Unit 11 Animal Physiology Flashcards
Smallpox
first infectious disease to be eradicated by vaccination
cowpox very similar
How do pregnancy tests work
monoclonal antibodies
https://www.youtube.com/watch?v=aOfWTscU8YM&feature=youtu.be
Cells are covered in uniquely shaped molecules
eg. polysaccharides of a bacterium’s cell wall, glycoproteins embedded in plasma membrane of eukaryote.
Surface molecules have wide range of functions (eg. include host binding for pathogens)
An organism recognises surface molecules present on its own cells, unsimilar surface molecules are regarded as foreign and provoke a specific immune response (antibody production)
Species Barriers regarding diseases (zoonosis)
Some pathogens are species specific (Polio, measles and syphilis only affect humans)
flu, ebola, salmonella, ets can be transmitted between species
A zoonosis is any disease of infection that is naturally transmissible from vertebrate animals to humans
Production of antibodies by Lymphocytes
Large variety of different lymphocytes and memory cells are present in blood.
Presence of antigen in blood is detected by one type of lymphocyte.
This lymphocyte will divide rapidly and produce a large number of cIone cells.
Each of activated lymphocyte clones then makes and secretes a specific antibody type.
This antibody binds to antigens detected in blood. Help phagocytosis of pathogens which have antigen on its surface.
B Cells
B-cell finds an antigen which matches its receptors.
waits to be activated by t-helper cell.
B-cell divides to produce plasma and memory cells.
plasma cells produce antibodies.
“eater cell” eats cells marked by plasmacells.
if the intruder invades again, memory cells help activate immune system.
Neutralisation
Attachment stops toxins from affecting or entering cells, viruses from invading cells, and bacteria from efficiently functioning and therefore attacking cells
Histamine
Released in white blood cells
Small organic molecule produced by two types of leukocyte: basophils and mast cells.
Loss of fluid from capillaries into surrounding tissues causes response symptoms: Inflammation/hives Itching Sneezing Watery eyes
Allergies are a group of conditions caused by hypersensitivity of immune system to something in environment that causes little or no problem on most people.
Antihistamine is a drug that opposes activity of histamine receptors
Mast cells are found in connective tissues. If simulated by an infection, they release histamine in infected area
Histamine has a number of effects upon body.
Key effect in immune response - increases permeability of capillaries to white blood cells and some proteins (eg. Antibodies). Allows components of immune system to engage pathogen early at site of infection.
Vaccines
Vaccination allow an individual to become immune to a disease without experiencing it.
Vaccines contain antigens in various forms that should not cause symptoms in a healthy person.
Monoclonal Antibody Production
An animal is injected with an antigen and in response produces specific plasma cells
Antagonistic muscle pairs in insect legs
plasma cells fused with tumor cells forming hydridoma
The elbow structure (biceps, triceps, humerus, radius/ulna, cartilage, synovial fluid, joint capsule, tendons, ligaments)
Biceps - Bends the arm (flexor)
Triceps - Straightens arm (extensor)
Humerus - anchors the muscle (muscle origin)
Radius/Ulna - Acts as forearm levers (muscle insertion) - radius for biceps, ulna for triceps
Cartilage - smooth surface to allow easy movement, absorbs shock and distributes load.
Synovial Fluid - provides lubrication, reduces friction in Joint.
Joint Capsule - Seals joint, contains synovial fluid.
Tendons - Non-elastic tissue connecting muscle to bone
Ligaments - Non-elastic tissue connecting bone to bone.
Sarcomere diagram
Dark bands - actin and myoin are overlapping
Light bands - shows actin fibres with no overlap
https://www.researchgate.net/figure/Striated-muscle-sarcomere-a-Schematic-diagram-showing-the-main-components-of-the_fig11_38012975
Types of Synovial Joints
Pivotal (vertebrae) Ball and socket (hip joint) Hinge joint (elbow) Condyloid joint (between radius and carpal bones or wrist) Plane joint (between tarsal bones) Saddle joint (between carpal bone and metacarpal bone)
Antagonistic Muscle Pairs
https://www.youtube.com/watch?v=_H4csvgZJ4s&feature=youtu.be
Muscles can only pull, not push
Therefore, work in pairs
One muscle of the pair contracts while the other relaxes.
as the agonist contracts, the antagonist relaxes or lengthens
Eg. Elbow - biceps/triceps
Knee - hamstrings/quadriceps
Striated Muscle Cells
Skeletal muscle tissue is striated
Dark and light bands
Contracts longitudinally
Muscle fibre cells are held together by plasma membrane (sarcolemma)
Multinucleated, with nuclei positioned along edges
Many mitochondria due to high demand of ATP
Contain sarcoplasmic reticulum (specialised ER) - stores calcium ions/pumps them out into sarcoplasm when muscle fibre is stimulated
Myofibril and Sarcomere
http://www.sumanasinc.com/webcontent/animati
ons/content/muscle.html
Basic rod like contractile units, grouped together inside muscle cells, which are known as muscle fibres
Sarcomere - repeating unit of striated muscle cell
In between z-lines - overlapping actin and myosin fibres.
Actin and myosin filaments
https://www.youtube.com/watch?v=U2TSaz8-yNQ&feature=youtu.be
Skeletal Muscle Contractions
When action potential (AP) reaches a striated muscle cell, SR releases Ca2+ into myofibrils
Calcium ions open up binding sites on actin
Myosin heads are bound to actin sites (making a cross bridge) and are stimulated to move.
Causes actin to slide over myosin, towards centre of sarcomere
Happens up to 5 times/sec and ends when no more Ca2+ is released.
https://www.youtube.com/watch?v=EIKglrCujxc&feature=youtu.be
https://www.youtube.com/watch?v=Ut-6pyIN7QE
Stages of gametogenesis
Germinal Epithelium - outer layer of cells in ovary
Primary Follicles - contains primary oocyte surrounded by single layer of supporting follicle cells.
Mature oocyte - contains the secondary oocyte, ready for ovulation
Secondary oocyte - haploid gamete. final stage of meiosis occurs after fertilisation
Medula - central main body of ovary (blood vessels, lymph and nerves)
Mature egg diagram
Follicle cells - provide nutrients to support early development of fertilised egg
Zona pellucida - consists of glycoprotein that protects egg and prevents polyspermy
1st polar body - not required and will break down
Nucleus - haploid contains 23 chromosomes to be passed from mother to child
Cytoplasm - contains nutrients to support early development of fertilised egg
Cortical granules - makes zona pellucida impenetrable to sperm (after fertilisation) to prevent polyspermy.
Process involved in Spermatogenesis
Begin with mitosis and later on involve meiosis Involve cell enlargement before meiosis Haploid cells (gametes) Produce specialised gametes Sperm produced in the testes Initiated during puberty No Pauses Sytokinesis - Equal Four sperm gametes Continuous production - released during sexual intercourse Continuous until death
Types of fertilisation
Some aquatic species - fertilisation is external. Eggs are released followed shortly by sperm. This method of fertilisation is susceptible to environmental variation and therefore animals that use it often produce large qualities of eggs and sperm to compensate for losses.
Terrestrial animals - mostly internal fertilisers to prevent dehydration of gametes or the developing embryo
Prevention of polyspermy
- sperm pushes through follicular cells and binds to receptors in zona pellucida
- Enzymes are released from acrosome of sperm and digest glycoprotein based zona pellucida.
- membranes of sperm and ovum fuse this tribulates by exocytosis cortical granules (vesicles)
- release proteases (enzymes) into zona pellucida causing it to harden and become impenetrable to sperm, preventing polyspermy.
implantation of blastocyst in endometrium
Ball of cells called a morula forms after a series of mitotic divisions
Ball of cells continues to divide, unequally forming a fluid filled cavity in middle - called a blastocyst
consists of:
Inner mass of cells (develops into embryo)
Outer layer (develops into the placenta)
A fluid filled cavity.
https://www.youtube.com/watch?v=ZGyh5mR2zaU
Menstrual Cycle (Pregnancy)
Blastocyst implants into endometrium - starts to release hcg hormone.
Hcg concentration continues to rise for 8-10 weeks. Hcg causes corpus luteum to secrete estrogen and progesterone.
Progesterone and estrogen inhibit fsh and lh, no more eggs released.
Progesterone maintains endometrium, where blastocyst develops into fetus and placenta forms
Exchange in materials from mother to fetus
Placenta’s structure aid in function
Deoxygenated blood and waste out via umbilical arteries, oxygenated blood and useful materials in via umbilical vein.
Mothers arteries deliver blood into the intervillous space, bathing the villi of placenta for maximal exchange of materials.
Few, thin membranes give shorn diffusion path for materials.
Chronic villi increas surface area for exchange of substances.
Placental (chronic) cells secrete hormones, eg. Hcg, oestrogen and progesterone
Mother to fetus: Oxygen Water Lipids, glocose, amino acids Vitamins and minerals Antibodies
Fetus to mother: Urea Water Carbon dioxide Hcg hormone
Placenta Importance
Life support system of fetus.
Releases progesterone and estrogen*
Exchange of materials between moher and fetal blood (bood does not mix)
Placenta takes over hormonal role of corpus luteum at week ten of pregnancy
Birth cicle positive feedback loop
Process of birth is stimulated by rise in estrogen levels.
Estrogen increases, no longer inhibited by progesterone
Estrogen increases responsiveness of muscular wall of uterus to oxytocin
Contractions stimulate stretch receptors - signal brain to release oxytocin from pituitary gland.
Oxytocin also stimulates muscle of uterine wall and contractions to grow stronger.
Contractions again stimulate stretch receptors causing more oxytocin
Contractions continue for short time after birth to eject the placenta
Stretch receptors are no longer stimulated - oxytocin levels fall and contractions cease.
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Opsonisation
antibodies attach and mark
pathogens
Allows for easier identifing by other immune cells
e.g. so macrophages can find and engulf and digest them
Agglutination
Antibodies attach to each other causing a clumping of pathogen
(enhancing effects of neutralisation and opsonization)
Complement Activation
Antibodies ‘encourage’ other components to attach to pathogen attacking it
e.g. breaking bacterial membrane and lysing cell
Mature sperm diagram
Acrosome - contains enzyme which can digest zona pellucida
Nucleus - same as egg
Midpiece - processes helical mitochondria which provides ATP for swimming
Flagellum - contains fibres and microtubules to strengthen and allow tail to move
Process involved in Oogenesis
Begin with mitosis and later on involves meiosis
Cell enlargement before meiosis Haploid cells (gametes)
Produce specialised gametes
Eggs/ova produced in the ovaries
initiated During development of fetus
Pauses during prophase I and between
prophase II and metaphase II
cytokinesis - Unequal, producing polar bodies
gametes - One ovum, polar bodies degenerate
release - 14th day, midpoint of the menstrual cycle
Ceases - menopause
