specific exam questions Flashcards
Detail the spinal cord and its associated sections (how many parts to each section)
Cervical nerves = 8, C1-C8
Thoracic nerves = 12, T1-T12
Lumbar nerves = 5, L1-L5
Sacral Nerves = 5, S1-S5
Coccygeal = 1
Detail Thyroxine as a negative feedback mechanism
Thyroxine is produced by thyroid gland
Low Thyroxine in bloodstream stimulates the hypothalamus to release TRH/Thyrotropin Release Hormone.
Thyrotropin Release Hormone causes the Pituitary gland to release TSH/Thyroid stimulating hormone so the Thyroid releases more thyroxine. So blood levels return to normal.
Normal thyroxine levels in the bloodstream inhibit Thyrotropin Release Hormone release from the hypothalamus and the production of Thyroid Stimulating Hormone by the pituitary, so normal blood levels are maintained.
Where is thyroxine produced
Thyroid
Low levels of thyroxine stimulate what?
Hypothalamus to release Thyrotropin Release Hormone
What is the role of TRH
Thyrotropin Release Hormone causes the pituitary gland to release Thyroxine Stimulating Hormone, so the Thyroid releases more Thyroxine
What is the role of TSH
To stimulate the Thyroid to release more Thyroxine
What is external respiration
The process of breathing. Respiration begins at the nose or mouth
Oxygenated air is brought in before moving down the pharynx, larynx, and trachea.
Trachea branches into 2 bronchi leading to lungs.
Each bronchus divides into smaller bronchi and again into smaller tubes Bronchioles.
At the end of bronchioles are air sacs alveoli where gas exchange occurs
What is internal respiration
Also called cellular respiration, it is the process by which organisms break down glucose into a form that the cell can use as energy
What is the function of the conducting zone
This is the area from the nose/mouth to the terminal bronchioles. Its function is to warm, humidify air and trap debris and pathogens from the incoming air
Define Homeostasis
The maintenance of a stable internal environment in a relatively constant state
Where is Long Term memory stored
Where is Short term memory Stored
Long Term memory is stored in hippocampus
Short term memory is stored in the Temporal Lobe
Define Negative feedback
Negative feedback is a feedback response in which the effector reverses/negates the effect of the initial stimulus/change in control condition e.g. temperature increase (effector produces sweating response to lower temperature)
Define positive feedback
Positive feedback is a feedback response in which the result of the effector amplifies/exacerbates the initial stimulus/change in control condition e.g. (effector contracting the uterus causing an increase in stretching of the cervix which was the original stimulus/change in control condition)
Give an example of Positive Feedback
Child Birth
Stimulus/Change in control condition = stretching of the cervix
Receptor = receptor in cervix send this information to CNS via afferent signal
CNS = processes info (hypothalamus) and sends efferent signal to the effector releasing oxytocin to cause uterus contraction
Effector = muscles in the uterus contract causing the cervix to stretch further exacerbating the initial stimulus/change in control condition.
This process continues until the baby is birthed and the stimulus is removed.
Example of negative feedback
Increase in body temperature
Stimulus/change in control condition = Hot weather
Receptor = receptors on the skin detect the change in temp and send a afferent signal to CNS
CNS = processes the information and decides what to do. Afferent signal is sent to the effector
Effector = Blood vessels dilate, heat radiates from skin surface Sweat glands secrete sweat helping to cool body. This process negates the initial stimulus/change in control condition.
What is the Nucleus
Largest organelles of a cell
Surrounded by nuclear membrane
Contains Chromosomes (hereditary info)
Function = Controls cell activity and assembles ribosomes for protein manufacture
What are Ribosomes
Organelles responsible for protein synthesis
Two types of ribosomes in a cell are free and fixed ribosomes
Free ribosomes - scattered throughout the cytoplasm create protein to be used within the cell
Fixed ribosomes - attach to Endoplasmic Reticulum where they are modified for use within the cell or secreted from the cell
What is the smooth Endoplasmic reticulum
Synthesizes lipids, phospholipid, carbohydrates (e.g. glycogen) and cholestural steroid hormones
Absorbs and transports fats
Detoxification of drugs (in liver and kidneys)
SER in skeletal muscle stores Calcium ions
What is Rough Endoplasmic Reticulum
Folds and processes proteins that have been made at the ribsomes on its surface (fixed ribosomes).
Many of these proteins are then modified and packaged for export to there next destination the Golgi apparatus
What are Golgi Apparatus
A group of Fluid filled membrane bound flattened sacs
Modify and packages and distribute proteins and lipids
What are Lysosomes
Vesicles filled with digestive enzymes
They can be used to digest invading cells or breakdown worn out components
What are mitochondria
Mitochondria large bean shaped organelles which provide energy for cells.
Consist of an unusal double membrane, outer membrane covers the whole of the organelle and the inner membrane contains folds known as Cristae (increase surface area).
Produce 95% of energy required by a cell in the form of AdenosineTriPhosphate ATP.
Found in cells whcih requiee lots of energy (mucles, sperm)
Describe in detail the phospholipid bi layer
Part of the plasma membrane
Two layer of phosoplipids
They have a head (phosphate) and a tail fatty acid tail (lipid)
Head is charged do to the presence of a phosphate molecule (Hydrophilic) soluble in water and faces externally (likes water)
Tail insoluble in water (Hydrophobic lipid body) project internally between the heads dosent like water
Also contains cholestural which provid fluidity to the membrane
Allows lipid soluble molecules to pass but doesnt allow ions and water soluble components to enter.
This is what makes the plasam membrane selectivley permiable
Explain the fluid mosaic model
The fluid mosaic model is used to describe the plasma membrane. It is composed of lipids with a “mosaic” of embedded proteins and other components, and its “fluidity” allows these macromolecule components to move laterally within the membrane.
Cholestural within the membrane provides shape and support for the membrane
What are the three fromed elements of blood
Erythrocytes (Red Blood Cell)
* Bi concave with
* no Nucleus
* Carry oxeygen bound to heamoglobin and some carbon dioxide
* life span of around 120 days
* Formation of Erythrocytes known as Erythropoiesis and takes 7 days
Leukocytes (White blood cells)
* Active in immunity protecting the body from invading cells and removing debris
* Can be subdivided into Granulocyte and Agranulocyte
Platlets (Thrombocytes)
* Disc shaped cell fragments
* Life Span of 8-11 days
* No nucleus but contain enzymes and Mitochnondria
* Created by Megakraryocytes (Bone marrow cells)
What is Albumin and why is it importnat
Albumin is a plasma protein and it helps to maintain osmotic pressure
Lack of albumin will cause a drop in osmotic pressure water will not be drawn into the capillary, instead it will remain in the interstitual spaces intrun causing oedema
It also is a carrier for fatty acids, some drugs and steroids.