Class Eight Flashcards
1
Q
what is a hormone
A
a molecule secreted into the bloodstream by an endocrine gland
has effects on distant target cells
2
Q
what is an endocrine gland
A
ductless gland → secretory products are picked up by capillaries
3
Q
what is an exocrine gland
A
secrete products into the external environment with ducts
4
Q
what is a hormone receptor
A
receptor with the hormone as the ligand
5
Q
what is autocrine activity
A
signalling molecules modifying the activity of the cell which secreted them
6
Q
examples of hydrophilic hormones
A
peptides & amino acid derivatives
7
Q
where do hydrophilic hormones bind
A
receptor on the cell surface
8
Q
example of hydrophobic hormones
A
steroids
9
Q
where do hydrophobic hormones bind
A
receptors in the cellular interior
10
Q
example of a polypeptide hormone
A
insulin
11
Q
what secretes insulin
A
B cells of the pancreatic islets of Langerhans
12
Q
when is insulin released
A
in response to high blood glucose
13
Q
parent A for catecholamines and thyroid hormones
A
tyrosine
14
Q
site of synthesis for peptides
A
rough ER
15
Q
site of synthesis for steroids
A
smooth ER
16
Q
what does calcitonin do
A
decreases calcium levels to regulate calcium homeostasis
17
Q
what are tropic hormones
A
hormones that have other endocrine glands as their targets
“hormones that regulate hormones”
18
Q
what is the hypothalamic-pituitary control axis
A
connection between hypothalamus and pituitary
hypothalamus controls the pituitary
19
Q
anterior pituitary gland aka
A
adenohypophysis
20
Q
posterior pituitary aka
A
neurohypophysis
21
Q
hormones of the posterior pituitary
A
ADH
oxytocin
22
Q
where does thyroid stimulating hormone come from
A
ant. pituitary
23
Q
cortisol is secreted by the..
A
adrenal cortex
24
Q
what is ischemia
A
inadequate blood flow → waste builds up
25
what are arteries
vessels that carry blood away from the heart
26
secretion of what substances affects vessel diameter
NO and endothelian
27
what is pulmonary circulation
flow of blood from heart → lungs and back to the heart
28
what is systemic ciruclation
flow of blood from the heart → rest of body & back to the heart
29
what vessel comes after the right ventricle
pulmonary arteries → lungs
30
how does blood enter the left atrium
via pulmonary veins
31
what is responsible for the heart's own BS
coronary arteries that supply blood to the wall of the heart
32
what merges to form the coronary sinus
coronary veins
33
where does the coronary sinus drain
right atrium
34
main purpose of valves
ensure one way flow through the circulatory system
35
where are AV valves found
in-between atria and ventricles
36
where is the bicuspid (mitral) valve found
in between the left A and V
37
where is the tricuspid valve found
in between the right A and V
38
why are valves needed in veins
theres not much of a driving force → blood losses pressure when passing through capillaries
39
why do varicose veins occur
when venous valves fail → increased BP in the veins
40
what happens in diastole
ventricles are relaxed
blood flows from atria → ventricles
atria contracts
41
what initiates systole
ventricles contracting
42
what happens during systole
ventricles contract
43
what is the lub sound
closure of AV valves at the beginning of systole
44
what is the dup sound
closing of the SL valves
45
what is stroke volume
amount of blood pumped with each systole
46
what is cardiac output
amount of blood pumped per minute
47
cardiac output formula
CO = SV x HR
48
Frank Starling mechanism
increasing stroke volume by increasing venous return
more blood = more stretch = stronger contraction
49
2 ways to increase venous return
increase blood volume (retain water)
propelling more blood into the heart (valves)
50
what are intercalated disks
the connections between cardiac muscle cells
51
what initiates AP in the heart
SA node
52
pacemaker of the heart
SA node
53
what has the most sodium leak channels of the conduction system
SA node
54
internodal tract
pathway that connects SA node to AV node
55
SA node pathway
SA node → AV node → bundle of His → bundle branches → Purkinje fibers
56
vagus nerve and SA node
postganglionic neurons innervate the SA node → releases ACh which inhibits depolarization by binding to receptors
57
what is vagal tone
constant level of inhibition provided by the vagus nerve
58
2 ways the sympathetic NS affects the heart
postganglionic neurons release norepinephrine
epinephrine from adrenal medulla binds to receptors on cardiac muscle cells
59
baroreceptors
found in the aortic arch and carotid arteries
monitor pressure
parasympathetic and sympathetic systems try to fix it
60
principal determinant of cardiac resistance
conscription of arteriolar smooth muscle aka precapillary sphincters
61
diastolic vs systolic pressure
S: highest pressure in the circulatory system
D: lowest pressure
62
what is pulse pressure
difference between systolic and diastolic pressures
63
what is local auto regulation
tissues in need of extra BF can requisition to themselves
not getting enough BF → waste builds up → vasodilation occurs
64
function of albumin in blodo
maintains oncotic pressure (osmotic pressure in capillaries due to plasma proteins)
65
function of fibrinogen in blood
blood clotting → hemostasis
66
what is urea
breakdown product of AAs
67
what is bilirubin
breakdown product of heme
68
hemocrit
V of blood that is RBCs
69
where do formed elements of blood come from
bone marrow
70
where is erthythopoeitin made
kidney
71
what does erythropoietin do
stimulates RBC production in the bone marrow
72
hemolytic disease of the newborn
Rh- mom with anti-Rh antibodies from previous pregnancy has a Rh+ baby
73
universal recipients
AB+
74
universal donors
O-
75
what WBCs move by amoeboid motility (crawling)
macrophages and neutrophils
76
precursor to macrophage
monocyte
77
macrophage function
phagocytose debris + microorganisms
78
B cell function
mature into plasma cells and produce antibodies
79
T cell function
kill virus infected cells
80
neutrophil function
phagocytose bacteria
81
eosinophil function
destroy parasitres, allergic reactions
82
basophil function
store + release histamine, allergic reactions
83
what are platelets derived from
megakaryocytes
84
fibrin function
forms a mesh to keep a platelet plug together
85
how does fibrinogen turn into fibre
with thrombin
86
hemophilia
X linked recessive - excessive bleeding
87
how many oxygens can one hemoglobin carry
4
88
level of oxygen in active tissues
low
89
3 ways carbon dioxide is transported in blood
as carbonic acid
stuck to hemoglobin
dissolved in the blood
90
what goes through intercellular clefts
nutrients, waste and WBCs
91
why does water tend to flow out of capillaries (2)
hydrostatic pressure squeezes it out
high osmolarity of tissues draws it out
92
what is the largest lymphatic vessel + location
thoracic duct in the chest
93
3 types of immunity
innate
humoral
cell-mediated
94
what is innate immunity
general, nonspecific protection the body provides
95
what is humoral immunity
specific protection by antibodies or immunoglobins
96
what are antibodies made up of
light chains and heavy chains, joined by disulphide bonds
97
IgM location + function
blood & B cell surface
initial immune response
98
IgG location + function
blood
ongoing immune response: most abundant antibody in the blood
99
IgD location + function
B cell surface
antigen receptor on B cells
100
IgA location + function
secretions (e.g. breast milk, saliva)
protects newborns
101
IgE location + function
blood
involved with allergic reactions
102
what products antibodies
B cells
103
clonal selection
hypothesis that a B cell expresses receptors specific to the distinct antigen, determined before the antibody ever encounters the antigen
104
T helper cell function (CD4)
activate B cells and T killer cells
105
how does the T helper cell communicate with other cells
by releasing lymphokines and interleukins
106
what is the host of HIV
T helper cells
107
T killer cell function (CD8)
destroy abnormal host cells
108
where do T cells develop during childhood
thymus
109
where is MHC I found
on the surface of every nucleated cell
110
where is MHC II found
only on antigen presenting cells (e.g. macrophages and B cells)
