11. Animal Physiology Flashcards
11.1 What are the steps of the immune response (antibody production)?
1) Pathogens are ingested by macrophages, antigens are absorbed and displayed
2) T-cells w/ specific receptors bind to antigens and activate
3) Helper T-cells bind to antigen specific B-cells and signal with the release of protiens
4) Activated B-cells undergo mitosis, producing a large number of plasma cells, but also some memory cells
11.1 What is a plasma cell?
Plasma cells are mature B-lymphocytes.
-Expanisve RER to produce a lot of antibodies
11.1 What are antigens?
Every organism has unique molecules on their cell’s surface
- Most common = protiens + polysaccharides
11.1 Antibody modes of destruction
P - recipitation: soluble pathogens become insoluble
A: gglugation: Links cell-bound antigens together causing clumping
N: uetralisation: covers dangerous parts
I: nflamation: Triggers histamine release
C: Complement activation: complement protiens perforate cell (lysis)
11.1 What are histamines?
Histamines dialate blood cells to allow more fluid w/ immune components
- Mast cells secrete this
Effects: Allergy response
11.1 What are mast cells?
Immune cells in connective tissue
11.1 What are monoclonal antibodies?
Highly specific, pure antibodies
- produced by hybridoma cells
- used as treatment + diagnosis of diseases
EX: hCG antibodies for pregnancy test
11.1 How are hybridoma cells produced?
1) A mouse is injected with an antigen and produces plasma cells
2) The plasma cells are fused with myeloma cells (tumor cells)
3) The resulting cell is the hydbridoma cell
11.1 What are myeloma cells?
Cancer plasma cells
11.2 What is the purpose of bones and exoskeletons?
Provide anchorage for muscles and act as levers
11.2 Lever diagram parts
F: Fulcrum, (triangle)
R: Resultant Force
E: Effort
11.2 What are the three types of movement levers
First Class: Traditional lever
Second Class: R + E are on the same side (E is furthest), F on opposent
Third Class: R+ E on same side (E closer to middle), F on opposet
11.2 What are synovial joints?
Joints that surrond the surface of two bones, they allow certain movement but not others
11.2 Six types of sinovial joints ( in order of mobility)
Plane joints
ex: between tarsal bones of foot
Hinge Joints
ex: elbow
Pivot Joint
ex: vertebrae
Condyloid
ex: wrist (radius + carpal)
Saddle
ex: Base of thumb
Ball and socket:
ex: Hip
11.2 Logistics of skeletal muscles
These work in antagonistic pairs, where one contracts and one extends
11.2 Draw a human elbow joint
11.2 What is the microstructure of muscle fibers?
Bundles of myofibrils (muscles cells) are surronded with a sacrolemma with a sarcoplasmic reticulum wrapping around all fibrils
- there are extra nuclei and mitochondria
11.2 Structure of a myofibril
Myofibrils are composed of units called sacromere:
Each sacromere spans the length between z-lines.
There is a light band of actin and the dark band of myosin in the middle
Each thick myosin is surronded by six thin actin
11.2 Draw a sacromere
11.2 Mechanism of muscle contraction
Mysoin heads bind to sites on actin and cause cross-briging
-using ATP they exert force and the actine slides along which shorterns the sacromere
11.2 What controls muscle contraction
Relaxed muscle: Tropomysosin blocks binding site on actine
- When motor nueron signals, sacroplastic reticulum releases calcium
- Calcium binds to troponin which causes tropomyosin to move
11.2 Role of ATP in muscle contraction
1) Myosin head attaches to actin binding site forming cross-bridge
2) ATP binds to head, causing detachment
3)ATP is hydrolysed into ADP + P causing myosin head to shift
4) Head attaches to new binding site
5) ADP+P are released causing head to move back to original positi, sliding actin
11.3 Draw a kidney
11.3 Osmoregulator vs osmoconformer
Osmoregular: maintain constant internal solute concentration
- all terestrial, freshwater
- some marine
Osmoconformer: internal = external
11.3 What is the malphighian tubule system?
Instead of blood, arthropods have hemolymph.
The malphighne tubules branch off from nisect intestine tract
1) Ulric acid, Na, K are transported into tubules, H2O follows (osmosis)
2) Tubules empty into gut
3) Some ions are actively reabsorbed in hindgut + water
4) Dehydrated uric paste is released
11.3 Renal artery vs renal vein
Renal artery: brings in unfiltered blood, renal vein = filtered
Renal artery blood:
- higher in toxins and substances ingest + absorbed, not metabolized (drugs)
- Waste products (urea)
Non excretory:
excess water + salt
11.3 What is a nephron?
The filtering unit of the kidney
11.3 Describe the structure of the glomerulus.
The glomerulus is a tiny cluster of looping blood vessels surronded by bowman’s capsule, which is connected to the proximal tubule.
- Afferent arteriole = enterance
- Efferient arteriole = exit
The capillary wall is fenestrated with gaps between cells
The capillary is surronded by a basemented membrane covering podocytes.
11.3 Purpose of the glomerulus
Capillary pressure and wall permeability allow fluid to be pushed out (glomerular filtrate)
Most solutes are filtered freely. except protiens (ultrafiltration)
11.3 What is the basement membrane’s structure?
It covers the capillary wall, made of negative glycoprotiens which prevents plasma protiens filtering out
11.3 What are podocytes?
Specialized epithelial cells . They have extensions that wrap around capillaries and short branches called foot processes
11.3 Endothelial vs epithelial cells
Endothelial: line internatl pathways
Epithelial: Lines outside
11.3 What does the proximal convoluted tubule absorb?
Na
Cl
Glucose
Water
11.3 Structure of the loop of henle/vasa recta + connections
Proximal tubule –> descending limb –> ascending limb –> distal tubule –> collecting duct
Capillary flows opposite (still goes away from bowmans capsul but descending capillary is next to ascending limb)
11.3 Gradient of loop of henle
The mOsM at the top (cortex) is about 300, low salt and high water
The mOsM at the bottom is about 1,200 (High salt, low water)
11.3 Absorption from the loop of henle
The descending limb losses water as the mOsM rises
The ascending limb loses salt as the mOsM lowers (Na, Cl)
11.3 Purpose of the loop of henle
Maintains hypertonic conditions of medulla
Water and salt follow conditions of gradient in medulla (vasa recta collects released products to maintain gradient, even with release)
11.3 Length of loop of Henle
longer loop = more water reabsorbed
11.3 Purpose of ADH
ADH controls the amount of water reabsorbed
- Released by posterier pituitary when dehydrated (sensed by osmoreceptors in hypthalamus, when blood mOsM is too high)
- Increased permeability of collecting duct walls which leads to less water in the filtrate
11.3 Release of nitrogeneous waste
When animals break down amino acids, ammonia is produced which can alter pH balance
Freshwater/marine: direct release
Terrestrial: convert into less toxic urea
11.4 Describe process of oogenesis
Starts in ovaries of female fetus
1) Germ cells in ovaries divide via mitosis and distribute throughout cortex
2) When they are large enough to undero meiosis, which they begin but stop in prophase 1 when follicle cells surrond them
11.4 Primary follicle vs secondary follicle
Primary: initial meiosis cell + follicle cell
Secondary: stimulated by FSH @ menstration
11.4 Oogenesis during menstration
1) FSH triggers continued division of some primary follicles, this creates unequal size cells
2) One cell becomes the secondary oocyte, the other a polar body. The secondary begins the second meiotic division byt stops in metaphase 2
3) The secondary oocyte is released from the ovary during ovulation, ruptured follicle becomes corpus lutuem, and enters the follopian tube
4) If fertilization occurs, mesosis 2 will complete (other polar body forms) and egg forms an ovum before forming a zygote once sperm nucleus is fused
11.4 Microstructure of testes
Testes are composed of narrow tubes, seminiferous tubules, with small cells in gapas called interstitial cells
- The outer layer of the tubules are germinal epithelium cells : sperm production
11.4 Spermatogenesis
1) Germial epithelium cells divide endlessly
2) Diploid cells grow into primary spermatocytes
3) Primary spermatocytes undergo meiosis
4) Produce 2 spermatides (n)
5) Spermatids associate with sertoli cells and develop into spermatozoa
6) Detach
11.4 Draw an egg (ovum)
11.4 Draw a sperm
11.4 Key differences in gametes
Sperm have almost no cytoplasm, egg has increased cytoplasm
During egg meosis, theres a polar body, uneven division
Egg formation happens once per menstration cycle, sperm = contineous
Sperm production begins at puberty, egg production begins prenatal
11.4 Types of fertilization
External: common with water animals
- susceptible to environmental influences
- Large quantities of gamete released
Internal: typical terrestrial
- more protection, but dependent on parent survival
11.4 Process of fertilization
Designed to prevent polyspermy
1) Acrosome reaction: The acrosome (sac o’ emzyme) of the sperm attaches to the zona pellucida (coat of glycoprotiens) and digests the coat
2) Penetration of egg membrane:
Now exposed sperm top has protiens to bind to membrane, nucleus enters cell
3) Cortial reaction
Cortial granules (vesicles) release content, in mammals its an enzyme to digest binding protiens. Zona pellucida hardens.
11.4 Blastocyte implantation
Fertilized ovum divides via mitosis, divisions are unequal and mitigation of cells leads to hollow ball (blastocyte)
(~7 days) reached utures, zona pellucida fully broken down. Sinks into uterus linining. Outer layer develops projections to penetrate
(~8 wks) Embryo –> fetus
11.4 What is the placenta?
A disc formed from development of fetal tissue that invades uterine wall.
Maternal blood pools into open ended arterioles into intervillous spacees called lacunae.
Placental villi occupy this space with fetal capillaries very close to maternal blood (seperated by placental barrier)
11.4 Types of maternal material exchange (types of animals)
Placental mammals
Monotremes : eggs
Marsiupials : underdeveloped
11.4 Exchange of materials maternal
Co2 –> Maternal blood
Fetal blood <– O2
Fetal blood <— glucose
Fetal blood <— antibodies (endocytosis)
Fetal <—Water –> Maternal
11.4 Role of hCG
hCG is produced by blastocyte, it promotes maintenece of corpus lutuem in ovary and stimulates secretion of progesterone
11.4 Corpus Luteum Secretion
The corpus luteum secretes estrogen and progesterone
11.4 Placenta hormone secretion
At about 9 wks, the placenta takes over for the corpus luteum.
- danger of miscarrage if fails
11.4 Parturition
Progesteron inhibits secretion of oxytocin and myometrium contractions (outer wall of uterus)
At end of pregnancy, hormones that inhibit progesterone are secreted
- oxytocin stimulates contract
- stretch receptors increase oxytocin production (positive feedback)
- cervix muscles relax
- amniotic sac breaks
