Chapter 4: Animal tissue Flashcards
(172 cards)
1
Q
Name and describe the 4 basic types of tissue found in animals
A
- Epithelial tissue
(forms the outer layer of the body and is the lining of many of the body cavities, where it has a protective function) - Connective tissue
(helps with the support and protection of organs and limbs and depending on the location in the body where it occurs, it may also connect separate organs or body parts) - Muscular tissue
(enables different forms of movement, both voluntary and involuntary) - Nervous tissue
(is responsible for carrying electrical and chemical signals/ impulses from the brain and central nervous system to the peripheral nervous system and vice versa)
2
Q
What kind of cells are epithelial tissues formed by and give examples
A
Cells that cover surfaces (eg. skin) and line tubes and cavities (eg. digestive organs, blood vessels, kidney tubules and airways)
3
Q
What kind of layers do epithelial tissues consist of
A
Usually a single layer of cells, however in certain cases there may be more than one layer
4
Q
Fill in the missing word
All epithelial tissues are ______ attached to the _____ layers of a _____
A
All epithelial tissues are free surfaces attached to the underlying layers of a basement membrane
5
Q
True or false
Epithelium can occur in glands where it is responsible for the secretion of minerals and enzymes
A
False
Epithelium can occur in glands where it is responsible for the secretion of hormones and enzymes
6
Q
Describe the cells that epithelium consists of
A
Cells that are typically tightly arranged with little between the material and virtually no intercellular spaces.
Epithelium occurs in one or more cell layers, simple epithelium (single layer) and stratified epithelium (more than one cell layer)
7
Q
What are the functions of epithelium
A
- Excretion
- Selective absorption
- Protection
- Trans cellular transport
- Sensors of extracellular conditions (intercellular communication)
8
Q
What is the epidermis
A
The epithelium that forms the outer layer of the skin
9
Q
What is the endothelium
A
The epithelium that covers the lining of blood vessels (arteries, veins, the inside of the heart)
Capillary vessels consist only of endothelium.
10
Q
What is the basal membrane
A
It provides the framework on which the epithelium appears
It is a thin layer of loosely associated fibres and cells found between the epithelium and connective tissue
11
Q
What are the cancers of the endothelium and mesothelium known as
A
sarcomas
12
Q
What are cancers of the other epithelium (excluding the endothelium and mesothelium)
A
carcinomas
13
Q
Name and describe the basis that epithelium can be classified under
A
- Shape of cells
They can be squamous (flattened cells), cuboidal, columnar/cylindrical, or transition cells - Stratification (more than one cell layer)
- Specialisation
Ceratinized and ciliated epithelium
14
Q
What are glands formed by
A
Glands are formed by folds of the epithelium
15
Q
Name and describe the glands formed by the epithelium
A
- Endocrine gland
They are vascular, ductless glands that release their secretions directly into the bloodstream. The blood transports the hormones to the target organs where they perform their functions eg. adrenal gland - Exocrine gland
They are glands that release their secretions via ducts to a body cavity or to the outside eg. salivary glands that secrete saliva into ducts that open in the mouth cavity
16
Q
Describe the sensory function of the epithelium
A
Ciliated epithelial cells may contain receptors that can detect specific chemical compounds (eg. nose), be sensitive to heat (eg. skin) and also detect mechanical vibrations (eg. ear)
17
Q
Define ceratinized tissue
A
hard, dead epithelial tissue for protection eg. outer layer of skin
18
Q
Define the ciliated epithelium
A
epithelial cells that contain many tiny hair like projections eg. mucous membrane of airways
19
Q
Describe the location of the squamous epithelium
A
- Forms the walls of the alveoli
- Lines the blood vessels on the inside
- The mouth, oesophagus and vagina are lined with squamous epithelium
20
Q
Describe the structure of the squamous epithelium
A
- Thin and flat cells that are elliptically shaped and lie on the basement membrane
- Simple squamous epithelium is one cell thick
- Stratified squamous epithelium consists of many layers of thin flat cells
21
Q
What are the functions of the squamous epithelium
A
- Diffusion of gasses takes place effectively through the thin squamous epithelium
- Endothelium lining blood vessels reduces friction of blood flow
- Cover and protect underlying tissue
22
Q
Describe the location of the cuboidal epithelium
A
- Occurs in glands such as the thyroid gland, salivary gland and the renal tubules
- Are also found in the skin of sweat glands and sebum glands
23
Q
Describe the structure of the cuboidal epithelium
A
It has a cubic shape
24
Q
What are the functions of the cuboidal epithelium
A
- Serve as a protective function against bacteria and the wearing away of certain organs by lining various structures
- Prevent water loss
- Secretes substances (secretory tissue), such as saliva through the salivary glands and sebum or oil through the sebum glands
- It excretes substances (secretions) such as urine and the waste products in sweat
25
Describe the location of the columnar epithelium
It occurs in the small intestine and stomach
| Villi structures which aid in absorption and consist of a single layer column epithelium
26
Describe the structure of the columnar epithelium
1. Elongated cells, nuclei located at base of the cell
2. Cells connected by tight conjunctions and receive their nutrients from the basement membrane
3. Goblet cells (unicellular glands) occur between the columnar cells
27
What is the function of the columnar epithelium
In the villi, the columnar epithelium is responsible for the absorption of digested food, water, vitamins and minerals
Goblet cells in the villi secrete mucus
28
Describe the location of the ciliated columnar epithelium
It is found in moist environments in the body and lines the nostrils, trachea, bronchi, fallopian tubes (ovaries) and sperm tubes
29
Describe the structure of the ciliated columnar epithelium
Consists of columnar epithelium that contain little finger like projections called cilia. The cilia beat in a wave like motion to move particles, mucus or other substances around the body.
Goblet cells that secrete mucus occur between the ciliated epithelial cells
30
What are the functions of the ciliated columnar epithelium
1. The combination of mucus and wave movements of the cilia allows the movement of substances in the various tubes
2. In the airways, dust particles and foreign matter are moved out and excreted to protect the lungs
3. In the fallopian tubes and sperm tubes, the wave movements of the cilia enable the movement of the egg cells and sperm cells
31
Columnar and cuboidal epithelial cells often turn into _______ cells that form ______
Columnar and cuboidal epithelial cells often turn into specialised gland cells that form multicellular glands
32
Describe the location of the glandular epithelium
Single cell glands (goblet cells) are found in the small intestine and airways
Multicellular glands such as salivary glands, the thyroid gland and lymph glands are formed by infoldings of the epithelium
33
Describe the structure of the glandular epithelium
Consists of cuboidal or columnar epithelium
Single cell glands consists of single, isolated gland cells eg. goblet cells distributed among other non glandular cells
Multicellular glands arise where epithelial tissue forms infoldings
34
What are the functions of the glandular epithelium
Goblet cells produce mucus that acts as a lubricant in the digestive tract to facilitate food movements and to keep the airways slimy and moist
Multicellular glands secrete enzymes that digest food as well as hormones, sweat, wax and saliva
35
Describe the nervous system
It is the body's main control and communication centre.
It allows for a continuous flow of information between the environment, the brain and all other organs of the body.
This allows orderly co ordination of all the body's functions and mechanisms.
36
How does the nervous system function
1. Sensory function
(sensory receptors)
Detects changes in the external and internal environments
2. Integrative function
(central nervous system)
Receives the information from the sensory receptors and coordinate a response to try restore the balance
3. Motor function
(effectors)
Receive instruction from the integrative neurons to bring about an appropriate response and will restore the balance eg. muscles or glands
37
What are the main functions of the nervous system
1. Gathers information using the senses
2. Transmits information to processing areas
3. Processes the information
4. Formulates a response to stimuli
5. Sends information back through the network to effector organs to execute a response
38
What are stimuli
Any physical or chemical changes in the environment that are capable of causing a response in an organism
It is a detectable change that will be received by a receptor and converted into an impulse, which will cause a response.
39
What are external example of stimuli
Changes in weather temperature
Changes in light
Dangerous circumstances
40
What are internal examples of stimuli
Changes in pH
Changes in blood pressure
Tension in muscles
41
What is a nerve impulse
A minute electrical signal (wave of depolarisation) which is caused by a stimulus and creates a difference in electrical charges across the membrane of a nerve fibre.
42
Name the main categories of stimuli
mechanical, chemical, thermal or electrical
43
# Fill in the missing words
The cell membrane surrounds the neurons that are more permeable to ______, giving them _____
The cell membrane surrounds the neurons that are more permeable to sodium and potassium ions, giving them conducting properties
44
Describe what happens when a stimulus occurs
A stimulus generates a nerve impulse, the nerve impulse is then carried along the nerve fibres to the target muscle etc. The stimulus is never carried along the nerve fibres
45
What do nerves do
They respond to stimuli and transmit impulses from one body organ to another
46
What is the basic unit of the nervous system
nerve cells or neurons
47
What are nerves
Collections of nerve fibres held together in connective tissue bundles
48
What do neurons do
They carry electrochemical messages (impulses) through the body
49
What are bundles of neurons called
They are called nerves in the PNS and tracts in the CNS
50
Describe the basic structure of a nerve
1. Consists of a large number of neuron fibres held together into bundles by connective tissue called perineurium
2. Inside the bundles the neurons are surrounded by delicate tissue called the endoneurium
3. The entire nerve is surrounded by a sheath of connective tissue, the epineurium
4. An artery and a vein occur between the bundles, to nourish the fibres and remove waste
51
What does nervous tissue consist of
neurons and neuroglia
52
Describe neuroglia
The protective and supportive cells (also known as glial cells)
Plays an important role in making myelin which will protect the neurons
53
Describe neurons
1. Basic cell units of nervous tissue
2. Carry electrochemical messages (impulses) throughout the body
3. Can function for a lifetime
4. Cant undergo mitosis (cant be replaced when destroyed)
5. Very high metabolic rate so they need a continuous supply of oxygen and glucose for survival
54
List and describe the classification of neurons
1. Sensory neurons
(afferent neurons, unipolar)
Receive information and sends impulses to the spinal chord and brain
2. Motor neurons
(efferent neurons, multipolar)
Conduct impulses from the spinal chord and brain to muscles and glands
3. Interneurons
(connective neurons, multipolar)
Found throughout the brain and spinal chord that relay impulses from the sensory neurons to motor neurons
55
Briefly describe the structure of a neuron
The cell body is made up of a cell membrane, cytoplasm, cell organelles and a nucleus.
In addition they have long thin processes (fibres of cytoplasm) that extend from the cell body and allow nerve impulses to be carried in long distances.
The fibres in a typical neuron are dendrites and axons
56
Describe what dendrites are
1. Afferent outgrowths
2. Always carry the impulse to the cell body
3. They are short, tapering processes that branch extensively to provide a large surface area to receive signals from other neurons
57
Describe what axons are
1. Efferent outgrowths
2. Always carries the impulse away from the cell body
3. Each neuron has a single axon although certain axons may give off branches along their length
4. An axon usually branches extensively at its end to form terminal branches
58
What is another word for sensory neurons
unipolar neurons
59
Describe unipolar neurons
1. They have one axon and one dendrite branching off in opposite directions from the cell body
2. These cells pass signals from the outside of the human body, such as touch, along to the central nervous system
60
Describe multipolar neurons
1. Have one axon and many dendrite branches
| 2. They carry signals from the central nervous system to other parts of the body such as the muscles and glands
61
Describe reflex actions
It is a rapid, involuntary (automatic) response of an effector to a stimulus received by a receptor
It initially takes place subconsciously. The brain only becomes aware of it after the effector organ has already responded.
They have a protective function as they allow the body to react very rapidly to harmful stimuli and this protects the body from further injuries
62
Where do reflex centres that control protective reflexes mainly occur
They mainly occur in the spinal chord and include the withdrawal of the hand or foot away from painful stimulus and the knee jerk reflex
63
What are reflexes such as coughing, sneezing and blinking controlled by
The Medulla Oblongata in the brain
64
What are innate reflexes
They are natural/ unconditioned reflexes like coughing, sneezing and blinking. We are born with them and they occur automatically in response to a stimulus
65
What are acquired reflexes
They are conditioned/ learned reflexes that are learnt through repetition such as walking, writing and reading
66
What categories can be used to classify reflexes
1. Somatic reflexes
(somatic nervous system)
involves skeletal muscles
2. Autonomic reflexes
(autonomic nervous system)
active smooth muscles or cardiac muscles and glands
67
What is the difference between a reflex action and a reflex arc
A reflex action is the response and a reflex arc is the pathway of that response
68
Give the definition of a reflex arc
It is the neural pathway along which nerve impulses are transmitted from a receptor to an effector to bring about a response to a stimulus during a reflex action
69
What is the functional unit of the nervous system
the reflex arc
70
What is the structural unit of the nervous system
neurons
71
Name and describe the parts of the reflex arc
1. Receptor: detects a stimulus and converts it into a nerve impulse
2. Sensory neuron: conducts the nerve impulse from the receptor to the grey matter of the CNS
3. Interneuron: serves as the reflex centre in the grey matter of the spinal chord and conducts the nerve impulses from the sensory neuron to the motor neuron
4. Motor neuron: conducts the nerve impulses from the CNS to the effector
5. Effector: muscle or gland that responds to the original stimulus
72
# Fill in the missing word
Nerve impulses are also conducted from the spinal cord in the ascending tracts, to the _______ of the brain or the _____ where the sensation is interpreted as pain
Nerve impulses are also conducted from the spinal cord in the ascending tracts, to the cerebral cortex of the brain or the parietal lobe where the sensation is interpreted as pain
73
What is the significance of the reflex arc
1. The reflex action is taken very rapidly to protect the hands, feet etc. from further injury
2. It prevents overload of higher cognitive centres of the brain as it is not a conscious response
74
Neurons join together to form a ________ system throughout the body
Neurons join together to form a continuous conduction system throughout the body
75
True or false
| Successive neurons are not in direct contact with each other, they are separated by a small gap
True
76
What is the gap between successive neurons called
the synaptic cleft
77
What is the physiological (functional) connection that develops between successive neurons
the synapse
78
Where do nerve impulses move
Nerve impulses move along the axon to the synaptic knobs of the terminal branches
79
Describe synaptic knobs
In each synaptic knob there are multiple synaptic vesicles filled with neurotransmitters (acetylcholine, norepinephrine, epinephrine or seratonin)
Mitochondria are also found which provide energy for transmission.
The synaptic cleft is bordered by a pre-synaptic membrane on the axon side of the synaptic knob and by a post-synaptic membrane on the dendrite side
80
What happens when the synaptic vesicles on the surface of synaptic knobs burst
The nerve impulses cause the synaptic vesicles to burst on the surface and release the neurotransmitters into the cleft
The neurotransmitters move across the cleft and attach to the post synaptic membrane
It acts as a trigger for electrical signals that, via the dendrite, act as nerve impulses to the cell body of the next neuron.
81
Why are synapses important
1. They ensure that the flow of impulses occurs in only one direction (because the vesicles containing neurotransmitters occur only in the axon terminal buds)
2. They allow the spread of impulses because, when an impulse reaches the synapse it stimulates several post synaptic neurons and transports the impulse to different destinations
3. They also continuously filter out all unnecessary or unimportant stimuli. If a neuron is constantly stimulated, the synapses will not be able to renew its supply of transmitters quick enough
82
What do muscles consist of
muscle fibres, connective tissue, nervous tissue and vascular tissue
83
What are the 3 main types of muscles
Smooth muscles, skeletal/voluntary muscles and cardiac muscle
84
Describe the locality of skeletal/voluntary/striated muscles
The muscles that join the tendons to parts of the skeleton
85
Describe the structure of skeletal/voluntary/striated muscles
1. They consist of numerous muscle fibres joined in bundles by a sheath of connective tissue known as the perimecium
2. Each bundle of fibres, surrounded by a perimecium, is known as a fascilulus
3. Numerous fassiculi are surrounded by epimeicium
4. Each muscle fibre (2.5 mm long) is surrounded by a tough sheath, the sarcolemma. The ground tissue of the muscle fibre (cytoplasm) inside the sarcolemma is called the sarcoplasm
5. Many oval nuclei occur in the sarcoplasm
6. Each muscle fibre consists of a number of myofibrils that form the contractile units of the muscle
7. The muscles have alternating dark and light bands (striata), that give voluntary muscles their striated appearance
8. Nerve fibres are attached to the sarcolemma. The nerve fibres conduct messages from the brain to muscles to initiate the contraction or relaxation of the muscle fibres , which bring about movement. Blood capillaries are found among muscle fibres to assist in the exchange off nutrients, gases and waste products
86
Describe the locality of smooth muscles
Occurs in the walls of organs like the digestive canal, blood vessels, the bladder, uterus and in the eye
87
Describe the structure of smooth muscles
1. Consists of spindle shaped cells, each with a central nucleus- contains sarcoplasm surrounded by a sarcolemma
2. Does not have a striated appearance
88
Describe the functions of smooth muscles
1. Is under control of the autonomic nervous system and controls involuntary muscles
2. Causes rhythmic contractions and relaxation in the digestive canal, called peristalsis. It pushes food on along the canal
89
Describe the location of cardiac muscle
It is only found on the walls of the heart
90
Describe the structure of cardiac muscle
1. Consists of branched fibres with nuclei
2. Among the muscle fibres connective tissue with blood vessels and nerves occur
3. The branched fibres are joined by small muscle bridges(intercalated discs) to form a continuous muscle mass (sincytium)
4. Cardiac muscle is also striated but as conspicuous as skeletal muscle
4. Cardiac muscle continuously contracts and relaxes and is involuntary
5. Cardiac muscle is responsible for the pump action of the heart
91
What are the functions of muscles overall
1. Muscle fibres contain contractile filaments (myofibrils) that can exert power and cause movement
2. That can lead to the movement of limbs, the entire organism or organs in the organism
3. The contraction of the cardiac and smooth muscles is involuntary and is necessary for the survival function of the body eg. the beating of the heart and for the peristaltic movements of the intestine to transport food through the digestive system
4. The contraction of the voluntary muscles is delicately controlled. That enables accurate movements eg. the movement of the eye and even that of the bigger limbs
92
What are the types of connective tissue
1. Proper connective tissue (aerolar and dense)
2. Supporting connective tissue (bones and cartilage)
3. Liquid connective tissue (blood)
93
What are the types of connective tissue
1. Proper connective tissue (areolar and dense)
2. Supporting connective tissue (bones and cartilage)
3. Liquid connective tissue (blood)
94
What are the most important cells of connective tissue and decribe them
The most important cells of connective tissue are fibroblasts, that inter alia synthesize fibres. Almost all types of connective tissue contains fibres. Fibroblasts are mobile cells, can undergo mitosis and can synthesize all types of connective tissue.
95
What are the most important cells of connective tissue and describe them
The most important cells of connective tissue are fibroblasts, that inter alia synthesize fibres. Almost all types of connective tissue contains fibres. Fibroblasts are mobile cells, can undergo mitosis and can synthesize all types of connective tissue.
96
What other substances can also be found in some types of connective tissue
Macrophages, lymphocytes and sometimes leucocytes
| Some types of connective tissue contain specialised cells that are not found in other connective tissue
97
Describe the matrix of connective tissue
It has a high concentration of cells and fibres are relatively less dense
98
What are the organic parts of connective tissue
The protein fibres are collagen, elastic or reticular fibres
99
What does collagen do in connective tissue
It gives sturdiness and strength and prevents that connective tissue separates from surrounding tissues
100
What do elastic fibres consist of
They consist of the protein elastin, that can stretch one or one and a half times their length and return to their original length and shape.
101
What do elastic fibres do
They make the connective tissue pliable
102
What do reticular fibres consist of
They consist of a network of thin collagen fibres that give support to the tissue and organs to which it is attached
103
Describe the locality of areolar connective tissue
Surrounds blood vessels and organs
104
Describe the structure of areolar connective tissue
1. It contains parts of all other types of connective tissue and has the consistency of a ball of cotton pulled apart
2. Collagen fibres are wide and elastic fibres are thin
3. The cavities among the cells and fibres are filled with the matrix
105
What are the functions of areolar connective tissue
1. Joins organs and supports cell and tissue structures
2. Is elastic and allows movement
3. Assists the immune system in the defence against diseases and the healing of wounds
4. Anchors epithelium
106
Describe the locality of dense fibrous connective tissue
1. Occurs in tendons and ligaments
| 2. Forms part of the skin
107
Describe the structure of dense fibrous connective tissue
1. Contains large amounts of collagen fibres and relatively few cells or little matrix
2. May have a regular appearance with fibres that are arranged in parallel, or an irregular appearance. Irregular fibrous connective tissue is found in localities where there is tension in the tissue eg. the dermis of the skin
108
What are the functions of dense fibrous connective tissue
1. Tendons attach muscles to one another and attach muscles to bone
2. Ligaments attach bone to one another
109
Describe the location of cartilage
1. Skelton of sharks
2. Whole skeleton of foetus
3. Hyaline cartilage covers ends of long bones and in joints, between the ribs and breast bone, in the larynx, bronchi and trachea
4. Elastic cartilage in the outer ear and part of the larynx
5. Fibrous cartilage in the discs between vertebrae and in knee joint (prevents friction)
110
Describe the structure of cartilage
1. Cartilage is connective tissue with much matrix and a variable amount of fibres
2. Chondrocytes produce the matrix and fibres. They are found in fluid filled cavities in the cartilage, the lacunae. Hyaline cartilage has few collagen and elastic fibres, milky/clear matrix and the lacunae are randomly spread
3. Elastic cartilage has large amounts of elastic fibres that make it flexible
4. Fibrous cartilage has a large amount of collagen that makes it very strong
111
What are the functions of cartilage
1. Hyaline cartilage on the ends of long bones reduces friction and serves as a cushion for the articulation of these bones(joints) and keeps air passages open
2. Elastic cartilage gives shape and pliability
3. Fibrous cartilage serves as a shock absorber between vertebrae and deepens the articular cavities in some joints to prevent injuries
112
What type of matrix material does bone contain
organic and inorganic matrix
113
What does inorganic matrix consist of
mineral salts, mainly calcium salts that make bone hard
114
What happens when there is insufficient organic matrix in the bone tissue
The bones may soften or bend
115
What type of cells does bone tissue contain
osteoblasts, osteocytes and osteoclasts
116
What do osteoblasts do
They produce new bone tissue for growth and repair.
Osteoblasts also deposit bone material in the matrix and the matrix surrounds it and keeps it alive, but in a reduced metabolic state
117
What are osteocytes
Living cells with a high metabolic rate. They are found in lacunae in bone tissue
118
What do osteoclasts do
They break bone down for repair and release stored calcium
119
Where do osteoclasts usually occur
The surface of bone tissue
120
What are the types of bone tissue
Compact bone and spongy bone
121
Where can compact bone and spongy bone be found
Compact bone is found in the shafts (diaphysis) of long bones and the surface of flat bones, while spongy bone is found at the ends (epiphysis) of long bones
122
What are the sub units of compact bone
osteons
123
What is in the centre of each osteon
The haversian canal which contains a blood vessel, nerve and lymph duct
124
Fil in the missing words
There are _____ called lamellae around the haversian canal. In the lamellae, small cavities known as the _____ are found. ____ occur in the lacunae.
There are concentric layers, called lamellae around the haversian canal. In the lamellae, small cavities known as the lacunae are found. Osteocytes occur in the lacunae.
125
What is periosteum
Connective tissue surrounding bone
126
With what are osteocytes connected
Osteocytes are connected with one another as well as the haversian canal and periosteum by tiny canals such as canaliculi
127
What do osteons form
Osteons form haversian canals, that together form bone tissue
128
What does spongy bone consist of
Spongy bone consists of small platelets, know as trabeculae. They support and strengthen spongy bone
129
What is spongy bone filled with and how can aging affect it
Spongy bone is filled with red bone marrow and contains red blood cells in different stages of development. With age these platelets may break and make bone less resistant to injuries
130
What are the functions of bone tissue
1. Bone tissue forms the internal skeleton of vertebrae and gives structure and sturdiness to these animals as well as places for attachment of muscles
2. It forms a system of joints and levers to enable movement
3. Bones protect delicate organs eg. the skull that protects the brain and bones of the ribcage that protect the heart and lungs
4. Red bone marrow in spongy bone produces red blood cells
131
True or false
Adipose/ fat tissue is not regarded as connective tissue, although it contains fibroblasts
False
Adipose/ fat tissue is regarded as connective tissue, although it does not contain fibroblasts or a real matrix, it contains only a few fibres.
132
What does adipose tissue consist of and what does it do
Adipose tissue consists of adipocytes (fat cells) that collect and store fat in the form of triglycerides for energy metabolism when needed
133
What functions can adipose tissue have in the body
Adipose tissue serves as insulation to maintain body temperature of endothermic animals.
It also protects certain organs against injuries, like the eyes and the kidneys
134
How does adipose tissue look under a light microscope and why does it look that way
Under the light microscope adipose tissue looks empty, because the techniques of preparation for microscopy extract the cells from the fat
135
Why can blood be regarded as connective tissue
It has a matrix
136
What are the living cells in the blood and which is more abundant
Red blood cells (erythrocytes) and white blood cells (leucocytes)
137
Where are red blood cells made
in the red bone marrow
138
Describe the structure of red blood cells
They do not have a nucleus and are biconcave in shape
139
How does the shape of red blood cells benefit them
Their biconcave shape makes them flexible so that they can squeeze through narrow capillaries
It also gives them a bigger surface to volume ratio so that they can absorb and release gasses faster
140
How long is the lifespan of red blood cells
120 days
141
What protein do red blood cells contain, describe this protein
Haemoglobin, it contains a pigment known as heme that has an iron (Fe) at its centre that combines with oxygen. Haemoglobin releases oxygen as required and takes up carbon dioxide
142
How do red blood cells assist gaseous exchange
Red blood cells transport oxygen from the lungs to the tissues and returns carbon dioxide from the tissues to the lungs
143
What are leucocytes and where are they produced
White blood corpuscles(cells), they are produced by the red bone marrow, spleen and lymph glands
144
What are leukocytes
Leukocytes are the most important white blood cells found in peripheral blood(blood in the blood vessels)
145
What colour do white blood cells have
They are colourless
146
How long is the lifespan of white blood cells
a few days/hours
147
Describe the shape of white blood cells
They have nuclei and the shape of the nucleus can be used to differentiate between the different types
148
What types of white blood cells are there
lymphocytes, neutrophils, monocytes, macrophages, eosinophils and basophils
149
What are the 2 classifications of white blood cells
granular and agranular
150
What do lymphocytes do
They protect the body against foreign antigens and other foreign substances.
The B lymphocytes produce antibodies that protect the body against antigens
151
What are neutrophils
Phagocytic cells that take in and destroy microorganisms like bacteria that enter the body, early in immune control
152
What do monocytes do
They give rise to phagocytic macrophages that remove dead and damaged cells in the body
153
What do eosinophils and basophils do
They assist with inflammatory reactions in the body
154
Give another word for platelets
thrombocytes
155
Where are platelets produced
In the bone marrow and they are fragments of bone marrow cells
156
Do thrombocytes have a nucleus
They have no nuclei
157
What do platelets do
They assist in the clotting of blood and prevent excessive bleeding
158
What is plasma
Th pale yellow component of blood that allows the rest of the components of blood to float in suspension
159
How much of the blood is plasma
55%
160
What does plasma contain
dissolved proteins, hormones, urea and carbon dioxide
161
What is the function of plasma
The main functions are to transport nutrients, cells and metabolic waste products and maintain blood volume
162
What is the ABO system
The main blood groups; A, B, AB and O
163
What do erythrocytes have on their surface
They carry specific antigens on their surfaces
164
Where are antibodies found
In the blood plasma
165
What happens when agglutination occurs in the erythrocyte
The antibodies in the blood plasma cause agglutination if the same type of antigen occurs in the red blood cell
166
What happens if two different blood types are mixed and agglutination occurs
The two blood types are incomplete
167
What does Rh+ or Rh- mean
It is the rhesus factor indicating that a persons blood has the Rh protein and negative means the protein is absent
168
What determines ABO and Rh
The genetic combination from the mother and father
169
Which is dominant in Rh
the positive is dominant
170
What happens when blood from different blood groups are mixed
Agglutination can occur if the blood groups are incomplete and can even cause death
171
What is the universal donor
Blood group O, it is compatible with all other blood groups because it contains no antigens
172
What is the universal recipient
Blood group AB, because it contains no antibodies and blood group A and B can be donated safely to them
