Blood Is a Connective Tissue, and That Is Not a Mistake
Learn the types of epithelial tissue and where each is found, how connective tissues such as blood, bone and cartilage support the body, how the three muscle types differ, and what nervous tissue does.
How can blood be a connective tissue?
Because connective tissue is defined by its structure, not by whether it looks like a rope.
A connective tissue is one whose cells are loosely spaced in an intercellular matrix. In bone that matrix is hard, in cartilage it is firm and flexible, and in blood it is a fluid called plasma. The cells — red cells, white cells, platelets — float in it, widely separated.
So blood fits the definition exactly. And it connects in the most literal sense available: it links every tissue in the body to every other, carrying oxygen from the lungs to the toes and hormones from a gland to whatever organ they act on.
That is the pattern in animal tissues — the name describes the arrangement of cells and matrix, not the everyday meaning of the word. This page covers the second part of the CBSE Class 9 Science chapter on tissues.
A connective tissue is one whose cells are loosely spaced in an intercellular matrix. In bone that matrix is hard, in cartilage it is firm and flexible, and in blood it is a fluid called plasma. The cells — red cells, white cells, platelets — float in it, widely separated.
So blood fits the definition exactly. And it connects in the most literal sense available: it links every tissue in the body to every other, carrying oxygen from the lungs to the toes and hormones from a gland to whatever organ they act on.
That is the pattern in animal tissues — the name describes the arrangement of cells and matrix, not the everyday meaning of the word. This page covers the second part of the CBSE Class 9 Science chapter on tissues.
What are the types of epithelial tissue and where is each found?
Epithelium is the covering and lining tissue, with cells packed tightly together and almost no intercellular material. It rests on a basement membrane.
Its general job is to form a barrier between two environments and to control what crosses it — so wherever one region of the body meets another, there is epithelium.
Squamous epithelium — flat, thin cells like tiles.
- Lining of the mouth, oesophagus, blood vessels and the alveoli of the lungs
- Thin, so substances diffuse across easily — which is exactly what alveoli need
- Stratified squamous epithelium is many layers thick and forms the skin, where wear is heavy
Cuboidal epithelium — cube-shaped cells.
- Kidney tubules and the ducts of salivary glands
- Provides mechanical support and carries out absorption and secretion
Columnar epithelium — tall, pillar-shaped cells.
- Lining of the stomach and intestine
- Suited to absorption and secretion, because a tall cell has room for the machinery
- Ciliated columnar epithelium carries hair-like cilia and lines the respiratory tract and the fallopian tube, where it sweeps mucus or moves an egg along
Glandular epithelium — cells modified to secrete, forming glands.
Everyday evidence. The lining scraped gently from the inside of your cheek, the standard slide in a school laboratory, is squamous epithelium. Dust trapped in mucus and moved up out of the windpipe is the work of ciliated columnar cells.
Structure follows function here more clearly than anywhere else. Where the job is diffusion, the cells are as thin as possible — squamous, in the alveoli. Where the job is absorption, the cells are tall — columnar, in the intestine. Where the job is resisting wear, the cells are stacked in layers — stratified squamous, in the skin. Given a location, you can usually predict the type.
Epithelium is the opposite of connective tissue. Its cells are crowded with almost no matrix; connective tissue cells are sparse in abundant matrix. Holding those two extremes in mind makes both easier to remember.
Its general job is to form a barrier between two environments and to control what crosses it — so wherever one region of the body meets another, there is epithelium.
Squamous epithelium — flat, thin cells like tiles.
- Lining of the mouth, oesophagus, blood vessels and the alveoli of the lungs
- Thin, so substances diffuse across easily — which is exactly what alveoli need
- Stratified squamous epithelium is many layers thick and forms the skin, where wear is heavy
Cuboidal epithelium — cube-shaped cells.
- Kidney tubules and the ducts of salivary glands
- Provides mechanical support and carries out absorption and secretion
Columnar epithelium — tall, pillar-shaped cells.
- Lining of the stomach and intestine
- Suited to absorption and secretion, because a tall cell has room for the machinery
- Ciliated columnar epithelium carries hair-like cilia and lines the respiratory tract and the fallopian tube, where it sweeps mucus or moves an egg along
Glandular epithelium — cells modified to secrete, forming glands.
Everyday evidence. The lining scraped gently from the inside of your cheek, the standard slide in a school laboratory, is squamous epithelium. Dust trapped in mucus and moved up out of the windpipe is the work of ciliated columnar cells.
Structure follows function here more clearly than anywhere else. Where the job is diffusion, the cells are as thin as possible — squamous, in the alveoli. Where the job is absorption, the cells are tall — columnar, in the intestine. Where the job is resisting wear, the cells are stacked in layers — stratified squamous, in the skin. Given a location, you can usually predict the type.
Epithelium is the opposite of connective tissue. Its cells are crowded with almost no matrix; connective tissue cells are sparse in abundant matrix. Holding those two extremes in mind makes both easier to remember.
How do connective tissues support and connect the body?
By surrounding sparse cells with a matrix whose properties do the work — hard, flexible, fibrous or fluid.
Blood — a fluid matrix called plasma, holding red blood cells, white blood cells and platelets.
- Transports oxygen, carbon dioxide, digested food, wastes and hormones
- The transport tissue of the body, which is how it connects
Bone — a hard matrix rich in calcium and phosphorus compounds.
- Forms the framework of the body, protects delicate organs, and anchors muscles
- Strong and largely inflexible
Cartilage — a solid but flexible matrix of proteins and sugars, with widely spaced cells.
- Smooths the surfaces at joints so bones move over each other easily
- Found in the nose, the outer ear, the trachea and the larynx
Ligament — connects bone to bone at a joint. Very elastic and strong, with little matrix.
Tendon — connects muscle to bone. Fibrous, with great strength but limited flexibility.
Areolar tissue — fills the space inside organs, supports internal organs, and helps repair tissue after injury.
Adipose tissue — stores fat below the skin and between internal organs, and acts as an insulator.
Everyday evidence. The bendable tip of your nose and the rim of your outer ear are cartilage, which is why they spring back when pressed while a finger bone does not. A sprained ankle is a stretched or torn ligament. The thick cord you can feel at the back of your heel is a tendon, joining calf muscle to heel bone.
Ligament against tendon is the classic swap. Fix it by the word muscle: a tendon is the one that involves a muscle, joining muscle to bone. A ligament joins two bones and no muscle at all. Getting this pair the wrong way round is the most frequently penalised error in the chapter.
Why cartilage and bone differ at a joint. Bone provides the rigid lever, but two rigid surfaces rubbing directly would grind. Cartilage covers the ends, giving a smooth flexible surface — which is why worn cartilage makes a joint painful even when the bones are intact.
Blood — a fluid matrix called plasma, holding red blood cells, white blood cells and platelets.
- Transports oxygen, carbon dioxide, digested food, wastes and hormones
- The transport tissue of the body, which is how it connects
Bone — a hard matrix rich in calcium and phosphorus compounds.
- Forms the framework of the body, protects delicate organs, and anchors muscles
- Strong and largely inflexible
Cartilage — a solid but flexible matrix of proteins and sugars, with widely spaced cells.
- Smooths the surfaces at joints so bones move over each other easily
- Found in the nose, the outer ear, the trachea and the larynx
Ligament — connects bone to bone at a joint. Very elastic and strong, with little matrix.
Tendon — connects muscle to bone. Fibrous, with great strength but limited flexibility.
Areolar tissue — fills the space inside organs, supports internal organs, and helps repair tissue after injury.
Adipose tissue — stores fat below the skin and between internal organs, and acts as an insulator.
Everyday evidence. The bendable tip of your nose and the rim of your outer ear are cartilage, which is why they spring back when pressed while a finger bone does not. A sprained ankle is a stretched or torn ligament. The thick cord you can feel at the back of your heel is a tendon, joining calf muscle to heel bone.
Ligament against tendon is the classic swap. Fix it by the word muscle: a tendon is the one that involves a muscle, joining muscle to bone. A ligament joins two bones and no muscle at all. Getting this pair the wrong way round is the most frequently penalised error in the chapter.
Why cartilage and bone differ at a joint. Bone provides the rigid lever, but two rigid surfaces rubbing directly would grind. Cartilage covers the ends, giving a smooth flexible surface — which is why worn cartilage makes a joint painful even when the bones are intact.
How do striated, smooth and cardiac muscle differ?
By their shape, their location, and whether you can control them — and one of the three breaks the pattern you would expect.
Striated muscle — also called skeletal or voluntary muscle.
- Long, cylindrical, unbranched fibres
- Multinucleate — many nuclei in one fibre
- Shows light and dark bands, which is what striated means
- Attached to bones, and moves them
- Voluntary: under your conscious control
- Tires relatively quickly
Smooth muscle — also called unstriated or involuntary muscle.
- Spindle-shaped cells, pointed at both ends
- A single nucleus per cell
- No striations
- In the walls of the stomach, intestine, blood vessels and the iris of the eye
- Involuntary
Cardiac muscle — the muscle of the heart.
- Cylindrical but branched
- Uninucleate
- Striated
- Found only in the heart
- Involuntary, and contracts rhythmically throughout life without tiring
Everyday evidence. You decide to raise your arm, and it rises — striated muscle. You cannot decide to stop food moving along your intestine, nor widen your own blood vessels by choosing to — smooth muscle. Your heart has been beating without a single instruction from you since before you were born — cardiac muscle.
Cardiac muscle is the exception that questions are built on. It is striated like skeletal muscle but involuntary like smooth muscle. So striated therefore voluntary is a false rule, and any question pairing those two words is probably testing this case. Learn cardiac muscle as the one that takes a feature from each of the other two.
The other feature worth separating. Multinucleate belongs to striated muscle alone; smooth and cardiac cells each have one nucleus. And branched belongs to cardiac muscle alone.
Muscle can only pull. A muscle shortens when it contracts, and shortening pulls. It cannot push, which is why muscles are arranged in opposing pairs — a point taken up in the next part of this chapter.
Striated muscle — also called skeletal or voluntary muscle.
- Long, cylindrical, unbranched fibres
- Multinucleate — many nuclei in one fibre
- Shows light and dark bands, which is what striated means
- Attached to bones, and moves them
- Voluntary: under your conscious control
- Tires relatively quickly
Smooth muscle — also called unstriated or involuntary muscle.
- Spindle-shaped cells, pointed at both ends
- A single nucleus per cell
- No striations
- In the walls of the stomach, intestine, blood vessels and the iris of the eye
- Involuntary
Cardiac muscle — the muscle of the heart.
- Cylindrical but branched
- Uninucleate
- Striated
- Found only in the heart
- Involuntary, and contracts rhythmically throughout life without tiring
Everyday evidence. You decide to raise your arm, and it rises — striated muscle. You cannot decide to stop food moving along your intestine, nor widen your own blood vessels by choosing to — smooth muscle. Your heart has been beating without a single instruction from you since before you were born — cardiac muscle.
Cardiac muscle is the exception that questions are built on. It is striated like skeletal muscle but involuntary like smooth muscle. So striated therefore voluntary is a false rule, and any question pairing those two words is probably testing this case. Learn cardiac muscle as the one that takes a feature from each of the other two.
The other feature worth separating. Multinucleate belongs to striated muscle alone; smooth and cardiac cells each have one nucleus. And branched belongs to cardiac muscle alone.
Muscle can only pull. A muscle shortens when it contracts, and shortening pulls. It cannot push, which is why muscles are arranged in opposing pairs — a point taken up in the next part of this chapter.
How does nervous tissue let the body sense and respond?
By carrying electrical impulses along long cells, far faster than any substance could diffuse.
Nervous tissue is made of neurons, or nerve cells. A neuron has three parts:
- Cell body (cyton) — contains the nucleus and cytoplasm, and receives incoming signals
- Dendrites — short branched projections from the cell body, which pick up stimuli
- Axon — a single long fibre carrying the impulse away from the cell body, sometimes over a metre long in a human
Nervous tissue makes up the brain, the spinal cord and the nerves that run through the body.
What it achieves, in three steps. A stimulus is detected, an impulse is conducted rapidly to the brain or spinal cord, and a response is triggered — usually a muscle contracting or a gland secreting.
Everyday evidence. Touch something hot and your hand pulls away before you have consciously decided to move it. The signal travelled from skin to spinal cord and back to the muscle so fast that the conscious thought arrived afterwards.
Why speed requires a special tissue. A chemical message drifting by diffusion would take far too long to cross a body. An impulse travelling along an axon covers the distance in a small fraction of a second, and that is the whole reason a large fast-moving animal is possible at all.
Nervous and muscle tissue work as a pair. Nervous tissue decides and signals; muscle tissue acts. Neither is any use alone — a nerve impulse with nothing to contract produces no movement, and a muscle with no signal never contracts. Almost every rapid response in the body is these two tissues in sequence.
A neuron is a cell, not an organ. Students sometimes describe the axon as a nerve. A nerve is a bundle of many axons wrapped together, like a cable containing many wires — so a nerve is made of neurons, and not the other way round.
Nervous tissue is why plants have none of this. As the previous part of the chapter noted, a rooted organism does not need to detect and escape danger in a fraction of a second, so plants have no nervous tissue and no muscle — the two tissues that cost an animal the most energy are exactly the two a plant does without.
Nervous tissue is made of neurons, or nerve cells. A neuron has three parts:
- Cell body (cyton) — contains the nucleus and cytoplasm, and receives incoming signals
- Dendrites — short branched projections from the cell body, which pick up stimuli
- Axon — a single long fibre carrying the impulse away from the cell body, sometimes over a metre long in a human
Nervous tissue makes up the brain, the spinal cord and the nerves that run through the body.
What it achieves, in three steps. A stimulus is detected, an impulse is conducted rapidly to the brain or spinal cord, and a response is triggered — usually a muscle contracting or a gland secreting.
Everyday evidence. Touch something hot and your hand pulls away before you have consciously decided to move it. The signal travelled from skin to spinal cord and back to the muscle so fast that the conscious thought arrived afterwards.
Why speed requires a special tissue. A chemical message drifting by diffusion would take far too long to cross a body. An impulse travelling along an axon covers the distance in a small fraction of a second, and that is the whole reason a large fast-moving animal is possible at all.
Nervous and muscle tissue work as a pair. Nervous tissue decides and signals; muscle tissue acts. Neither is any use alone — a nerve impulse with nothing to contract produces no movement, and a muscle with no signal never contracts. Almost every rapid response in the body is these two tissues in sequence.
A neuron is a cell, not an organ. Students sometimes describe the axon as a nerve. A nerve is a bundle of many axons wrapped together, like a cable containing many wires — so a nerve is made of neurons, and not the other way round.
Nervous tissue is why plants have none of this. As the previous part of the chapter noted, a rooted organism does not need to detect and escape danger in a fraction of a second, so plants have no nervous tissue and no muscle — the two tissues that cost an animal the most energy are exactly the two a plant does without.
Exam tip
Exam tip: give location and structure, not function alone
Answer with structure, location and function — most questions here carry marks for all three, and naming the tissue alone earns the fewest.
Epithelium has cells tightly packed with almost no matrix; connective tissue has cells sparse in abundant matrix. These are opposites, and remembering that fixes both.
Match epithelium to its job: squamous where diffusion happens (alveoli), columnar where absorption happens (intestine), cuboidal in kidney tubules, ciliated columnar where something must be swept along, stratified squamous where wear is heavy (skin).
Tendon joins muscle to bone; ligament joins bone to bone. Remember that tendon is the one with a muscle in it.
Name the matrix: blood fluid, bone hard with calcium and phosphorus, cartilage solid but flexible.
Cardiac muscle is striated but involuntary, and branched — it is the exception, so expect it to be asked.
Only striated muscle is multinucleate. Smooth is spindle-shaped with one nucleus.
A neuron has cyton, dendrites (receive) and a single axon (carry away). A nerve is a bundle of axons, not a single cell.
Label diagrams — neuron and muscle-fibre diagrams are standard, and the labels themselves carry the marks.
And when a question gives a location, name the tissue and say why that structure suits that place.
Epithelium has cells tightly packed with almost no matrix; connective tissue has cells sparse in abundant matrix. These are opposites, and remembering that fixes both.
Match epithelium to its job: squamous where diffusion happens (alveoli), columnar where absorption happens (intestine), cuboidal in kidney tubules, ciliated columnar where something must be swept along, stratified squamous where wear is heavy (skin).
Tendon joins muscle to bone; ligament joins bone to bone. Remember that tendon is the one with a muscle in it.
Name the matrix: blood fluid, bone hard with calcium and phosphorus, cartilage solid but flexible.
Cardiac muscle is striated but involuntary, and branched — it is the exception, so expect it to be asked.
Only striated muscle is multinucleate. Smooth is spindle-shaped with one nucleus.
A neuron has cyton, dendrites (receive) and a single axon (carry away). A nerve is a bundle of axons, not a single cell.
Label diagrams — neuron and muscle-fibre diagrams are standard, and the labels themselves carry the marks.
And when a question gives a location, name the tissue and say why that structure suits that place.
Did you know
The muscle that never gets to rest
Hold your arm straight out and wait. Within a couple of minutes it aches, and before long you cannot hold it any longer. Striated muscle tires.
Your heart has been contracting and relaxing since long before you were born, without one break, and it does not tire at all. Cardiac muscle is built differently for exactly that reason, and three of its features are what make the difference.
Its cells are branched, and the branches interlock with neighbours, so a contraction spreads through the whole wall as a coordinated squeeze rather than as separate fibres pulling. A heart whose regions contracted independently would not pump.
Its contraction is involuntary and rhythmic, generated within the heart itself rather than commanded by the brain. That is why a heart continues beating when its nerve supply is interrupted, and why you cannot stop it by deciding to.
And its cells are exceptionally rich in mitochondria — the organelle from the previous chapter — because the energy demand never stops. A skeletal muscle fibre can run up an energy debt during a sprint and repay it afterwards while you catch your breath. Cardiac muscle has no afterwards, so it works almost entirely by aerobic respiration and must have oxygen continuously.
That last requirement explains something important. Cut the blood supply to a skeletal muscle and it aches; cut the blood supply to cardiac muscle and it is damaged within minutes, because there is no alternative supply and no opportunity to rest.
So striated but involuntary is not a quirk to be memorised for an examination. It is the description of a tissue designed for a job no other muscle in the body has to do.
Your heart has been contracting and relaxing since long before you were born, without one break, and it does not tire at all. Cardiac muscle is built differently for exactly that reason, and three of its features are what make the difference.
Its cells are branched, and the branches interlock with neighbours, so a contraction spreads through the whole wall as a coordinated squeeze rather than as separate fibres pulling. A heart whose regions contracted independently would not pump.
Its contraction is involuntary and rhythmic, generated within the heart itself rather than commanded by the brain. That is why a heart continues beating when its nerve supply is interrupted, and why you cannot stop it by deciding to.
And its cells are exceptionally rich in mitochondria — the organelle from the previous chapter — because the energy demand never stops. A skeletal muscle fibre can run up an energy debt during a sprint and repay it afterwards while you catch your breath. Cardiac muscle has no afterwards, so it works almost entirely by aerobic respiration and must have oxygen continuously.
That last requirement explains something important. Cut the blood supply to a skeletal muscle and it aches; cut the blood supply to cardiac muscle and it is damaged within minutes, because there is no alternative supply and no opportunity to rest.
So striated but involuntary is not a quirk to be memorised for an examination. It is the description of a tissue designed for a job no other muscle in the body has to do.
Exam relevance
Why does NEET keep asking about muscle and connective tissue?
Because this page is the foundation for three separate Class 11 Biology chapters, and NEET returns to all three.
Structural Organisation in Animals in Class 11 covers exactly the four tissue types named here, in more detail, and then applies them to the anatomy of specific animals. The epithelial types and their locations are taken as known.
Locomotion and Movement in Class 11 develops the muscle section into the structure of a muscle fibre — the sarcomere, actin and myosin, and the sliding filament theory of contraction. The Class 9 point it depends on is the striated appearance, because those light and dark bands are the sarcomeres seen from outside. A student who learned striated as a mere adjective meets that chapter without a foothold.
Body Fluids and Circulation in Class 11 develops the single word blood into plasma composition, blood groups, clotting and the cardiac cycle. Recognising blood as a connective tissue with a fluid matrix is where that begins.
Nervous tissue feeds into Class 11 Neural Control and Coordination, where the neuron is treated in full — resting potential, action potential, synapse — and the three parts named on this page become the parts that theory is built on.
What the questions look like. Match-the-column items pairing a tissue with its location are the most frequent form in NEET. Assertion-reason questions favour cardiac muscle, and a standard pairing offers cardiac muscle is involuntary with a reason about striations. Diagram-based questions ask you to label a neuron or to identify a muscle type from its shape and nuclei. Statement-count questions of the how many of the following are correct kind suit this topic because there are so many small pairings to keep straight.
How board and competitive emphasis differ. A board paper asks you to draw a neuron and label it, or to give three differences between striated and smooth muscle. A NEET item is more likely to describe a feature — branched, uninucleate, striated, involuntary — and ask which tissue it is, which rewards knowing the combinations rather than the individual adjectives.
The single trap that costs the most marks. Swapping ligament and tendon. It is asked directly, it is asked inside joint questions in the next part of this chapter, and it reappears in Class 11 Locomotion and Movement. Fix it once: tendon contains the word-association with muscle, ligament joins bone to bone.
A second trap worth naming. Assuming striated implies voluntary. Cardiac muscle is striated and involuntary, and that combination is the single most examined fact on this page.
Structural Organisation in Animals in Class 11 covers exactly the four tissue types named here, in more detail, and then applies them to the anatomy of specific animals. The epithelial types and their locations are taken as known.
Locomotion and Movement in Class 11 develops the muscle section into the structure of a muscle fibre — the sarcomere, actin and myosin, and the sliding filament theory of contraction. The Class 9 point it depends on is the striated appearance, because those light and dark bands are the sarcomeres seen from outside. A student who learned striated as a mere adjective meets that chapter without a foothold.
Body Fluids and Circulation in Class 11 develops the single word blood into plasma composition, blood groups, clotting and the cardiac cycle. Recognising blood as a connective tissue with a fluid matrix is where that begins.
Nervous tissue feeds into Class 11 Neural Control and Coordination, where the neuron is treated in full — resting potential, action potential, synapse — and the three parts named on this page become the parts that theory is built on.
What the questions look like. Match-the-column items pairing a tissue with its location are the most frequent form in NEET. Assertion-reason questions favour cardiac muscle, and a standard pairing offers cardiac muscle is involuntary with a reason about striations. Diagram-based questions ask you to label a neuron or to identify a muscle type from its shape and nuclei. Statement-count questions of the how many of the following are correct kind suit this topic because there are so many small pairings to keep straight.
How board and competitive emphasis differ. A board paper asks you to draw a neuron and label it, or to give three differences between striated and smooth muscle. A NEET item is more likely to describe a feature — branched, uninucleate, striated, involuntary — and ask which tissue it is, which rewards knowing the combinations rather than the individual adjectives.
The single trap that costs the most marks. Swapping ligament and tendon. It is asked directly, it is asked inside joint questions in the next part of this chapter, and it reappears in Class 11 Locomotion and Movement. Fix it once: tendon contains the word-association with muscle, ligament joins bone to bone.
A second trap worth naming. Assuming striated implies voluntary. Cardiac muscle is striated and involuntary, and that combination is the single most examined fact on this page.
Key takeaways
Animal tissues: quick revision
- Epithelium: cells tightly packed, almost no matrix, on a basement membrane. Covers and lines, and controls what crosses.
- Squamous (flat, thin) lines mouth, oesophagus, blood vessels and alveoli — thin for diffusion. Stratified squamous forms skin, for wear.
- Cuboidal lines kidney tubules and gland ducts — support, absorption, secretion.
- Columnar (tall) lines stomach and intestine — absorption and secretion. Ciliated columnar lines the respiratory tract and fallopian tube, sweeping mucus or an egg.
- Glandular epithelium secretes, forming glands.
- Connective tissue: cells sparse in abundant matrix — the opposite of epithelium.
- Blood has a fluid matrix (plasma) with red cells, white cells and platelets; it transports gases, food, wastes and hormones.
- Bone has a hard matrix of calcium and phosphorus compounds — framework, protection, muscle anchorage.
- Cartilage has a solid but flexible matrix — in nose, outer ear, trachea and larynx, and smoothing joint surfaces.
- Ligament joins bone to bone; tendon joins muscle to bone. Remember tendon by the muscle.
- Areolar fills spaces and helps repair; adipose stores fat and insulates.
- Striated muscle: long, cylindrical, unbranched, multinucleate, banded, attached to bone, voluntary, tires.
- Smooth muscle: spindle-shaped, single nucleus, no striations, in stomach, intestine, blood vessels and iris, involuntary.
- Cardiac muscle: cylindrical and branched, uninucleate, striated yet involuntary, only in the heart, and it does not tire.
- Striated does not mean voluntary — cardiac muscle is the exception, and only striated muscle is multinucleate.
- Muscle can only pull, never push, which is why muscles work in opposing pairs.
- Nervous tissue is made of neurons: cyton with the nucleus, dendrites that receive, one long axon that carries the impulse away.
- It forms the brain, spinal cord and nerves, and allows detection, rapid conduction and response — far faster than diffusion.
- A nerve is a bundle of axons, not a single cell.
- Nervous and muscle tissue work as a pair, and they are the two tissues plants do without.
Give yourself six locations in the body and name the tissue at each, then add the one structural feature that makes it right for that place — that second half is where the marks are.
- Squamous (flat, thin) lines mouth, oesophagus, blood vessels and alveoli — thin for diffusion. Stratified squamous forms skin, for wear.
- Cuboidal lines kidney tubules and gland ducts — support, absorption, secretion.
- Columnar (tall) lines stomach and intestine — absorption and secretion. Ciliated columnar lines the respiratory tract and fallopian tube, sweeping mucus or an egg.
- Glandular epithelium secretes, forming glands.
- Connective tissue: cells sparse in abundant matrix — the opposite of epithelium.
- Blood has a fluid matrix (plasma) with red cells, white cells and platelets; it transports gases, food, wastes and hormones.
- Bone has a hard matrix of calcium and phosphorus compounds — framework, protection, muscle anchorage.
- Cartilage has a solid but flexible matrix — in nose, outer ear, trachea and larynx, and smoothing joint surfaces.
- Ligament joins bone to bone; tendon joins muscle to bone. Remember tendon by the muscle.
- Areolar fills spaces and helps repair; adipose stores fat and insulates.
- Striated muscle: long, cylindrical, unbranched, multinucleate, banded, attached to bone, voluntary, tires.
- Smooth muscle: spindle-shaped, single nucleus, no striations, in stomach, intestine, blood vessels and iris, involuntary.
- Cardiac muscle: cylindrical and branched, uninucleate, striated yet involuntary, only in the heart, and it does not tire.
- Striated does not mean voluntary — cardiac muscle is the exception, and only striated muscle is multinucleate.
- Muscle can only pull, never push, which is why muscles work in opposing pairs.
- Nervous tissue is made of neurons: cyton with the nucleus, dendrites that receive, one long axon that carries the impulse away.
- It forms the brain, spinal cord and nerves, and allows detection, rapid conduction and response — far faster than diffusion.
- A nerve is a bundle of axons, not a single cell.
- Nervous and muscle tissue work as a pair, and they are the two tissues plants do without.
Give yourself six locations in the body and name the tissue at each, then add the one structural feature that makes it right for that place — that second half is where the marks are.