Blood and Nervous System Flashcards
What is blood?
It is a fluid connective tissue
What does blood allow?
Communication between distant cells
What does the blood transport around the body?
Oxygen Nutrient Carbon dioxide Nutrients Waste products Hormones Protective substances (antibodies etc) Clothing factors Heat
What pH is the blood?
7.4
What percentage of liquid and solids is the blood composed of?
55% liquid
45% solids
What are the main components of the blood?
Plasma
Erythrocytes
Leukocytes
Thrombocytes
What’s percentage of water is in plasma?
90-92%
What substances are dissolved or suspended in the plasma?
Plasma proteins Electrolytes Nutrients Waste products Hormones Gases
Why can plasma proteins not enter the blood?
It is too large so remains in the blood
What the purpose of plasma remaining in the blood?
To maintain osmotic pressure
What is osmotic pressure?
The pressure exerted by water in a solution
What is the most abundant plasma protein?
Albumin
What is the second most common plasma protein?
Globulins
What is the least abundant plasma proteins?
Fibrinogen and prothrombin
What causes the viscosity of the blood?
The plasma proteins
Mainly albumin and fibrinogen
What is the main function of albumin?
To maintain normal osmotic pressure and is responsible for transport of drugs
What is globulin proteins used for?
Used as antibodies and for transportation
What is fibrinogen and prothrombin plasma proteins involved it?
Blood clotting
What are the four main electrolytes in the body?
Na+
K+
Ca2+
Cl-
What are the
products of digestion which are also used as nutrients?
Glucose Amino acids (make up proteins) Fatty acids Glycerol Vitamins Minerals
Where are waste products produced and where is it transported?
The liver and transported to the kidneys for excretion
How is urine produced for excretion in kidneys?
Protein breakdown
How is uric acid produced in the kidney?
Breakdown of proteins
How is creatinine produced in the kidney?
Breakdown of muscle tissue
What percentage of oxygen is carried in the haemoglobin?
98.5%
When oxygen and haemoglobin bind what does it become?
Oxyhaemoglobin
What percentage of oxygen is transported in solution in the plasma?
1.5%
What percentage of carbon dioxide is transported in the plasma?
77%
What percentage of carbon dioxide is carried in haemoglobin?
23%
When carbon dioxide and haemoglobin bind, what does it form?
Carbaminohaemaglobin
What are the three types of blood cells?
Erythrocytes
Platelets
Leukocytes
Where is blood cells produced and what is the name of the process?
They are produced by haemopoiesis in red bone marrow
What is haemopoiesis?
The production of blood cells
What percentage of blood cells are erythrocytes?
99%
What are the three characteristics of erythrocytes?
No nucleus - more space of O2
Biconcave to maximise surface area
Flexible to squeeze through capillaries
What do erythrocytes contain?
Haemoglobin
What does haemoglobin contain?
4 haem groups
What is the life span of an erythrocyte?
120 days
What percentage of erythrocytes are replaced daily?
1%
Where is erythrocytes destroyed (haemolytic)?
In the spleen, bone marrow and the liver
What is haemolysis?
Breakdown of red blood cells
What is haemoglobin made up of?
A protein (globin) and an iron complex
How many oxygens can one haem unit carry?
1 O2
How many haemoglobins do erythrocytes carry?
280 million
When the four sites on a haemoglobin is occupied by oxygen, what is it described as?
Saturated
What colour is oxygen saturated blood?
Red
Under what conditions will haemoglobin release it’s oxygen? (3)
Low pH
Hypoxia
High temperature
What is the role of leukocytes?
Defence and immunity
What is the function of leukocytes?
Detect foreign material and destroy it
What blood cell is the largest?
Leukocytes
What are the two main types of leukocytes?
Granulocytes and Agranulocytes
What is the key physical difference between erythrocytes and leukocytes?
Leukocytes has nuclei
What are the three granulocytes?
Neutrophils
Eosinophils
Basophils
What are the two Agranulocytes?
Monocytes
Lymphocytes
What is the function of neutrophils? (2)
Destroy and remove foreign substances (eg. Bacteria) by surrounding foreign body, engulfing it and breaking it down using hydrolytic enzymes
Can squeeze through capillary walls
What is the role of eosinophils? (3)
It has two roles in destroying foreign substances like parasites such as worms, engulfing them and destroying them.
Contains toxic chemicals
It also regulates inflammation
What is the role of basophils? (3)
Causes body to produce antibody immunoglobulin which then bonds to basophils and mast cells. These then eels was substances such as histamine and serotonin.
Associated with allergic reactions
Promotes inflammation
What is the role of monocytes? (3)
Monitors environment and differentiates into macrophages (phagocytosis etc) and dendritic cells (Antigen Presenting Cells) as needed.
Stimulates hypothalamus which produces a rise in body temp
What is the role of lymphocytes?
These are specialised macrophages found in tissue which works to identify and destroy invading antigens
What are some of the main types of lymphocytes?
Natural killer cells
T cells
B cells
What is the role of T lymphocytes? (2)
Send chemical instructions to the rest of the immune system so that your body can then produce and kill invaders
Other types of T cells recognise and kill virus infected cells directly
What is the role of B lymphocytes? (2)
Work alongside T lymphocytes
Produce antibodies so that the body can then produce toxic substances
What is the purpose of platelets?
Promote blood clotting
Where are platelets stored?
1/3 is stored in the spleen
How long do platelets survive?
8-11 days
When would platelets be destroyed?
If they’re not used in haemostasis they are destined by macrophages
What is haemostasis?
stopping of blood flow
What causes haemostasis?
Vasoconstriction and platelet plug formation
What causes vasoconstriction during haemostasis?
Serotonin
How is a platelet plug formed during haemostasis?
Clumping occurs and released chemical attract more platelets
How long does it take for platelet plug to form?
6 minutes
What is the process of haemostasis? (11)
When tissue is damaged, platelets contact collagen (protein in skin) when skin is damaged
Triggers release of thromboplastin and serotonin.
Serotonin binds to receptors on smooth muscle causing contraction reducing blood flow
Clotting factors prothrombin activator and Ca2+ ions released (enzyme)
Prothrombin activator converts blood protein prothrombin to thrombin (enzyme)
Thrombin splits fibrinogen to form fibrin (insoluble protein)
Fibrin fibres form mesh over wound
Bleeding stops
Clot dries and forms scab preventing pathogens infecting
Wound held under scab
Enzyme plasmin released to dissolve clot
What is the role of the endocrine system? (3)
In charge of body processes that happen slowly such as cell growth
Secretes hormones (chemical messengers) directly into the blood stream whereas exocrine releases substances into ducts.
Hormones target cells and tissues
What does the endocrine system regulate?
Mood Growth Development Tissue function Metabolism Reproduction
What is the role of the nervous system? (2)
Faster than the endocrine system
Communication and controlling system
Coordinates activities and actions of individual body systems
What are the three principle functions of the nervous system?
Receive
Convey
Integrate
How does the nervous system function using the three principles?
It receive the stimuli from outside and inside the body. It analyses this information. It coordinates an appropriate response.
It then conveys impulses from the brain. It then stimulates or depresses activity in muscles, glands or other tissues.
It integrates the many different functions carried out by individual organs, tissues and cells.
What is the nervous system split into?
The central nervous system and the peripheral nervous system
What is the central nervous system split into?
The brain and spinal cord
What is the brain split into?
Cerebrum
Cerebellum
Brain stem
What is the brain stem split into?
Mid brain
Pons Variolli
Medulla Oblongata
What is the peripheral nervous system split into?
12 pairs of cranial nerves
31 pairs of spinal nerves
Somatic Nervous System (voluntary and conscious)
Autonomic Nervous System (involuntary)
What is the autonomic nervous system split into?
Parasympathetic and sympathetic nervous system
What is meninges?
It is the three membranes that envelop the brain and spinal cord
What are the three membranes of the meninges?
Dura mater
Arachnoid Mater
Pia mater
What is the first layer of the brain?
Skull
What is the second layer of the brain?
Dura Mater
What is the third layer of the brain?
Arachnoid Mater
What is the third layer of the brain?
Pia Mater
What sits in between the membranes is the meninges?
Cerebrospinal Fluid (CSF)
What allows the central nervous system to contact the peripheral nervous system?
Efferent Neurons (Motor)
What allows the peripheral nervous system to contact the central nervous system?
Afferent Neurons (sensory)
What is the purpose of neurones?
Conduct nerve impulses
What is the neuroglia and it’s role?
It is a unique connective tissue that supports Neurons
How many more neuroglia is there compared to neurones?
10
What are dendrites?
An extension of the cell body
White matter of the nervous system
What is white matter?
Areas of the CNS mainly made up of myelinated axons
What is grey matter in the brain? (2)
Contains most of the neuronal cell bodies
Includes regions of the brain involved in muscle control and sensory perception such as seeing and hearing, memory, emotions, speech, decision making and self control
What is the cell body?
Formed of grey matter of the nervous system
Where is the cell body of a neurone found?
I’m the periphery of the brain and the centre of the spinal cord
What is the axon?
Extension of the cell body which can be either myelinated and unmyelinated
What do terminal boutons contain?
Contains neurotransmitters
What is myelin formed of?
Layers of Schwann cells plasma membrane wrapped around the axon
What is the purpose of myelin? (3)
Insulated the axon
Transmits nerve impulses faster
Prevents impulse from being lost
What is the purpose of Nodes of Ranvier? (2)
Assist in rapid transmission of nerve impulses
Allows impulses to jump along axon known as Saltatory Conduction
What happens at the terminal boutons and why does this occur?
The impulse is changed from electrical to chemical
This is because the nerves do not come into direct contact and therefore electricity can not be passed from one neurone to the next
What are neurotransmitters made of?
Nerve cells
Where are neurotransmitters stored?
Terminal boutons
What is the purpose of neurotransmitters?
Convey info from one neurone to the next
What is acetylcholine (Ach)?
One of the most abundant neurotransmitters in the body
What is the function of Ach?
Stimulates muscle contractions
Memory and cognition
Where is Ach found?
CNS and PNS
What is a nerve?
Numerous neurones that are collected into bundles
What is afferent? (3)
Sensory
Carry information from the body to the spinal cord
Can be automatic
What is efferent? (3)
Motor
Originate in the brain and spinal cord
Transmit impulses to the effector organs: muscles and glands
What are the four types of neuroglia?
Astorcytes
Oligodendrocytes
Ependymal cells
Microglia
What is the function of astrocytes?
Insulated parts of nerve cells that lack protective myelin sheath and helps oligodendrocytes create myelin sheath
What is the function of oligodendrocytes?
Provides support and insulation to axons in the CNS by forming myelin sheath
What is the function of ependymal cells?
Facilitated transport of hormones and other substances in the brain.
What is the function of microglia?
These are the primary immune cells of the CNS which responds to pathogens and injury migrating to sites of infection/injury where they destroy pathogens and remove damaged cells
What is sympathetic?
Fight or flight
What is parasympathetic?
Rest and digest
How many pairs of cranial nerves are there?
12
Where do cranial nerves originate from?
Nuclei within the brain
What is the vagus nerve?
It is the 10th cranial nerves which forms part of the parasympathetic nervous system
What are the key spinal nerves that you must know?
8 Cervical 12 Thoracic 5 Lumbar 5 Sacral 1 Coccygeal
What may be some responses from sympathetic nervous system?
Increase heart rate (increase blood flow)
Pupil dilation (see better)
Reduced saliva secretion
Faster breathing (more O2)
Reduce digestion and urine production
Vasodilation
What may be some responses from parasympathetic response?
Reduction in heart rate
Pull constriction
Increased saliva secretion
Vasoconstriction
Increase digestion and urine secretion
Reduce breathing