Topic 2: Integument Flashcards
(73 cards)
1
Q
What is integument?
A
- One of the largest most extensive organ system in the body
- Covers the entire animal
- Forms the integument system
2
Q
What does integument include?
A
- Skin (or hide)
- Claws
- Horns
- Hooves
- Hair
- Sweat and oil glands
3
Q
What are the do the general componets of the integument system do?
A
- Frequent injuries occur in this layer, but it is able to regernate and heal
- Everything is dead - Keratinization
- These components are considered modifcations of surface epithelium: which are sheets of cells covering external surface of body
4
Q
What does the integment system protect the body from
A
- Protecting the body from invasion by microbes, insects & external parasites
- Exposure to enviroment chemicals and UV radiation
5
Q
What does the integment system produce?
A
- Vitamin D
- The synthesis of vitamin D –> in dairy cattle vitamin D3 takes place in all areas of the skin
- When the skin is covered the animals produce less vitamin D3
6
Q
What does the system do (Integament)
A
- Maintains body temp, through sweat, cutaneous blood flow & hair coat
- Detects sensory information (touch and pressure) –> heat
- Transfer the information to central nervous system
-Metabolic actions –> sysnthesis of vitamin D
- Excreates of organic waste and excess of salts (sweat)
-Contact physical abrasion includes: rubbing, scraching, animals contact with the ground and surrounding enviroment
7
Q
What does cutaneous mean?
A
- Means of the skin
8
Q
Provide a beif background on the skin
A
- Covers the external surface of the animal
- Skin has the ability to regenerate and heal
- Skin thickness and how loose or firmly the skin is attached may differ between and within species
9
Q
What are the 3 basic layers of the skin
A
- Epidermis
- Dermis
- Hypodermis
10
Q
What cell is the epidermis mainly made up of
A
- Formed by layers of flat cells
- Keratinocytes
11
Q
What are keratinocytes and where are they most found?
A
- Produce a tough, fibrous, waterproof protein called keratin that gives the skin resiliency and strength
- These cells are close to blood vessels in the dermis, there are adequate nutrients to support cell divison by mitosis
- Mostly found in epidermis
12
Q
What part of the body tends to have the thickest region of skin and why?
A
-Shoulders and back
- They have the greatest exposure to the enviroment
13
Q
What part of the body tends to be the thinest region of skin and why?
A
- Eyelids, in between legs
- This is where the animal is most protected
14
Q
Explain skin and underlying structures
A
- Skin might be tightly attached tp underlying structures or maybe loosely attached to allow considerable movement
15
Q
What skin heals faster
A
- Loose skin heals faster as skin can stretch to cover injuries
16
Q
What is the epidermis consist of?
A
- formed by layers of flat cells –> keratinocytes
- made up of stratified eqamous equilibrium
- No blood vessels/nerve endings in this layer (avascular)
- contais a basal layer which is located adjacent to the dermis
- Nutrients must diffuse from capillaries located in dermis to meet epidermal cell requirements
17
Q
What are the layers of the epidermis (bottom to top)
A
- Stratum Basale
- ” spinosum
- “grandulsoum
-“corneum
18
Q
What are keratinocytes
A
- a cell
- produce a tough, fibrous, waterproof protein called keratin that gives the skin resiliency and strength
- can support cell divsion by mitosis
19
Q
What happens in the stratum basale layer
A
- deep layer of the epidermis
- composed of single layer cubodial cells
- Important for skin renewal
- has a single row of keratinocytes–> attached to the basement membrane and engaged in cell divison
- right above dermis
20
Q
What happens in the stratum spinosum
A
- “spikie layer”
- Cells are polyhedral to slightly flattened
- Layer is arranged in 2-4 layers depending on species
- Langerhan cells present which are projections form a web-like frame around the keratinocytes
- cells are held together by demosomes
- Infrequnent divisons are seen
21
Q
What happens in the stratum granulosum
A
- composed of flattened cells with shrunen nuclei
- conatins keratin granule- precurors for keratinization processes
- has diamond shaped keratinocytes
- contains lamellated granuales: which contain waterproofing glycolipids which play a role in waterproofing the skin
- part where cell dies
22
Q
What happens in the stratum corneum
A
- Provide removal of surface pathogens (as it renews continuosly)
- contains antimicrobial peptides and lipids which aid in bacteria and chemical defense
- has remanats of keratinocytes: dandruff
- dominates the epidermis
- this layer is renewed continiously
23
Q
Explain the process of what happens in the epidermis
A
- As daugther cells are produced they push older cells to the surface of the epidermis
- this prevents the older cells to obtain adeque nutrieents
- older cells flatten and die an dundergo changes including loss of nuclei, cytosol and organelles
24
Q
What do dead cells have theit content replaced by?
A
- Keratin: tough fibrous protein –> primary protein
- Granules: contain glycolipid which acts to waterproof the skin and also protect against water loss across the epidermus
25
Explain the process of keratinization and hardening
- cells are exposed to the enviromet = dry out and become harder
- while the cells are dead, the keratin has a protective function to make the skin tough and resistant
- the outside layer of the epidermis shed on a daliy basis (exfloileated) per day without any impact on the animal
26
What are the charatceristics of the dermis
- Located underneath the epidermis
- Makes up 80% of the total mass of the skin
- vascular
-compsied of dense irregular connective tissue --> collagen, elastin, reticular fibers all in random directions
- Has a rich tissue community
- Has sensory receptors and blood vessels
27
what does the dermis contain high amounts of
- Collagen
- Elastin
- Reticular fibers
28
What does collagen do
responsible for strength of the skin
29
What does elastin do
responsible for the strength and resistance of the skin
30
What does the reticular fibers do
responsible to join connective tissue to other tissues and maintains the skins structure
31
What does the presence of sensory receptors do in the dermis
- send info from external CNS
- CNS can respond to ensure homeostasis
- includes meissiners corpsules
32
What is meissiners corpsules
- Nerve ending or pain and touch receptors or temp change receptors
33
What does the presence of blood vessals do for the dermis
- Provides nutrients to the epidermis: glucose and amino acids
- does watse removal and regulates temp
34
Hypodermis layer
-aka subcutaneous fat layer
- thick layer located underneath the dermis
- Works like glue/anochor to attach this dermis to the bone/muscle/anything beninf it
- Allows for flexibility and movement
35
What is areolar connective tissue
- Most common type of connective tissue
- Allows the skin to move without tearing
- no problems occur when skin moves underlying bone and muscle
- Cushion and protect skin and underlying muscle and organs
36
What is thr hypodermis made up of
- Areolar connective tissue
- adipose tissue
- Lymphatic vessels
- Nerves
37
What is adipose tissue
- Act as shock absorber and thermal insulator
- Source of energy for the animal
38
Blood vessals in the hypodermis
- Appears in a large # assocaited to adipose tissue and disposition and mobilization
- Excess of energy intake = increase in lipid deposition in fat tissue
- Energy intake deficiency = mobilization of lipids from fat tissue to supply energy source to the animal
39
Explain sweat glands
- aka: subdoriferous glands
- found all over our body
- located in both hypodermis and dermis
40
What are the types of sweat glands
- Eccrine
- aprocrine
41
Explain the eccrine sweat glands
- has excretory portion as simple as coiled tube located at dermis and hypodermis
- connected to the surface of skin, by long duct
- Limited number of eccrine sweat glands in domestic animals
- Hydrates and moisiturizes the skin
42
Explain aprocrine sweat glands
- Have copied excretory portion in dermis and hypodermis
- Presents a single excretory duct
- empty into hair follicle and not into the skin surface
- produces a secretion containing water, fatty acids, proteins
- Aorocrine very active in horses
43
Explain the process of temp regulation skin in farm animals
- changes in blood flow thru skin capillaries alters amount of warm blood near the body surface which affects thermoregulation
- increasing the amount of blood near body surface enables animal to dissipate heat to help cool themselves
44
Explain oil glands
- Found all over body in dermis
- Releases secreation (sebum) into hair folicules or to skin surface
- Oil glands degrade epitheial cells to produce lipid-based sebum
45
What is the function of the sebum
- To keep hair from becoming fragile --> traps moisture to prevent excessive drying
- Prevents excess evaportaion of mositure from skin
- Keeps skin soft
- Has bacteriostatic and anti fungal properties
- Lipid based
46
What are the parts of the hair strand
- hair shaft
- root
47
Explain hair shaft
- part visable above the skin
-avascular
- Dead
48
Explain the root of the hair strand
- part buried within the skin
- Located in the dermis
49
What are the different hair follicles and what is the hair follicule
- Invagination of epidermis that extends from skin surface to dermis
- simple hair folicule
- compound hair follicule
- primary hair folicule
- secondary hair folicule
- hair bulb
- papilla
- matrix
50
explain the simple hair follicule
- Where a single hair enzymes from singular orificr
51
explain the compound to hair follicule
- where a multiple hair emerges from a singular orifice
- each hair from compound follicle have their own papilla which contains blood vessels, nursouishes hair
52
Explain the primary hair folicule
- have a large diameter, are rooted more deeply in dermis or subcutis and is asscoiated with subareas and epirichialk sweat glands and arrector pili muscle --> goosebumps
53
Explain the secondary hair follicule
- More superficially rooted and may be accompanied by a sebacceous gland but lack sweat gland and arrector pili muscle
- are small in diameter
54
Explain the hair blub
- formed by the expansion of the deepest part of their follicule
- located in the base layer of the hair
55
Explain the papilla
- Mound of dermal cells covered w matrix
- in dermis and hypodermis
- Brings oxygen and nutrients
56
Explain the matrix
- Rapidly dividing epithelital cel;ls
- does the keratinization
- cite of cell division
57
explain the hair production steps
1. occurs at the base of follicule
2. Matrix cells are nourished by blood flow from vessels
3. nourishment stimulates cell divison and growth
- as cell divides, older cells are pushed up away from papilla
- these cells die due to lack of nutrients and beocme kertinized
58
What are the steps in the hair cycle
1. anagen
2. Catagen
3. Telogen
59
What is the anagen phase
- active growing, matrix cells divide and produce hiar shaft
- Depends on genetics--> animals more growing
60
What is the catagen phase
- hair growth stops, follicule detaches from dermal pathway --> lasts 2-3 weeks
- Hair follicle shrinks
61
What is the telogen phase
- Resting period, no hair growth
- Last from weeks to years
- Shedding period
62
Explain the hoof
- extension of skin from lower limbs
- Has continuious growth
- made up of modified epidermis
- techinical name: ungula
- hoofed animals = ungulates
- avascular
63
what are the hoof functions?
- Maintain traction
- Defense against predators
64
What kind of animals are odd digit ungulated
- supporting weight on one hoof --> horses
65
What kind of animals are even digit ungulates
- supporting weight on two hoofs --> ruminants
66
Explain the horns
- epidermal in origin --> dead
- Structured similar to hair
- emerges from the horn process of frontal bones of the skull
67
What is the germinal center of the horns
- found on the frontal bone
68
What is the core of the horns
- Covered by dermis or corium
69
what is horn growth influenced by
- sex
- nutrition
- sepcies
-genetics
70
Where do horns elongate from
- horns elongates from the core base w the horn nmade up of dense keratin
71
What are the dehorning methods
- surgical removal of horn button s
- Destruction of horn button hot iron or caustric paste (cauterization) --> do it early
72
What is the coronary horn
- beneth outer layer
- contains blood vessels
- supply of nutreints and can sense pain
73
What are horseshoes
- Provides a barrier between the hoof and ground protecting hoofs from ice
- Prevents expansion of hoof when carryinf weight
- strengthens the foot
-increases integrity of hoof wall and tractions
