Physiology - L2 - Cells & Transport

Paramedic specific content Physiology Lecture 2 (including cell worksheet answers from Lecture 1)

Molecules can be made up of

The same atoms (elements) or different atoms (compounds)

List the following in order of size: Water, sodium ion, respiratory system, red blood cell, protein fibre, mitochondria, tendon, heart

sodium ion, water, protein fibre, red blood cell, tendon, heart, respiratory system 

Organic Compounds

Molecules that exist only in living systems

Carbon atoms

what organic compounds are made around

Three main organic compounds

Carbohydrates, lipids, proteins

Cells are involved in

growth, repair, reproduction

Phospholipid bilayer

Makes up the structure of the cell membrane with a hydrophobic lipid tail and a hydrophilic phosphorus water loving head it acts as a barrier to water allowing the cell to function while helping to create a relatively stable environment within the cell

Head of phospholipid bilayer

Hydrophilic phosphorous

Tail of Phospholipid bilayer

hydrophobic lipid

A

Phospholipid bilayer

B

Cholesterol

C

Proteins

D

Carbohydrates

Proteins in the cell

allow the cell to interact with their environment such as transport and enzymatic activity

Transport

moving substances in and out of cells

Enzymatic activity

converting inactive substances to active ones or vice versa

Receptors

allow communication with cells and their surrounding areas

Extracellular Fluid (ECF)

The fluid surrounding the cell that creates the external environment of the cell and includes every substance contained within it

Controlling composition of ECF

by creating relatively stable state e.g. homeostasis

Red Blood Cells

Disc shaped cells used to transport oxygen around the body in the form of oxyhaemoglobin - shape allows flexibility which aids in preventing blood clots

Skeletal Muscle Cells

Elongated cells with a very elastic and resistant plasma membrane, containing contractile proteins for movement

1

Plasma/cell membrane

2

Ribosomes

3

Mitochondria

4

Rough Endoplasmic Reticulum

5

Chromatin/chromosomes

6

Nuclear envelope

7

Cytosol

8

Nucleus

9

Smooth endoplasmic reticulum

10

Microvilli

11

Golgi complex

12

Lysosome

Nucleoli

Contains the genetic material of the cell, involved in assembling ribosomes and alteration of transfer (RNA)

Cytosol

Fluid in which all cytoplasmic elements are suspended

Microvilli

Folds in the cell membrane to increase cellular surface area

Mitochondria

the organelle that breaks down food molecules to produce energy ATP

ATP

Adenosine Triphosphate - energy carrying molecule

Smooth Endoplasmic Reticulum 

makes lipids, cholesterol and other fatty compounds as well as breaking down drugs and other substances

Rough Endoplasmic Reticulum 

Proteins synthesised by ribosomes enter here for processing and sorting

Chromatin/Chromosomes 

Compacted DNA and proteins that bears genetic information

Cell Membrane

A thin protective barrier surrounding every cell that separates the cells contents from its surroundings to allow cells to perform different functions and chemical reactions

Makes up a cell membrane

Carbohydrates, Proteins, Cholesterol, Phospholipid bilayer

Golgi Complex/Aparatus

Modifies, sorts and packages proteins and lipids from the Endoplasmic Reticulum to transport/secrete them to another location

Ribosome

in which amino acids are hooked together to make proteins (protein synthesis)

Nucleus

Contains the cells dna, other genetic material and is the control centre of the cell

Lysosomes

Digests food particles, wastes, cell parts and foreign invaders

Properties of Epithelial Tissue

consists of epithelial cells arranged in continuous sheets either in single or multiple layers

Epithelial Cells

Tightly packed together these cells make up epithelial tissue

Simple Epithelium Cells

A single layer of cells that functions in diffusion, osmosis, filtration, secretion or absorption.

Squamous Epithelial Cells

thin allowing for the rapid passage of substances through them

Stratified Epithelial Cells

Consists of two or more layers of cells that protect underlying tissues in locations where there is considerable wear and tear

Pseudostratified Epilated Cells

Appear to have multiple layers of cells because the cell nuclei lie at different levels but are actually only a single layer

Columnar Epithelial Cells

Cells that are much taller than they are wide and protect underlying tissues, they often have cilia and microvilli specialised for secretion or absorption

Ciliated cells

Cells with cilia, fine hair-like extensions on the cells membrane, that reach the surface of a tissue and beats rhythmically to move substances across a surface e.g. continuously moving mucus our of airways

Goblet Cells

Modified columnar epithelial cells that secretes mucus to collect foreign objects

Homeostasis

The ability for all living systems to maintain stable internal conditions despite changes occurring outside of the body

Normal temp range

36-38

Temp above 38

usually means infection

Normal heart rate

60-100bpm

Bradycardia

slow heart rate less than 60bpm

Tachycardia

fast heart rate over 100bpm

Normal oxygen levels

94-100%

Other name for blood glucose

BM

Normal Respiratory Levels

12-20

Negative Feedback

this is when changes are reversed to bring internal conditions back to the norm 

Examples of Negative feedback

thermoregulation, blood glucose regulation, breathing rates 

Thermoregulation

the homeostatic regulation of body temperature even when the surrounding temp is different such as shivering or sweating

Positive Feedback

the physiological change that tends to strengthen or reinforce the initial change in one of the bodys controlled conditions increasing it further away from the norm

Examples of Positive Feedback

clotting during wound healing, during childbirth, platelets during cuts and wounds

Pyretic

abnormal, regulated elevation of an organism’s core body temperature known as a fever

Hypothalamus

a small vital structure deep within the brain that acts as the body’s control centre for homeostasis

Vasodilation

Blood vessels widening (dilating) to allow more blood to flow from the warm body core to increase heat loss through the surface of the skin in response to the body being too hot

Vasoconstriction

Blood vessels narrowing (constricting) to reduce blood flow and therefore heat loss through the surface of the skin in response to the body being too cold

Diaphoresis

a biological process in which sweat glands release an abnormally strong and excessive amount of sweat that may affect the entire body, evaporating it to the surrounding air helps cool down the body

Reasons for Diaphoresis

underlying medical conditions, hormone imbalance or strong emotional stimulus 

To increase heat loss from the lungs 

patient will breathe deeper through their mouth instead of the nasal passages

when too warm

hair erector muscles relax lowering the hair to prevent a layer of air being trapped to insulate heat

when too cold

hair erector muscles contract, raising the hair to trap a thick layer of air above the skin to prevent heat loss by insulating

Patient is pyretic - how would body temp get back down

The hypothalamus receives information from sensors in the skin and brain the body temperature is too high and begins to cool it down using vasodilation, diaphoresis, breathing deeper through the mouth, relaxing hair erector muscles - assisting the body achieve homeostasis 

Osmosis

The movement of a solvent molecule across a semi permeable membrane down a concentration gradient/from a region of high solvent concentration to a region of low solvent concentration

Osmosis occurs in

Renal filtration, Gastrointestinal tract, Nerve conduction

Passive/Simple Diffusion

the free movement of molecules across a membrane going down a concentration gradient that does not cost energy and continues until equilibrium is reached

Facilitated Diffusion

the transport of molecules that cannot diffuse directly through a phospholipid bilayer, by a channel or carrier protein receptor down a concentration gradient that does not require atp and continues until equilibrium is reached

Active Transport

the movement of a substance from an area of low concentration to an area of high concentration which costs ATP energy

Active Transport’s relationship with homeostasis

necessary for the homeostasis of ions and molecules with a significant portion of the available energy going toward maintaining these processes

Sodium Potassium Pump

Mechanism for active ion transport across the cellular membrane e.g. in cardiac tissue causes heart to contract

Sodium Potassium Pump alternative name

Na+K+ATPase