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.
Describe the path of blood flow through the heart
Deoxygenated Right Atrium - Through Tricuspid Valve - Right Ventricle - Pulmonary Semilunar Valve - Pulmonary Artery (to the lungs to receive oxeygen)
Oxygenated Blood recieves oxeygen and travels back to the heart through the Pulmonary Veins - Left Atrium - Mitral Bicuspid Valve - Left Ventricle - Aortic Semi Lunar Valve - Aorta - Aortic Arch (Upper body tissue cappilaries) - or Desending Aorta (lower body tissue cappilaries) blood give 02 and recieves c02
Blood Returns Through the Superior Vena Cava (upper body) - or Inferior Vena Cava (lower body) to Right Atrium
Label The Heart
What is the Conduction system of the heart
This basically refers to the cells that initiate and distribute stimulus for the heart to contract. The conduction system consists of the following parts:
* The Sinoatrial Node
* The Atrioventricular Node
* Conducting cells = AV Bundle and Purkinje fibres
Describe the Impulse conduction through the heart
SA Node (Sinoatrial) located in the Right Atrium is the pacemaker of the heart. It sends an electrical impulse (Posotive Charge Depolarization) through the Atrial Myocardium to the AV Node (Atrioventricular) 100 msec pause to allow for atrial contraction before the ventricles do.
AV Node sends the Posotive charge through fibres known as the bundle of HIs.
Branches of this Bundle of His branch throughout the heart muscles and are known as Purkinje fibres.
The Purkinje fibres conduct the impulse and distribute it to the Ventricular myocardium muscles and Ventricualr contraction begins.
Draw the heart conduction system
Detail the feature of Systole
Contraction of the Heart chambers to push blood into aorta and Pulmonary Artery
Increases blood pressure in the arteries
Decreases the volume of the heart chamber and forces blood out of them
Systolic pressure represent the maximum pressure excerted on the arteries
Detail the features of Diastole
Relaxation of the Heart chambers between contrations. During Diastole the Heart chambers fill with blood
Decreases Blood Pressure in the Arteries
Increases the volume of the Heart chambers back to their origional size to recieve blood
Blood Vessels relax during Diastole
Diastolic Pressure represents the minum pressure in the arteries
Where is the AtrioVentricular Node located
Located in the wall of the Right Atrial Septum near the Atrioventricular Valve
What 2 factors can affect whether oxygen may be taken up by haemoglobin
PH Level (acidity of the blood) and Carbon Dioxide Level
There are two factors that affect the rate of diffusion in the lungs. What are they and how can they affect the rate.
The thickness of the membrane around the alveoli. The thicker it is the slower the rate of diffusion. The surface area of the alveoli, as any reduction in the surface area will reduce the rate
What are the 6 main components to Homeostasis
Stimulus - Initial change in environment
Receptor - they detect the change in environment
Afferent Signal - this is a signal going toward the control center
Control Center - Brain evaluates information and makes a decision
Efferent Signal - A signal going away from the control center
Effector - Receives efferent signal and makes a change
What is the epidermis
- Epidermis is Avascular (Has no blood vessels)
- Outermost layer of the skin which forms primary Protective layer for the body (waterproof barrier) preventing water loss and maintaining Homeostatic balance
- Made up of three types of cells Keratinocytes, Melanocytes and Langerhans
- Produces new skin cells via the Stratum Basale Layer
What are Keratinocytes
- Keratinocytes - Highly specialized cells which produce the protein keratin in order to form a protective barrier and stop foreign substances form entering the body.
- They also play a structural role in the skin forming tight bonds with other cells in order to maintain them in place by way of Desmosomes
- Produced at the Stratum Basale Layer
What are Largerhans cells
- Langerhans cells are a form of dendritic cells (Antigen presenting cells) which perform phagocytoses (ingest and eliminate foreign substances) protecting against microorganisms and foreign substances.
- They are most common in the Stratum spinosum layer
- After performing phagocytoses the transport portions of the microbe they ingested to the cell membrane presenting it to other immune cells helping to stimulate immune reactions
What are Merkel Cells
- Merkel cells are mechanoreceptors receptor which function as a sensory receptor for touch
- Found in the stratum basal layer
Explain Facilitated Diffusion
- Certain molecules cannot cross the cell membrane due to the Size, Charge, Polarity
- Glucose, some amino acids, and ions are transported passively (along concentration gradient) even though they cannot pass the phospholipid bilayer. This is done through Facilitated Diffusion
- Facilitated Diffusion uses Carrier Proteins or Channel proteins to bypass the phospholipid bilayer
- Carrier proteins change their shape allowing them to envelope and release transported substances shielding them form the nonpolar regions of the membrane
- Channel proteins are lined with hydrophilic amino acids and filled with water molecules; they allow water soluble molecules to pass through the phospholipid bi layer
Give an example of facilitated diffusion using channel proteins
Sodium ions moving into the cell
* Sodium is usually more abundant outside of cells than inside the cell
* Sodium ions are charged and cannot pass through the non-polar lipid bilayer
* Membrane proteins form sodium channels so that Na+ ions can move down their concentration gradient from outside the cell inside the cell
Give an example of facilitated diffusion using channel proteins
Sodium ions moving into the cell
* Sodium is usually more abundant outside of cells than inside the cell
* Sodium ions are charged and cannot pass through the non-polar lipid bilayer
* Membrane proteins form sodium channels so that Na+ ions can move down their concentration gradient from outside the cell inside the cell
Give an example of facilitated diffusion using carrier proteins
Movement of Glucose into the cell
* Although glucose can be more concentrated outside of a cell, it’s both too large and polar, and therefore, repelled by the phospholipid membrane
* Carrier proteins called a glucose transporter changes its shape allowing glucose to bind to it and transporting the glucose molecule into the cell to facilitate inwards diffusion
Explain why the plasma membrane can be described as having a fluid mosaic structure
- It describes the arrangement of the molecules in the plasma membrane
- Phospholipid molecules form a continuous bilayer which is fluid because they are constantly moving
- Different proteins are scattered throughout the bilayer (e.g., carrier, channel, receptor, glycoproteins,) like tiles in a mosaic
- Cholesterol helps to maintain the shape of the membrane
What is Filtration
A form of passive transport where water and dissolved substances pass through a semi permeable membrane down a pressure gradient from an area of high pressure to an area of lower pressure. A mechanical force is usually responsible for this pressure, with the membrane acting as a filter preventing larger substances from passing.
Rate of filtration dependent upon:
- force of the fluid pressure
- Size of the molecule relative to the size of the pores in the membrane
A cells plasma membrane controls the movement of substances between the
internal and external cell environments. Diffusion and osmosis are two forms of
passive transport across this membrane. Describe these processes.
1)Diffusion moves substances from areas of high concentration to lower
concentration.
2) Lipid-soluble molecules (oxygen, carbon dioxide)
3) Can dissolve in the lipid substance of the matrix
4) Other substances move through tiny pores in the membrane
5) Several factors can influence the speed of diffusion e.g.
6) Temperature – higher concentration levels – number and size of pores –
lighter weighted molecules
7) (give up to 2 marks for providing example)
8) Osmosis is the movement of water molecules
9) It is regulated by the concentration of non-diffusible particles on each side
of the membrane
10) Water moves from the side with lower concentrations (less particles) to an
area of higher concentration (more particles) – it dilutes it.
11) Osmotic pressure influences the rate of osmosis.
How does the structure of the plasma membrane of a cell facilitate its function enclosing the cell components and the control of movement into and out of the cell
Fluid lipid layer which is relatively impermeable barrier, containing phospholipids with hydrophobic tails and hydrophilic heads.
Contains cholesterol which gives the cell shape as it stiffens the membrane
Contains proteins which can form channels and carriers in order to transport molecules and allow free passage to selective molecules and water
peripheral proteins on the cell surface act as receptors involved in signalling systems
External coating (glycocalyx) of membrane provides cell to cell recognition and adhesion
The plasma membrane controls the movement of substances in and out of the cell in several ways. Diffusion, Osmosis, and filtration are three ways in which cell attempt to maintain homeostasis. explain how these processes occur
Purpose of diffusion is to achieve a uniform concentration of molecules within a solution, with particles moving along their concentration gradient from a high concentration to low concentration. (Gaseous exchange in the lungs)
Rate of movement affected by temperature, molecular weight, concentration gradient, number and size of openings, surface area
Osmosis is the movement of water from high concentrations of water to low concentrations of water through a partially permeable membrane
Or the movement of water from low solute concentration to high solute concentration because that is where the concentration of water is lower.
Rate of osmosis affected by osmotic pressure
Filtration is when materials are moved through a physical membrane by physical force
How are proteins made
Ribosomes are responsible for protein synthesis
Amino acids bonds to tRNA within the cell
mRNA instructs the ribosome to connect to the tRNA removing one amino acid
tRNA is released and searches for a new amino acid to bond too
Ribosomes form polypeptide chain which will eventually part of a larger protein
What does insulin do
Decreases energy production from other sources Glycogen, fat and portein metabolism
Promotes the storage of Glucose
Decreases Blood Glucose Levels
Detail the Wernickes are what does it do and where is it located
It is essential for Language comprehension and partly written word Comprehension
Located in the Left Temporal Lobe
Detail Brocas Area
Located in the Frontal Lobe near the Motor Cortex
Known as Motor Speech area
Function = Involved in Motor speech, words are formulated here through repetition
How is Insulin Made
mRNA Moves toward the RER
Creates Pre pro Insulin
Pre part is removed as it is Hydrophobic and cannot move through the cytoplasm
parcelled into an vesicle in the golgio body where it matures to become Insulin
Leaves the golgi body to sit on a Beta cell in the cell membrane
Explain the biological action of Insulin/ How it acts on the cell
Insulin Binds to a receptor on the surface of a cell e.g. fat cell (alpha subunit on the outside of the cell)
Passes through the beta subunit on the insdie of the cell into the body of the cell
Releasing an Insulin Responsive Substrate (Insulin is broken down into tiny pieces)
Insulin then acts on a Glut 4 Transporter in the cell cytoplasm
it moves the Glut 4 transporter to the surface of the cell membrane where a glucose channel is opened allow glucose to enter the cell
Describe the process of Insulin release
Glucose is taken up by a Beta cell of the surface of the cell membrane
It passes through a Glut 2 Transporter into the cell
Glucokinase acts upon the Glucose molecule starting Glycolysis and Phosphorylation
This produces ATP. ENergy produced form ATP closes the Potassium channel depolarzing the cell
The change in charge of the cell causes the a Calcium channel to open in the cell allowing for an influx of Calcium Ions into the cell
This influx of Calcium causes Insuline granule Translocation
What is the function of the Temporal Lobe
Auditory Proccessing
Understanding Speech and Sound
Encoding of memory
Function of the Frontal Lobe
Controls Voluntary Movement
Involved in Higher cognotive ability
Also known as the Emotional Brain
Function of the Pariatal Lobe
Processing sensory information e.g. touch, temp, pain, smell
Linked to the sensory Cortex
What are Hemidemosomes
Anchor Basal epethilal cells to the underlying basement membrane
What is the Rough Endoplasmic Reticulum
Folds and processes proteins made at its surface by fixed ribosomes.
These proteins are secreted from the cell for external use
what are golgi vesicles
Small fluid filled membran bound sacs that carry newly synthesised proteins and glycoprotiens destined for export outside of the cell
what is the function of the Smooth Endoplasmic Reticulum
Synthesis lipids, phopholipids, carbohydrates and cholestural steroid hormones
Absorbs and transports fats
Detoxifiy drugs
stores calcium in skeltal muscle
What is the occipital lobe function
Visual proccesing
Detail Long Term Memory
Reffered to as declarative memory
Stored in the (hippocampus)
Consists of the Retention of facts
Recall = Hippocampus
emotion and fear = amygdala
