Human Physiology Lab Midterm

4 Primary Tissues

Epithelial, Connective, Muscle, Nervous

Epithelial Tissue

sheets of tightly packed cells (membranes and glands); in charge of protection, secretion, excretion, absorption

Which epithelial tissue is this?

Simple

Which epithelial tissue is this?

Stratified

Which epithelial tissue is this by cell shape?

Squamous (flat)

Which epithelial tissue is this?

Cuboidal (cube)

Which epithelial tissue is this?

Columnar

Exocrine Glands

Part of epithelial tissue; have ducts, secrete chemicals out of body or into digestive tract

example: sweat glands, majority of pancreas

Endocrine Glands

Part of epithelial tissue, no ducts, secrete chemicals (hormones) into blood

example: adrenal gland, certain cells of pancreas

Connective Tissue

Sparse scattering of cells in extracellular matrix that bind/support

4 Types of Connective Tissue

Connective Tissue Proper, Cartilage, Bone, Blood

Connective Tissue Proper

binds, fills spaces, etc

example: tendons, ligaments, dermal of skin

Adipose (fat)

type of connective tissue found throughout the body that store energy and act as insulation

Cartilage

Support and protect; prevent bone-on-bone

example: joint surfaces, nose, ear

Bone

Structure, support, and protection

example: skeleton

Blood

found in blood vessels, transport materials (oxygen, nutrients, etc)

extracellular matrix is plasma

Muscle Tissue

Specialized for contraction; contraction leads to movement of skeleton or internal organs

What are the types of muscle tissue?

Skeletal, Cardiac, Smooth

Skeletal Muscle

attaches to bone, causes movement of skeleton

characteristics:

\-long, unbranched, tightly packed cells

\-multi-nucleated

\-striated (striped)

\-voluntary (conscious control)

Cardiac Muscle

heart muscle, contraction leads to blood pumping

characteristics:

\-branched, interconnected cells

\-1 nucleus/cell

\-striated

\-involuntary

Smooth Muscle

contraction leads to movement within internal organs (except heart)

characteristics:

\-tapered cells

\-1 nucleus/cell

\-no striations

\-involuntary

Nervous Tissue

composed of cells that generate and conduct electrical impulses and some are supporting cells; fast coordination of body

types:

\-neuron: conducts electrical impulses

\-glial (support) cells: various functions and structural support of neurons

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homeostasis

maintenance of relatively stable internal environment

normal range

variability around allowed or acceptable variability around set points

highest and lowest acceptable values

set point

targeted value

1/2(min +max)

negative feedback

response mechanism that maintains homeostasis by counteracting change; drives variable back to set point

stimulus (changes that evoke response) → sensor (detects stimulus) → integrating center (receives input, controls effector tissue) → effector (generates response)

response in negative feedback

action that brings back to set point

solutions

homogeneous mixture of 2 or more components

solute

substances present in smaller amounts

solvent

substance present in largest amount

mg/dL

weight per volume

grams solute/mL solvent x 100

percentage (%) solutions

molarity (M)

mol solute/L solution

molality (m)

mol solute/kg of solvent

osmolality (osm)

molality \* # of particles in H2O

What is solubility of different molecules?

like dissolves like

hydrophilic molecules like polar and ionic solutes

hydrophobic molecules like non-polar solutes

plasma membrane is largely non polar “solvent”

hydrophobic molecules easily pass through

hydrophilic molecules (ions and large polar molecules) need channels, carriers, or transporters to cross

What is the solubility of the plasma membrane?

diffusion

net movement of atoms or molecules from area of high concentration to low concentration

osmosis

movement of water across a semi-permeable membrane; H2O cross through aquaporins

solutes that are unable to move are “osmotically active'“

osmotic pressure

how strongly solution draws H2O to it; greater concentration of osmotically active solute → greater osmotic pressure

osmolality

ionic molecules split apart in H2O, covalently bonded molecules don’t split

isotonic

equal inside and out

hypertonic

more outside than inside cell; leads to crenate

hypotonic

less outside than inside cell; leads to lysis

purpose of concentration

tells us normal ranges

What happens when there’s excessive glucose?

pancreas release insulin → insulin sends signal to live → liver takes glucose from blood → glucose turned into glycogen during glycogen synthesis

glycogen synthesis

dehydration/condensation reaction; removes OH- and H+ from two glucose molecules to make H2O and glycogen

What happens when there’s low glucose?

pancreas releases glucagon → glucagon sends signal to live → liver breaks glycogen during glycogen breakdown → glucose enters blood

glycogen breakdown

hydrolysis reaction with glycogen, addition of H2O to break bond

Type 1 Diabetes

pancreas can’t make insulin

treatment: more insulin

Type 2 Diabetes

liver tissue loses sensitivity to insulin

treatment: metformin

lipids

non polar compounds that are insoluble in polar solvents (hydrophobic)

tend to big and bulky with lots of carbon, usually a double bond somewhere

example: triglycerides, phospholipids, cholesterol, steroid hormones, prostaglandins

phospholipids

head is hydrophilic (oriented on outside of cells)

tail is hydrophobic (oriented on inside of cells)

What is a blank comprised of in a colorimeter or spectrophotometer?

cuvette, reagent, and water

Beer’s Law

Concentration is proportional to amount of light absorbed by solution

Low concentration → low absorbance

conc soln 1/conc soln 2 = abs sol 1/abs sol 2

enzymes

allow reactions to go faster by lowering the necessary activation energy

biological catalysts, typically proteins, end in “-ase”

doesn’t change during the reaction

characteristics of enzymes

very specific to substrates they bind (lock and key model at active site)

require optimal conditions (temperature, pH, etc)

active site

place where substrate binds and where reaction takes place

How does pH affect enzyme reactions?

optimum depends on enzyme location in body or cell

How does temperature affect enzyme reactions?

optimized for each enzyme and where reaction occurs

at extreme temperatures enzymes denature

How does substrate concentration affect enzyme reactions?

Reaction rate increases as this concentration increases until reach saturation

Saturation

all or most enzymes are bound to substrate

Enzyme Concentration

increasing this concentration increases reaction rate so long as there’s enough substrates

Iodine Test

tested starch presence

changed lighter if no/less starch

Benedict’s Test

detected presence of maltose

blue (none) → rusty red (a lot)

Neuron

electrical conducting cells of nervous system

Synapse

functional connection between neuron and second cell (another neuron, effector cell)

Central Nervous System

brain and spinal cord, integration and interpretation of information

Peripheral Nervous System

sensory and motor neurons; transmits information to and from CNS

Reflexes

involuntary motor response to stimulus without involvement of higher brain tissue

prevents potential tissue damage

Where is the reflex action processed?

processed by spinal cord

Where is the reflex sensation processed?

processed by brain

Reflex Arc

nerve impulse pathway of reflex

Stimulus → sensory neuron (afferent: sends message to central nervous system) → interneuron → motor neuron (efferent: sends message from central nervous system to effector) → effector

Monosynaptic Reflex

only 2 neurons and 1 neuron-neuron synapse

stimulus → sensory neuron → motor neuron → effector

Muscle Spindle Apparatus

clusters of special cells (spindle fibers) in muscle

Knee-Jerk

first: hit patellar ligament or tendon stretches; quadriceps also stretch because attached to tendon

second: spindle fiber stretched (neuron activated and send info to central nervous system)

third: synapse between sensory and motor neurons in spinal cord

fourth: activated motor (efferent) neuron signals quadriceps muscle (effector) to contract

Chemoreceptors

perceives taste, smell, pH

Mechanoreceptors

perceives touch, pressure, stretch, sound, and balance

Photoreceptrs

perceive sight

Thermoreceptors

perceive an increase or decrease in temperature

Perception

Limited by limited ability to detect various forms of energy

brain manipulating incoming data comparing to other info and memories

Receptive Fields

area of skin that can activate single neuron

big area → few receptors

small area → more receptors

high density of sensory neurons → large portion of brain (sensory cortex) associated with generating perception for body part

What happens when there is a constant stimulus?

Our receptors decrease firing rate (phasic receptors); our brain stop paying attention to certain constant stimuli

What is the exception to sensory adaptation?

Most pain receptors; maintain firing rate (tonic receptor)

photoreceptors

sensory cells that transduce light energy into electrical impulses; located in retina of eye

What spectrum is visible light?

400-700 nm

How does light travel through eyes?

cornea → pupil → lens → retina

lens

concentrate and amplifies light in eye; works like a light house

retina

innermost layer of eye; has two structures: fovea and optic disk

fovea

pinhead sized pit; only contains cones; visual acuity highest; 1 ganglion per cone → highest resolution

optic disk

fibers and neural fibers exit here; doesn’t contain photoreceptors; blind spot

refraction

bending of light as passes through different materials

How does refraction work in the eye?

light bends as it passes through the lens and cornea; the light is then focused on the fovea

myopic

near sighted; poor distance vision

usually eyeball too long or lens too strong so light is focused in front of the fovea/retina

corrected with concave lens

negative dioptric value for concave lenses

hyperopic

far sighted; poor near vision

usually eyeball too short or lens too weak so light is focused behind the fovea/retina

correct with convex lens

positive dioptric value for convex lens

visual acuity

sharpness of vision; measured with snellen chart

What does 20/70 vision mean?

What that person can see at 20 feet is what “normal” people can see at 70

astigmatism

irregularities in curvature of cornea or lens causes light not to focus

diopter

1/focal length in m

as focal length increases, diopter decreases

When a lens has a power of 3 diopters, what does this mean?

The lens focuses light in 1/3 of a meter.