Exam 4 Flashcards
colloid
liquid that contains suspended substances
blood components
plasma (55-65%) formed elements (35-45%)
plasma
What is it mostly
What is it
What is suspended in it
liquid fraction
Is mostly water
Is a colloid
proteins are suspended in plasma
formed elements
erythrocytes (RBCs)
leukocytes (WBCs)
thrombocyte (platelet)
plasma proteins in suspension
albumin
globulins
fibrinogen
albumin
function
In plasma
regulates water balance between tissues, blood, and osmotic pressure
transport of hormones (T3 and T4) and other molecules
globulins
function
In plasma
transport of hormones (E2 and CORT) and other molecules
fibrinogen
function
In plasma
clotting
serum
what is it
liquid fraction of blood that was allowed to clot, then centrifuged
does serum contain clotting factors
no
what is plasma
liquid fraction of blood
blood that is collected with anticoagulant and then centrifuged
does plasma have clotting factors
yes
white blood cells
Types
granulocytes
agranulocytes
highly motile
white blood cells
granulocytes
Types
neutrophils
eosinophils
basophils
agranulocytes
white blood cells
Types
lymphocytes
monocytes
WBC chemotaxis
movement of WBC between circulation and tissue
WBC chemotaxis in response to
toxins
chemicals released from damaged/infected tissue
WBC chemotaxis
inflammation
What does it do
3
vasodilation (histamines)
increased capillary permeability
neutrophils and macrophages accumulation
pus
WBCs
dead WBCs, bacteria, cell debris
neutrophils
how common
function
most common (60-70%)
first responders to infections
phagocytize bacteria, antigen-antibody complexes, and other foreign bodies
most common WBC
neutrophils
eosinophils How common What does it defend against Function Regualtes what?
less common (2-4%)
defense against parasites
attach to parasites and release chemicals to kill it
regulation of inflammatory response
response to inflammatory response
eosinophils
What does it do
What does it destroy
aggregate in tissues during allergic reaction
destroy inflammatory chemicals, prevent spread of allergic inflammation
basophils
How common
function
rare (.5-1%)
proliferate during allergic reaction
what happens when basophils proliferate during allergic reactions
Releases what?
release heparin
release histamines
heparin
anticoagulant
histamine release
What does it do
increases blood flow
leads to itching, redness associated with allergies
lymphocytes
How rare
What types
fairly common (20-25%)
B lymphocytes
T lymphocytes
natural killer cells
natural killer cells
lymphocytes
destroy tumor and virus- infected cells
B lymphocytes
Originate where
Differentiate into
originate in bone marrow
differentiate into plasma cells or memory cells
b lymphocytes
function
Produce what
production of antibodies specific to pathogens
immunological memory
T lymphocytes
Originate where
What type of cells
originate from in bone marrow, mature in thymus
cytotoxic T cells
helper T cells
cytotoxic T cells
lymphocytes
destroy tumor and virus-infected cells
helper T cells
lymphocytes
secrete cytokines to activate B cells and cytotoxic T cells
monocytes
How common
function
somewhat common (3-8%) leave circulation and transform into macrophages
what happens when monocytes become macrophages
Stimulates what?
phagocytize bacteria, debris
stimulate chemotaxis of other cells-
release chemical messengers
Red blood cells
Primary function
Oxygen and CO2 transport
Red blood cells
Characteristics
Anucleated and biconcave
What does the anucleated and biconcavity of red blood cells allow for
Increased surface area, more space for hemoglobin, can fold and pass through small capillaries
What are the 4 subunits of hemoglobin
Globin (polypeptide) bound to heme
What is heme
Red pigment molecules, contains one Fe atom
What binds to heme
Oxygen
Where does oxygen bind on heme
At Fe in center (reversible binding)
Where does CO2 bind on hemoglobin
Attaches to globin not Fe
How is hemoglobin molecule arranged
4 subunits Beta 2 Beta 1 Alpha 2 Alpha 1 Heme in center Globin around heme
Adult hemoglobin
2 alpha globins and 2 beta globins
Embryonic hemoglobin
2 zeta globins and 2 epsilon globins
Fetal hemoglobin
2 alpha globins and 2 gamma globins
When is hemoglobin fetal
After 6 months after birth go to adult
Hemoglobin
Forms and affinities
Adult, embryonic, and fetal hemoglobin
Embryonic and fetal have high affinity for oxygen
Oxygen from mother’s blood at placenta in lower quantities
Sickle cell disease
What is it
What does it do
Abnormality if hemoglobin gene, irregular RBC shape
Cell blocks blood flow or breaks, reduces oxygen delivery to tissues
What does sickle cell carry
Carries some protection from Plasmodium parasites (malaria)
Production of formed elements
What is it called
Hematopoiesis
Hematopoiesis
Blood cell production
Fetal hematopoiesis
Where 5
In yolk sac, thymus, spleen, lymph nodes and red marrow
Post-natal hematopoiesis
Where
Mostly in red marrow
Hemocytoblast
Stem cell origin of all formed elements
Hematocytoblast division
1 daughter cell remains as hematocytoblast
Other daughter cell forms either:
1 myeloid stem cell
2 lymphoid stem cell
Myeloid stem cell
Develop into
Develops into RBCs, platelets, or most WBCs
Lymphoid stem cells
Develops into
Develops into lymphocytes
Erythropoiesis
Red blood cell production
Erythropoiesis
Steps
Hemocytoblast- makes copy of itself and myeloid stem cell
Myeloid stem cell commits to proerthroblast
proerthroblast goes to early erythroblast
early erythroblast goes to intermediate erythroblast
Intermediate erythroblast goes to late erythroblast
Late erythroblast goes to reticulocytes
Reticulocytes goes to mature blood cells
Proerythroblast
Undergoes mitotic divisions
Early erythroblast
Nucleolus disappears
Intermediate erythroblast
Start producing hemoglobin
Nucleus condenses
Other organelles degernate
Late erythroblast
Nucleus ejected
Hemoglobin at max levels
Reticulocytes
Reticulum
Enter bloodstream
Reticulum
Fragments or clumps of residual ribosomes and mitochondria
Mature red blood cells
Reticulum disappears (2 days) Cells attain biconcavity
What regulates erythropoiesis
Erythropoietin
What is erythropoietin (EPO)
Peptide hormone produced by kidney
Stimulates red marrow to produce RBCs
What is the stimulus for release for erythropoietin
Low blood oxygen levels
Erythropoietin negative feedback loop
Stimulus- low blood oxygen levels
Kidneys- increased EPO secretion through blood stream to
Target tissue- red marrow- increase in RBC production
Increases blood oxygen levels
Where does negative feed back happen?- at kidneys
ABO blood group
Blood type based on antigen on surface of RBCs
Antibodies associated with each blood group
Important for matching blood donors
How blood type works
Type a
Antigen A
Produces Anti B antibody
Antigen and antibody reaction- agglutination
Agglutination
Clumping
Rh blood group
First studied in rhesus monkeys Based on antigen D on RBCs Positive if present, negative if absent Genetically determined Rh antigen can develop through transfusion and blood crossing placenta from mother to fetus
Tubular reabsorption
water and solutes reabsorbed over entire length
of tubule system
Bulk reabsorption
1 Mostly in PCT- 70% filtrate ( water, glucose, amino acids, bicarbonate) actively transported out of PCT
2 In loop of Henle- reabsorption of Na+
Tubular reabsorption- PCT
Apical side
Has brush border, increases reabsorption
Tubular reabsorption- PCT
Reabsorption mechanisms
5
- Active transport
- Secondary active transport
- Electrostatic attraction
- Osmosis
- Solvent drag
Tubular reabsorption-PCT
Reabsorption mechanism
Active transport
Na+ pumped out of PCT into blood against concentration gradient (requires ATP)
Tubular reabsorption-PCT
Reabsorption mechanism
Secondary active transport
Glucose and amino acids move with Na+
Tubular reabsorption-PCT
Reabsorption mechanism
Electrostatic attraction
Negative ions follow Na+
Tubular reabsorption-PCT
Reabsorption mechanism
Osmosis
Water reabsorption
Tubular reabsorption-PCT
Reabsorption mechanism
Solvent drag-
Other solutes follow water
Tubular reabsorption- PCT
Transport limit
- Limit to how much can be reabsorbed
2. High concentration of substances will result in some of that substance appearing in urine
Tubular reabsorption
Loop of Henle
Thin descending
Permeable to water
Water reabsorbed
Concentrates filtrate
Passive transport
Tubular reabsorption
Loop of Henle
Thin ascending limb
Permeable to small solutes,
impermeable to water,
water retained in filtrate, dilutes filtrate
Passive transport
When does filtrate reach its highest concentration
At bend of loop of Henle
Tubular reabsorption
Loop of Henle
Thick ascending loop
Active reabsorption of Na+, K+, Cl-
Impermeable to water (water retained in filtrate, dilutes filtrate)
What happens in the loop as water and solutes are reabsorbed
Loop first concentrates the filtrate, then dilutes it
Tubular reabsorption/Collecting duct
Regulated reabsorption
Reabsorption at DCT and collecting duct under hormonal control
Tubular reabsorption DCT
Hormone
Aldosterone
Secreted by
Does what
Secreted by adrenal cortex
Increases Na+ reabsorption
Tubular reabsorption DCT
Hormone
Parathyroid hormone
Secreted by
Does what
Secreted by parathyroid glands
Increases Ca++ reabsorption
Tubular reabsorption DCT
Hormone
Atrial natriuretic factor
Secreted by
What does it do
Secreted by atrial myocardium
Reduces Na+ and water reabsorption
Reduces blood volume and BP
Tubular reabsorption DCT
Hormone
Vasopressin
Secreted by
Does what
Secreted by posterior pituitary
Increases water reabsorption
What does coffee and alcohol do
Block vasopressin secretion
Has a diuretic effect
Tubular secretion
What does it remove
What does it regulate
Removal of substances from blood, secreted into filtrate
Regulation of pH- secretion of H+ or bicarbonate into filtrate
What can be secreted by tubular secretion
5
Various ions, ammonium, creatine, urea, drugs/toxins
What is the nephron
Functional unit of kidney
Components of nephrons
A renal corpuscle
Tubules
Collecting duct
Nephron
Renal corpuscle
Glomerus
Bowman’s capsule
Renal corpuscle
Glomerus
Network of capillaries, blood supply for filtration, blood flows under high BP (60 mm Hg) compared to other capillary systems
Renal corpuscle
Bowman’s capsule
Receives fluid filtered through glomerus (filtrate)
Nephrons
Tubules
Types
Proximal convulted tubule (PCT), loop of Henle, distal convulted tubule (DCT)
Nephrons
Collecting duct
Drains to ureter via the renal pelvis
Reabsorption
Pulling substances out of filtrate and returned to blood
Secretion
Secreting substances from the blood
Nephron type
Cortical
Juxtamedullary
Nephron type
Cortical
Corpuscle in cortex
Short loop of Henle (not far into medulla)
Nephron type
Juxtamedullary
Corpuscle next to medulla
Long loop of Henle (extensive water reabsorption/ produces more concentrated urine.
General urine formation
Glomerular filtration
Tubular reabsorption
Tubular secretion
Excretion
Where does bulk reabsorption and regulated reabsorption occur
At tubular reabsorption
Renal circulation
Afferent arterioles Efferent arterioles Peritubular capillaries Coritical nephrons Juxtamedullary nephrons
Renal circulation
Afferent arterioles
Supply glomerulus with blood to be filtered
Renal circulation
Efferent arterioles
Transport “cleaned” blood away from glmerulus
Renal circulation
Peritubular capillaries
From branches of efferent arterioles
Reabsorption into blood from tubules
Secretion from blood into tubules
Renal circulation
Cortical nephrons
Entire tubular system surrounded by peritubular capillaries
Renal circulation
Juxtamedullary nephrons
Dived into vasta recta
Helps formation of concentrated urine
What drives glomerular filtration
By pressure in capillaries GCP (50-60) out Capsular pressure (10) in Colloid osmotic pressure (30) in Filtration pressure= GCP-Capsular-Colloid= 50-10-30= 10
Glomerular filtration
What is filtered
Where does filtrate go
Plasma filtered through holes of glomerular capillaries
Filtrate captured in Bowman’s capsule
Substances filtered through pores into Bowman’s capsule
Average glomerular filtration rate (GFR)- 180L/day
Urine output 1-2L/day
Filtered substances in glomerular filtration
Small molecules filtered out of blood
Water, electrolytes, glucose, amino acids, nitrogenous wastes
Glomerulus capillaries are impermeable to protein (too big) and blood cells, and other large substances
Regulation of renal activity
Renin- angiotensin- aldosterone system (RAAS)
Regulation of BP and kidney activity
Where is dysregulated RAAS commonly found
In people with high BP
What medication is used in people with dysregulated RAAS
ACE inhibitors
RAAS System
How it works
Stimulus: decreased BP
Kidneys produce enzyme renin
Liver produces protein Angiotensinogen
Renin cleaves angiotensinogen to produce Angiotensin I
Lungs produce enzyme angiotensin converting enzyme (ACE)
ACE converts angiotensin I to angiotensin II- potent vasoconstrictor
What is a potent vasoconstrictor
Angiotensin II
how does angiotensin II work
Stimulates vasoconstriction (increases BP)
Stimulates aldosterone (increases Na+ reabsorption, increases BP)
Stimulates secretion of vasopressin (increases water reabsorption which increases BP, increases BP on its own)
Stimulates SANS activity (increases BP)
Ovaries
Female gonads
Gamete production, hormone production
Follicle
Structure that houses ovum (gamete) made up of 2 different cell types
Granulosa cells
Gamete development, aromatase production
Thecal cells
Produce androgens, these are converted to estrogens by granulosa cells
Two types of follicle cells
Granulosa cells
Thecal cells
How many gametes are ovulated
Females
Only a couple of hundred
Uterus
What does it do
Supporting and maintaining pregnancy
Reproductive cycles and HPG axis
Repeat in predictable manner (28-30 days)
Inter relationship between hypothalamus, pituitary, and ovaries
Leads to monthly preparation of uterus to accommodate fertilized egg
Menstruation
Shedding of uterine lining in absence of implantation
Menarche
Initial onset of menstruation
Average age in US is 12 years old
Menopause
Permanent cessation of menstruation
After 40 years old, cycles become irregular and finally ceases
Ovaries no longer respond to LH/FSH
Without negative feedback, GnRH, LF/LSH may increase in effort to stimulate ovaries
Ovarian cycle
Predictable cyclic changes in oocyte/ovarian follicle (28-30 days)
Two components to ovarian cycle
Oogenesis
Folliculogenesis
Oogenesis
Steps
Oogonium- diploid
Mitosis- one daughter cell replaces oogonium, other primary oocyte
Primary paused in prophase I
This occurs before birth
When puberty starts
Meiosis I resumes
Uneven division of primary oocyte
One is small polar body (degrades), one becomes secondary oocyte (pauses at metaphase II until penetrated by sperm)
After penetrated by sperm, completes meiosis II
Splits again into polar body (degrades), one becomes mature ovum
Oogonium
Formed during fetal development
primary oocyte
Starts to go through meiosis I
secondary oocyte
Starts meiosis II
Gets released during ovulation
Pauses at metaphase II
If sperm penetrates oocyte meiosis II completes
Follicogenesis
Development of follicle that houses the egg
Primordial follicle- granulosa cells- proliferate,
Proliferation of thecal cells- outside of follicle,
Within follicle production of follicular fluid
When ovulation occurs secondary oocyte is expelled from follicle
Follicle ruptures, produces hormones
Becomes corpus luteum
Follicular fluid
Nourish oocyte
Collects in antrum
Hormones of ovarian cycle
Phases
Follicular phase
Luteal phase
Follicular phase
GnRH from hypothalamus- stimulates anterior pituitary to secrete LH and FSH
These travel to ovaries
At first negative feedback from estradiol occurs
Follicle secretes estradiol in very high concentrations triggers switch to positive feedback
High estradiol leads to more secretion of GnRH, LH/FSH
LH surge- large peak of LH secretion- causes ovulation- expulsion of ovum from follicle, follicle ruptures
Luteal phase
Corpus luteum (ruptured follicle) Produces large amounts of progesterone Some E2 produced (switch back to negative feedback)
FSH
Stimulates what
Stimulates growth of follicle
LH stimulates
Stimulates production of estradiol by granulosa/thecal cells
what happens if pregnancy does occur
Development of blastocyst which secretes human chorionic gonadotropin
What happens if pregnancy does not occur
Corpus luteum stops function and cycle begins again
Human chorionic gonadotropin
Preservation of corpus luteum
Corpus luteum keeps producing hormones to support pregnancy
Hormonal birth control
Exogenous ethinyl estradiol (synthetic estradiol)
Constant level of E2 and progesterone
Negative feedback to pituitary and hypothalamus to suppress secretion of FSH and LH- no follicle development, no LH surge/ovulation
Relies on proper pill use
