protection

Question 1

list some of the structure found in the epidermis layer

Answer 1

Keratinocyte, Granstein cell, lagerhans cells, melanocyte.

Question 2

What are the functions of the skin

Answer 2

Protection, sensory receptore, storage, VD3 production, thermoregulation, communication

Question 3

describe in the dermis layer and things in it

Answer 3

soft tissue made from fat, collagen, blood vessels, gland, pili and nerve fibers, it is split into reticular (denser with thick collagen) and papilary layer (loose connective and empty space).

Question 4

describe the hypodermis layer and thins in it

Answer 4

connective tissue from fat, thicker in areas with skin folds. the fat type depends on the species

Question 5

list the 3 layers of the skin

Answer 5

spidermis, dermis, hypodermis

Question 6

list the five layer of the skin

Answer 6

Basla layer (stratum basale)
Prickle -cell (stratum spicosum)
Granular (stratum Granulosum)
Clear (Stratum lucidum)
Horny/ cornified (stratum corneum)

Question 7

what are melanocytes and describe their function

Answer 7

meanocytes produce melanin, this is stimulated by melanin stimulating hormone (anterior pituitary) and UV exposure which absorbed VD3 (this is taken to the kidney and transformed into calcitroid).
meanocytes darken the skin

Question 8

describe the structure of a hair follicle

Answer 8

the hair shaft is made from - Medulla (inside) cortex (middle) and cutlice (outside) which is singl celled. thr root of each hair anchors the hair follicle. the deepes part of the hair follicle has a bulb which is mitoticly active, this is surronded by the root sheath.
Each hair has a pilioerector muscle whihc connect the bottom of the hair to the top and movea it.

Question 9

describe the types of hair

Answer 9

Guard hair: stiff and on the top coat of all domestic animals (except sheep)
Tactile hair: innervated hairs which aid in sensory information
Wool: Crumpled and lack medulla, these are finner and wavy, they form the undercoat and winter coat if needed. Sheep only have this kind of hair.

Question 10

what is piloerection and how does it happen

Answer 10

Pilli erection - hairsstand.
This means that insulation increases and can make animals look larger (cat). This also compresses the sebaceous gland. This gland secretes oil sebum which coats the skin in a thin lubricant with made from fat, this means the body hold a waterproof quality which aids in temperature regulation.

Question 11

Name the two main types of skin glands and their functions

Answer 11

sebaceous - eptied whien the pilioerector muscle is contracted, it secreats and oil wich coat the hair finle, proving a waterproof layer.
sweat - secretes sweat (dilute) to decrease body tempreture via evaporation. (apocrine and accrine)

Question 12

Name the two main types of sweat glands and their diffrences

Answer 12

Apocrine - secretes into the hiar, producing an odour
Eccrine - releases diluted water into exposed skin to decrease body tempreture.

Question 13

List the common cornified epidermal structures found in animals.

Answer 13

hoof, beak, horn, claw, shell, scales.

Question 14

List the major functions of the immune system

Answer 14

pathogen resistance
RBC removal and tissue removal
ID and removal of foreing / mutant cells
inappropriate reaction (allergies ect.)

Question 15

Identify the organs and tissues of the immune system

Answer 15

spleen, liver, skin, thymus, lymp nodes, tonsils, adenoids and peyers patches (small intestine surface)

Question 16

Describe the major differences between the innate and acquired (or adaptive) immune systems

Answer 16

innate - we are bone with, skin, inheritade resistance, ect.
Acuired - develped through exposure, memory T cells, ect.

Question 17

what is the first line of defence and describe its function

Answer 17

The barrier acts to prevent entry of pathogens. It is covered in glands that secrete peptides which hold antimicrobial properties to prevent growth.

Question 18

describe how inflamatation occurs

Answer 18

Break in the skin introduces bacteria, in response macrophages engulf pathogens and secrete cytokine and chemotaxis (this causes fever). The mast cells are active which release histamines. The cytokines cause blood vessels to dilate and this increases blood flow to the area as well and expands the capillary pores so the cytokines can enter the vessel. (cytokines cause monocytes and neutrophils to attach to blood vessels) (chemotaxis attracts neutrophils and monocytes). The monocytes produce macrophages and they help the neutrophils engulf pathogens.

Question 19

what function does inflamatation serve

Answer 19

kills bacteria through the use of macrophages and neutrophils, the high blood pressure is from the disposal of waste and toxins

Question 20

what is interferon

Answer 20

ubstance that is released from a cell when infected with a virus, the substance triggers the killer cells to produce enzymes capable of blocking the virus from replicating and inhibits the virus growth in the cell.

Question 21

what is the complement system and describe its key traits

Answer 21

sequentail activation of 9 peptide which form an attack membrane that kills pathogen via lysis. it is triggered by carbohydrate chain/ pathogen antibodies destection

Question 22

what are the two types of defence on the third line

Answer 22

antibody-mediated/humoral immunity.
Cell-mediated immunity.

Question 23

what cell is involved in cell mediated immunity

Answer 23

T lymphocytes destroy viruses and invaded cells/ cancer cells

Question 24

what cell is involved in humoral/ antibody mediates immunity

Answer 24

B lymphocytes activate plasma cells to secrete antibodies into the blood as immunoglobulins

Question 24

Explain B lympocyctes and how they work

Answer 24

Antibodies are made from two chains in a Y formation. When the antigen attaches to the B cell it will respond based on its subclass: Neutralisation, complement, phagocytes, agglutination, NK cell stimulation

Question 25

list some of the antibody subclasses

Answer 25

IgM - Sits on the B cell receptors. IgG - (most common) opsonin to enhance phagocytosis IgE - Protection against worms and allergies (histamine secretion) IgA - In secretions of the digestive, respiratory, genitourinary tracts IgD - On the surface of many cells

Question 25

Describe the difference between active & passive immunity, and the 3 ways immunity can be generated.

Answer 25

Active: the production of antibodies from the exposure to an antigen. (vaccinations, ect.) - Vaccination, Live vaccination, Inactivated (killed) vaccination Passive: transfer of preformed antibodies from one animal to another (IgG are inherited from mother to child) - Natural exposure to a pathogen, Vaccination, Inheritance from generations

Question 26

what is autoimmune disease

Answer 26

The body fails to identify the self from pathogens, this results in the body attacking its own cells.

Question 27

explain how t lymphocyctes work

Answer 27

bound to the plasa memebrane of cells they have a binding site, with alfa and beta chains. the antigen bind to the T cell and forms immune synapes when the cytotoxic T cell bind to the antigen. Cytotoxic T cells release chemicals that destroy the cell before the virus can replicate inside the cell.

Question 28

how is autoimmune disease caused

Answer 28

Exposure during injury. Antigen modification by chemicals, viruses or mutation. T cell exposure to foreign antigen which is similar to itself.

Question 28

what are the two type of T lymphocytes

Answer 28

Class one is on the surface and responds to viral and cancer cells. Class two are on the surface of dendritic cells, macrophages and B cells.

Question 29

list animals and the fat colour in their hypodermis

Answer 29

hore -yellow pig - grey/white cow - white young - brown

Question 30

Respiratory barriers first line of defence consist of:

Answer 30

Cilia cells which reject microbes (coughing) Nasal hairs are sensory and react to stimuli (sneezing) Lymphoid tonsils (swell and filter lymph)

Question 31

GI tract barriers first line of defence consist of:

Answer 31

Lymphoid tissue Acid pH saliva

Question 32

Genitourinary tracts barriers first line of defence consist of:

Answer 32

Acid, mucous