypodermis, skin functions lost, numb (no sensory endings), granulation forms, skin grafting may be needed no pain > - Glands  Mechanism of secretion Merocrine (sweat gland) Normal exocytosis Apocrine Apical surface (mammary gland) pinched off Holocrine (sebaceous gland) Entire cell released  4 types of exocrine cutaneous glands Merocrine sweat gland 1. Sweat glands - Secrete water & electrolytes - 2 types: merocrine secretion (most common) & apocrine secretion (puberty) 2. Sebaceous glands - Secrete oily lipid (sebum) that coats hair & skin surface Lubricates the epidermis, Sebaceous gland - Holocrine secretion excrete waste, assists in thermoregulation 3. Ceruminous glands - Secretes earwax (apocrine secretion) 4. Mammary glands - Secretes breast milk (apocrine secretion)  Apocrine glands Ceruminous glands Cerumen - Secrete waxy cerumen (ear wax found in external ear canal – traps foreign particles, prevents entrance, reduces risk of bacterial & fungal infections) Mammary Mammary glands glands & ducts - Specialized for milk production to feed infant (lots of immunity in the secretion) - Regulated by interaction of sexual & pituitary hormones  Sweat glands (sudoriferous glands) Release secretions onto the skin (directly or via hair follicle) Two types: Merocrine sweat gland Hair Apocrine sweat gland Secrete regular sweat (water Secrete odiferous sweat at & electrolytes) puberty (water, electrolytes, Widespread (more numerous lipids, proteins - acted on by on palms, soles, & forehead) J bacteria to produce odor) Tube secretes directly onto Specific to some body skin surface (sweat pore) intothe regions (axilla, groin, breast Regulates body temperature areola, facial hair) (cooling of the body) Duct opens into a hair follicle Controlled by the Strongly influenced by sexual sympathetic nervous system hormones (autonomic) Stimulated during emotional Can also be released due to stress & arousal stress, fear, embarrassment Sebaceous glands (holocrine gland) Sebum – inhibits bacterial growth) duct Hair open onto a hair follicle (some directly onto skin) ↳ all hair (not just on nead) Keeps hair & skin from becoming dry, Sebaceous glands brittle, & cracked (ironically we wash sebum off to replace with lotion – usually synthetic or sheep sebum) Acne is inflammation of sebaceous glands ↳ Stimulated by hormones ↳ over secretion = blockage = ache Inflammation results from blockage of ducts & bacterial infection of glands Usually occurs at onset of puberty (glands increase in size & sebum secretion increases in response to sex hormones) Hair  Hair Both hair & nails are composed of dead keratinized cells (with HARD keratin) Pilus (pili): slender filament of keratinized cells that grow from a tube (follicle) Cover all body surfaces, except volar skin (hands & feet), lips, nipples, & parts of genitalia Similar to all persons – differs in texture & pigmentation Functions UV protection Thermal insulation for head Particle filtration for eyes & nose Touch sensation for most of body  Anatomy of hair follicle (3 parts) Exposed shaft of hair Shaft (3) (above the skin/ epidermis) youc Hair follicle has an epithelial Sebaceous gland asso). root sheath & a CT root sheath wi hair Hair receptors (nerve fibres) Arrector pili Root (2) associated with the root sheath muscle (penetrates - Arrector pili: smooth muscle from dermal collagen fibres (at & anchors to dermis) the papillary layer of the dermis) to the root sheath (sympathetic nervous system – Bulb (1) Hair matrix (deep in goose bumps) (keratinization) dermis, Vasculature epithelial cell growth occurs) Hair papilla: sole source of nutrition + division  fine , no colour in utero Differences in hair ↑ ONLY 3 types: lanugo (fine hair foetus to birth); vellus (most hair on body surfaces); terminal hair (longer, coarser, & pigmented) ↳ eyebrows eyelashes , , pubic hair Hair can vary in shape, length, diameter, and colour Cross-section of the hair: circular, triangular, or flattened, influencing the curl of the hair (from flat, curly, to coiled) Texture can be coarse (pubic hair) or fine (arm hair) depending on the keratin content (genetically predetermined) Colour is a result of synthesis of melanin by the melanocytes (different types of melanin) in the hair matrix  melanocytesare Anatomy of a follicle 2 Cortex: densely packed elongated Medulla: 2-3 layers of “soft” cells or whiteus greated keratinized cells (most of the hair) num irregular shape with presence of air J on the amount of air ↳ aging Root sheaths: epithelial & dermal melanocytes produce less melanin Melanocytes Hair papilla: hair matrix (germinal cells around papilla that give rise to all hard + scaly cells, including internal & external epithelial root Cuticle: single mu layer of sheaths) scaly (hardest keratin) flat cells overlapping one another (exposed edge pointing up) – coats the hair ↳ split ends  Hair growth cycle & hair loss Growth (active) stage: stem cells from hair matrix multiply & push existing cells superficially, these cells become keratinize & die (2-6 years in scalp hair) Regression stage: cells in hair matrix stop dividing, preventing further growth (club hair). Hair follicle atrophies (shrinks: 2-3 weeks) Resting stage: Metabolic activity is reduced, hair loses its anchorage & falls out after 3 months 85% of hair in growth stage at any given time, influenced by illness, diet, stress, hormones (70-100 hairs lost/day) Nails  Nail anatomy Free edge Eponychium Nail root Nail body (under skin) Nail body Nail body Food (?) Lunula -frommostem Distal Hyponychium Eponychium phalanx (cuticle) Clear scale-like modification of epidermis on distal, dorsal surface of fingers & toes (hard dead keratinized cells) Grow 1 mm/week from nail root (stratum basale - lunula)littleWhatna ~ Cells are clear, solid, and visible at the nail body (stratum corneum) Z Pink – oxygen in dermal layer; free edge is white (no underlying capillaries) Cuticle (eponychium): band of epidermis (stratum corneum) Hyponychium: nail bed (stratum corneum) serves to secure the nail Heart and Great Vessels Jennifer Hocking, PhD Division of Anatomy Faculty of Medicine and Dentistry University of Alberta 1  About me Anatomy Embryology Developmental Biology 2  Objectives Introduce heart and cardiovascular system Locate the heart within the body Follow the path of blood flow through the heart Discuss phases and regulation of the heartbeat Identify the great vessels 3 Components of cardiovascular system Pump > - of which there are I - The heart Conducting vessels - Arteries & veins Sites for exchange with the tissues - Capillaries Drainage system for excess tissue fluids - Lymphatic vessels 4 Functions of cardiovascular system Maintain homeostasis Transport of: - Metabolites and wastes - Hormones and signaling molecules - Dissolved gasses - Cells involved in immune and inflammatory responses Regulation of body temperature 5  Cardiovascular system O from to heart "figures" back body ③ ② ⑪ back to lungs body 2 circuits: - pericardium -diaphragm Do you see the heart? Nope ! 8  Pericardium tissue tough connective · pericardium external rt hea wall inside of heart ↓ fat Heart is encased within a tough fibrous sac, the pericardium/pericardial sac. 9  Pericardium and heart wall inner layer Myocardium · muscle Parietal (serous) pericardium epithelium smooth· Fibrous pericardium Endocardium (serous) Epicardium (aka Visceral pericardium) Serous fluid lubricates the smooth interface between pericardial sac (parietal pericardium layer) and epicardium of heart. prevents friction  blo t Anterior od pericardial sack Posterior collect anchored to limbs view diaphragm view ↑Superior A Superior vena cava most vena cava ↑ wheres ra base Right Right atrium atrium apex Inferior ventricles pointy vena cava part diaphragm Blood returning to the heart from systemic circulation enters the right atrium via the superior vena cava (SVC) and inferior vena cava (IVC) blood atroom A deox to right - 11  thin wall b collects blood Right atrium > - there' ventricle right "anti-chamber" Atrial appendage (auricle) Superior vena cava "Feeth on a ↑ comy" A ↓ Pectinate muscle Right posterior atrium o anterior enate appendages have Inferior vena cava Coronary sinus Right lateral view lower part pockets of heart are not flat of body & - muscular parts 12  Tricuspid valve and right ventricle flows pumonary ↳ seal togener ! opening trunk closed value flap in ought ventricle valve cusp mechanism to close is blood & once ventrice contracts ↳ papillary muscle chordae tendinae ↑ attached Trabeculae carnae Heart valves prevent blood backflow Papillary muscles and chordae tendinae Anterior view prevent cusps from prolapsing into atrium horizontal , close Canal 13 Pulmonary valve and right ventricle leaflets w/ packets pulmonary trunk Pulmonary semilunar valve when blood falls back , it pushes the blood again Pulmonary valve has three semilunar leaflets or cusps, Anterior view closed by backflowing blood. 14  Pulmonary trunk right pulmonary artery left pulmonary artery pulmonary trunk right would atrium what you right ventricle - touch Anterior view 15  Pulmonary arteries and veins ↳ named relative to the heart right pulmonary artery left pulmonary artery left pulmonary veins right pulmonary veins Anterior view Arteries carry blood away from the heart. Veins carry blood to the heart. ↳ blue Gred 16  Left atrium left pulmonary artery right pulmonary artery left pulmonary veins (2) left (2) atrium right pulmonary veins blood bring back left to heart from ventricle lungs Note the 4 pulmonary veins entering the heart. Posterior view 17  turn walled Left atrium contracts eentricle tot bit o ↳ collects blood Left atrial - Left atrium also has a smooth portion appendage and a portion with left atrium pectinate muscle. mitral (bicuspid) valve - AU value left ventricle z leaflets (bi) · The two AV valves · blood forces (tricuspid/mitral) work leaflets up in the same way, but the mitral valve has only 2 cusps. Left lateral view 18 Left ventricle and aorta ascending aorta RV LV LV Anterior view 19  Left outflow arrows for BF ascending aorta semilunar values - i mitral > left ventricle Left lateral-anterior view 20  Aortic semilunar valve Openings of the left and right coronary arteries aortic sinus nodule ↳ should meet cusp & value middle 21  Valves of the heart U value all arh located semilunars open same on the Anterior ↑ Pulmonary plane (BF) arrid Aortic Posterior entice Tricuspid ventricles when Bicuspid (mitral) when are contract ventricles relaxed 22 Blood flow & Heart valves i ↓ A R Atrium↓→ R Ventricle PT Tricuspid valve a LA RA L Atrium → L Ventricle Bicuspid (Mitral) valve R Ventricle → Pulmonary Trunk LV Pulmonary Semilunar valve RV L Ventricle → Aorta Aortic Semilunar valve Cardiac Septa wall Interatrial septum Interventricular septum Septa separate right and left atria, and right and left ventricles. Note difference in wall thickness between right and left ventricles.  Coronary blood vessels (coronary arteries and cardiac veins) aorta from extend - ↑ Left coronary artery undemardium ? Right coronary artery Anterior view Coronary vessels are the vascular supply to the heart tissue. 25  Coronary arteries usually short Left Coronary right Artery (LCA) atrium I branches : into splits right left ventricle ventricle 1) Circumflex branch Aorta of LCA right atrium (in coronary sulcus) a ar Right Coronary widoaker 2) Artery (RCA) left Anterior right (in coronary sulcus) ventricle ventricle interventricular artery Anterior view ie. ! (in anterior IV feeds sulcus) the ventricles and stuff conducting 26  extra : Coronary arteries "right sided " heart" left ventricle right ventricle Circumflex branch left of LCA ventricle RCA right finto ventricle Posterior interventricular Posterior view artery (in posterior IV sulcus) 27  Cardiac veins Anterior view Posterior view Great cardiac vein * anterior LV RV IV LV drains RV sulcus into Coronary sinus Coronary sinus collects deoxygenated blood from the heart tissue and delivers it to the right atrium. 28 Conduction system  Conduction system Contractile cells: 99% of myocardium Are responsible for contraction of heart Conductive cells: 1% of myocardium Specialized myocardial cells optimized for spontaneous depolarization and transmission of electrical signals disks include. intercalated [Gap junctions& present between cardiac myocytes allow ion flow to 1) synchronize muscle contraction and 2) transmit electrical signal. 30 fell Conduction system asleepew MANDA ! 1 Bachmann’s Bundle Sinoatrial Node contains lots ③ cells AV Bundle (of His) of conductive U Left bundle branch ⑪ Purkinje fibers S Y Atrioventricular (AV) node Right bundle branch ↳ pauses SA node is the pacemarker of the heart because it has fastest rate of spontaneous depolarization. 31  Cardiac cycle All the events associated with one heartbeat The two atria contract while the ventricles relax The two ventricles contract while the atria relax Diastole = relaxation phase 6 Systole = contraction phase vivalternicular 32 Cardiac * not too many cycle details  Heart Sounds Normal values closing sound of Lub = AV valves closing, Dub = Semilunar valves closing  Listening to the heart Pulmonary Valve Area Aortic Valve Area Mitral Valve Area Tricuspid Valve Area By placing the stethoscope at specific areas of the chest, the sounds of individual valves can be amplified. "don't need to know exact placement" 35  Electrocardiogram (ECG, EKG) lead : of electrodes pairing By placing electrodes on the skin, one can measure the electrical activity of the heart. Each region produces its own signal, which all add together to create a characteristic waveform for each heartbeat. 36 Electrocardiogram (ECG, EKG) same thing ! normal abnormal don't need to read ECE 37 Great vessels 38 Arch of aorta branches anterior > - posterior arch - Right common carotid artery Right subclavian artery ↳ under clavicle Brachiocephalic head Trunk ↓ one ! only 39 Arch of aorta branches Left common carotid artery Left subclavian artery 1 23 No brachiocephalic trunk on the left! 40  Pulmonary trunk Left pulmonary Right artery pulmonary Pulmonary trunk artery 41  Great vessels: veins Pulmonary veins (x4) Superior vena cava Inferior vena cava 42  7 1a 3a 3b 3a 7 1a 3 4a 5 4b 1 1 * 2 6 1b 6 2 Anterior view Posterior view 43 Terms of Use & Students of the Faculty of Medicine & Dentistry, University of Alberta may display, download, or print slides and images associated with this presentation for personal and educational use only. 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Users may not disseminate any portion of this presentation through electronic means except as outlined above, including mail lists or electronic bulletin boards. 44  / 45 1. Right Atrium (1a =SVC, 1b =IVC) 2. Right Ventricle 3. Pulmonary Trunk (3a=left pulmonary artery, 3b=right pulmonary artery) 4. Pulmonary Veins (4a=Left, 4b=Right) (note, there are inferior and superior left and right pulmonary veins. The ones labelled are the inferior ones) 5. Left Atrium 6. Left Ventricle 7. Aorta Red arrow = RCA, Blue arrow = Anterior interventricular artery, White asterisk = coronary sinus Blood and Lymph Systems Jennifer Hocking, PhD Division of Anatomy, Department of Surgery University of Alberta 1  Objectives Introduce components and functions of blood and lymph Discuss attributes of various blood vessels Cover major arteries and veins Discuss the lymphatic system, including vessels, organs and tissues 2 Classification of Blood and Lymph 3  Fluid Connective Tissues Blood - composed of formed elements & plasma - plasma forms fluid matrix Lymph - composed of lymphocytes & lymph fluid - lymph fluid is a dilute solution of proteins & excess interstitial fluid 4  Blood Distributes nutrients, oxygen and hormones to body cells Carries metabolic wastes away from cells, primarily to the kidneys for excretion Carries carbon dioxide away from tissues to lungs Transports cells of the immune system that provide protection against infection and disease 5  Blood Volume in body - 5-6L in average male - 4-5L in average female - Normovolemic vs. hypovolemic/hypervolemic pH = 7.35 – 7.45 Temperature = 38℃ 6 Blood Plasma Blood Plasma 7  Formed Elements in Blood Red blood cells (erythrocytes) – carry O2 and CO2 (99% of cells in the blood) White blood cells (leukocytes) - Neutrophils: destroy bacteria - Eosinophils: anti-parasitic, allergic response - Basophils: inflammatory response - Monocytes: become macrophages - Lymphocytes: immune response Platelets – clotting reaction 8  Red Blood Cells Biconcave disc-shaped cells > - SA advantage Plasma membrane surrounds cytoplasm containing water (66%) and proteins (33%) - Intracellular structures, including nucleus, are ejected from cell during development – not needed for main purpose of gas transport 9  Platelets not cell , cellular fragments Megakaryocyte Lung Platelets Formed from large stem cells called megakaryocytes in the red bone marrow and lung Platelets are membrane-bound enzyme packets that pinch off from the cytoplasm of the megakaryocyte Responsible for the clotting reaction in blood 10  Blood Vessels Pathways for blood to circulate throughout the body Blood flows in two directions: - Away from heart - Arteries, arterioles, capillaries - Toward the heart - Veins, venules, capillaries 11 Structure of Blood Vessels Composed of connective tissue, attaches vessel to surrounding tissue Composed of elastic fibers & smooth muscle, regulates diameter Composed of simple squamous epithelium (endothelium) & thin layer of connective tissue 12 Structure of Artery and Vein Media is largest layer in arteries. Adventitia is largest layer in veins. 13 Elastic (Conducting) Arteries Largest diameter arteries Media contains high density of elastic fibers. Also has smooth muscle, but less per volume. Intima Media Stretch & recoil in response to Adventitia pumping of heart Even out pressure surges Muscular (Distributing) Arteries Medium-sized arteries Distribute blood to skeletal muscles & internal organs Adventitia Media Media contains predominantly endothelium smooth muscle Intima Able to vasoconstrict (close) & vasodilate (open) 15  Arterioles Small to microscopic vessels Poorly defined adventitia Smooth Media composed of scattered muscle cells smooth muscle cells Intima Deliver blood to capillaries Basement membrane Change in luminal diameter regulates blood pressure 16  Capillaries Smallest blood vessels, connect arterioles to venules Have an endothelium and basement membrane Mediate exchange between blood and surrounding tissues Basement membrane 17  Capillaries Mediate exchange through: diffusion, active transport, gaps between cells or holes in cells (fenestrations) Basement membrane ! have holes Continuous capillary Fenestrated capillary Discontinuous capillary (e.g., in muscle) (e.g., in kidney) (e.g., in liver) 18  Sinusoids Sinusoids are expanded capillaries in the liver, spleen and bone marrow. They are fenestrated, discontinuous, and have an incomplete basement membrane. 19 Control of Blood Flow in Capillary Bed Precapillary sphincters control blood flow through capillaries Metarterioles connect arterioles to capillaries. When sphincters are closed, they shunt blood to venules via throughfare channels. 20  Veins Collect blood from organs & tissues & return it to the heart Contain 65-70% of the blood in the body Veins have larger capacity to stretch than arteries and can therefore act as a blood reserve. Medium & Large Veins - Slender media, adventitia is thickest layer Venules - Collect blood from capillaries - Wall composed primarily of intima 21  Venous Valves Valves in the walls of veins prevent the backflow of blood in arms and legs. Venous compression caused by contraction of adjacent muscles aids in maintaining blood flow. ↑ BE 2 leaflets v> 3 in dout a 22  Arteries of thorax A P Arch of the aorta Ascending aorta Descending aorta Left lateral view Anterior view 23  Posterior Intercostal Arteries ↓ under the rib wrap around Anterior view , the torso Superior view P A Posterior intercostal arteries 3-11 arise from the descending aorta 24  Anterior Intercostal Arteries Anterior view Superior view P Subclavian artery A anastomosis" * * artery > - artery Right and left internal thoracic arteries (internal mammary arteries, IMA) d branches of subclavian arteries Internal view Anterior intercostal arteries branches to the ribs giving 25  Intercostal Arteries P Superior view A Anterior and posterior intercostal arteries anastomose with one another. 26  Common Carotid Arteries Right common Left common carotid artery carotid artery Anterior view 27  Common Carotid Arteries Internal carotid arteries Left internal are the primary blood carotid artery supply to the brain. Left external External carotid arteries carotid artery supply the neck and face. Left carotid sinus Carotid sinus (swollen split * > - region at base of Left common internal carotid) contains carotid artery baroreceptors that measure blood pressure Anterior view 28  Vertebral Arteries Another blood supply to brain (20%). Branches of subclavian arteries. vertebral Left arteries vertebral common carotid artery arteries Subclavian a. Anterior view Anterior-superior view Posterior-right lateral view 29  Subclavian Arteries blood to limbs major supply upper Boundary 1: First rib Axillary artery Boundary 2: Brachial Teres major artery muscle All subdivisions of the same artery: Subclavian: Emerges from aorta (left)/brachiocephalic artery (right) and travels under clavicle Axillary: Passes through armpit (axilla) Brachial: Travels through upper limb until branches into radial and ulnar arteries 30  Common Iliac Arteries Right common Left common iliac artery iliac artery Descending aorta Arteries to * Left external iliac artery abdominal viscera Left internal iliac artery Descending aorta divides into left and right common iliac arteries, which each divide into external and internal iliac arteries. Internal iliac arteries supply pelvic viscera. 31  Femoral Arteries External iliac artery Inguinal ligament where femoral her Femoral artery External iliac artery becomes femoral artery when it passes below the inguinal ligament. 32 Veins Veins trace similar paths to arteries and typically have the same name (e.g., facial artery, facial vein). However, there are some exceptions. 33 * note "antagonist" arteries Veins of Thorax skull originate in Right internal jugular v. Left internal jugular v. as opposed to the common carotid ( Right subclavian v. Left subclavian v. * * Right brachiocephalic v. Left brachiocephalic v. Superior vena cava 34  Internal Jugular Vein m O Internal jugular vein Common carotid artery Internal jugular vein transports deoxygenated blood from brain. Also Left lateral view of neck receives branches from head and neck. 35  Inferior Vena Cava blood collecting below the diaphrage Note the large renal Inferior vena cava veins. But where are the Common iliac veins veins draining the GI Ifusion of external system? and internal Femoral veins 36  Hepatic Portal System liver Hepatic portal vein stomach All blood returning from the abdominal GI system is directed into the hepatic portal vein, which distributes it to the liver for processing before the blood can enter into general circulation. 37  Body Fluids ⑳in Intracellular fluid – cytoplasm, nucleoplasm, etc. Extracellular fluid - Blood plasma – in the circulatory system - Interstitial fluid – bathes the cells of the body - Filtrate of fluid and small solutes out of capillaries to the areas surrounding cells - Called “lymph” when it enters the lymphatic vessels 38  Lymphatic System contract : not a circuit. essentially "dead" Produce, maintain and distribute lymphocytes - Function in the immune response Assists with maintaining normal blood volume - Vascular pressure forces water and solutes across capillary membrane into interstitial space - That fluid is returned to the vasculature by the lymph vessels Alternate route for transport of hormones, nutrients, metabolic waste - E.g., Lipids absorbed by digestive tract enter bloodstream via lymph rather than via capillaries of the vasculature 39  Lymphatic System Includes: - Lymphatic vessels - Thin vessels that transport lymph, eventually returning it to blood - Lymphatic Organs - Organs where lymphocytes differentiate or reside - Enclosed by a fibrous capsule - Bone marrow, thymus, lymph nodes, spleen - Lymphatic Tissue - Connective tissue network containing dense aggregates of lymphocytes - No capsule - E.g., Tonsils, lining of appendix 40  Lymphatic System Lymph flows passively along a pressure gradient (i.e., no pump). Lymphatic system is extremely low pressure Vessels very thin walled Lymph nodes are oval lymphoid organs 1 – 25 mm in diameter 41 Lymphatic Vessels ~ 3.6L, 70% of blood volume, enters interstitial fluid every day. Lymphatic capillaries absorb fluid through gaps between overlapping endothelial cells. Act like one-way valves so fluid can’t leak back out. 42  Valves in Lymphatic Vessels Lymphatic vessels have many valves to prevent backflow. Valves are similar to those in veins, but region around valve bulges, giving lymphatic vessels a beaded appearance 2 flaps 43  Lymphatic Ducts brachicephalisa Drainage of right lymphatic duct I Right zorta lymphatic duct ↑ Drainage of thoracic duct Thoracic duct Cysterna chyli feeds into ↳ in some ppl thorac duct Lymphatic ducts collect lymph and empty it into large thoracic veins.  Lymphocytes Lymphocytes are the primary WBCs of the lymphatic system. Components of adaptive immune system: B-cells (“from bone marrow”): produce antibodies in response to foreign antigens T-cells (“from thymus”): produce cellular responses to foreign antigens, including killing invading cells or signaling to prompt responses from other immune cells. Component of innate immune system: Natural killer cells: surveillance cells, can attack any cells that appear foreign or diseased, including cancer.  Lymphocytes ① ② ① ① circulate Continuously Reside in lymph Reside in bone circulate through nodes, spleen, marrow, spleen, peripheral tissue lymphoid tissue lymphoid tissue 46  Lymphatic Organs Discrete structures enclosed by a fibrous connective tissue capsule Primary – produce, maintain and store lymphocytes - contain stem cells that generate B, T, and NK cells - E.g., bone marrow, thymus gland Secondary (peripheral) structures – where most immune responses are initiated - Activated lymphocytes divide to produce additional lymphocytes of same type - The front line where invading bacteria first encountered - E.g., spleen, lymph nodes 47  Thymus Gland Lies posterior to manubrium in the superior mediastinum Two lobes Large in early life, it undergoes involution in later life Source of T lymphocytes (differentiate, mature, proliferate here)  Spleen A Largest lymphoid organ P Sits in upper left quadrant of abdomen, against posterior body wall. Filters the blood, removing abnormal blood cells and components by phagocytosis Stores iron recycled from metabolized RBCs Initiates immune response by B and T cells in response to circulating antigens Visceral Surface  Lymph Nodes Many afferent vessels penetrate fibrous capsule Lymph nodes filter the lymph, removing 99+% of antigens Capsule Resident lymphocytes (major site of immune response to antigens) Lymph “glands” – large nodes at base of neck, axillae, groin “Swollen glands” – enlarged nodes due to inflammation or infection One efferent vessel exits nodes  Lymphoid Tissues Connective tissues dominated by lymphocytes. Lack a surrounding capsule, so are not lymphoid organs Often present near external surfaces Diffuse - mucous membranes of respiratory and urinary tracts Nodules - Aggregations of densely packed lymphocytes supported by dense reticular fibres - Boundaries often indistinct due to lack of fibrous capsule - Mucosa of digestive tract - wall of pharynx (tonsils) - lining of small intestine (Peyer’s patches) - appendix – mass of fused lymphoid nodules - Immune defenses are sometimes overwhelmed è tonsillitis, appendicitis, etc 51  Lymphoid Nodules Small intestine Tonsils Densely packed accumulations of lymphocytes. Have germinal centres where lymphocytes are dividing. Terms of Use Students of the Faculty of Medicine & Dentistry, University of Alberta may display, download, or print slides and images associated with this presentation for personal and educational use only. Educational use refers to classroom teaching, lectures, presentations, rounds, and other instructional activities. Distribution or posting of these slides or presentation materials outside of the Faculty of Medicine & Dentistry is prohibited unless the express permission of the author(s) is obtained. Under no circumstances is commercial use of these presentation materials permitted. Users may modify the downloaded slides or handouts for personal educational use. Such modification might include note-taking. However the authorship, source and any attributions embedded in any form of this presentation may not be modified. Users may not otherwise copy, print, transmit, rent, lend, sell or modify any of the slides or notes associated with this presentation. Users may not modify or remove these guidelines or any other usage notices contained herein, or create derivative works based on these materials. Users may not disseminate any portion of this presentation through electronic means except as outlined above, including mail lists or electronic bulletin boards. 53 The Nervous System Christine A. Webber, PhD Division of Anatomy Faculty of Medicine and Dentistry University of Alberta 15 October 2024 Anatomy 200 - Webber 1  Objectives Describe the organization of the nervous system Contrast the different types of cells in the nervous system and explain their functions and actions Contrast the differences and similarities among glial cell types within the central and peripheral nervous systems Explain the relevance of the meninges Describe the regions of the cerebrum and explain their significance Explain how information is transported within the brain. Give examples of when this would occur. Describe the cerebellum and brainstem. Provide examples of their functions. Explain how the brain receives its blood supply. 15 October 2024 Anatomy 200 - Webber 2  Overview of the Nervous System Nervous System Central Nervous System Peripheral Nervous System (CNS) (PNS) Brain Spinal Cord Everything Else 3 15 October 2024 Anatomy 200 - Webber  NERVOUS SYSTEM CNS PNS Integrates, processes & coordinates sensory data Carries sensory information & motor commands from receptors to CNS (Afferent division) Seat of higher functions: Carries motor commands -Intelligence from the CNS to periphery -Memory (Efferent division) -Learning -Emotions  NERVOUS SYSTEM CNS PNS BRAIN SPINAL CORD CRANIAL Nerves Cerebrum SPINAL Nerves Cerebellum Brainstem Cell bodies are in ganglia Cell bodies are in nuclei Axons are in nerves Axons are in tracts  Peripheral Nervous System PNS Somatic Autonomic (Visceral) Motor Sensory Motor Sensory Sympathetic Parasympathetic 15 October 2024 Anatomy 200 - Webber 6  nn=nerve Review gg=ganglia Nervous System CNS PNS Brain Spinal Cord Cranial nn, Spinal nn, Peripheral gg Cerebrum Somatic Autonomic Cerebellum Motor Sensory Motor Sensory Brainstem Sympathetic Parasympathetic 15 October 2024 Anatomy 200 - Webber 7  Cells in the Nervous System Neurons - Nerve cells that conduct signals Neuroglia - Support cells for the neurons 15 October 2024 Anatomy 200 - Webber 8  Neurons The brain has about 100 billion (1011) neurons Neurons form connections to other cells via synapses - 1015 synapses - Each neuron has about 100,000 connections with other neurons 15 October 2024 Anatomy 200 - Webber 9  Functional Unit= Neuron Neurons encode information and conduct it over considerable distances and transmit it to other neurons or various non-neuronal cells 10  The Action Potential Pres Postsynaptic Neuron yna Dendrites Neu pt i ron c N AXON Synaptic Terminal Schwann Nodes of Receptors/Ion Cells Channels Ranvier 11  The Action Potential Microtubules 12 The Action Potential 13 Synapse: -Point of contact of an axon terminal with another cell -Transmits nerve impulse via neurotransmitter 14  The Action Potential Na+ Na+ Action Potential reaches synaptic terminal: -neurotransmitters released into synaptic cleft 15  Sensory Neuron Motor Neuron Dendrites Dendrites Axons Axon Bipolar Basic Classification of Neurons Unipolar Multipolar  Terminology: Nerve Cell Bodies and Axons Nucleus - A collection of nerve cell bodies within the central nervous system Tract - A collection of nerve cell bodies within the central nervous system Nucleus Ganglion A collection of nerve cell bodies in the peripheral nervous system Nerve Ganglion - A collection of axons in the peripheral nervous system 15 October 2024 Anatomy 200 - Webber 17  Neuroglia - Support cells for the neurons - PNS: Schwann cells and satellite glial cells - CNS: Astrocytes, Oligodendrocytes, Microglia, Ependymal cells 15 October 2024 Anatomy 200 - Webber 18 Cells of the PNS Satellite Cells -surround sensory neuronal cell body -supportive role (regulate neurotransmitters, O2, CO2) Node of Ranvier Sensory Neuron Schwann Cells -Myelinate peripheral axons (sensory and motor) -One Schwann cell per myelinated segment 19  Cortical Neuron (CST motor neuron) 20  CNS Protection Meninges – cover and protect the CNS - Dura Mater - Tough outer layer - Arachnoid Mater - CSF – cerebrospinal fluid - Pia Mater - Intimate contact CNS floats in cerebrospinal fluid 15 October 2024 Anatomy 200 - Webber 21 Brain (under Pia Mater) Arachnoid Mater Dura Mater Calvaria – Skull Cap Pericranium Scalp  Dura Mater Arachnoid Mater Arachnoid Mater  Surface of brain is Sulcus (sulci) Gyrus (gyri) covered by pia mater Anterior 3 main parts of the Brain Cerebrum Anterior Brainstem  Cerebrum Higher cognitive functions - thought, intellect, planning, creativity Language and speech - formulation & comprehension Somatic motor function - regulates skeletal muscle activity - regulates and coordinates movement (basal ganglia) Somatic sensory function - interpret stimuli from environment Regulates the emotional aspects of behaviour 15 October 2024 Anatomy 200 - Webber 27  Superior view (looking down onto brain) Left Right Hemisphere Hemisphere Longitudinal (Interhemispheric) Fissure Superior view (looking down onto brain) Frontal Pole (Anterior) Temporal Temporal Pole Pole Occipital Pole (Posterior)  Lateral view (looking at the brain from the side) LOBES OF THE CEREBRUM Sulcus (sulci) Gyrus (gyri) Central (Rolandic) sulcus Anterior FRONTAL PARIETAL Lateral (Sylvian) fissure OCCIPITAL TEMPORAL LOBES OF THE CEREBRUM Lateral view (looking at the brain from the side) Parietal Lobe ex ex Frontal Lobe Cort Cort sory Motor otor Perception n Planning Occipital Lobe tose of self in ary M space o ma Prim Perception Vision ry S a Prim Thinking, Planning, Learning & Memory Personality Hearing Temporal Lobe PreCG=precentral gyrus (primary motor cortex) PosCG=postcentral gyrus (primary sensory cortex) Neurons reside in the ‘cortex’  Motor Homunculus PreCG=precentral gyrus (primary motor cortex) 15 October 2024 Anatomy 200 - Webber 32  Somatosensory Homunculus PosCG=postcentral gyrus (primary sensory cortex) 15 October 2024 Anatomy 200 - Webber 33 LOBES OF THE CEREBRUM Parietal Lobe leg/foot/toes knee knee hip hip trunk trunk Frontal Lobe arm arm hand hand Motor Perception Planning of self in Occipital Lobe space face face Perception Vision lips lips tonguetongue Thinking, Planning, Learning & Memory Auditory Cortex, Personality Hearing Learning & Memory Temporal Lobe PreCG=precentral gyrus (primary motor cortex) PosCG=postcentral gyrus (primary sensory cortex) Coronal Section of Cerebral Cortex White Matter (medulla)  Neuronal cell bodies reside in cortex (gray matter) Axons extend into medulla (white matter)  Fibre Tracts in the Brain Association fibres - intrahemispheric connections - short or long Commissural fibres - interhemispheric connections Projection fibres - travel to and from cortex 15 October 2024 Anatomy 200 - Webber 37  Coronal Section of Brain i) Short association fibers ii) Long association fibers iii) Commissural fibers iv) Projection Fibers (i) (iii) White matter (iv) ii) Long association fibers  GYRUS CORTEX SULCUS (grey matter) i) SHORT ASSOCIATION FIBERS MEDULLA (interconnect adjacent gyri) (white matter) ii) LONG ASSOCIATION FIBERS (interconnect cerebral lobes) Cingulum  Cerebral Cerebral hemisphere hemisphere iii) COMMISSURAL FIBERS (interconnect hemispheres) Corpus callosum iv) PROJECTION FIBERS (crossed) Motor tract Sensory tract Definition: Axon bundles within the CNS= tract 3 main parts of the Brain Cerebrum Anterior Brainstem  Cerebellum Superior view (looking down onto Cerebellum)  Cerebellum Acts as a comparator – compares intended movement with evolving movement and corrects for errors Ensures movements are smooth, coordinated and purposeful (skilled) Regulates posture and balance Disease – cerebellar ataxia (intention tremor, lack of balance and coordination) 15 October 2024 Anatomy 200 - Webber 45 3 main parts of the Brain Cerebrum Anterior Brainstem  Brainstem Midbrain Pons Medulla (Obl