Homeostasis Flashcards
Define Homeostasis.
Homeostasis refer to the dynamic mechanisms that detect and respond to deviations in physiologic variables from their “set point” values by initiating effector responses that restore the variable to the optimal physiological range.
Is homeostasis an energy consuming state?
Yes
What is constancy?
Standing still
What is Equilibrium?
Variations around a normal
What is a steady state?
Variations around a normal that require energy to maintain
Water makes up ______ of the human body.
2 / 3rds
How does homeostasis use water?
Homeostasis uses water and its dissolved substances to create a steady state.
Body fluids can be divided into what two categories?
Intracellular Fluid (ICF) and Extracellular Fluid (ECF)
Extracellular fluid is the fluid _______ the cell.
Outside
25% of the ECF in the fluid protion of the _______ known as _______.
Blood
Plasma
75% of the ECF lies around/between the cells known as _________ _______.
Interstitial fluid
ECF = ________ + ________
Plasma + Interstitial fluid
Define diffusion
The movement of a solute from an area of greater solute concentration to an area of lower solute concentration.
The difference in solute concentrations is known as the ___________ _________.
Concentration gradient
Define Osmosis
The movement of water down the concentration gradient across a semi permeable membrane
Active transport requires _____, ______ , and _______ for molecules to be moved into the cell.
- life
- biological activity
- expenditure of metabolic energy by the cell
Water and small uncharged molecules move across a cell membrane through ______ _______.
Passive transport
Large molecules (glucose) and Ions (Na+, HCO3-) move across a cell membrane through ______ _______.
active transport
What is facilitated diffusion?
The use of protein transporter to move a solute across a membranewithout expending energy
What is an example of a molecule that uses facilitated diffusion?
Glucose
Active transport move ___ the concentration gradient.
Up
Describe endocytosis (THINK: Packaging)
A section of the plasma membrane enfolds a substance out side the cell, folds across the membrane, separates from the membrane forming a vesicle that moves inside the cell - (EX: Nutrients)
Describe Exocytosis
Secretion of material from inside the cell using vesicles at the cell surface
The cell membrane is made up of a ________.
Phospholipid bilayer
A cell’s phospholipid bilayer is also known as _________.
amphipathic
A cell membrane is ________ permeable.
Selectively
What things do cells need to bring in?
Food (Glucose), O2, Water, Nutrients, Messages
What things do cells need to send out?
Trash (CO2), Goods (Hormones, carrier proteins)
What things do cells need to keep in?
Water, orangelles
What things do cells need to keep out?
Pathogens
What is the primary function of the nucleus?
Cell division and the control of genetic information
The endoplasmic reticulum specializes in _________.
The synthesis and transport of proteins and lipid components.
The golgi apparatus has membranous folds which help create ______ _______.
Secretory vesicles
Lysosomes are the ____________ of the cell.
Garbage men
Mitochondria are responsible for _______ and __________.
Cellular respiration
Energy production
What is the ratio of ATP molecules from 1 glucose molecule in AEROBIC respiration?
34 : 1
What is the ratio of ATP molecules from 1 glucose molecule in ANAEROBIC respiration?
4 : 1
What type of cells do the most aerobic respiration?
Liver and Muscle
Fuel for the Kreb’s/Citric acid cycle always comes from what molecule?
Acetyl-CoA
Proteins need which group removed in order to be burned in the Kreb’s cycle?
Amino Group
What two molecules (other than ATP) are produced in the Kreb’s cycle?
NADH
FADH2
Half of the energy from the Kreb’s cycle is lost as _______.
Heat
The Kreb’s cycle occurs where?
In the mitochondria cytoplasm
What is the toxic mechanism of CO?
Blocks the electron transport chain
Autocrine cell signaling are cells communicating with _______.
Themselves
Autocrine signaing is a _______ feedback loop.
Negative (Cell produces signaling molecule -> binds to receptor on cell –> tells cell to stop making molecule)
Paracrine signaling travels a ______ distance between cells.
short
Nitric Oxide is an example of ________ signaling.
Paracrine
Paracrine messengers have _____ specificity.
high
Endocrine signaling are cells talking to each other _____ or _____.
near
far
Endocrine messenger have _____ specificity
low
Neuroendocrine signaling occurs when ________.
The nervous system talks directly to the endocrine system.
Name an example of neuroendocrine signalling.
In the hypothalamus, when nervous tissue communicates with the pituitary gland
Name the 11 organ systems.
- Circulatory
- Digestive
- Endocrine
- Immune
- Integumentary
- Lymphatic
- Musculoskeletal
- Nervous
- Reproductive
- Respiratory
- Urinary
What are the four tissue types in the body?
- Connective
- Epithelial
- Nervous
- Muscle
The primary function of muscle tissue is to _______.
Connect, Lengthen, and respond to nerve signaling
The primary function of nervous tissue is to ________.
Send rapid signal, release neurotransmitters
The primary function of connective tissue is to ______.
Connect, hold, store, transfer
The primary function of epithelial tissue is to ________.
Cover, protect, defend, absorb.
The lining of the intestines are an ___________ tissue.
Epithelial
Blood is a _________ tissue.
Connective
The heart is a _________ tissue.
Muscle
The nerves are a ___________ tissue.
Nervous
What are the 3 types of cellular junctions?
- Desomosomes
- Gap Junctions
- Tight Junctions
Desmosomes are very ________ sound (Think welding).
Structurally
What type of tissues use desmosomes?
Epithelial
Describe a gap junction.
Two cells separated by interstitial fluid
Name an example of somewhere in the body that gap junctions exist.
The heart: Allow conduction
What are tight junctions? (THINK Sealant)
Create a water tight seal between cells
In water tight junctions, ECF can not travel between cells, instead it must travel ________ cells.
through
Name an example of where Tight junctions are found in the body.
GI tissues
A positive feedback loop ______ the production of the product
Enhances
A negative feedback loop ______ the system once a ______ has been reached.
shuts off
set point