1
Q
Cell
A
- basic structural unit in the human body
- each cell digests nutrients, ejects waste and carries out activities necssary to stay alive
- cells typically do not operate independently
- work in groups
2
Q
Tissues
A
- groups of similar cells that perform a common function
- epithelial tissue
- connective tissue
- nervous tissue
- muscle tissue
3
Q
epithelial tissue
A
- sheet of cells that covers a body surface or lines a body cavity
- forms the outer layer of skin
- lines the open cavities of the digestive, respiratory, urinary and reproductive systems
- lines glands of th body
- forms a boundary between the inner body and the external environment
4
Q
types of epithelial tissue cell
A
- squamous
- cuboidal
- columnar
5
Q
epithelial tissue- general featurs
A
Simple- single layer of cell
stratified- two or more layers of cells
6
Q
simple squamous
A
- single layer of flattened cells with disc-shaped central nuclei and sparse cytoplasm; the simplest of the epithelia
7
Q
simple squamous- endothelium
A
simple squamous epithelium lining lymphatic and blood vessels and heart
8
Q
simple squamous - mesothelium
A
simple squamous epithelium of the serous membrane that lines the ventral body cavity
9
Q
simple columnar
A
- single layer of tall cells with round-oval nuclei; some cells bear cilia; layer may contain mucus-secreting unicellular glands (goblet cells)
10
Q
simple squamous- function
A
allows materials to pass by diffusion and filtration in sites where protection is not important
11
Q
simple squamous- location
A
- kidney glomeruli
- air sacs of lungs
- lining of heart, blood vessels, and lymphatic vessels
- lining of ventral body cavity
12
Q
simple columnar- function
A
- absorption
- sercretion of mucus, enzymes. ciliated type propels mucus by ciliary action
13
Q
simple columnar- location
A
non ciliated- line most of digestive tract (stomach to rectum), gallbladder, and excretory ducts of some glands;
ciliated variety- lines small bronchi, uterine tubes and some regions of the uterus
14
Q
pseudostratified epithelium
A
- single layer of cells of differing heights (some not reaching surface)
- nuclei seen at different levels
- may contain mucus-secreting cells and bear cilia
15
Q
pseudostratified epithelium- function
A
- secrete substances (mucus)
- propultion of mucus by ciliary action
16
Q
pseudostratified epithelium- location
A
- nonciliated type in male’s sperm-carrying ducts
- ducts of large gland
- ciliated lines trachea and most of the upper respiratory tract
17
Q
stratified squamous
A
- thick membrane composed of several cell layers
- basal cells are cuboidal or columnar and metabolically active
- surface cells are flattened
- in the keratinised type, the surface cells are full of keratin and dead
- basal cells are active in mitosis and produce the cells of the more superficial layers
18
Q
stratified squamous- function
A
protect underlying tissues in areas subject to abrasion
19
Q
stratified squamous- location
A
- nonkeraitinised type form the moist linings of the esophagus, mouth, vagina
- keratinised forms the epidermis of the skin, a dry membrane
20
Q
connective tissue
A
- most abundant tissue type in body
- 4 classes: connective tissue proper, cartilage, bone, blood
21
Q
connective tissue- functions
A
- binding and support of other tissues
- protection of organs
- insulation of organs
- storage of energy reserves(fat)
- transporting substances within the body
22
Q
connective tissues- fibres
A
- provide support
- collagen fibres: strength
- elastic fibres: stretch and recoil
- reticular fibres: similar to collagen, finer fibres
23
Q
Connective tissue cells
A
- fibroblast- secrets the fibres
- mast cells: activate the inflammatory response
- macrophages:dispose of dead cells and foreign substances
- fat cells:energy reserve
- WBC: migrate to site in response to infection or injury
24
Q
connective tissue: ground substance
A
- unstructured material that fills the space between the fibres and cells
- contains fluid that enables nutrients and substances to diffuse between blood vessels and cells
25
Loose CT
Loose irregular arrangement of the fibres
- areolar: cushions organs, holds fluid
- adipose: energy reservoir
- reticular: reticular
26
Dense CT
- closely packaged fibres arranged in one direction
- high strength and resistance to tension
(tendon)
27
Dense irregular CT
- bundles of CT arranged irregularly
| - endure pulling forces from different directions
28
Dense elastic CT
- dense regular arrangement of elastic fibres
- walls of some blood vessels
- endure stretch to return blood vessel to original shape
29
integumentary system
- skin
| - accessory structures(hair, nails, various glands)
30
Epidermis
- keratinised stratified squamous epithelium
31
Cells of epidermis- Keratinocytes
- most numerous cell in epidermis
| - produce keratin & lamellar ganules (protects the skin)
32
Cells of epidermis- melanocytes
- located in basal layer
- produce pigment melanin
- protects nucleus of keratinocytes from UV radiation damage
33
Cells of epidermis- langerhans cells
- ingest foreign substances
- located in stratum spinosum
- easily damaged by UV radiation
34
Cells of epidermis- merkel cells
- tactile cell
- located in basal layer
- detect sensation of touch
35
Dermis
- deep to epidermis
- bundles of collagen & elastic fibres
- endure pulling action from multiple directions
- rich supply of blood vessels and nerves
- hair follicles, sweat and oil glands present
36
Dermis- papillary layer
- top region
- areolar CT
- macrophages easily wander through the dermis
37
Dermis- reticular layer
- deeper region
- dense irregular CT
- endured pulling action from multiple directions
38
Skin colour
melanin:
- produced by melanocytes
- same number of malanocytes in most people
- amount of melanin produced differs
carotene: yellow/orange pigment
hemoglobin: pink colour to skin
39
Hair- layers
medulla- core
cortex- several layers of flattened cells
cuticle- single layer of overlapping cells
40
Skin glands
- sudiferous(sweat) glands- produce sweat
- sebaceous glands produce oil
- ceruminous glands produce ear wax
- mammary glands produce milk
41
Sudiferous glands
Eccrine sweat glands
- abundant on palms, soles of feet & forehead
- secrete sweat
- 99% water, NaCl and other wastes
- pH 4-6
- body temperature regulation
42
Sudiferous glands
Apocrine sweat glands
- located in axillary & anogenital regions
- sweat that contains fat and proteins
- codourless, however bacteria decompose the proteins in the sweat to produce an unpleasant body odour
- become active at puberty
- not involved in body temperature regulation
- function unknown
- suggested to be equivalent to animals sexual scent glands
43
Sebaceous glands
- absent on palms and soles of feet
- open in to hair follicles
- secretes oily product (sebum)
- softens hair and skin
- prevents hair becoming brittle
- prevents excess water evaporation
- inhibits certain bacterial growth on skin
44
Functions of skin - protection
Physical barrier - continuous layer of keratinised epithelium that is impenetrable and waterproof
Chemical barrier:
- sebum contains antibacterial substances
- acidic pH prevents bacterial growth
- melanin protects against UV radiation
Biological barrier
- langerhans cells
- dermal macrophages
45
Functions of skin - body temperature regulation
Increaseing body temp
- sweat production and blood vessel dilation
- removal of ecess body heat
decrease body temp:
- vasoconstriction
- conservation of body heat
46
Functions of skin- cutaneous sensation
- abundance of sensory receptors
touch
pain
temperature
47
functions of skin - vit D synthesis , excretion
- important in calcium storage in bones
| - elimination of small amounts of wastes via sweating
48
Integumentary system across lifespan- newborn
- skin is very thin, prone to injury& possible infections
- born with vernix caseosa
49
integumentary system across lifespan- infancy and childhood
- skin thickens and subcuateous fat deposits increase
50
integumentary system across lifespan- adolescence
- increase sebaceous gland activity
| - appearance of acne
51
integumantary system across the lifespan- pregnancy
- pigmentation on skin of face (chloasma)
- striae gravidarum
- linea nigra
52
integumentary system across lifespan- elderly
- reduced melanin production (grey hair)
- decreased cell replacement in epidermis (skin thins)
- reduced melanocytes and langerhan cells (risk of cancer)
- reduced hair follicle activity (thinning of hair)
- reduced production and qual of collagen and elastic fibres in dermis (wrinkles)
- reduced sebaceous gland activity (skin and hair become dry and brittle)
- reduced subcutaneous fat (intolerance to cold)
Bioscience 1
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