Human Physiology Exam 1

what is regulated by homeostasis?

temperature, pH, and chemical concentration

what are the homeostatic controls?

receptor, control center, and effector

what is the pathway for homeostasis?

stimulus, receptor, afferent pathway, *control center*, efferent pathway, response

is we’re carbon based, why is it not the most prevalent element?

bc of water and oxygen consumption

how does water stabilize temperature?

absorbing and holding large amounts of heat energy with minimal temperature changes – prevents rapid changes in body temp

what is high heat capacity of water?

ability to absorb and release heat with little temp change

what is high heat of vaporization of water?

evaporation requires a lot of heat – makes for effective cooling mechanism

how is water involved in chemical reactions?

necessary for hydrolysis and dehydration synthesis

how is water involved in cushioning body?

protects from physical trauma (ex: CSF)

example of bodily buffer?

carbonic acid and bicarbonate system – carbonic acid as hydrogen reservoir that takes up and releases protons

examples of monosaccharides

glucose, galactose, and fructose

examples of disaccharides

lactose, maltose, and sucrose

glucose plays a significant role in the synthesis of…

ATP

examples of polysaccharides

starch, glycogen, and cellulose

structure of polysaccharides/ branched or linear

what is starch? What is glycogen?

starch = storage in plants, glycogen = storage in humans and animals in liver and muscles

what triggers breakdown of glycogen?

glucagon

what are lipids used for?

long term storage of energy, building blocks of hormones and plasma membrane

examples of lipids?

triglycerids, phospholipids, steroids, eicosanoids

what are the two essential fatty acids?

omega 3 and 6

main functions of triglycerides?

energy storage, insulation, and protection

___ fats contribute to plaques and can cause heart attacks while ___ fats can improve cholesterol levels

saturated, unsaturated

What are trans fats?

artificially hydrogenated oils to increase shelf life and form semisolid, ex: margarine

What are phsopholipids?

modified triglycerides that had a glycerol, phosphorous group, and two fatty acids

What is cholesterol?

type of steroid, found in plasma membrane

What do steroids do?

serve as starting materials for synthesis of vitamin D, steroid hormones, and bile salts (cholesterol specifically

What are eicosanoids?

special form of steroids derived from a fatty acid and found in cell membrane, contribute to blood clotting and inflammation

How many essential and nonessential amino acids?

essential = 9, nonessential = 11

How can a protein denature?

heat, pH, physical agitation

What is a nucleotide composed of?

a sugar, phosphate, and a nitrogenous base

How is ATP used for energy?

high energy phosphate bonds can be hydrolyzed to release energy

Function of plasma membrane

selectively permeable membrane

Function of cytoskeleton

maintains cell shape and assists in movements of cell parts

What are parts of cytoskeleton?

microtubules, intermediate filaments, and actin filaments

What do microtubules do?

cylinders of protein molecules, infrastructure of cilia and flagella (part of cytoskeleton)

What do microfilaments do?

in cell periphery, support cell shape and microvilli
What do intermediate tubules do?

What do actin filaments do as part of cytoskeleton?

protein fibers that play a role in movement of cell and organelles

What are centrioles?

short cylinders of microtubules

What are centrosomes?

microtubule organizing center that contains a pair of centrioles

What is a lysosome?

vesicle containing digestive enzymes

What is chromatin?

diffuse threads of DNA and protein

What is the nucleolus?

region that produces subunits of ribosomes

What is the RER?

contains ribosomes on surface and involved in protein synthesis

What is SER?

lacks ribosomes, synthesizes lipid molecules

What are polyribosomes?

string of ribosomes simultaneously synthesizing the same protein

What is the golgi apparatus?

processes, packages, and secretes modified cell parts
Difference between passive and active transport?

What is carrier mediated transport?

uses a membrane protein to transport a substance across membrane

What is diffusion?

type of passive transport, no protein involved, just does it by itself

Examples of diffusion?

drugs, oxygen, and carbon dioxide

What factors increase simple diffusion?

increase temp, steepness of conc. Gradient, membrane surface area, membrane permeability, decrease molecular weight (larger molecules move slower)

Carrier protein exhibit ___ for their solutes

specificity – binds to specific receptor

What does it mean when a carrier protein reaches “transport maximum”?

as solute concentration increases, the rate of transportation will increase until a certain point when all carriers are occupied

What are the different types of cotransport?

uniport – carrier moves one type of solute (ex: Ca2+ pump), symport – carrier of two or more solutes in the same direction (ex: sodium-glucose transporters), antiport – carrier that moves two or move solutes in opposite directions (sodium-potassium pump)

What are the different mechanisms of carrier-mediated transport?

facilitated diffusion, primary active transport, and secondary active transport

What is primary active transport?

carrier moves solute against conc. Gradient with ATP

What is secondary active transport?

carrier moves solute through membrane, but only uses ATP indirectly
What is an example of a secondary active transporter?

Endo vs exocytosis?

endo = into cell, exo = out of cell

Type of endocytosis and what they do

phagocytosis – engulfing papthogens, pinocytosis – engulfing fluid with small particles, receptor-mediated – particle binds to receptor on plasms membrane before engulfing

How is receptor-mediated endocytosis different from pino or phagocytosis?

its is specific bc of its receptor

What is transcytosis?

transport of materials across cell by grabbing it on one side and kicking it out on the other side

What is a secondary messenger system?

when small, non-protein intracellular molecules or ions relay and amplify signals received by cell surface receptors to target molecules inside cytosol/nucleus. First messenger would be extracellular ligand, secondary acts as a “middle man” to trigger bigger internal response

What would happen if we didn’t have ribosomes (from neuro perspective)

no electrical signaling bc channels must constantly be replaced to maintain excitability

What are Nissl bodies?

huge RER regions, can be bc need a lot of protein synthesis

What does SER do other than lipid synthesis?

stores calcium ions, which are essential for neurotransmitter release and muscle contraction

What does the golgi apparatus do, from a neuro perspective

packages neurotransmitters into synaptic vesicles

What do lysosomes do, from neuro perspective?

break down damaged ion channels and receptors, clear vesicles and membrane debris after high firing rates, maintain neuronal health and prevent build up of toxic proteins

What do peroxisomes do from a neuro perspective?

detoxify neurons and muscles from reactive oxygen species produced by high metabolic activity, protects these tissues from oxidative damage

How are centrioles important for neurons?

used during development of nervous tissue – neural stem cell division

What do neurofilaments do?

maintain axon diameter -> affects conduction speed

What are cellular inclusion?

storage products or foreign matter in cytoplasm, never enclosed in a membrane and never essential for cell survival

What are examples of inclusions?

glycogen granules, oil droplets, ciruses, dust particles, etc.

What are microvilli?

plasma membrane extensions, increase surface area, appear as brush border in light microscopy. Important for absorption

What are cilia?

motile organelles, supported by microtubules

What are flagella?

motile, usually singular, ex: propels sperm cell

What are the types of junctions between cells?

adhesion, tight, and gap jxns

What are adhesion jxns?

attach cytoskeleton to adjacent cells

What are tight jxns?

produce a barrier

What are gap jxns?

two channels fuse, can communicate between cells

What is the purpose of tight junctions?

prevent anything from slipping between the cracks of cells, tightly laced between cells that only water or small minerals can fit through

What do tight junctions block?

bacteria, viruses, and large, undigested food chunks

When are gap junctions useful?

for ion sharing connections that synchronize activity in neural circuits

What are the three functions of the nervous system?

taking in sensory input, integrating it, engaging motor output

Somatic vs visceral sensory fibers

sensory convey impulses from skin, skeletal muscles, and joints to CNS while visceral takes impulses from visceral organs to CNS

Peripheral NS is split into:

afferent and efferent divisions

Efferent division of peripheral NS is divided into…

somatic and autonomic NS

What are the division of the NS:

CNS, PNS -> Afferent and efferent NS -> somatic and autonomic NS -> sympathetic and parasympathetic NS

What are the functions of the nervous system?

sensory input (internal and external), integration, homeostasis, mental activity (consciousness, thinking, etc.), and control of muscles and glands

What are the two types of nervous tissue?

neurons – functional units of nervous tissues, neuroglia – supporting cells

What are the types of neuroglia?

CNS: astrocytes, oligodendrocytes, microglia, and ependymal cells, PNS: satellite cells and schwann cells

what do astrocytes do?

star-shaped cells with many processes that support neurons by interacting with neurons, blood vessels, and CT to maintain concentrations of chemicals and help with neuron development

what do microglia do?

smaller macrophage-like cells that ingest and digest dead and diseased cells or pathogens

what do ependymal cells do?

line cavity of brain and spinal cord, creates carrier between CSF and tissues, circulates CSF

what do oligodendrocytes do?

produce myeline in CNS

what do satellite cells do?

support cell by surrounding cell bodies of neurons, analogous to astrocytes in CNS

what do schwann cells do?

creates myelin sheath, analogous to oligodendrocytes in CNS, vital for regenerationof damaged axons

what are characteristics of neurons?

extreme longevity (up to 100 years), amitotic (don’t divide), high metabolic rate (constantly need oxygen and nutrients)

neurons all have what structures?

a cell body and one or more processes

most neuron cell bodies are in the ___

CNS

what are nuclei (referring to neurons)?

clusters of neuron cell bodies in PNS

what are ganglia?

clusters of neuron cell bodies in PNS