Billy - Anatomy & Physiology - Membranes Handout

Front 1

what is a membrane?

Back 1

-it is formed by the union of 2 or more tissues (the simplest combination of tissues)
- there are epithelial, connective and cutaneous membranes

Front 2

what are the epithelial membranes?

Back 2

-serous and mucous membranes.
-contain epithelium and connective tissues; the epithelium varies, but the connective tissue is always areolar tissue (called lamina propria)

Front 3

what are mucous membranes?

Back 3

-the line body cavities that are open to the outside
-made of lamina propria (connective tissue) and varying epithelium
-stratified squamous epithelium and C.T form mucous membranes that line the mouth and esophagus
-columnar epithelium and C.T form mucous membranes that line the stomach and intestines
-transitional epithelium and C.T form mucous membranes found in the bladder
-PSCCEwGC and C.T. form mucous membranes in the trachea and bronchi

Front 4

what are serous membranes?

Back 4

-line closed cavities, secreting watery serous fluid
-DOUBLE LAYERED: Parietal layer always lines the cavity, Visceral layer always lines the organs within the cavity

Front 5

what is the pleura?

Back 5

-the serous membrane in the pleural (thoracic) cavity
-parietal pleura lines the thoracic cavity
-visceral pleura lines the exterior of the lungs

Front 6

what is the pericardium?

Back 6

-serous membrane in the cardiac cavity
-parietal pericadium lines the cardiac cavity
-visceral pericardium covers the heart surface

Front 7

what is the peritoneum?

Back 7

-serous membrane in the abdominopelvic cavity
-parietal peritoneum lines the abdominopelvic cavity
-visceral peritoneum covers the organs in the cavity

Front 8

what is mesentary?

Back 8

-forms when the parietal and visceral peritoneum unite at the dorsal body wall
-suspends organs in cavity

Front 9

what is deep fascia?

Back 9

-deep to superficial fascia
-composed of dense white fibrous & dense elastic tissue
-serves as connective tissue wrappings of muscles, bones and cartilage

Front 10

what are synovial membranes?

Back 10

-membranes that line the inside of joint capsules
-made of dense white fibrous and areolar tissue with elastic fibers and adipose tissue
-secrete watery synovial fluid that keeps joints lubricated

Front 11

what are connective tissue membranes?

Back 11

-composed of 2 or more connective tissues
-also called fibrous membranes

Front 12

what is the superficial fascia?

Back 12

-C.T. membrane composed of areolar and adipose tissue
-forms hypodermis under the skin
-site of edema

Front 13

what is the periosteum?

Back 13

-dense white fibrous connective tissue
-covers bones

Front 14

what is the perichondrium?

Back 14

-dense white fibrous connective tissue
-covers cartilage

Front 15

what is dura mater?

Back 15

-dense white fibrous connective tissue
-covers and protects the brain and spinal cord

Front 16

what is the cutaneous membrane?

Back 16

-SKIN!
-the integumentary system

Front 17

what are glands?

Back 17

-epithelial tissue specialized to secrete a product different from blood or interstitial fluid
-derived from epithelial membranes covering adjacent surfaces
-synthesize macromolecules: protein in the form of insulin secreted form the pancreas, lipids in the form of sebum secreted by the sebaceous glands, glycoproteins in the form of saliva, or all 3 in the form of breast milk secreted by mammary glands

Front 18

what are exocrine glands?

Back 18

-glands that carry secretions to an epithelial surface using a duct

Front 19

what are the exocrine gland classifications?

Back 19

-merocrine glands
-holocrine glands
-apocrine glands

Front 20

what are merocrine glands?

Back 20

-glands whose secretions leave the cell with NO loss of cellular material
-the pancreas, salivary glands, and some sweat glands
-most exocrine glands are this type

Front 21

what are holocrine glands?

Back 21

-glands in which the entire cell and its contents are shed along with the secretion
-cell is destroyed by this process
-sebaceous glands

Front 22

what are apocrine glands?

Back 22

-glands in which the apex of the cell pinches off and some cellular contents are lost by the process
-large sweat glands and mammary glands

Front 23

what are the 3 shapes of exocrine glands?

Back 23

-tubular
-acinar
-tubuloacinar

Front 24

what are tubular exocrine glands?

Back 24

-exocrine glands that are shaped like a tube
-may be either coiled tubular, branched, with many tubes, or compound, with many branches and each branch having several tubes

Front 25

what are acinar exocrine glands?

Back 25

-flask shaped, sac-like exocrine glands
-may be either branched acinar or compound acinar

Front 26

what are tubuloacinar exocrine glands?

Back 26

-exocrine glands that look like a cock and balls

Front 27

what are endocrine glands?

Back 27

-glands formed from epithelial membranes but the duct connection to the surface degenerates and is lost
-secretions are called hormones and are released into interstitial fluid, picked up and distributed by circulatory system
-form glands: heterocrine and mucous glands, and cells: goblet and serous cells

Front 28

what are heterocrine glands?

Back 28

-a mixed, exocrine and endocrine gland
-has different distinct cell types
-pancreas

Front 29

what are mucous glands?

Back 29

-unicellular glands found in digestive and respiratory systems

Front 30

what is a goblet cell?

Back 30

-a secretory cell
-secretes a viscous substance called Mucin, a glycoprotein

Front 31

what are serous cells?

Back 31

-cells that are common in the digestive system and salivary glands
-secretion is watery, but very high in enzymes

Front 32

what are the functions of the cutaneous membrane?

Back 32

-to prevent dehydration
-to prevent infection
-protection from ultraviolet rays
-thermoregulation via: vasodilation (to lose heat), vasoconstriction (to retain heat) and perspiration (cooling)
-the major organ of sensation
-excretion of water, salts and urea
-synthesizes vitamin D

Front 33

what is the epidermis?

Back 33

-uppermost 4 - 5 layers of cells
-made of stratified squamous epithelium
-anchored to basement membrane
-no blood vessels of its own, blood vessels of the dermis penetrate via Volkman's canals
-contains keratinocytes, merkel's cells, and melanocytes
-may be thick or thin; when thin it lacks the stratum lucidum, and when thick stratum lucidum is present and there are many more layers of keratinzed cells in the stratum corneum

Front 34

what are keratinocytes?

Back 34

-most predominant cell in epidermis
-synthesizes keratin

Front 35

what are merkel's cells?

Back 35

-the only touch receptor (neuron) in the epidermis

Front 36

what are melanocytes?

Back 36

-cells that synthesize pigment (melanin)

Front 37

what are the 5 layers of the epidermis?

Back 37

-stratum basale
-stratum spinosum
-stratum granulosum
-stratum lucidum (only present in thick skin)
-stratum corneum

Front 38

what is the stratum basale?

Back 38

-the lowermost layer of the epidermis
-one layer of cuboidal cells anchored by basement membrane to the dermis
-only epidermal layer in which cells divide mitotically; older cells die as they are pushed upward away from the dermis and its blood vessels carrying nutrients
-MELANOCYTES are present in this layer
-MERKEL'S CELLS are present in this layer

Front 39

what is the stratum spinosum?

Back 39

-8 - 10 rows of polyhedral cells

Front 40

what is the stratum germinativum?

Back 40

-the stratum basale and the stratum spinosum together

Front 41

what is the stratum granulosum?

Back 41

-3 - 5 rows of cells
-nuclei are dying and bcome pycnotic (dark staining)
-cells contain keratohyaline

Front 42

what is keratohyaline?

Back 42

-the precursor to keratin
-evidence that cells are dying
-first seen in the stratum granulosum

Front 43

what is keratin?

Back 43

-a waxy protein which waterproofs the skin
-made from eleidin

Front 44

what is the stratum lucidum?

Back 44

-epidermal layer only found in thick skin, such as the soles of the feet
-cells are clear and transparent
-keratohyaline has been converted to eleidin

Front 45

what is the stratum corneum?

Back 45

-the uppermost epidermal layer
-25 - 30 rows of flat dead scalelike squamous cells
-filled with keratin

Front 46

what is the dermis?

Back 46

-lower layer of the cutaneous membrane
-composed of dense irregular connective tissue with numerous collagen, elastic and reticular fibers
-contains blood vessels, nerve receptors, sebaceous and sweat glands, hair follicles and hair, nails and muscle fibers
-divided into 2 regions: papillary and reticular

Front 47

what is the papillary region?

Back 47

-upper layer of the dermis
-cone like projections called papilla
-forms dermal ridges called fingerprints
-contains MEISSNER'S CORPUSCLES, NAKED NERVE ENDINGS, and CAPILLARY ROOTS

Front 48

what are meissner's corpuscles?

Back 48

-receptors in the papilla of dermis for light touch

Front 49

what are naked nerve endings?

Back 49

-receptors in the papilla of the dermis for pain

Front 50

what are capillary roots?

Back 50

-found in the papilla of dermis to link arteries and veins located in the dermis and hypodermis below
-can move up and down as large blood vessels constrict and dilate; conserves or dissipates heat

Front 51

what is reticular region?

Back 51

-dense irregular connective tissue with bundles of collagen and elastic fibers

Front 52

what are pacinian corpuscles?

Back 52

-specialized nerve endings for deep pressure
-located deep in the dermis, and sometimes in the hypodermis

Front 53

hair and hair follicles

Back 53

-hair provides protectino for eyes and prevents heat los
-hair follicles forms as stratum basale turns inward growing down into the dermis, forming a tubelike follicle

Front 54

describe the structure of a hair follicle

Back 54

-the follicle is a multilayered epidermal sac which forms and encloses the hair
-2 parts: the BULB, which is the enlarged base of the follicle with a small indentation, and the PAPILLA, which receives blood vessels and nerves; has germinal cells which divide to form the cells of the hair

Front 55

what is the hair root?

Back 55

-the portion of the hair in the follicle in the dermis and epidermis
-arises from the bulb, cells die as they are pushed upward
-cells are living in the bulb, dying the root, and dead in the shaft

Front 56

what is the hair shaft?

Back 56

-the portion of the hair protruding from the follicle above the skin
-3 parts: Cuticle - transparent, waxy protective outer layer of hair, Cortex - solid middle layer, filled with pigment granules, and the Medulla - the hollow center of the hair composed of dead cells and air spaces

Front 57

waht is the arrector pilli muscle?

Back 57

-smooth muscle going from hair follicle to stratum basale
-contraction causes hair to stand on end
-causes a layer of insulation in animals, only goosebumps in man

Front 58

what are the sebaceous glands?

Back 58

-glands always found with hair follicles
-compound acinar holocrine gland
-located in dermis
-secretes sebum to keep skin and hair lubricated and flexible

Front 59

what are eccrine sweat glands?

Back 59

-the most common gland in the body
-coiled tubular epithelial glands which secrete a watery substance (sweat), which contains salt, urea and NH3
-thermoregulatory gland
-excretory gland

Front 60

what are apocrine sweat glands?

Back 60

-large sweat glands located in axilla (armpits) and pubic areas
-simple branched tubular gland
-viscerous secretion is high in protein resulting in body odor due to bacterial breakdown of proteins in secretion

Front 61

what are ceruminous glands?

Back 61

-glands that secrete ear wax
-modified sudoriferous gland
-simple coiled tubular gland

Front 62

what are sudoriferous glands?

Back 62

-sweat glands that are not associated with hair

Front 63

what are the 3 factors that determine overall skin color?

Back 63

-carotene
-blood
-melanin

Front 64

what is carotene?

Back 64

-yellow to orange pigment derived from beta carotene
-adds yellow or tawney tones to skin
-protects agains ultraviolet rays

Front 65

how does blood affect skin tone?

Back 65

-the less the other tones dominate the more we see pink tones due to the presence of capillaries under the skin
-in some people capillaries are very deep set and skin is paler than others

Front 66

what is melanin?

Back 66

-substance produces by melanocytes in stratum basale
-released in vessicles (melanosomes); migrate into upper layers of epidermis, mostly the stratum spinosum
-the ratio of melanocytes to basal cells, 1:4 - 1:20 determines how dark skin is
-sunlight stimulates melanocytes to increase the rate of melanin synthesis

Front 67

what is melanoma?

Back 67

-cancer of the melanocytes
-fatal unless caught early and surgically removed; melanocytes are found low in the skin's layers, cancer can easily migrate into the blood stream and travel throughout the body
-sunblock DOES NOT prevent

Front 68

what is basal & squamous cell cancer?

Back 68

-cancer of the basal or spinosum cells
-basal cell cancer is relatively treatable
-squamous cell cancer is often fatal but relatively uncommon
-sunblock prevents both

Front 69

what is thermoregulation?

Back 69

-response of skin to increased or decreased temperature
-the hypothalamus, in the thyroid, is the thermostat; receives info from receptors in the skin and blood and sends nerve impulses to skin and muscles

Front 70

what are epidermal ridges?

Back 70

-fingerprints and planes of clevage
-body is marked by ridges and grooves; either straight or as loops and whirls
-due to arrangement of dermal papilla
-sweatglands open into ridges; fingerprints are actually condensation from the sweat glands left behind on surfaces