Reviewer Anatomy And Physiology PDF

lOMoARcPSD|45814163 Reviewer Anatomy AND Physiology Anatomy and Physiology (Our Lady of Fatima University) Scan to open on Studocu Studocu is not sponsored or endorsed by any college or university Downloaded by...

lOMoARcPSD|45814163 Reviewer Anatomy AND Physiology Anatomy and Physiology (Our Lady of Fatima University) Scan to open on Studocu Studocu is not sponsored or endorsed by any college or university Downloaded by LIL ANN DELA CRUZ ([email protected])  lOMoARcPSD|45814163 ANATOMY AND PHYSIOLOGY NOTES/REVIEWER 1ST SEMESTER – PRELIM EXAMS REVIEWER Autoregulation -Cells lack oxygen, chemicals would be released dilate OUTLINE blood vessels. I Main Topic 1 Extrinsic Regulation A Subtopic 1 -During exercise nervous system commands inc of heart i Subsubtopic 1 rate so blood will be circulate faster. ii Subsubtopic 2 B Subtopic 2 ESSENTIAL LIFE PROCESSES C Subtopic 3 1. Organization -living things are highly organized II Main Topic 2 2. Metabolism -includes all the chemical processes that A Subtopic 1 occur in the body. B Subtopic 2 C Subtopic 3 3. Responsiveness -the body’s ability to react to changes in environment both internally or externally. 4. Reproduction -formation of new cells for growth, INTRODUCTION OF HUMAN ANATOMY AND PHSIO repair or replacement or the production of a new Human Anatomy individual. -Study of the normal structures of the body and their 5. Movement -motion occurring inside the human body, relationships with one another. either the whole body or individual cells or even the Human Physiology organelles within these cells. -Study of different functions of the normal structures of the 6. Differentation -development of cells from an human body and the involved processes of how these body unspecialized to a specialized state. parts work. 7. Growth -an increase in body size that results from an DIVISIONS OF HUMAN ANATOMY increase in the size or number cells. Gross/ Macroscopic Anatomy STRUCTURAL ORGANIZATION OF THE BODY -Study of normal structures of the humanbig enough to be studied by unaided eye. 1. Chemical level 1. Systemic Anatomy 2. Cellular level 3. Tissue level Study of normal structures of specific body 4. Organ level systems. 5. System level 2. Regional Anatomy Study of structures by body regions. Cells 3. Surface Anatomy o Smallest units of life Study of the landmarks on the body surface of o Perform all activities necessary to maintain life different visceral organs. Ex. Metabolism, assimilation, digestion, excretion, Microscopic Anatomy reproduction -Study of structures of human body through the use of Tissues microscope. o Made up of different types of cells 1. Cytology o Epithelial -covers and protects Chemical and microscopic study of cells. o Connective -binds and support other tissues. 2. Histology o Muscle -movement Study of normal tissues of the body. o Nervous -connects sensory structures to motor Embryology structures. -Study of development of the human body from o Hemopoietic -pertaining to the formation of blood fertilization of ovum up to the period of extrauterine life cell; stem cells in bone marrow. Neuroanatomy Organs -Study of normal microscopic, gross features and o Tissues with same function grouped together. development of the nervous system. Ex. Liver and stomach Systems DIVISIONS OF HUMAN PHYSIOLOGY o A group of organs that perform a common Cell Physiology function. -Study of the functions of living cells BODY SYSTEMS -Cornerstone of human physiology 1. Integumentary System Special Physiology -provides protection, regulates temperature, prevents -Study of functions of specific organs water loss, help produce vitamin D. Systemic Physiology Ex. Hair, Skin -All aspects of the functions of specific organ system. 2. Skeletal System Pathologic Physiology -provides protection and support, allows body -Study of the effects of diseases on organ or system movement, produces blood cells, and stores minerals function. and adipose tissue. Ex. Skull, clavicle, sternum, ribs, humerus, vertebral HOMEOSTATIS column, pelvis, radius, ulna, femur, tibia, fibula -Maintenance of the body’s internal environment. 3. Articular System -Negative feedback loop. -The articular system deals with joints of the body and HOMEOSTASIS REGULATION the surrounding tissues. Downloaded by LIL ANN DELA CRUZ ([email protected]) 1  lOMoARcPSD|45814163 Ex. Major joints: synovial joints, fibrous joints, 2. Sagittal Plane -one side is not proportional cartilaginous joints. 3. Coronal/Frontal Plane -front and back Tissues: ligaments, tendon, cartilage 4. Horizaontal/Transverse Plane -up and down 4. Mascular System -produces body movements, maintains postures, and produces body heat. Ex. Temporalis, pectoralis major, biceps brachii, rectus abdominis, sactorius, quadriceps femoris, gastrochemius. 5. Lymphatic System -removes foreign substances from the blood and lymph Ex. Tonsils, thymus, cervical lymph node, axilliary lymph node, inguinal lymph node, mammary plexus, thoracic duct, spleen, lymphatic vessel 6. Respiratory System -exchanges oxygen and carbon dioxide Ex. Nasal cavity, nose, pharynx (throat), larynx, trachea, bronchi, lungs 7. Digestive System -absorption of nutrients, and elimination of wastes. Ex. Pharynx, oral cavity, salivary glands, esophagus, stomach 8. Nervous System -A major regulatory system that detects sensations and controls movements, physiological processes, and intellectual functions. SECTIONS OF THE BODY Ex. Brain, spinal cord, nerves, and sensory receptors. 1. Longitudinal/Vertical Section 9. Endocrine System 2. Transvere/Cross Section -A major regulatory system that influences metabolism, 3. Oblique Section growth, reproduction, and many other functions. Ex. Glands, such as the pituitary, that secrete hormones. 10. Cardiovascular System -Transports nutrients, waste products, gases, and hormones throughout the body; plays a role in the immune response and the regulation of body temperature. Ex. Heart, blood vessels, and blood 11. Urinary System -Removes waste products from the blood and regulates blood pH, ion balance, and water balance. Ex. Kidneys, urinary bladder, and ducts that carry urine. 12. Female Reproductive System -Fertilization and fetal development Ex. Mammary gland (in breast), uterine tube, ovary, uterus, vagina 13. Male Reproductive System -Produces and tranfers sperm cell to the female and produces hormones that influence sexual functions THE ATONOMICAL TERMS OF RELATIONS and behaviors. A. Superior (cranial or cephalad) Ex. Seminal vesicle, ductus deferens, prostate gland, -toward the head end or upper part of a structure or the testis/testes, epididymis, penis body; above Ex: the forehead is superior to the nose. BODY REGIONS 1. Head 2. Neck 3. Trunk a. Thorax b. Abdomen c. Pelvic Cavity d.Perineum 4. Upper Extermities 5. Lover Extermities ATONOMICAL PLANES B. Inferior (caudal) -away from the head end or toward the lower part of a 1. Median Plane -the very center point structure of the body; below Downloaded by LIL ANN DELA CRUZ ([email protected]) 2  lOMoARcPSD|45814163 Ex: the navel is inferior to the breastbone. Ex: the elbow is proximal to the wrist C. Anterior (ventral) -toward or at the front of the body; in front I. Distal Ex: the breastbone is anterior to the spine -farther from the origin of body part Ex: the knee is distal to the thigh D. Posterior (dorsal) -toward or at the backside of the body; behind Ex: the heart is posterior to the breastbone J. Superficial - toward or at the body surface Ex: the skin is superficial to the skeleton E. Medial - toward or at the midline of the body; on the inner side Ex: the heart is medial to the arm K. Deep - away from the surface; more internal Ex: the lungs are deep to the rib cage F. Lateral -away from the midline of the body; on the outer side of body. Ex: the arms are lateral to the chest. ABDOMINOPELVIC QUADRANTS Right Upper Quadrant Left Upper Quadrant Right Lower Quadrant G. Intermediate Left Lower Quadrant -between a more medial and a more lateral structure Ex: the armpit is intermediate between the breastbone and ABDOMINOPELVIC REGIONS shoulder Right Hypochondriac Region o Liver o Gallbladder o Right Kidney Epigastric Region o Stomach o Liver o Pancreas H. Proximal o Right and left kidneys -close to the origin of the body part or attachment of a Left Hypochondric Region limb to the body trunk o Stomach Downloaded by LIL ANN DELA CRUZ ([email protected]) 3  lOMoARcPSD|45814163 o Liver (tip) 8. Organization o Left kidney PRINCIPAL PARTS OF EUKARYOTIC CELL o Spleen 1. Cell Membrane Right Lumbar Region o Trilaminar o Liver (tip) o Semipermeable o Small intestines 2. Cytoplasm o Ascending colon o Colloidal o Right kidney o With organelles, inclusions, and Umbiligal Region cytoskeletion o Stomach 3. Nucleus o Pancreas o With DNA in the form of: o Small Inestines a. Heterochromatin (inactive) o Transverse colon b. Euchromatin (active) Left Lumbar Region o Small intestines o Descending colon The Cell Membrane o Left kidney -Double phospholipid layer with embedded proteins (TRILAMINAR) Right Iliac Region o Small intestines Membrane transport o Appendix -selectively permeable membrane o Cecum o Osmosis o Assending colon o Protein channels o Active transports Pubic Region o Fluid mosaic model o Small intestines o Sigmold colon o Bladder TRANSPORT PROCESS ACROSS CELL MEMBRANE Left Iliac Region Passive o Small intestines o Simple Diffusion o Descending colon o Facilitated Diffusion o Sigmold colon o Osmosis o Filtration CELL Active The cell is the basic unit of biological organization. o Hold Basic composition Phagocytosis -holds contents of o Protoplasm/cytoplasm secretory vesicles o Cell membrane o Release o Nucleus Pinocytosis -release contents of Two types of cells: secretory vesicles o Prokaryotic Simple Diffusion o Eukaryotic -movement of solute from an area of high solute concentration to an area of low solute concentration. PROKARYOTIC VS EUKARYOTIC Facilitated Diffusion -movement of solute from an area of high solute PROKARYOTIC EUKARYOTIC concentration to an area of low solute concentration Organism Bacteria Protist, fungi, with a carrier. plants, and Osmosis animals -movement of solvent (water) from an area of low Organelles Few/none Nucleus, solute concentration to an area of high solute mitochondria, ER, concentration. etc. Active Transport DNA Circular/ in the Linear/Circcular -movement of solute from an area of low solute cytoplasm Bounded by a concentration to an area of high solute concentration. membrane RNA and Protein RNA and Protein RNA synthesized synthesized in the in the same nucleus/protein I Cytoplasm of the cell compartment the cytoplasm o Mostly water with chemical compounds in solution or colloid Cell Division Binary Fission Mitosis/meiosis o Polar compounds go into solution o Nonpolar compounds go into colloidal PHYSIOLOGIC PROPERTIES OF CELL suspension 1. Irritability/Excitability o With organells. Inclusions, cytoskeleton 2. Conductability 3. Contractility 4. Absorption and secretion 5. Excretion ORGANELLES 6. Respiration 1. Mitochondria (chondriosome) 7. Growth and Reproduction 2. Ribosomes Downloaded by LIL ANN DELA CRUZ ([email protected]) 4  lOMoARcPSD|45814163 3. Endoplasmic Reticulum b. Endogenous - from inside the organism or is a. Rough/Granular ER synthesized inside the organism. b. Smooth/Non-Granular ER Ex. hormones, illness (like endogenous depression), 4. Golgi Complex (Dictyosomes) and mutations. 5. Lysosomes 1. Lipofuscin a. Primary Lysosome 2. Melanin b. Secondary Lysosome 3. Hemoglobin c. Residual Bodies 4. Bilirubin 6. Peroxisomes/Microbodies 7. Melanosomes 4. Cytals 8. Secretory Granules a. Crystals of reinke b. Crystals of charcot – bottcher THE MITOCHONDIRIA Powerhouse of the cell CYTOSKELETON Cristae -inner folds where cellular respiration occurs 1. Microfilaments (7nm in dia.) Synthesize ATP -provide mechanical support and generate force for Energy requirements of cell determine cristae number movement. Also accumulate Ca+, synthesize nucleic acids and 2. Internediate Filaments (10nm in dia.) protein, oxidation of fatty acid. -larger than microfilaments but smaller than microtubules. THE RIBOSOMES a. Keratin -epithelial cells b. Vimentin -mesenchymal cells Distributed throughout cytoplasm c. Desmin -muscle cells Attach to RE reticulum d. Glial fibrillary protein -glial cellsof nervous No memberane covering system Site of protein synthesis free ribosomes—protein for e. Neurofilaments -neurons intracellular use 3. Microtubules (25nm in dia.) -They are the stiff components of cilia and flagella ENDOPLASMIC RETICULUM (ER) a. Centrioles -determine polarity of cell System of membrnes that makes up channels b. Basal bodies -anchoring points of cilia and Connects with outer nuclear and cell membranes flagella Types of ER: c. Cilia -line respiratory tract o Rough -for protein synthesis attached d. Fagella -tail of spermatozoa ribosomes o Smooth -fat transport and sex hormones CENTRIOLES synthesis, HCL synthesis, release and Two centrioles at the right angles to each other recapture Ca+ in skeletal muscle. Composed of nine sets of triple fibers Form spindle fibers during cell division GOLGI APPARATUS Guide duplicated chromosomes to daughter cells Collection of flat saclike cisternae Concentration and collection of cellular compounds CILLA AND FLAGELLA Storage warehouse of the cell Hairlike protrusions from cell membrane Carbohydrate synthesis site Nine double fibrils around two single central fibrils “Packaging” Cilia move materials across cell surface LYSOSOMES THE NUCLEUS Digestive enzymes packages Control center of the cell With acid hydrolaces Nuclear memberane has pores to allow substances Lack oxidaces and catalases passage Function: Chromatin -genetic material inside nucleoplasm -it plays a role in cellular deffense ❖ Digest stored food CELL CYCLE ❖ Maintenance and repair of organelles Interphase ❖ Suicide agens for old or weak cells 18-24 hours Inactive/resting phase PEROXISOMES Four phases of INTERPHASE: Catalase 1. G1 (gap 1) phase Oxidase (-)DNA synthesis Inclusions: (+)RNA and protein synthesis 1. Glycogen 30-50% of length of interphase 2. Lipid 2. G0 phase 3. Pigments Cells pull out of the cycle a. Exogenous - from outside the organism, whether it be 3. S (synthesis) phase illness, mutation, or injury. DNA synthesis/replication 34-35% of length of interphase 4. G2 phase Downloaded by LIL ANN DELA CRUZ ([email protected]) 5  lOMoARcPSD|45814163 Phase before onset of mitosis 10-20% of length interphase SHAPES OF THE CELLS 1. Squamous- thin and flat cells that allow diffusion and CELL DIVISION filtration 2 Types: 2. Cubodial- cubed-shape cells that may have microvilli 1. Mitosis or cilia at their apical surface for secretion and ❖ Two daughter cells with exactly the absorption. same genetic material 3. Columnar- tall and thin cells that may have microvilli ❖ Cellular division for growth, or cilia at their apical surface for secretion and maintenance and repair absorption. 2. Meiosis ❖ Four daughter cells with half the genetic II. CONNECTIVE TISSUE material FUNCTIONS OF CONNECTIVE TISSUE: ❖ Cellular division for reproduction Provides matrix that supports and connects other tissues and cell together in organs PHASES OF MITOSIS Imterstitial fluid gives metabolic support to cells as 1. Prophase medium for diffusion of nutrients and waste product. o Chromosomes progressively shorten and thicken to form double structures CLASSIFICATION OF FIBROUS CONNECTIVE TISSUE o Nucleolus gradually disappears o Mitotic apparatus begins to form 1. Collagenous Connective Tissue o Degeneration of the nuclear membrane a. Loose Connective or Loose Areolar 2. Metaphase -Consists of collagen and elastic fiber o Chromatids align at the equatorial plane -Most common cells found are fibroblast 3. Anaphase -Fibroblats are responsible for the production o Separation of sister chromatids and migrate of the fibers of the matrix. towards the opposite poles by the b. Dense Regular Connective Tissue (DRCT) translocation of the spindle microtubules -Same direction of collagen fibers 4. Telophase c. Dense Irregular Connective Tissue (DICT) o Nucleoli and nuclear membranes reappear -Different direction of collagen fibers at the opposite ends of the cell 2. Elastic Connective Tissue o Mitotic apparatus gradually disappear CLASSIFICATION OF EMBRYONIC CONNECTIVE TISSUE INTRODUCTION TO TISSUE 1. Mesencyme Fundamental types of tissue: Source of all adult connective tissue 1. Epithelial 2. Mucus 2. Connective Found only in the umbilical cord 3. Muscle 4. Nervous CLASSIFICATION OF SPECIALIZED CONNECTIVE TISSUE 1. Reticular Connective Tissue I. EPITHELIAL 2. Adipose Components: 3. Bones 1. Epithelial cells 4. Cartillages 2. Extra/intercellular substance 5. Blood Characteristics: -contiguous cells CLASSIFICATION OF BONES -basal lamina 1. Compact Dense -avascular 2. Spongy / Cancellous c -sheet or layers -can undergo metaplasia to adapt to a toxic CARTILLAGES CLASSIFICATION OF environment 1: Hyaline Cartilage CLASSIFICATIONS OF EPITHELIAL TISSUES 2. Elastic cartilage 1. Lining/Surface Epithelium 3. Fibrocartilage 2. Glandular Epithelium -Type of epithelium consisting of glands that secrete a III. MUSCLE TISSUE particular substance. composed of elongated specilized for contrace ton and Endocrine gland- ductless and secrete movement. substance and called hormones directly into Types of Muscle Tissue: the intertitial fluid then to the blood A. Skeletal Exocrine gland- a gland that secretes its B. Cardiac product into a duct, which then empties onto C. Smooth a body surface. IV. NERVOUS TISSUE SUBTYPE OF LINING/SURFACE EPITHELIUM -Has two major divisions: Based on the number of layer of cells: ❖ Central Nervous System (CNS) 1. Simple- single layer of cells ❖ Peripheral Nervous System (PNS) 2. Stratified- more than one layer of cells Downloaded by LIL ANN DELA CRUZ ([email protected]) 6  lOMoARcPSD|45814163 -Composed of cells with long, fine processes specialized to Cornification is brought on by keratinization receive, generate, and transmit nerve impulses and the hardening, flattening process that takes place as the cells die and are pushed INTEGUMENTARY SYSTEM to the surface. Composed of: Friction at the surface of skin stimulates 1. Skin-heaviest, largest organ additional mitotic activity of stratum basale, 2. Skin Appendages resulting in the formation of a callus for a. Sweat gland additional protection. b. Sebaceous gland 2. Stratum Lucidum (Clear Layer) c. Hairs Nuclei,organelles,and cell membranes are d. Nails no longer visible so this layer appears clear Exists only in the lips and the thickened skin of soles & palms Contains a transluscent substance called eleidin 3. Stratum Granulosum Consists of only 3-4 flattened rows of cells Cells here appear granular due to the presence of keratohyaline granules 4. Stratum Spinosum Cuboidal or slightly flattened cells Contains several layers of cells Spiny appearance due to changed shape of keratinocytes With limited mitosis This layer plus stratum basale are collectively called Stratum Germinativum Also called integument 5. Stratum Basale Composed of single layer of cells in contact Simply means covery with the dermis. FUNCTIONS: 1. Keeps water and other precious molecutes the body. 4 type of cells: 2. Keeps water out a. Keratinocytes- produce keratin which 3. Protects the body from external agent toughens & waterproofs skin 4. Insulates and cushions deeper body organs. b. Melanocytes- synthesize the pigment 5. Protects body from mechanical and chemical melanin providing a protective barrier to UV 6. Regulates heat loss from body surface radiation in sunlight 7. Acts as mini-excretory system, urea, salt water are c. Tactile cells (Merkel cell)- aid in tactile lost when we sweat. (touch) reception 8. Manufactures several proteins important to immunity. d. Non-pigmented granular dendrocytes 9. Storage of Vitamin D precursor (Langerhans cells)- protective macrophagic 10. Contains cutaneous receptors that serve as sensors cells that ingest bacteria & other foreign for touch, pressure, temperature and pain. debris. THE SKIN COLORATION OF THE SKIN 2 Principal Layers: Caused by expression of a combination of 3 pigments Epidermis 1. Melanin 2. Cerotene Dermis 3. Hemoglobin ✓ EPIDERMIS ❖ MELANIN Superficial protective layer of the skin o Brown-black pigment produced by the Composed of stratified squamous Keratinized melanocytes of stratum basale Epithelium that varies in thickness o Guards skin against damaging effect of UV All but the despest layers of epidermis are composed rays of sunlight of dead cells o Gradual exposure to sunlight promotes Composed of 4-5 layers, depending on its location increased production of melanin; hence within the body. tanning of skin Palms and soles have five lavers beanuse these o In albino, there is a normal number of areas are exposed to most friction. melanocytes but lacks enzyme tyrosinase, LAYERS OF SKIN that converts the amino acid tyrosine to 1. Stratum Corneum melanin 25-30 layers of flattened, scale-like o Freckles- caused by aggregated patch of anucleated cells, which arecontinuously melanin shed as flake-like residues of cells. o Vitiligo- lack of melanocytes in localized This surface layer is cornified and is the real areas of the skin causing distinct white spots protective laver of the skin. Downloaded by LIL ANN DELA CRUZ ([email protected]) 7  lOMoARcPSD|45814163 ❖ CAROTENE CUTANEOUS GLANDS o A yellowish pigment found in epidermal cells 1. SEBACEOUS (OIL) GLANDS & fatty parts of dermis ▪ Found all over the skin, except on palms and o Abundant in skin of Asians soles o Together with melanin, accounts for the ▪ Ducts usually empty into a hair follicle but yellowish-tan color of Asians some open directly onto skin surface ❖ HEMOGLOBIN ▪ Secretion is called sebum, a mixture of oily o Not a pigment of the skin, rather it is the substance and fragmented cells that keep oxygen-binding pigment found in RBc skin soft and moist and prevents hair from o Oxygenated blood flowing through the becoming brittle dermis gives the skin its pinkish tones 2. SWEAT GLANDS ▪ Also called sudoriferous glands SURFACE PATTERNS ▪ Widely distributed in the skin; numerous in 1. CONGENITAL PATTERNS palms, soles, axillary and pubic regions o Fingerprints or friction ridges present on palms and ▪ Secretion evaporates and cools in the body soles formed by the pull of elastic fibers within the ❖ 2 TYPES OF SWEAT GLANDS: dermis 1. Merocrine o Function to prevent slippage when grasping objects o More numerous and found all over 2. ACQUIRED LINES the body especially in forehead, ▪ Deep Flexion Creases back, palms and soles o found on the palms Shallow Flexion Lines o Secretion reaches skin surface via o seen on knuckles and surface of other joints a duct that opens directly on ▪ Furrows in the forehead and face (wrinkles) surface of skin through sweat pores o acquired from continual contraction of facial o Secretion is mostly water with few muscles, such as from smiling or squinting in salts bright light or against the wind; facial lines 2. Apocrine Sweat Gland become more strongly delineated as one o Much larger, localized gland found ages in axillary and pubic regions where 3. LANGER LINES they secrete into hair follicles ▪ Lines of tension in the skin produced by the o Not functional until puberty orientation of collagen and elastic fibers in nonrandom o Secretion is thick and rich in pattern or arrangement organic substances which is ▪ Surgical incision should be made parallel to Langer odorless when released but quickly lines to promote better wound healing broken down by bacteria into substances responsible for body odor ✓ DERMIS ▪ Deeper and thicker than the epidermis ▪ A strong and stretchy envelope that helps to hold the body together ▪ Blood vessels within the dermis nourish the living portion of the epidermis ▪ With numerous collagenous, elastic and reticular fibers that give support to the skin ▪ Highly vascular and glandular ▪ Contains many nerve endings and hair follicles LAYERS OF DERMIS 1. Papillary Layer ▪ In contact with epidermis ▪ Accounts for about 1/5 of the entire dermis ▪ With numerous projections called Dermal 3. MAMMARY GLAND Papillae, that extend from the upper portion ▪ Found within the breasts of the dermis into the epidermis ▪ Specialized sudoriferous or sweat gland that ▪ Dermal papillae contain capillary loops, secrete milk during lactation which furnish nutients to the epidermis ▪ Under the stimulus of pituitary gland 2. Reticular Layer 4. HAIR ▪ Deepest skin layer ▪ Characteristic of all mammals, but its ▪ Contains blood vessels, sweat & oil glands, distribution, function, density and texture and deep pressure receptors (Pacinian varies across mammalian species Corpuscles) ▪ Humans are relatively hairless, with only the ▪ Many phagocytes are found here; they scalp, face, pubis & axilla being densely engulf bacteria that have managed to get haired through the epidermis ▪ Men with more obvious hair because of the male hormone Downloaded by LIL ANN DELA CRUZ ([email protected]) 8  lOMoARcPSD|45814163 ▪ Certain regions of body are hairless like the palms, soles, lips, nipples, penis, labia minore PARTS OF HAIR 1. Shaft- the visible but dead portion of hair projecting above surface of the skin 2. Root- enclosed in the follicle 3. Hair bulb matrix- the growth zone; contains melanocytes that give color to hair ▪ Fingernails grow at approximately 1 mm per week ▪ Growth of toenails is slower ▪ Nails are transparent and nearly colorless but they look pink because of the rich blood supply in the underlying 3 LAYERS OF HAIR IN CROSS SECTION: dermis 1. Medulla- inner part 2. Cortex- thick middle part REFERENCES 3. Cuticle- covers cortex and forms toughened outer portion Lis down your references here. Hope this helps! DISTINCT KINDS OF HAIR IN HUMANS 1. LANUGO ▪ fine, silky fetal hair that appears during the last trimester of development ▪ Usually not evident on a baby at birth unless it has been born prematurely 2. ANGORA ▪ grows continuously in length, as on scalp and on face of males 3. DEFINITIVE ▪ grows to a certain tength and then cases to grow ▪ most dominant type of hair Ex:eyelashes, eyebrow,pubic, and axillary hair ▪ A sebaceous gland and an arrector pili muscle are attached to the hair follicle ▪ When the muscle involuntarily contracts due to thermal or psychological stimuli, the hair follicle is pulled into an upright position, causing the hair to"stand on its end" and producing goosebumps 5. NAILS ▪ Found on distal dorsum of each fingers and toes ▪ Forms from a hardened, transparent, stratum corneum of epidermis Consist of: 1. Nail body- visible attached portion 2. Nail Root- part of nail covered by skin 3. Nail Bed- where nail root and nail body are attached 4. Free Edge- the distal exposed border attached to undersurface of hyponychium 5. Hyponychium- beneath the free edge 6. Eponychium (Cuticle)- covers the nail root 7. Nail Matrix- proximal part of the nail bed 8. Lanula- whitish crescent (half moon) shaped area at the proximal aspect of nail. 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