body anatomy and disease resistance Flashcards
3 and 4 (60 cards)
1
Q
what 2 body parts help prevent the entry of pathogens?
A
skin
mucus membranes
2
Q
what is another word for skin
A
integument
3
Q
define skin/integument
A
covers the outside of the animal
is a very efficient barrier against the environment
4
Q
what are the 2 layers of the skin called?
A
epidermin (exterior layer)
dermis (interior layer)
5
Q
what part of the skin are blood vessels and sweat glands located?
A
dermis
6
Q
what layer of the skin is the stratum corneum and the stratum germinativum located?
A
epidermis
7
Q
what is the most superficial layer of the epidermis called?
A
stratum corneum
8
Q
describe the stratum corneum (2)
A
- non-vascular
- cornified layer that’s constantly being shed and replaced
9
Q
what is the inferior section of the epidermis called?
A
stratum germinativum
10
Q
what is a melanocyte and what does it produce?
A
- is a pigment cell (gives the skin its color)
- produces melanin
- are found in the stratum germinativum
11
Q
what is another name for the dermis?
A
corium
12
Q
what is located in the dermis/cornium?
A
- arteries
- veins
- capillaries
- lymphatics
- nerve fibers
13
Q
what layer is located below the dermis?
A
hypodermis
14
Q
describe the hypodermis and what is located in that layer
A
- a subcutaneous layer
- contains: connective and adipose tissue
15
Q
what are the functions of the integumentary system? (3)
A
- protective barrier
- sense organ (touch)
- site for vitamin D synthesis
16
Q
what glands and nerve receptors are found in the integument? (5)
A
- Meissner’s corpuscle (touch receptor)
- sweat glands
- Ruffini’s endings (heat receptors)
- Pacini’s corpuscles (pressure receptors)
- sebaceous glands
17
Q
what is a Meissner corpuscle
A
touch receptor
18
Q
what is a ruffini’s ending?
A
heat receptor
19
Q
what is a Pacini’s corpuscule?
A
pressure receptor
20
Q
How does the skin keep harmful organisms out of the body? (3)
A
- skin cells are formed in the stratum germinativum (deep layer of the skin). As the cells grow and mature they are sloughed off at the stratum corneum (skin surface). The sloughing of the cells makes it difficult for bacteria to become established in the layers of the skin.
- keratin is found in the skin and is a protein that acts as a waterproofing agent and a barrier against bacteria.
- the pH of the skin is kept between 3-4 (acidic) due to the presence of fatty acids. This pH makes it difficult for bacteria to thrive.
21
Q
is hair a component of the integumentary system?
A
yes
22
Q
where is hair produced?
A
within a follicle in the skin
23
Q
where does hair growth begin?
A
in the bulb region
24
Q
what is the portion of the hair found below the skin called?
A
root
25
what is the portion of hair above the skin called?
shaft
26
is the number of hairs per follicle consistent?
no, it can vary
27
what is each hair follicle supplied with?
sebaceous glands
arrector muscle of hair
28
what are the different types of hair?
- (normal) guard/cover hair
- wool hair (no medulla)
- tactile or sinus hair (e.g. whiskers) (used to feel, is very sensitive)
29
what does specialized integument include?
- horns
- claws
- hooves
30
where do specialized integuments grow from and what do they consist of?
- grows from a specialized dermis
- consists of cornified epidermal cells
31
describe the mucous membrane
- moist layer of epithelial cells
- lines the internal passageways of the body that open to the exterior (e.g. mouth, esophagus, gastrointestinal tract, urinary bladder, urethra, respiratory passage
32
what does the term epithelial refer to?
the type of tissue that lines the passageway
33
what different shapes can epithelial cells be and what are the shapes called?
- cube (cuboidal)
- column (columnar)
- elongated and flattened (squamous)
34
what is the mucous membrane made up of?
- lamina propria
- muscularis mucosa
35
what does the lamina propria do?
supports the epithelium
36
what is the muscularis mucosa?
tiny layer of muscle that lays under the lamina proria
37
where is mucus produced and what purpose does it serve?
- produced in the mucus membrane
- lubricates the internal passageways
- mucus has a washing action that aids in keeping bacteria from becoming established and causing disease
38
describe the conjunctiva
specialized mucus membrane that lines the orbital cavity and contributes to general body defence
39
what is the orbital cavity?
the outside of the eyeball
40
where is the mucus gland of the eyeball located?
upper eyelid
41
another word for tears
lacrimal fluid
42
what does lacrimal fluid do? (4)
- constantly flows over the eye surface
- drains into the nasal cavity
- helps wash and mechanically remove bacteria and microorganisms
- contains lysozyme which will lyse certain types of bacteria
43
what does the blink reflex help with?
the washing action of the tears
44
what in the respiratory tract helps prevent disease and how? (4)
1. mucus membrane. helps prevent disease-causing organisms from entering the body. there is an inhibitory substance which prevents bacteria or viruses from multiplying
2. Cilia (tiny hairs) lining the tract helps propel foreign materials to the outside of the body
3. cough reflex. reacts to large particles and irritating gases. It helps remove harmful agents.
4. Sneezing. It occurs when the turbinates (bones lining the inside of the nasal cavity) are irritated. It helps remove harmful or irritating substances.
45
what defenses are found in the mouth and how do they help prevent disease? (2)
1. the mouth is lined with epithelium which sloughs off in layers preventing bacteria from becoming established.
2. Saliva is bacteriostatic (keeps bacteria from multiplying) and also bacteriocidal for some sp. of bacteria
46
What defenses does the stomach have to help prevent disease? (2)
1. The vomiting reflex helps remove irritating materials
2. low pH (acidic) which is inhibitory or destructive to bacteria
47
what defenses do the intestines have that help prevent disease?
1. normal flora, compete with the pathogen for nutrients and space
2. diarrhea, if unwelcome microorganisms multiply and irritate the intestines, peristalsis will increase which results in rapid evacuation of the intestinal contents
48
how does the urogenital tract protect from disease? (3)
1. urinating has a cleansing action. The urine flow is unidirectional making it difficult for bacteria to become established (flushing action).
2. the mucus membrane resists infection
3. during pregnancy a plug forms in the cervix that seals the uterus from the outside environment
49
What typically dictates how an infection will spread?
the anatomy of the affected tissue
50
how are pathogens often distributed?
lymphatics
blood
cerebrospinal fluid
51
what are individual factors that affect the ability to get a disease?
- nutrition
- debilitation
- stress
- heredity
52
what vitamins and minerals are particularly important in disease resistance? (3)
- vitamin A
- zinc
- dietary protein
53
define virulence
the ability of a microorganism to cause disease
is a spectrum
the more virulent the worse the prognosis
54
define an avirulent organism
an organism that is relatively harmless
e.g. kennel cough or the common cold
55
what are the factors that increase a microorganism's virulence?
1. ability to produce a toxin
2. the presence of a capsule
3. not having been attenuated yet
4. is in a tissue that suits it well
5. the host is in poor condition
56
what does it mean when an organism is attenuated?
it has lost its disease-producing ability but will grow and reproduce, which stimulates the immune response
57
what is the main function of skin?
protect the underlying layers
58
what are 3 structures that are derived from the skin and serve protective roles
hair
feather
fur
59
what are the different layers of a hair follicle?
1. inner medula
2. thick cortex
3. cuticle (keratinized layer)
60
what is responsible for raising a hair follicle?
the contraction of its arrector muscle
