Unit 1: Cells & Tissues Flashcards
homeostasis definition
regulating internal levels based off of our external environment
hierarchy of the body (largest to smallest)
- organism (human)
- body system
- organ
- tissue
- cell
- chemical
tissue types
- epithelial
- connective
- muscle
- nerve
excitable tissue definition
tissues with an action potential
excitable tissue types
- neurons
- muscle cells
muscle cell types
- skeletal muscle cell
- smooth muscle cell
- cardiac muscle cell
epithelial tissue structure
- cells close together
- minimal intercellular substance
- no nerves or blood vessels
intracellular definition
inside cell
intercellular definition
in between cells
epithelial tissue function
- regulate passage of material
- trap foreign substance
functional types of epithelial tissue
- lining
- glandular
gland types
- exocrine
- endocrine
exocrine gland
connects to surface epithelium with ducts
endocrine gland
- ductless
- secrete into blood
exocrine gland example
saliva
endocrine gland example
thyroid gland/hormone
connective tissue
- structure and metabolic support
- cells, fibers, and matrix
connective tissue example
blood, bone, cartilage
bone
- calcium matrix
- hydroxyapatite
- support, rigid, force transmission
outside of bone
fibrous periosteum
cavity of bone
marrow for blood production
muscle purpose
- contraction and relax
- force generation
- movement
- posture
muscle purpose side effect
generates heat
skeletal muscle
- contractile
- striations
- single innervation (1 nerve ending per fiber but 1 neuron supplies many fibers)
- all or none contraction
which muscles are involuntary
- smooth
- cardiac
cardiac muscle
- continuous, rhythmic
- cells in sync 24/7
how is the electric signal propagated through the heart
- gap junctions
- specialised muscle cells
smooth muscle types
- multi-unit
- single-unit
multi-unit smooth muscle
- each cell innervated
- variable force
single-unit smooth muscle
- greater diffusion distance
- cells coupled
- synchronous contraction
nervous tissue types
- central
- peripheral
central nervous tissue
- brain
- spinal cord
peripheral nervous tissue
input/output to gut, skin, muscle
nervous tissue function
- information in
- processing/integration
- information out
neuron parts
- cell body
- nerve fibers
- nerve terminals
do males or females have a higher red blood cell concentration and why
- men
- testosterone contributes to RBC production
negative feedback
- counteracts the change in the controlled variable
- predominant feedback
negative feedback components
- controlled variable
- sensor
- integrator
- effector
- compensatory response
negative feedback example
when cold, shiver to produce heat
positive feedback
reinforces the change in the controlled variable
positive feedback example
- contractions during birth
- clotting
cells purpose
- exchange materials (O2 for CO2)
- perform chemical reactions
- synthesize cellular components
- sense and respond to change
- reproduce
cell definition
fundamental unit of life
plasma membrane purpose
- separates inside and outside of the cell
- controls the passage of materials
- has proteins and molecules
plasma membrane parts
- phosphate head (hydrophilic)
- phosphate tail (hydrophobic)
- cytosol (intracellular fluid)
nucleus job
contains dna
nucleolus job
produce and assemble the cell’s ribosomes
endoplasmic reticulum membrane
- encloses space
- continuous with nuclear envelope
endoplasmic reticulum types
- smooth er
- rough er
is rough or smooth er studded with ribosomes
rough
rough er job
protein synthesis
smooth er job
produce and store lipids, calcium
golgi apparatus job
- process and package molecules into vesicles for transport
vesicles
membrane bound sphere
mitochondria job
- energy production
- generate atp
protein roles within cell
enzyme, signal, structure
protein roles cell membrane
transport
protein role outside cell
- digest enzyme
- hormone
protein synthesis
long line of amino acids
cytoskeleton definition
dynamic array of filaments
cytoskeleton purpose
- confer shape
- allow movement
cytoskeleton parts
- microfilaments
- intermediate filaments
- microtubules
blood % of total body weight
8%
3 types of specialized cellular elements of blood
- erythrocytes (RBC)
- leukocytes (WBC)
- platelets
erythrocytes
- RBC
- O2 transport
- hemoglobin
leukocytes
- WBC
- immune system
platelets
- cell fragments that lack a nucleus
- important in hematosis
- release serotonin to vasoconstrict and reduce blood flow to clot area
- secrete growth factors to maintain integrity of blood vessel wall
- 5-9 day life span, removed from circulation by tissue macrophages
plasma and hematocrit %
55% plasma and 45% hematocrit
hematocrit
packed cell volume
buffy coat
platelets and leukocytes
composition of plasma
- water (90%)
- electrolytes
- nutrients, waste, gas, hormones
- plasma proteins
plasma water function
- transport medium
- carries heat
plasma electrolytes function
- membrane excitability
- osmotic distribution of fluid between ECF and ICF
- buffer pH change
plasma nutrients, wastes, gases, hormones function
- transported in blood
- CO2 plays a role in acid-base balance
plasma protein % of blood
6-8%
types of plasma proteins
- albumins
- globulins
- fibrinogen
albumins function
- contribute to the colloid osmotic pressure
- transport molecules that are poorly soluble in plasma
most abundant plasma protein
albumin
globulins subclasses
- a/B
- a
- y
a/B globulins function
- transport molecules
- blood clotting factors
a globulins function
- inactive precursors protein
- converted to angiotensin
y globulins function
immunity antibodies
fibrinogen function
- clotting factor
- converted to fibrin
blood vessels _________ when cold to preserve heat
constrict
what produces the plasma proteins
- the liver
- except y globulins which are produced by lymphocytes
serum definition
plasma from which fibrinogen and other clotting proteins have been removed
in centrifuged blood, the liquid portion is ______
serum
blood pH
7.35-7.45 (alkaline)
composition of erythrocytes
- lack nuclei, mitochondria, and ribosomes
- biconcave
life cycle of RBC
120 days
hemopoiesis definition
production of blood cells
progressive differentiation
- change from relatively undifferentiated stem cell
- gradual acquisition of specific characteristics of end cell
stem cell becomes either
a myeloid or lymphoid
anemia definition
a below normal O2-carrying capacity of the blood
possible causes of anemia
- iron deficiency
- haemolysis
- reduced RBC production
- increased RBC loss
haemolysis definition
destruction of rbc
types of anemia
- nutritional anemia
- pernicious anemia
- aplastic anemia
- renal anemia
- hemorrhagic anemia
- hemolytic anemia
nutritional anemia
iron deficiency, can’t make sufficient hemoglobin
pernicious anemia
inability to absorb vitamin B12
aplastic anemia
failure of bone marrow to produce enough RBC even though all the things necessary are present
renal anemia
- reduced RBC production
- impaired EPO synthesis due to kidney disease
hemorrhagic anemia
caused by losing a lot of blood
hemolytic anemia
- rupture of RBCs
- caused by malaria and sickle cell disease
thrombopoietin
- hormone produced by liver
- increases number of megakaryocytes and platelet production
haemostasis definition
process of keeping blood within a damaged blood vessel
opposite of hemorrhage
haemostasis
2 major steps of haemostasis
- formation of a platelet plug
- blood clotting
formation of the platelet plug
- platelets aggregate on contact with exposed collagen in damaged wall of the vessel
- platelets release ADP
- surface of nearby circulating platelets become sticky
- adhere to first layer of aggregated platelets
blood clotting
- reinforces platelet plug and converts blood in vicinity into a non-flowing gel
- clotting factors aways present in blood plasma in inactive precursor form
- covert fibrinogen into fibrin
2 pathways of blood clotting
- extrinsic
- intrinsic
clot dissolution
- plasmin dissolves clots
- plasmin is produced from plasminogen by clotting factors
- phagocytic WBCs remove waste products of clot dissolution
clot prevention
- tissue plasminogen activator
- prevents inappropriate clot formation
- used clinically as a clot buster
thrombomodulin
- binds thrombin (no fibrinogen conversion)
- activates protein c (anticoagulent)
thrombus
abnormal intravascular clot attached to a vessel wall
emboli
free-floating clots
factors that can cause thromboembolism
- roughened vessel surfaces associated with atherosclerosis
- clotting/anti-clotting system imbalances
- slow-moving blood
- release of tissue thromboplastin into blood from traumatized tissue
hemophilia
excessive bleeding caused by a factor of the clotting cascade
body fluid importance
primary transport system between cells
do females have more or less total body water and why
less, more fat
what % of body mass is total body water
60
total body water is made of (w/ L)
intracellular fluid (28 L) + extracellular fluid (14 L)
extracellular fluid is made of (w/ L)
plasma (3 L) + interstitial fluid (11 L)
water can move _______ fluid compartments
between
intracellular/interstitial fluid barriers
- cell membrane boundary
- selectively permeable ion pumps
interstitial fluid/plasma barriers
- capillary wall boundary
- permeable to small molecules
interstitial fluid composition
Na+ high
Cl- high
K+ low
intracellular fluid composition
Na+ low (pump)
Cl- low
K+ high (pump)
osmosis
- water moves from lower to higher solute concentration
- cell membrane is permeable to water but not solute
- passive
tonicity
effect of solute concentration on cell volume
hypotonic solution
cell gains water, swells
hypertonic solution
cell loses water, shrinks
fluid replacement (hemorrhage)
- replace blood with isotonic saline (NaCl)
- no change in cell volume
fluid replacement (rehydration salts)
replace water and ions
lymphatic system
returns lymph to the cardiovascular system
systemic capillaries
allow exchange of materials between blood and body tissues
starling’s law
- capillary wall is very permeable
- bulk flow of water and solutes
- rapid plasma and interstitial fluid interchange
- plasma is carefully regulated
interstitial fluid is the …
environment for all cells
normal daily inputs
- ingestion (fluid and food)
- metabolism
normal daily outputs
- gut
- urine
- breathing/skin
- sweating
which normal daily inputs/outputs are used to regulate fluid volume
- fluid
- urine
the immune system
a network of cells and tissues that
- defend the body against invading pathogens
- destroys abnormal/mutant cells within the body
- removes worn-out cells
harmful effects of the immune system
- allergies/autoimmune disease
- tissue rejection
infection-causing organisms
- bacteria
- parasite
- fungus
- virus
tissue immune system
primary and secondary lymphoid organs
cells immune system
- lymphocytes
- granulocytes
- monocytes/macrophages
- dendritic cells
- natural killer cells
soluble mediators immune system
- cytokines and chemokines
- complement proteins
central (primary) lymphoid tissues
- bone marrow (site of B cell development)
- thymus (site of T cell development)
peripheral (secondary) lymphoid tissue
- spleen
- lymph nodes
- gut associated lymphoid tissue
- adenoids
- appendix
- tonsils
neutrophils
- destroy bacteria by phagocytosis
- clean up debris
- first defenders on scene of bacterial invasion
most abundant leukocyte
neutrophil
an increase in eosinophilia is associated with:
- allergic conditions (asthma, hay fever)
- internal parasite infections (attach to worm and secrete substances to kill it
eosinophilia
increase in circulating eosinophils
monocytes
- emerge from bone marrow while immature and circulate before settling down in various tissues
- become professional phagocytes
- act as antigen presenting cells
monocytes mature and enlarge to become…
macrophages
nonspecific (innate) immunity and examples
- initial and immediate response against invasion by pathogens
- phagocytosis, inflammation
nonspecific (innate) immunity main mechanisms
- physical barriers (skin, mucous membranes)
- inflammation and phagocytosis
- interferon, NK cells
- complement
specific (adaptive) immunity
- comes after nonspecific responses
- respond to specific pathogens on 2nd or later exposure
inflammatory response signs
- redness
- heat
- swelling
- pain
inflammatory response results
- destroys or inactivates invaders
- removes debris
- prepares for healing and repair
stages of phagocytosis
- attachment
- internalisation (0.1 sec)
- degradation
- exocytosis
interferon
- a, B, y
- cytokine released by virus-infected cells
- protects other cells from any virus
- induces expression of enzymes that prevent viral replication
interferon anti-cancer effects
- slows cell division
- enhances action of NK cells and cytotoxic T cells
natural killer cells
- attack virus-infected cells
- causes lysis via release of perforins
complement system
- a number of small proteins that normally circulate as inactive precursors in the blood
- activation results in the formation of a cell-killing membrane attack complex
- induces lysis of invading microorganisms
- complements the ability of other immune mechanisms to clear pathogens
specificity (specific immunity)
- lymphocytes (B and T cells) bind and respond to foreign molecules (antigens) via antigen receptors
- antibody-antigen interactions are specific
diversity (specific immunity)
the body possesses lymphocytes that recognize and respond to antigens
memory (specific immunity)
- 1st exposure: generates lymphocytes and memory cells
- next exposure: memory cells react faster and with stronger response
self-tolerance (specific immunity)
lymphocytes distinguish normal antigens from foreign material
2 types of lymphocytes
- B lymphocytes (B cells)
- T lymphocytes (T cells)
B lymphocytes (B cells)
- produce antibodies that circulate in the blood)
- defend against bacteria toxins and viruses in body fluids
- antibody-mediated or humoral immunity
T lymphocytes (T cells)
- do not produce antibodies
- directly destroy specific target cells by releasing chemicals that punch holes in the victim cell
- target cells include body cells invaded by viruses and cancer cells
which part of specific immunity failing results in an autoimmune disease
- self-tolerance
- attack normal healthy cells
how do antibodies function
- neutralization (block the activity of a pathogen)
- agglutination (multiple pathogens are aggregated by antibody molecules)
- opsonization (bound pathogens are more efficiently engulfed by phagocytes)
- complement activation (antibodies activate lysis of the cell)
- enhanced NK cell activity (abnormal body cells are lysed)
lysis definition
- rupture of the cell membrane
- destroying a cell
T cell types
- helper
- cytotoxic
helper T cells
- activated by MHC on antigen-presenting cells
- secrete cytokines that enhance the activity of cytotoxic T cells (enhance phagocytosis)
- stimulate development of B cells into plasma cells (indirect action)
cytotoxic T cells
- activated by MHC on virus-infected cell
- kill infected cells by lysis
immune disorders
- rheumatoid arthritis
- multiple sclerosis
rheumatoid arthritis symptoms
inflammation and damage to cartilage and bone of joints
multiple sclerosis cause and symptoms
- T cells attack myelin
- blurred vision
- muscle weakness
- ataxia (co-ordination, balance, and speech difficulty)
AIDS is caused by …
Human Immunodefiency Virus (HIV)
what does HIV do
- binds to the surface of helper T cells and it’s DNA/RNA enters the cell
- HIV uses cell to make copies of itself
- destroys helper T cells
- immune response weakens and other diseases develop
passive diffusion
- molecules diffuse from higher concentration to lower concentration
- down concentration gradient
passive diffusion is proportional to
- size of gradient
- membrane surface area
- membrane permeability (high lipid solubility, small molecules, barrier thickness)
- O2, CO2, fatty acids, steroid hormones
passive facilitated diffusion
- conformational carrier molecules in membrane
- binding leads to conformational change
passive facilitated diffusion rate depends on
- number of carriers in the membrane
- affinity
- concentration of transported substance
affinity definition
the strength of the attaction between two substances
passive diffusion through ion channels
- both sides open
- specific to ions
- some have binding sites
- depends on electrochemical gradient
passive transport types
- diffusion
- facilitated diffusion
- diffusion through ion channels
passive transport meaning
no ATP used
active transport meaning
- ATP used
- opposes electrochemical gradient
active transport types
- primary active transport (uses energy directly)
- secondary active transport (uses a gradient created by active transport)
sodium pump (Na+, K+, ATPase)
- phosphorylation (leads to: conformation change, change in affinity)
- one ATP used per cycle
- 3:2 ratio of Na+ out to K+ in
- crucial for ICF/IF difference
secondary active transport types
- cotransport
- countertransport
secondary active transport - cotransport
- Na+ moves into cell down gradient
- releases energy used for glucose co-transport against gradient
secondary active transport - countertransport
Na+ and H+ go in opposite directions
membrane potential
- plasma membrane of all living cells has a membrane potential
- separation of opposite charges
- due to difference in concentration and permeability of key ions
electrical driving force
- separation of charge across a membrane
- alignment of opposed charges
charged particles of electrical driving force
- anions (-ve)
- cations (+ve)
is extracellular fluid net positive or negative
positive
is intracellular fluid net positive or negative
negative
electrical driving force depends on
- size of membrane potential
- quantity of charge
typical membrane potential
-70 mV
net movement depends on…
the balance of all forces
membrane potential consequences of Na+, K+, ATPase pump
- membrane potential (-50-90 mV)
- balance between electrical and chemical (diffusional) forces
membrane potential significance
- potential energy (secondary active transport, action potential)
- uses 20% of resting (basal) metabolic rate
resting (basal) metabolic rate definition
the number of calories you burn as your body performs basic (basal) life-sustaining function
