Chapter 3 Systems Flashcards
How do platyhelminths and annelids respire?
exchange of gas with the environment, easily diffuse
platyhelminths (flatworms)
annelids (segmented worms)
How do fish respire?
evanginated (outgrowths)
larger surface area
(can be internal or external)
What is the gill cover called?
operculum
How do insects respire?
Tracheae - tubular system lined with chitin
- openings in trachea …
What are the openings in trachea for insects called?
spiracles
Where are chemoreceptors found and what do they do involving respiration?
- medulla oblongata, aorta, carotid arteries
- detect partial pressure of O2 (if low = respirate more)
- detect pH (if acidic = respirate more = increase CO2 dissociated into H+ ions and bicarbonate)
What circulatory systems do insects and molluscs have?
open circulatory system
What does the open circulatory system consist of?
hemolymph (blood, interstitual fluid, lymph)
- flows through internal cavity = hemocoel
- returns to heart via holes = ostia
What type of cells is the cardiac cycle regulated by?
auto-rhythmic cells: function independently without external stimulation
What causes movement of blood through the arteries?
hydrostatic pressure
- blood pressure is very high in arteries and ultimately 0 in venules
What circulatory system and mode of respiration do annelids have?
closed circulatory system!
diffusion of gasses (gas distributed through the animal upon diffusion through skin)
(note: annelids are ringed/segmented worms)
From stem cells to immature blood cells, how do RBC develop?
- lose nucleus
- decrease size
- increase Hb content
What is hemostasis?
blood clotting
platelets = cell fragments
release - fibrinogen, fibrin
How does lymph circulate throughout the body?
- smooth muscle contractions
- valves prevent backflow
What is the role of lymph nodes?
- to filter for infectious materials - pathogens
- hold lymphocytes (WBC) which produced in bone marrow
In the urinary system, where is there high pressure and low pressure in terms of blood vasculature?
high: efferent arterioles are narrow therefore making glomerulus high pressure too
low: peritubular capillaries - therefore absorbs the small molecules (high to low gradient)
Where does filtration occur?
bowman’s capsule - glomerular filtrate
- from blood in glomerular capillaries to bowmans capsule makes filtrate
Where does reabsorption occur?
starting in the PCT and Loop of Henle
Where can all glucose, a.a., vitamins, hormones, and water all be reabsorbed?
proximal convoluted tubule
Which part of the loop of henle is permeable to water and impermeable to salt?
- descending limb
Which part of the loop of henle is impermeable to water and permeable to salt?
- ascending limb
What is the counter current exchange?
vasa recta
loop that flows in the opposite direction that absorbs water and salt in the other way
What hormones influence osmoregulation?
ADH
aldosterone
What is the role of ADH?
- ADH stimulates reabsorption of water
What is the role of aldosterone?
- aldosterone stimulates the reabsorption of sodium (Na+) and water follows via osmosis
Where do these osmoregulating hormones act on?
ADH: collecting duct
aldosterone: DCT and collecting duct
How is nitrogen excreted in mammals?
ammonia (NH3) is converted into urea in the liver
urea is much less toxic
How do fish excrete nitrogen?
directly NH3/NH4+ excretion to water
How do birds, insects, and reptiles excrete nitrogen?
as uric acid crystals
(insoluble as water)
- precipitate allows conservation of water
How do eggs excrete nitrogen?
via allantois sac (develops to the umbilical cord)
What does salivary amylase break starch down to?
maltose
Is the digestive system voluntary or involuntary control?
involuntary
except in the mouth = voluntary
What are the 3 main parts of the stomach?
upper fundus
body
lower antrum
What is the function of the fundus and upper body?
- thin walled portion
- receptive relaxation -> ability to increase volume to accommodate, without increasing intraluminal pressure
What is the function of the lower body and the antrum?
- thick walled portion
- mixing and propulsion into the duoddenum
What are 2 forms of mechanical digestion in the stomach?
- peristaltic
- segmental movements
What are 4 components to gastric juice?
pH 1-2
- pepsinogen (converst to pepsin)
- HCl (to activate pepsinogen)
- intrinsic factor (required for vit B12)
- mucin (protect stomach lining)
Where does retropulsive turbulent flow occur?
At the pyloric sphincter
food hits barrier and further mixing
What are the main functions of the small intestine?
- neutralize acidic chyme
- absorb nutrients and water
What does the duodenum directly secrete?
- proteases
- maltase
- lactase
- phosphates (nucleotide breakdown)
What does the pancreas secrete?
- into the small intestine
- alkaline pH 7-8
- pancreated amylase
- pancreatic lipase
- proteases (inactive zymogens) (trypsinogen -> trypsin) via enterokinase
What makes bile and what secretes bile?
bile is produced by the liver
secreted by the gall bladder
released into bile duct and into the pancreatic duct into the duodenum
What is the role of gastrin?
- hormone that releases gastric juices in preparation for eating
What is the role of secretin in the digestive system?
- produced in the duodenum when food enters stomach
- stimulates the pancreas to produce bicarbonate to neutralize the acidic chyme
What is the role of cholecystokinin?
- produced in the small intestine in response of fats
- stimulates bile release from gallbladder
- stimulates release of digestive enzymes from pancreas
4 parts of the the cerebral cortex (a part of the cerebrum - forebrain)
- frontal
- parietal
- occipital
- temporal lobes
Role of the frontal lobe:
higher order thinking
Role of the parietal lobe:
sensory info: orientation, recognition, perception
Role of the parietal lobe:
visual processing
Role of the temporal lobe:
sensory info: auditory, memory, speech
What is the corpus callosum
bundle of axons
bridge left and right hemispheres
What are parts of the hindbrain?
cerebellum
pons
medulla oblongata
What are parts of the midbrain?
thalamus and hypothalamus
What is the function of the cerebellum?
movement, balance, posture
Function of the hypothalamus?
part of limbic system (endocrine (pituitary) and autonomic system)
- i.e. ADH: thirst, hunger, temperature,
Hippocampus
part of limbic system; learning and memory
Medulla oblongata
heart rate, breathing, vital functions
1 property of membrane potential: What is the concentration gradient of physiological ions?
- high [Na+] EXtracellularly
- high [K+] and negatively charged proteins/nucleic acids INTracellularly
What maintains the concentration gradient of the neuronal membrane?
3 sodiums out
2 potassiums in
Sodium-Potassium pump (ATP required pump)
therefore -ve inside relative to the +ve outside
What happens in “depolarization” of an action potential?
- resting membrane potential -70mV
- Na+ channels open - INflux of positive Na+ down it’s concentration gradient
- -30mV - depolarized
Repolarization = ?
K+ channels open at a delay (which causes hyperpolarization)
= outflux of K+ ions down its concentration gradient to repolarize the membrane
Refractory period?
concentration gradients no longer established, sodium potassium pump needs to restore the gradient
How do you increase speed of action potentials?
- increase axonal diameter (invertebrates)
2. axonm insulation with myelin (vertebrates)
What type of cells make up the myelin sheath?
- schwann cells in the PNS
- oligodendrocytes in the CNS
How does saltatory conduction work?
- depolarization will spread a larger distance and reach from node of ranvier to another node (reboost) to next with each influx of sodium
How are signals transmitted between neuron to neuron?
pre- to post-synaptic neuron via synaptic cleft - chemical transmission
- heart - electrical signal
A typical synapse from pre- to post-synaptic (from axon to dendrite) is called?
axodendritic
Spine synapse = excitatory
Shaft synapse = inhibitory
Axosomatic synapses are between:
axon presynaptic to soma post-synaptic
What happens when an action potential reaches the presynaptic cleft at the axon terminal?
voltage gated Ca2+ ion channels open
- calcium INFlux at the PRE-synaptic vesicle
What occurs regarding neurotransmitters in the axon terminal?
vesicle fusion due to Calcium signal
- neuron stores NT in synaptic vesicle
- vesicle moves to membrane
- release NT to synpatic cleft
The postsynaptic membrane is excited or inhibited. True of false?
True.
- EPSP: excitatory postsynaptic potential = Na+ channels open to depolarize = action potential
- IPSP = inhibitory postsynpatic potential = K+ channels open induce hyperpolarization - difficult to generate action potential
How are Neurotransmitter is degraded or recycled?
by enzymes in synaptic cleft
or retaken up by presynaptic neuron
Which of the 3 NT are likely to stimulate muscular contractions? Acetylcholine, Epinephrine, Dopamine, Serotonin, GABA?
acetylcholine
- involved with neuromuscular junctions
- excitatory to stimulate muscle contraction
Fascicles are bundles of…?
skeletal muscle fiber that run in the same direction
What type of movement does skeletal muscle control?
voluntary movement - conscious
What type of muscles types are there?
- skeletal
- cardiac
- smooth
Which muscle type is multinucleated?
skeletal
What do the I band and A band represent?
I band - actHin segments - light (no overlap)
A band - myosin segments - dark
Z line ?
Z-discs
H zone
only length of the myosin that does not overlap
Which bands/zones change during contraction?
A, H, I, Z
A- band stays the same, but H zone gets smaller
I-band gets smaller, since it is the area of actin that does not overlap
Z-lines are therefore closer
What molecule is involved with skeletal muscle contraction?
calcium (release of calcium across 2 pools)
- binds to troponin on myosin head
What is the role of tropomyosin protein and troponin?
Exposure to Ca2+ allows for Ca2+ to bind to troponin which causes tropomyosin to expose binding sites and allow for myosin heads to bind to actin filaments
What is reigor mortis?
state of ATP not replenished
cycle cannot continue
locked in state of contraction
What is the plasma membrane of a muscle cell called?What hormone binds here?
sarcolemma
acetylcholine binds to open Na+ channels for depolarization
transmitted throughout T tubule
What types of muscles are striated? skeletal, smooth, cardiac.
skeletal and cardiac
What is the purpose of lysozyme?
- enzyme protein that acts as first line of defence
- saliva, sweat, tears
What is the second line of defence?
innate immunity = non-specific cellular and humoral cmpnts
no memory
What are 3 humoral factors?
molecules that can be dissolved and transported in fluids
- complement proteins (attract phagocytes)
- interferons (virus infected cells secrete for warning)
- inflammatory response
What are 3 reasons that cause inflammatory response?
- phagocytes (attracted via complement proteins) stimulate basophils
- histamine: released by basophils
- vasodilation by basophils
List 6 cellular components of the innate immune system.
- neutrophils: most abundant, first line of defence - slight digestion - pus
- eosinophils: parasitic infections
- basophil: allergic inflammatory response
- macrophage: TOLL-like receptor which recognize pathogen associated membrane pattenr molecules on bacterial surface
- natural killer cells: cells kill self and non self; all “self” have MHC1, for nkc to recognize; lymphoid lineage
- dendritic cells: interact with and phagocytose bacteria; myeloid and lymphoid lineage
PAMPS , TLR, MDNF is associated with which cellular response?
macrophage
- pathogen associated molecular/membrane patterns
- TOLL-like receptors
- macrophage derived neutrophil chemotactic factor (recruits neutrophil)
Pus, dead bacteria, NET is associated with which cellular response?
neutrophil activity
- neutrophil extracellular net, dead neutrophils and pus = dead bacteria
What cellular component activates the innate and adaptive response?
dendritic cell links the innate and adaptive response after it travels to the lymph nodes
What is the third line of defence?
adaptive immunity - specific to invaders = memory
What is the difference between MHC class I and class II molecules?
MHC class 1 are present on all cells MHC class 2 are present on antigen presenting cells (dendritic cell, macrophage, B cell)
Cell mediated adaptive immunity is referred to as?
t-cell activation
Humoral adaptive immunity is referred to as?
b cell development
One antigen one polypeptide sequence is what immune response?
cell mediated adaptive immunity - t cell activation
= epitome
What are the 3 types of T cells
helper t cells
cytotoxic/killer t cells
regulatory t cell (downregulates immune response i.e. autoimmunity)
Where do b cells and t cells originate?
bone marrow
What is the main difference between b cells and t cells?
- b cells produce and secrete immunoglobulin/antibody that recognize same epitome, vs t cell has the antigen receptor
What are the main parts of an antibody?
- variable region: varies for each b cell; recognizes the epitome (antigen)
- heavy chain and light chain, antigen binds the heavy chain - constant region: receptors on some cells
What are 2 types of B cells?
- plasma b cells: circulate in blood and bind to antigens
- memory b cells: membrane bound and long lifespan (what vaccination relies on)
Arginine vasopressin AVP is also known as?
ADH - antidiuretic hormone
Name some amino-acid hormones
- epinephrine/norepinephrine
- triodothyronine (T3) / T4 thyroxine
- melatonin
Name some steroid hormones
- cortisol (adrenal cortex)
- aldosterone (adrenal cortex)
- estrogen
progesterone - testosterone
What is the role of cortisol?
- adrenal cortex (stimulated by ACTH)
- sympathetic flight or fight
- increase blood glucose
- increase Na+ and K+ reabsorption
(exact same as aldosterone)
What is a tropic hormone vs normal?
tropic hormones target other glands/organs
What is the difference between alpha and beta cells of the pancreas?
- glucagon releasing = alpha
- insulin releasing = beta
What does LH stimulate/target?
- ovaries and testes
- corpus luteum formation
- testosterone production
What does FSH stimulate/target?
- maturation of ovarian follicles to secrete estrogen
- maturation of seminiferous tubules and sperm production
Layers of the epidermis: (outer to inner)
stratum corneum stratum lucidum stratum granulosum stratum spinosum stratum basale (germinativum) (can ladies grow skin back?)
what is a keratinocyte?
skin cell
where does the life cycle of a skin cell begin?
keratinocyte begins at stratum basale/germinativum (germinates here in basement membrane)
what is the purpose of lamellar granules?
lipid containing
surface of stratum corneum - water repellent
What types of cells to keratinocytes derive from?
- Merkel cells
- skin stem cells
What is the papillary region?
- outermost region of the dermis that has loose connective tissue
- interdigitates with stratum basale
(phagocytes, lymphatic capillaries, nerves, small blood vessels)
What is the reticular region?
- inner region of dense connective tissue with tight mesh of collage nand elastin
(oil glands, sweat ducts, fat, hair follicles)
What type of muscle lines the walls of blood vessels?
smooth muscles
note: these are not striated and have no T-tubules
