Revision Flashcards
1
Q
Negative feedback
A
- blood pressure drops
- brain detects change, signals heart to inc HR + constrict blood vessels
- pressure restored
2
Q
Positive feedback
A
- blood pressure drops
- blood flow to heart dec
- heart unable to pump enough blood to maintain pressure
- blood flow to cardiac muscles decrease
- pressure decreases further
3
Q
CNS
A
- brain and spinal cord
- intergrative and control centres
4
Q
PNS
A
- cranial nerves and spinal nerves
- communication lines between the CNS and rest of body
5
Q
sensory (afferent) div
A
- somatic and visceral sensory nerve fibres
- conducts impulses form receptors to the CNS
6
Q
motor (efferent) division
A
- motor nerve fibres
- conducts impulses from the CNS to effectors (muscles and glands)
7
Q
Autonomic nervous system (ANS)
A
- visceral motor (involuntary)
- conducts impulses from the CNS to cardiac muscles, smooth muscles and glands
8
Q
Somatic nervous system
A
- somatic motor (voluntary)
- conducts impulses from the CNS to skeletal muscles
9
Q
Sympathetic division
A
- mobilises body systems during activity
10
Q
Parasympathetic division
A
- conserves energy
- promotes housekeeping functions during rest
11
Q
- local potentials
A
- usually generated in the neurons dendrites accumulate and reach the trigger zone of the axon
12
Q
- action potential
A
- trigger zone depolarises to threshold and generates an AP
13
Q
action potential propagation
A
- the AP is propagated down the axon to the axon terminals
14
Q
astrocyte
A
- anchor neurons and blood vessels
- regulate extracellular environment
- facilitate formation of blood brain barrier
- repair damaged tissue
15
Q
ogliodendrocyte
A
- myelinate certain axons in CNS
16
Q
microglial cell
A
- act as phagocyte
17
Q
ependymal cell
A
- line cavities
- cilia circulate fluid around brain and spinal cord
- some secrete this fluid
18
Q
absolute refractory period
A
membrane potential -70→ 30
- Na+ channels activated
- K+ channels activating slowly
30 → -70
- Na+ channels inactivated
- K+ channels avtivated
19
Q
relative refractory period
A
- Na+ channels in resting state
- K+ channels remain activated
20
Q
acetylcholine
A
- acetyl-CoA & choline
- excitatory
- CNS: brain and spinal cord
- PNS: neuromuscular junction and ANS
21
Q
catecholamines (norepinephrine, epinephrine, dopamine)
A
- tyrosine
- excitatory
- CNS: brain and spinal cord
- PNS: ANS (symp. div)
22
Q
AP propagation - myelinated axons
A
- more energy sufficient - reliable
- SALATORY CONDUCTION: insilating prop. of myelin sheath inc. efficiency & speed
- AP propagates from 1 node of ranvier to next by generating currents that open ion channels
23
Q
AP propagation - unmyelinated axons
A
- passive, slow & unreliable
- ionic current flows across each adjacent segment of membrane
- step by step depolarisation & repolarisation of each voltage gated ion channel in membrane
24
Q
Cerebrum
A
- frontal, parietal, temporal, occipital lobes
- higher mental functions
25
diencephalon
- thalamus, hypothalamus, epi & sub thalamus
| - maintains HOMEOSTASIS
26
cerebellum
- coordination & movement
27
brainstem
- diencephalon, midbrain, pons, & medulla oblongata
| - helps maintain homeostasis, responsible for some reflexes
28
Sympathetic nerve fibres
- thoracic and lumbar spinal cord
- short preganglioic: acetylcholine
- long postganglionic: norepinephrine
29
Parasympathetic nerve fibres
- brainstem or sacral spinal corn
- long preganglionic
- short postganglionic
- both acetylcholine
30
spinal cord and reflex arc
1. PNS detects stimulus and delivers stimulus to CNS
2. CNS integrates information
3. PNS delivers motor response to effector organs
31
pulmonary circuit
- right side of heart receives deoxygenated blood from body & pumps to lung for gas exchange
- oxygenated blood returns to left side of heart
32
systemic circuit
- left side of heart receives oxygenated blood from the lungs and pumps to body
- deoxygenated blood returns to right side of heart
33
heart conducting system 1
Sinoatrial (SA) node generates an action potential, which spreads to atrial cells and the atrioventricular (AV) node
34
heart conducting system 2
After AV node delay, the AP is conducted to the AV bundle then to right and left branches
35
heart conducting system 3
AP spreads from the bundle branches along the Purkinje fibres to the contractile cells of the ventricles
36
P wave
atrial depolarisation
37
QRS complex
ventricular depolarisation (masking atrial repolarisation)
38
T wave
ventricular repolarisation
39
R-R interval
entire duration of a cardiac AP
40
P-R interval
duration of atrial repolarisation and AV node delay
41
Q-T interval
entire duration of a ventricular AP
42
Preload
- length or degree of stretch of sarcomeres in ventricular cells before they contract
- determined by vol of blood coming in from the pulmonary
43
Frank-starling law
increased ventricular muscle cells stretch, leads to more forceful contraction
44
afterload
- force that right and left ventricles must overcome in order to eject blood into respective arteries
- determined by pressure in systemic circuit
45
contractility
- hearts intrinsic pumping ability, or ability to generate tension
- determined by the heart's intrinsic pumping ability
46
systemic blood pressure
- pumping of heart generates blood flow
- pressure arises from resistance
- systemic BP is highest in the aorta and declines until it reaches 0 at the right atrium
- most pronounced change in BP occurs in arterioles
47
factors regulating blood pressure - peripheral resistance
Peripheral resistance
- blood vessel length
- vessel diametre
- blood viscosity
- obstruction in vessels
48
Response to low BP & vol
- Sympathetic nerve fibres release epinephrine and norepinephrine
- ADH & renin-angiotensin- aldosterone system (RAAS) help inc BP & vol
49
response to high BP & vol
- sympathetic input to heart and blood vessel is inhibited
| - ANP reduces BP & vol
50
Type I alveolar cells
90% of cells in alveolar wall,
| - very thin → allows for RAPID diffusion of gases → huge surface area; inc gas exc efficiency
51
Type II alveolar cells
- 10% of the cells - synthesis of SURFACTANT → reduces surface tensions on alveoli
52
Macrophages
mobile phagocytes derived from bone marrow; clean up & digest derbris that made its way into alveolus
53
pulmonary ventilation
- inspiratory muscles contract
- thoracic vol inc
- lung vol inc
- interapulmonary pressure decreases to below atmospheric pressure
- air flows into lungs
54
Boyle's law
Relationship between pressure and volume
55
Dalton's law
- Law of partial pressures
| - Total pressure = sum of all partial pressure of a gaseous mixture
56
Henry's law
Degree to which a gas dissolves in a liquid is proportional to both its partial pressure and its solubility in liquid
57
Charles' law
When temp inc. so does pressure of a gas
58
Response to inc. aretrial P CO2
- CO2 and/or H+ inc above normal range
- central chemoreceptors detect inc. in PCO2and/or H+
- chemoreceptors relay info to the DRG which stimulates VRG
- VRG triggers hyper-ventilation & additional CO2 is lost
59
skeletal muscle
contractions move body by pulling on bones - voluntary
60
cardiac muscle tissu
contractions in heart propel blood through vessels
61
smooth muscle tissue
contractions move fluids and solids along digestive tract and regulate the diametres of small arteries
62
Excitation-contraction coupling
1. end-plate potential stimulates an action potential
2. the AP is propagated down T-tubules
3. T-tubule depolatisation leads to opening of Ca2+ channls in SR, Ca2+ enter the cytosol
63
ATP and the powerstroke 1
1. energy from ATP breakdown places myosin into loaded or 'cocked' position
64
ATP and the powerstroke 2
2. myosin head binds to active sites
65
ATP and the powerstroke 3
3. ADP+P is released from myosin head causeing 'powerstroke' where myosin head uses stored energy to return to resting position
66
ATP and the powerstroke 4
4. ATP attaches to myosin head, detaching from active site
67
ATP and the powerstroke 5
5. attached ATP is then broken down/ hydrolysed to place the myosin head back into loaded position
68
Excitation
ACh triggers an end-plate potential in the motor end-plate
69
excitation-contraction coupling
resulting AP in the sarcolemma travels down the T-tubules and triggers Ca2+ release from the SR into cytosol
70
prep for contraction
Ca2+ bind to troponin, which moves tropomyosin away from active sites of actin
71
contraction
- actin and myosin bind, and myosin undergoes a powerstroke
| - ATP detaches actin and myosin, and the cycle repeasts, leading to contraction of the muscle fibre
72
relaxation
- neurons stops releasing ACh, and the AChE degreades the ACh in the synaptic cleft
- cytosolic conc. of Ca2+ returns to the resting level. active sites of actin are blocked, muscle fibre relaxes
73
mechanisms of action - hydrophilic
1. hydrophilic hormone (1st messenger) binds to its receptor in the plasma membrane
2. receptor activates a peripheral protein
3. peripheral protein activates an enzyme
4. enzyme catalyses formation of a second messenger
5. second messenger initiates a series of events in the cell that leads to changes in its activity
74
mechanisms of action - hydrophobic
1. hydrophobic hormone diffuses into the target cell
2. hormone binds to an intracellular receptor and enters the nucleus of the cell
3. hormone-receptor complex interacts with the DNA to initiate a cellular change
75
Regulation of hormone secretion - hormonal stimuli
- growth hormone-releasing (GHRH) stimulates secretion of growth hormone (GH) from an anterior pituitary cell
- HORMONAL INHIBITION: somatosatin inhibits secretion of growth hormone from an anterior pituitary cell
76
Regulation of hormone secretion - humoral stimulus
Glucose uptake by a pancreatic cell triggers insulin secretion
77
Regulation of hormone secretion - neural stimulus
Sympathetic neruons stimulate secretion of epinephrine and norepinephrine from an adrenal medulla cell
78
Hypothalamus and anterior pituitary gland FB
- 1st cont: hypothalamus releases hormones
- 2nd cont: anterior pituitary releases hormone
- 3rd cont: target organs release hormones
- effects:
hormone lvl inc.
effects on other cells - return to normal range
79
Thyroid and parathyroid glands FB
- stimulus: exposure to cold
- receptor: receptors in hypothalamus detect change
- 1st cont : hypothalamus release TRH
- 2nd cont: anterior pituitary secretes TSH
- 3rd cont: Produce T3& T4/ secrete T3&T4 in blood
- effects: increased levels of T3&T4 in blood → inc metabolic rate
80
thymus
Releases thyroid hormones (T3, T4, cell growth & protein production) and CALCITONIN (reduces blood calcium levels)
81
parathyroid gland
releases PARATHYROID HORMONE (inc blood calcium levels)
82
Adrenal glands - CORTISOL
increase nutrients in blood stream
83
Adrenal glands - ALDOSTERONE
increase sodium reabsorption in kidney
84
Adrenal glands - ANDROGENIC STEROIDS
can affect gonads and other tissues
85
Adrenal glands - EPINEPHRINE & NOREPINEPHRINE
sympathetic effects
86
Blood glucose regulation - insulin
- stimulus: Blood glucose level rises
- beta cells of pancreas release insulin into the blood
→ INSULIN
- liver takes up glucose and stores as glycogen
- blood glucose level decline
87
proximal convoluted tubule
- reabsorb nutrients from filtrate
88
Loop of henle
- establishment of an osmotic gradient in renal medulla
| - gradient promotes water reabsorption
89
distal convoluted tubule
- makes adjustments to tubular fluid composition → combination of secretion and reabsorption
90
collecting duct
- carries tubular fluid through the osmotic gradient in renal medulla
91
papillary duct
- collects tubular fluid from multiple collecting ducts and delivers to a minor calyx
92
Glomerular filtration rate
NET FILTRATION PRESSURE (NFP)
1. glomerular hydrostatic pressure (GHP)
2. glomerular colloid osmotic pressure (GCOP)
3. capsular hydrostatic pressure (CHP) - generated
93
Regulation of glomerular filtration rate - autoregulation
- myogenic and tubuloglomerular FB sys.
94
regulation of glomerular filtration rate - central regulation
- RAAS & sympathetic nerve input
95
RAAS SYSTEM
1. drop in BP & fluid vol
2. liver releases angiotensinogen
3. renin relase from kidney
4. renin acts on angiotensinogen to form ANGIOTENSIN I
5. ACE (angiotensin-converting enxyme) release from lungs
6. ACE acts on angiotensin I to form ANGIOTENSIN II → also acts directly on blood vessels stimulation vasoconstriction
7. angiotensin II acts on the adrenal gland to stimulate release of ALDOSTERONE
8. aldosterone actso on the kidneys to stimulate reabsorption of NaCL & H2O
96
aldosterone
- determines potassium conc. in ECF
97
Oral cavity (mouth)
- ingestion
- mechanical digestion (mastication)
- propulsion (swallowing)
- secretion
98
pharynx
- propulsion (swallowing)
99
esophagus
- propulsion (swallowing)
| - limited secretion
100
stomach
- propulsion
- chemical digestion
- mechanical digestion
- secretion
- limited absorption
101
small intestine
- chemical digestion
- mechanical digestion
- absorption
- secretion
- propulsion
102
large intestine
- absorption of water, electrolytes & vitamins
- propulsion
- limited secretion
- defecation
103
GI neural regulation - Sympathetic (fight or flight)
- main innervation via the thoracic and splenic nerve plexus
| - effect on GIT: decreases secretion and motility, increases sphincter closure
104
GI meural regulation - Parasympathetic (rest and digest)
- main innervation via the vagus nerve, some input from facial, glossopharyngeal & sacral
- effects on GIT: increases secretion and motility, decreases sphincter closure
105
Swallowing - voluntary phase
the tongue pushes the bolus posteriorly toward the oropharynx
106
swallowing - pharyngeal phase
the bolus enters the oropharunx; soft palate and epiglottis seal off the nasopharynx and larynx respectively
107
swallowing- esophageal phase
peristaltic waves move the bolus down the esophagus to the stomach
108
defecation regulation: long reflex
- involves spinal cord
- parasympathetic motor fibres from the SACRAL REGION induce intensifying peristalsis in descending and sigmoidal colon and rectum; also relaxes internal sphincter
109
defecation regulation: short reflex
- via myenteric plexus causes muscularis to contract and internal sphincter to relax → relatively weak
110
catabolism
- group of reactions where one substance is broken down into smaller parts
- exergonic reactions → release energy
- cells can harness the energy relased to drive other processes
- energy released is ATP
111
anabolism
- group of reactions which cause smaller mulecules to be combined to make a larger molecule
- ENDERGONIC reacutions USE energy
112
early prophase I
chromosomes form with two sister chromatids
113
mid-late prophase I
during synapsis, homologous chromosomes form tetrads and CROSSING OVER occurs
114
metaphase I
tetrads align randomly at equator
115
anaphase I
random orientationin metaphase I leads to INDEPENDENT ASSORTMENT
116
telophase I
cytokinesis may follow, resulting in two genetically different haploid cells w/ sister chromatids still attached
117
prophase II
chromosomes remain condensed
118
metaphse II
chromosomes line up along equator
119
anaphase II
sister chromatids separate
120
telophase II
cytokinesis follows
121
regulation of reproductive system
- Hypothalamus: GONADOTROPIN RELEASING HORMONE (GnRH)
- Pituitary gland releases FOLLICLE STIMULATING HORMONE (FSH) & LUTEINIZING HORMONE (LH)
- stimulates ovaries and testes to produce their hormones including TESTOSTERONE, and ESTROGEN & PROGESTERONE
122
spermatogenesis
1. spermatogonium undergoes mitosis to produce diploid primary spermatocytes
2. one primary spermatocyte undergoes meiosis I to produce two haploid seconday spermatocytes
3. the two secondary sparmatocytes each undergo meiosis II to produce a total of 4 haploid spermatids
4. spermatids elongate as they being spermiogenesis
5. spermatids continue to undergo spermiogenesis to eventually become mature sperm cells
123
high testosterone negative FB loop
1. hypothalamus releases gonadotropin releasing hormone →stimulates the pituitary to secrete LH & FSH
2. LH stimulates the Leydig cells to produce testosterone
3. FSH causes cells within the seminiferous tubules to release androgen-binding protein → high conc. of testosterone near spermatogenic cells
124
regulation of lactation
- controlled by NEUROENDOCRINE REFLEX
- production of milk by mammary glands is a positive FB sys
- hypothalamus release PROLACTIN-RELEASING HORMONE & OXYTOCIN
- anterior pituitary responds by releasing prolactin
125
Oxytocin
(hypothalamus) helps release milk from mammary gkands
126
prolactin
(anterior pituitary) stimulates milk production
127
Factors regulating blood pressure - Cardiac output and blood volume
Cardiac output
- Stroke vol
- HR
Blood vol
- water loss
- water gain
