biology year 1 Flashcards
What is taxonomy?
The theory and practice or identification and naming of organisms
What are the 2 main objectives of Taxonomy?
To sort out closely related organisms and assign them to separate species
Order species into broader categories
What are the taxonomic classification groups?
Kingdom, Phylum, Class, Order, Family, Genus and Species.
What are the 5 Kingdoms?
Animals, plants, fungi, protoctists and Prokaryotes
What is the circulatory system?
3 independent systems including the heart, lungs, arteries, veins, coronary and portal vessels. Its responsible for the flow of blood, nutrients, oxygen and other gases as well as hormones to and from cells
What is diffusion?
Diffusion is the net movement of anything from a region of higher concentration to a region of lower concentration
The functions of the circulatory system are?
- Carryoxygenfrom lungs to all the cells in the body.
- CarryCO2 from the body to the lungsfor removal.
- Transport nutrients and water around the body.
thermoregulation. - Transport waste products to the kidneys for excretion.
- To transport hormones.
What is the structure of the heart?
A muscular pump to create pressure tocirculate the blood
What is the function of the Blood vessels?
- Arteries –carry oxygenated blood
- Capillaries-allow blood diffusion
- Veins –carry deoxygenated blood
What is the structure of the blood?
Transport mechanism made up of plasma, red and white blood cells and platelets
What are the functions of the blood?
- Transport of nutrients and oxygen to thetissues
- Transport endocrine secretions
- Removal of waste products
- Temperature regulation
- Regulate acidity in the body
- Regulate water content
- Defenseagainst micro-organisms
- Immunity to disease
What is hematopoiesis?
The process through which the body manufactures blood cells. It begins early in the development of an embryo and continues for the life of an individual
What is plasma?
Liquid part of the blood - serum with dissolved substances such as carbon dioxide, amino acids,glucose and fatty acids that also contains waste materials such as urea, hormones, enzymesandantibodies.
Acts as a buffer to maintainpH
What is the structure of red blood cells?
- Contain a protein calledhemoglobinwitch Oxygen binds to.
- No nucleus or mitochondria (rely on anaerobic metabolism) = space for morehemoglobin
- Bi-concave shape = more surface area.- can travel alongcapillaries
What are platelets?
- Formed from megakaryocytes in the bone marrow. Aid blood clot formation duringhaemostasis
- Function of clot is to prevent further blood loss and entry of infective agents.
- When a blood vessel is damaged the platelets become sticky (Von Willebrand factor) and forma platelet plug.
What are the white blood cells?
-Fight disease, destroy germs and remove dead tissue.
Main types are:
-Lymphocytes – found in lymph, simple nucleus and clear cytoplasm
-Monocytes – Same as above but larger
Granulocytes – Irregular nucleus, granular cytoplasm
What are the arteries and what do they do?
- Carry blood from theheart
- Usuallyoxygenated blood except thepulmonary artery which carries deoxygenatedblood to thelungs
- Thick muscular walls – needed due to highpressure of blood being pumped from theheart
- Resistance vessels – store pressure to evenout bloodpressure.
- Divide into arterioles which are slightlysmaller
What are the veins and what do they do?
- Carry blood to the heart
- Thinner than arteries due to lower bloodpressure
- Valves present to prevent backflow of blood
- Skeletal muscle movement and the digitalcushion assists movement of blood throughthe veins, especially in the lower leg
- Hence legs may become filled when horsestabled for long period of time
- Swelling disperses when movement commences
What are the capillaries and what do they do?
- Walls one cell thick to enhance diffusion
- Exchange of gases, uptake of nutrients andremoval of metabolic waste products takeplace
- Capillary beds form the junction between thesmall veins and arteries – venules andarterioles
Describe the actions of the blood flow through the right side the heart
Deoxygenated bloodreturning from the rest of the body iscarried to the right atrium of the heart via the vena cava.
When full the atrium walls contract and propel bloodthrough the tricuspid valve into the rightventricle.
Ventricular contraction and increased pressure forcesblood through the semi-lunar valves into the pulmonaryartery which transports it to the lungs – picks up O2frominspired air.
When ventricle relaxes, semi-lunar valves close to preventbackflow of blood.
Describe the actions of the blood flow through the left side of the heart
From thelungsoxygenated bloodis carried in thepulmonary veinback to the heart.
When full, left atrium contracts and forces blood throughthe bicuspid valve into the left ventricle.
Ventricle walls contract and push blood through the semi-lunar valves into the aorta, the main artery of the body.
Hence, LHS of heart is more muscular than RHS.
Tendinous cords attached to the atrio-ventricular valvespull on the two or three flaps and prevent them from turninginside out.
What are the turbinate bones?
The function of theturbinate bones are tomoisten, warm andfilter the inspired airbefore it enters thelower respiratorytract.
Expand surface area toincrease number ofcells in contact with airduringinhale
What is the Pharynx?
- Located caudally toboth oral and nasalcavities
- Common structure toboth respiratory anddigestive system
What is the Larynx?
-Location: Lying betweenboth mandibles
-Consists of hyaline cartilage,fibrous tissue, muscle, andmucous membrane
-Suspended from the skull bya structure called the hyoid apparatus
What is the trachea?
A non-collapsible tubeextending from thelarynx to the point ofdivision into the leftand right bronchi.
What is the bronchi?
At the level of the 5thrib, the trachea dividesinto 2 bronchi. This istermed thetrachealbifurcation
Primary bronchi: divideinto small secondarybronchi
Continue branching intoeven smaller tertiarybronchi
What are the bronchioles?
Bronchioles are air passages inside the lungs that branch off like tree limbs from the bronchi. The bronchioles deliver air to tiny sacs called alveoli where oxygen and carbon dioxide are exchanged
Which parts of the respiratory system are part of the upper and lower systems?
Upper: Nasal cavity, pharynx, larynx, trachea and bronchi.
Lower: bronchioles and alveoli
What are Alveoli?
Bronchioles continue tobranch into alveolarducts
Each duct containingseveral alveolar sacs
Each sac consisting ofmany alveoli
The alveoli are tiny air sacs within the lungs where the exchange of oxygen and carbon dioxide takes place
What are the lungs?
Right and left – the righthaving + 1 lobe
Located in the thoraxeither side of themediastinum
Covered by pulmonarypleura and enclosedwithin the pleural cavity
What is the diaphragm?
A dome shapedmuscular partitionseparating the thoracicand abdominal cavities
Contraction causesinspiration due tovolume expansion ofthorax.
How does ventilation work?
Inhalationand Exhalation
This is by contraction of theDiaphragmandrelaxing of this muscle.
Contraction of theIntercostal Muscles’and relaxing of muscle.
Brings in oxygen and exhales carbon dioxide
How does oxygen enter the blood?
Inhaled oxygen entersthe lungs and reachesthe alveoli.
The layers of cells liningthe alveoli and thesurrounding capillariesare each only one cellthick and are in veryclose contact with eachother.Through diffusion
Where does gaseous exchange happen?
Gaseous exchange occurs at the alveoli in the lungs and takes place by diffusion. The alveoli are surrounded by capillaries so oxygen and carbon dioxide diffuse between the air in the alveoli and the blood in the capillaries.
What is the Respiratory system?
Your respiratory system is the network of organs and tissues that help you breathe. This system helps your body absorb oxygen from the air so your organs can work. It also cleans waste gases, such as carbon dioxide, from your blood. Common problems include allergies, diseases or infections.
What is the reproductive system?
a collection of organs and a network of hormone production that work together to create life
What is the structure of the reproductive system in females?
in women, the reproductive system includes the ovaries, the fallopian tubes, the uterus, the cervix, and the vagina.
What is the function of the reproductive system in males?
external organs include the penis, scrotum and testicles. Internal organs include the vas deferens, prostate and urethra.
What is the structure of the ovaries?
2 of them. Grows within a follicle until mature. Small organs located on each side of the uterus in the pelvic cavity
What is the purpose of the ovaries?
To produce eggs through the process of oogenesis. Oestrogen is also produced here
What is the structure of the uterus?
Made up of the horns, body and cervix. Thick muscular walls called endometrium, helps support a fertilised egg.
What is the purpose of the uterus?
Holds a fertilised egg in place during implantation and development through gestation.
What is the structure of the vagina?
Tube creating an acidic environment to prevent infection
What is the purpose of the vagina?
Place where sperm can enter the female during mating
What is the structure of the Vulva?
External opening of the urogenital tract.
What is the purpose of the vulva?
enlarges when female is in oestrus as visual stimulant
What is the structure of the Cervix?
Narrow opening between the vagina and the uterus
What is the purpose of the Cervix?
Acts as a plug to prevent pathogens entering the uterus. Dilates during parturition to allow offspring to pass
What is the structure of the Scrotum?
Contains the testes, large sac like structure