What is homeostasis?
Homeostasis is how the body maintains its internal environment
What is the internal environment made up of?
Blood and tissue fluid
Homeostasis is con
Events of the cardiac cycle
The figure shows pressure and volume changes in
the left atrium left ventricle and aorta during two
cycles. It also shows electrical signals emitted by the
heart and recorded by the ECG [ electrocardiogram]
Hormones and Metabolism
Steroids and peptide hormones
Hormones are chemical messengers, secreted by endocrine glands directly in the
bloodstream. The blood carries to them to target cells, where they elicit a
response. A wide range of chemical substances
7.2 Transcription & Gene
Essential Idea: Information stored as a
code in DNA is copied onto mRNA.
Image from https:/worldwide.promega.com/resources/productguides-and-selectors/protocols-and-applications-guide/epigenetics/
By Darren Aherne
Functions of the liver
The liver is composed of hepatocytes that carry out many important functions:
breakdown of erythrocytes
Conversion of cholesterol to bile salts
Production of plasma proteins
Nutrient storage and regulation.
Digestion and Absorption
Secretion of digestive juices
2 Types of glands:
secrete through a duct onto the surface of the body or into the lumen of the gut. (E.g. Digestive
Ductless and secrete hormones into the blood.
Define cell respiration
cell respiration is the controlled release of
energy by oxidation, of organic compounds
(carbohydrates fats and proteins) in cells to
functions of mitochondrial organelles
Matrix : contains enzymes and sol
Kidneys/ Excretion and
Is the cinc. i solutes in a solution m moles.
Organism can be:
Osmoregulators: Organisms with a constant (within a range) osmolarity in tissue
fluid. Osmoregulation (homeostasis).
Transport in the Xylem of
One of the key structural features of the xylem is the rings of lignin
The lignified walls of xylem help them to withstand the very low pressure inside
the xylem which drives the transpiration pull.
Movement and Muscles
Structure of Skeletal Muscle
Attached to bone and causes movement in animal bodies.
Consists of large multinucleated cells (muscle fibers)
Inside Muscle fibers are cylindrical structures called myofibrils
Around these are specialized
Flowering Plant- Life Cycle
plant Life Cycle
Why do some plants flower in winter/fall while others flower during summer/spring?
Period of dark
Prince me to transport organic compounds such as sugars and amino acids from one part of the plant
There are several cell types in phloem tissue.
The movement of organic compounds takes place in phloem sieve t
linked together by condensation reaction to form
disaccharides & polysaccharide polymers
glucose has the formula C6 H12 O6
it forms a hexagonal ring (hexose)
glucose is a form of sugar that fuels resperation
Nutrients that cannot be synthesised by the body and
must be ingested by diet
Carbohydrates are not considered essential nutrients
because in certain human diets energy is obtained
from other sources without ill effect
Transport of Respiratory
Is the concentration of gasses.
The greater of the concentration of dissolved oxygen in cells the higher the partial
O2 Dissociation curves of adult and fetal hemoglobin ad myoglo
Describes the production of female gametes (ova) within the ovary
The process begins during foetal development, when a large
number of cells (oogonia) are formed by mitosis before
undergoing a period of growth
These cells begin meio
Neurons and Synapses
The nervous system consists of 2 parts
1. The central nervous system (CNS) made up of the
brain and spinal chord
2. The Peripheral Nervous system (PNS) made up of all
Why digest food?
Large food molecules must be digested as they are crucial to our bodies. We
would die if we could not digest them
The membranes of epithelial cells in the villi of small
The Blood System
Arteries carry blood away from the heart
They are carrying blood at high pressure
They have a tough outer layer called the Tunica externa
They have a thick layer of smooth muscle called
What is the difference between ventilation, Gas
exchange and breathing?
The act of breathing in and out
Exchange of carbon dioxide and oxygen between alveoli an
What is digested in the mouth?
Starch to maltose
Polysaccharide to Disaccharide
What is digested in the Stomach?
What is digested in the Small
1. Digestion of fat begins
6.3 Defence against Infectious Disease
What is your primary defence?
This is how your skin stops pathogens from entering
Skin acts as a barrier
- epidermis is the outer layer which is con
Define a nutrient
A nutrient is a chemical substance found in foods that is used by the body
What is an essential nutrient ?
Some nutrients are essential in the human diet, because food are the only
possible source of
D4 human physiology
Striated, shorter, and wider than skeletal muscles
Y shaped cells
The junction between cells has an intercalated disc with gap
function. This connects cytoplasm so ions diffuse quick
FUNCTIONS OF THE
1. Storage Of Excess
Nutrients Glucose stored as glycogen , iron, vitamin A and vitamin D when in excess
2. Regulate Nutrients Excess Proteins can be stored into the body so its broken down into urea.
Photosynthesis is a metabolic pathway.
Carbon dioxide and along with water is
used to produce carbohydrates. Oxygen
is released as a waste gas.
Light energy is transferred to chemical energy
Hormones and Homeostasis
Hormones are used when signals need to be widely
Thyroxine is a hormone produced by the thyroid gland
Its key role is in controlling the metabolism of cells
It affects almost every physiological process in the body inc
Jet lag is caused by flying in an airplane and crossing one or more time zones,
which can disrupt the body's sleep and wake cycle (circadian rhythms). Jet travel
across time zones may make it difficult for you to fall asleep, stay asleep,
DNA Structure &
Essential Idea: The structure of DNA
is ideally suited to its function.
DNA is a double helix, consisting of two anti-parallel chains of polynucleotides
that are held together by hydrogen bonds between complementary bases on
Transcription & Gene Expression
Information stored as a code in DNA is copied into mRNA.
Only some DNA sequences code for polypeptides.
Non-coding regions have other functions:
rRNA production (ribosomal RNA)
Control gene expre