All Biology Flashcards
Describe the organisation levels of the human body
Atom Molecule Macromolecule Organelle Cell Tissue Organ Organ system Organism
What does the plasma membrane consist of
2 layers of phospholipids with protein molecules embedded in them
What does the head of the phospholipid molecule have
Electrically charged and hydrophilic
What does the tail of the phospholipid molecule have
No charge and hydrophobic
How is the phospholipid bilayer arranged
The hydrophilic heads aligned on the outer surface of the membrane and the hydrophobic tails form the central water repelling layer
What’s the largest organelle
The nucleus, this is contained within membrane similar to the plasma membrane but has tiny pores which some substances can pass between it and the cytoplasm
What does the nucleus contain
The body’s genetic material which directs activities of the cell
What forms chromatin
DNA and proteins called histones coiled together
During cell division what does chromatin become
Chromatin replicates and becomes more tightly coiled forming chromosomes
What are the functional subunits of chromosomes called
Genes
What are the organelles in eukaryotic cell
Nucleus, mitochondria, ribosomes, endoplasmic reticulum, Golgi apparatus, lysosomes, macrofilaments and microtubules
What shape is the mitochondria
Sausage shape
Where is the mitochondria located
In the cytoplasm
What’s the powerhouse of the cell
Mitochondria
What does the mitochondria do
Involved in aerobic respiration, the process by which chemical energy is made available in the cell (ATP)
What does ATP do in the mitochondria
Releases energy when the cell breaks it down
When is synthesis of ATP most efficient
In the final stages of aerobic respiration, a process requiring oxygen
What are ribosomes
Tiny granules composed of RNA and protein
How do ribosomes synthesise proteins?
From amino acids, using RNA as the template
When do the ribosomes make protein
When present in free units or in small clusters in the cytoplasm
What is the endoplasmic reticulum
A series of interconnecting membranous canals in the cytoplasm
What does the smooth ER do
Synthesises lipids abs steroid hormones
Associated with detoxification of some drugs
What does the rough ER do
Synthesises proteins that are exported from the cell
What does the Golgi apparatus consist of
Stacks of closely folded membranous sacs
What does the Golgi apparatus do
Proteins move from the ER to the Golgi apparatus where they are packaged into the membrane bound vesicles called secretory glands
What do the vesicles do in the Golgi apparatus
The are stored
When needed, they move to the plasma membrane through which the protein is exported
What are lysosomes
One type of secretory vesicle formed by the Golgi apparatus
What do the lysosomes contain
A variety of enzymes involved in breaking down fragments or organelles and large molecules inside the cell into smaller particles that are either recycled or extruded from the cell as waste material
What blood cells are lysosomes in
White blood cells - contain enzymes that digest foreign material such as microbes
What are microfilaments
Tiny strands of protein that provide structural support and maintain the characteristic shape of the cell
What are microtubules
Contractile protein structures in the cytoplasm involves in the movement of the cell, the movement of cilia and the organisation of proteins in the plasma membrane
What are the core requirements for the human to live
Pressure
Heat
Food
Oxygen water
What are the body cavities
Cranial
Thoracic
Abdominal
Pelvic
What cavity is the brain in
Cranial, it’s boundaries are formed by the bones of the skull
Where is the thoracic cavity situated
In the upper part of the trunk. It’s boundaries are formed by bony framework and support muscles
What organs are in the thoracic cavity
The trachea, 2 bronchi, 2 lungs The heart, aorta, superior + inferior vena cava, numerous other blood vessels Oesophagus Lymph vessels and lymph nodes Nerves
What’s the largest cavity in the body
Abdominal cavity
What shapes the abdominal cavity
Oval
Where is the abdominal cavity situated
Main part of the trunk (decided into 9 regions)
What organs are in the abdominal cavity
Stomach, small intestine and most of large intestine
Spleen
2 kidney, upper part of uterus
2 adrenal glands
Numerous blood vessels, lymph vessels, lymph nodes, neves
What shape is the pelvic cavity
Funnel shaped
Where is the pelvic cavity situated
Extends from the lower end of the abdominal cavity
What organs are in the pelvic cavity
Sigmoid colon, rectum, Anus
Some loops of small intestine
Urinary bladder, lower parts of the uterus and urethra
What organs are the respiratory system
Nose, pharynx, larynx, trachea, 2 bronchi, brochiolious and smaller air passages, 2 lungs and their coverings, the pleura
Organs of the digestive system (alimentary tract)
Mouth, pharynx, oesophagus, stomach, small intestine, large intestine, rectum, anus
Organs of the digestive system (accessory organs)
3 pairs of salivary glands, pancreas, liver and biliary tract
What are the glands/organs in the endocrine system
Hypothalamus 1 pituitary glands 1 thyroid gland 4 parathyroid glands 2 adrenal glands 1 pineal gland 2 ovaries (female) 2 testes (male)
What are the main parts of the nervous system
Central nervous system
Peripheral nervous system
What does medial mean
Structure nearer to the surface (heart is medial to humerus)
What’s lateral mean
Structure if further from the midline or at the side of the body ( humerus is lateral to the heart)
What does proximal mean
Nearer to a point of attachment (femur is proximal to fibular)
What’s does distal mean
Further from the point of attachment (fibular is distal to femur)
What does anterior or ventral mean
Part of the body being described is nearer the front of the body (sternum is anterior to vertebrae)
What does posterior or dorsal mean
Part of the body being described is nearer the back of the body (vertebrae is posterior to sternum)
What does superior mean
Structure nearer to the head (skull or posterior to scapulae)
What does inferior mean
Structure further from the head (scapulae are inferior to the skull)
What does homeostasis mean
The composition of the internal environment is maintained within narrow limits (maintaining internal balance)
How is homeostasis maintained
By control systems which detect and respond to change
What are the 3 components of that he control system
Detector, control centre, effector
What does the control centre do
Determines the limits within which variable factor should be maintained. It receives an input from the receptor/sensor and integrates the incoming information
What happens when incoming signals indicates that an adjustment is needed
The control centre responds and it’s output to the effector is changed.
What feedback systems are present in the body
Positive and negative
What does the effector do if the system is controlled by negative feedback
It decreases or negates the effect of the original stimulus, restoring homeostasis
What type of feedback is blood clotting
Positive
What type of feedback is shivering when you’re cold
Negative
What type of feedback is uterine contractions during labour
Positive
What does the stimulus do in positive feedback
Progressively increases the response
When does homeostatic imbalance arise
When a fine control of a factor in the internal environment is inadequate and the level of the factor falls outside the normal range
What are the four phases of mitosis
Prophase metaphase anaphase and telophase
What’s happening at prophase
DNA gets organised into chromosomes
What’s happening at metaphase
Chromosomes get lined up into the middle of the cell
What’s happening at anaphase
Chromosomes get pulled apart
What’s happening at telephone is
Separate cell membranes
What’s happening at cytokinesis
Divide into two separate cells
What is happening at interphase
Cell isn’t dividing but is getting ready to potentially divide
Why do cells divide and specialise
Lifespan of most individual cells are limited, many become worn out and die and are replaced by identical cells by mitosis
What is the cardiac cycle
Atrial systole
ventricular systole
atrial and ventricular diastole
What happens at atrial systole
A wave of contraction that spreads over the myocardium of both atria, emptying the atrium and filling the ventricles
What happens at ventricular systole
A wave of contraction sweeps upwards from the apex of the heart and pulls the walls of the ventricles, pumping blood into the pulmonary artery and the aorta
What happens at Atrial and ventricular diastole
Atria and ventricles are relaxed, during this time myocardium recovers until it contracts again and atria fill for the next cardiac cycle
What is an allele
Alternative forms of a gene for each variation of a trait of an organism (one from mum one from dad)
What is heterozygous
When there are two different alleles of that trait (Bb)
What are Homozygous
When there are two identical alleles for a trait (BB, bb)
How did two brown eyed people have a blue eyed baby
Because of the action of the dominant and recessive genes
What is the cell cycle
The cell cycle is a series of events that takes place in a cell as it grows and divides
The cell leaves interphase and undergoes mitosis (pmat)
How is a cardiac impulse initiated and conducted through the myocardium
The SA node triggers a wave of contraction that spreads over the myocardium of both atria
What is the SA node
Pacemaker of the heart - initiates impulses more rapidly
What’s the AV node do
Stimulated by impulses that sweep over the atrial myocardium
Initiate impulses that cause a contraction but slower than SA node
Where is the bundle of his
Crosses the fibrous ring that separate atria and ventricles
What are purkinje fibres
Fine fibres broken up from the bundle of his
What happens at the P-wave
Sinoatrial node is depolarising
What happens at the QRS complex
Ventricular depolarisation
What happens at the T wave
Ventricular repolarisation
What do the coronary veins do
Carry deoxygenated blood from the myocardium and empty them into the chambers of the heart
What do the coronary sinuses do
Responsible for draining most of the deoxygenated blood leaving the myocardium
What’s the difference between pulmonary and systemic circulation
Pulmonary moves blood between the heart and lungs
Systemic moves blood between the heart and the rest of the body
What organs make up the respiratory system
Nose, pharynx, larynx, trachea, 2 bronchi, bronchioles, 2 lungs
What’s the mechanism of breathing
When you inhale, your diaphragm contracts and moves downwards, lungs expand and ribs pull outwards
Where does gas exchange occur in the respiratory system
Alveoli
 how does gas exchange occur in the alveoli
They are small sacs where the exchange of oxygen and carbon dioxide takes place
Capillaries are thin blood vessels in the walls of the alveoli
What factors control breathing
Carbon dioxide, hydrogen ions, oxygen levels
What do coronary arteries do
Allow blood to flow to the heart muscle
What is hypoxia
Low oxygen levels
Why do you need food
Provides body with needed nutrients, needed for energy, raw building material for growth and repair, and to regulate chemical reactions
Why do you need oxygen
Used to release energy from food (1/5 or air, 21%) 
Why do you need heat
Product of metabolic reactions that controls reaction rate; temperature - measure of the degree of heat
Why do you need pressure
Atmospheric pressure is needed for breathing
Hydrostatic pressure is needed to move blood through the vessels
How does the respiratory and circulatory system interact with other body systems
To pump blood and oxygen around the body
What’s the difference between anatomy and physiology
Anatomy is the study of the structure, physiology is the study of the function
What is an atom
Simplest level (oxygen, hydrogen, carbon)
What is a molecule
Two or more atoms comprise a molecule
What is a macromolecule
Biologically important molecules inside a cell
What are organelles
Aggregates of macromolecules used to carry out a specific function in the cell
What’s a cell
The basic unit of structure and function for living things
What’s a tissue
Groups of cells functioning together
What are organs
Groups of tissues that have specialised functions
What does bilateral mean
Paired structures with one on each side
What does ipsilateral mean
Structures on the same side
What does contralateral mean
Structures on the opposite side
What does superficial mean
Near the surface
What does deep mean
More internal
What is the sagittal section
Divide the body into left and right positions. If it passes along the midline it is midsagittal section, a section lateral to the midline is parasagittal
What is a transverse section
Divided body into inferior and superior parts
What is a frontal section
Divide body into anterior and posterior sections
What can you find in the mediastinum cavity
Heart and a Oesophagus 
What’s in the plural cavity
Lungs
What is metabolism
Chemical reactions that are happening in the body to build things up or break things down to maintain homeostasis
What is anabolism
Build things up (protein etc)
Requires energy
What is catabolism
Breaks things down (digestive enzymes)
Produce energy
What happens to responses in negative feedback
Move in opposite direction from change
What happens to the set point in negative feedback
Reduces the amount of change from the set point
Where are the receptors for negative feedback
Anywhere in the body, detect the change (in blood glucose levels, oxygen levels, co2 levels etc) 
Wheres the control centre for negative feedback
Brain, hypothalamus and pancreas
Detects change sent from receptors and sends it to the effectors
What do effectors do
Respond to change (make the change) 
What happens to the set point in positive feedback
Responses move further from the set point, change from set point gets larger
What produces unstable conditions in the body
Positive feedback
What type of feedback is breastfeeding
Positive feedback
 what are the tissue types
Epithelial tissue
Connective tissue
Muscle tissue
Nervous tissue
where is the simple squamous tissue
Alveolar membranes to allow things to move through them
Very flat
Where is stratified squamous tissue
Skin, inside of mouth or anywhere you can lose lots of cells
Where is the transitional epithelial tissue
Bladder
Can go down really small but when filled up with something, it can stretch out again
What are epithelial tissue types
Simple squamous, stratified squamous, simple cuboidal, stratified cuboidal, simple columnar, transitional
What type of tissue is blood
Fluid connective tissue
What is the most abundant tissue in the body
Connective tissue
What makes different types of connective tissue
Bone, cartilage, fat, blood, tendons, ligaments
What are the two types of connective tissue
Loose and dense