bio 2040 - human physiology lectures 1-7

What is the study of Physiology?

Is the study of the normal functioning of a living organism and its component parts, including all its chemical and physical processes

What are the Subdivisions?

• Systemic to cellular
• based on organ systems(e.g., renal physiology, cardiovascular physiology, neurophysiology)

levels of structural organization?

chemical, cellular, tissue, organ, organ system, organismal

ten physiological organ systems

circulatory, digestive, endocrine, immune, integumentary, musculoskeletal, nervous, reproductive, respiratory, urinary

Four systems exchange materials with internal and external environments

respiratory/pulmonary; digestive/gastrointestinal; urinary/renal; reproductive

Remaining four systems extend throughout the body

cardiovascular/circulatory; nervous; endocrine; immune

Necessary Life Functions

1. Maintaining boundaries
2. Movement
3. Responsiveness
4. Digestion
5. Metabolism
6. Excretion
7. Reproduction
8. Growth

Homeostasis

To maintain homeostasis the human body monitors key functions, such as blood pressure or blood glucose concentration, which must stay within a particular range

control systems three components?

an input signal, a controller & output signal

Local control

restricted to the tissue or cell involved

reflex control

Widespread/throughout the body

Components of a Control Mechanism

receptor, control center, effector

Other examples of homeostatic regulation

- Withdrawal reflex in response to injury
- Regulating heart rate and blood pressure during exercise
- Changing breathing rate in response to increased carbon dioxide
- Parathyroid hormone release in response to decreased calcium
- Release of insulin by the pancreas in response to increased blood glucose

other examples of positive feedback

- Blood clotting cascade
- Uterine contractions of labor

an example of a homeostatic imbalance?

diabetes

Normal ranges for homeostatic variables

- Body temperature 98.6ºF
- Blood glucose 80-110 mg/dL
- Blood pressure 90-120/60-80 mm Hg
- Determined by sampling healthy individuals in a population
- Normal range is value for 95% of individuals sampled
- 5% of healthy population have values outside normal range

3 major body cavities

- The cranial cavity - contains the brain
- The thoracic cavity - heart and lungs
- The abdominopelvic cavity - stomach, liver, intestines, pancreas, bladder

General functions or roles of the plasma membrane

• Physical isolation
• Regulation of exchange with the environment - membrane controls what enters and leaves the cell
• Communication between a cell and its environment - membranes contain proteins that enable the cell to recognize and respond to molecules
• Structural support - proteins in the membrane can act as anchors for the cell skeleton (cytoskeleton) or proteins can act as adhesion molecules with other cell proteins

most important steroid?

cholesterol

Integral proteins

Integral go thru membrane
- Transmembrane
- Hydrophobic and hydrophilic
- Function as transport proteins (channels and carriers), enzymes, or receptors

Peripheral proteins

- Peripheral outside or inside, not embedded, loosely attached
- Compose half the membrane, generally
- Can have sugars bound
- Function as enzymes; motor proteins for shape change during cell division and muscle contraction; cell-to-cell connections

the cell is composed of: (3)

nucleus, cytoplasm, & cell membrane

the cytoplasm is composed of?:

• Cytosol, viscous, semitransparent fluid, suspends organelles and inclusions, sugars salts and proteins are found in it also
• Organelles, metabolic machinery of the cell
• Inclusions, glycogen (in liver and muscles), lipid droplets in fat cells, myoglobin O2 binding

membranous organelles

- Mitochondria
- Lysosomes
- Endoplasmic reticulum
- Golgi apparatus

non-membranous organelles

- Cytoskeleton
- Proteasomes
- Ribosomes

the endoplasmic reticulum:

builds proteins

Functions of Rough ER

synthesis, processing molecules, organelle formation & vesicle formation

functions of smooth er

synthesis, processing molecules, detoxification & vesicle formation

the golgi apparatus

"post office"; proteins are sent here to then be sent off somewhere else

lysosomes

"trash can"; proteins get trashed/recycled here

nucleus

Control center of the cell

Ribosomes

site of protein synthesis

Proteasomes

giant protein complexes that bind protein molecules and degrade them

types of primary tissue

epithelial, connective, muscle, nerve

what four elements make up 96.1% of body mass?

carbon, nitrogen, hydrogen & oxygen

inorganic compounds

Compounds that do not contain carbon; water, salts

organic compounds

Compounds that contain carbon; carbohydrates, fats, proteins & nucleic acids

biochemistry

study of chemical composition and reactions of living matter

most abundant molecule?

carbohydrates

functions of carbohydrates?

energy and structural support

functions of proteins?

Serve as catalysts (enzymes) in metabolic reactions
Act in defense
Aid in transport
Contribute to structural support
Cause movement
Perform regulation
Provide storage

lipoproteins =

protein + lipid

glycoproteins =

proteins + carbohydrates

glycolipids=

carbohydrates + lipids

covalent bonds

a chemical bond that involves the sharing of electron pairs between atoms

ions

gain or lose an electron, gain a charge. ions form the basis of electrical signaling in the body, sodium potassium

hydrogen bonds

holds separate dna strands together

An acid is any substance that

dissociates in water to produce both an H+ and an anion

ATP

usable form of energy inside out body

glucose, atp & fat all have

potential energy

potential energy

stored energy

kinetic energy

energy of motion

glucose oxidation

-step by step breakdown of glucose with energy release
-carbon dioxide and water formed

Glycosis

first step in releasing the energy of glucose, in which a molecule of glucose is broken into two molecules of pyruvic acid

membrane proteins two distinct populations

integral proteins and peripheral proteins

osmosis

movement of water across a membrane

hypotonic

more water outside the cell (very little solute); causes cell to enlarge

hypertonic

more water inside than outside the cell (high concentration of solutes); causes cell to shrivel up

isotonic

equal concentration

passive process

-movement down its concentration gradient
-no energy required

active process

-requires a source of energy to drive the reaction
-ATP, breaking of phosphate bond, potential energy into kinetic energy

uniporters, symporters, antiporters

Uniporters - move one substance at a time
Symporters - move two substances in the same direction
Antiporters - move two substances in opposite directions

active transport

the movement of materials through a cell membrane using energy

describe the transport of glucose from the g.i tract to the blood system

1- Na+ - glucose symporter brings glucose into cell against its gradient using energy stored in the Na+ concentration gradient
2-GLUT transporter transfers glucose to ECF by facilitated diffusion
3-Na+-K-ATPase pumps Na+ put of the cell, keeping ICF Na+ concentration low

Role of K+ in RMP

-most important determinant in specific value of RMP
-K+ moves down steep concentration gradient through leak channels from cytosol to interstitial fluid
-negatively change proteins remain inside cell
-electrochemical gradient

the role of Na+

-Na+ diffuses into cells from interstitial fluid to cytosol simultaneous to the loss of K+
-Enters through Na+ leak channels
-Down concentration gradient
-Pulled by electrical gradient
-Leak channels prevent as much Na+ into the neuron a K+ out
-Inside becomes more positive

Maintaining RMP

-Na+/K+ pumps significant
- maintains K+ and Na+ gradients following their diffusion
-Na+ pumped out
-K+ pumped in
-opposite directions
-against concentration gradient

Functions of the nervous system

sensory input, integration, motor output

Two anatomic divisions of the nervous system

central nervous system and peripheral nervous system

somatic sensory

receives sensory information from skin, fascia, joints, skeletal muscles, special senses

visceral sensory

receives sensory information from viscera

somatic motor

"voluntary" nervous system: innervates skeletal muscle

autonomic motor

"involuntary" nervous system: innervates cardiac muscle, smooth muscle, glands

sensory neurons

carry info about temperature, pressure, light and other stimuli to the CNS

motor neurons

conduct motor output from the ins to both somatic and autonomic effects

Interneurons

lie entirely with the CNS, receive info from other neurons and carry out integrative functions

anaxonic neuron

many dendrites but no axon, help in visual processes

bipolar neuron

bipolar neurons have two processes separated by the cell body

unipolar neuron

unipolar neurons have a single elongated process, w the cell body located off to the side

multipolar neuron

A neuron with a single axon and multiple dendrites; the most common type of neuron in the nervous system.

functional regions of a neuron

receptive segment, initial segment, conductive segment, transmissive segment

synapse

region where an axon terminal meets its target, another neuron or target cell

Neuroglia

are smaller than neurons and have the ability of producing new glial cells through cell division

glial cells of the CNS

astrocytes, ependymal cells, microglia, oligodendrocytes

Astrocytes

Provide structural and metabolic support for neurons.

ependymal cells

create a selectively permeable epithelial layer, separates the fluid compartments of the CNS

microglial cells

protect CNS against microorganisms

Oligodendrocytes

wrap around and insulate axons w a myelin sheath

Neurolemmocytes (Schwann cells)

wrap around and insulate axons in the PNS - form a myelin sheath