Q: Q1. State the main function of each of the following:\n(a) Areolar tissue\n(b) Adipose tissue\n(c) Dense regular connective tissue\n(d) Loose connective tissue\n(e) Specialised connect

Here are the main functions of the specified tissues:\n\n**(a) Areolar tissue:**\nIt serves as a supporting framework for epithelia. It fills space inside organs, supports internal organs, and helps in the repair of tissues. It is the most widely distributed connective tissue in the body.\n\n**(b) Adipose tissue:**\nIts primary function is to store fat. It acts as an energy reserve, insulates the body against heat loss, and cushions organs against mechanical shock.\n\n**(c) Dense regular connective tissue:**\nThis tissue provides great tensile strength in a single direction. Examples include tendons (which attach skeletal muscles to bones) and ligaments (which attach one bone to another bone). Tendons help in movement, while ligaments provide stability to joints.\n\n**(d) Loose connective tissue:**\nThis is a general category that includes areolar tissue and adipose tissue. Its main functions are to provide support, elasticity, and to bind organs together. It also serves as a reservoir for water and salts and plays a role in defense against pathogens.\n\n**(e) Specialised connective tissue (Cartilage and Bone):**\n* **Cartilage:** Provides support and flexibility to various parts of the body (e.g., tip of nose, outer ear joints, between adjacent bones of the vertebral column, limbs and hands in embryos). It also reduces friction at joints.\n* **Bone:** Forms the structural framework of the body, provides support and protection to softer tissues and organs. It also serves as a site for muscle attachment, allowing movement. Bones are also involved in mineral storage (calcium and phosphate) and hematopoiesis (production of blood cells in bone marrow).

Q: Q3. Mark the odd one out:\n(a) Areolar tissue; Blood; Neuron; Tendon\n(b) RBC; WBC; Platelets; Cartilage\n(c) Exocrine; Endocrine; Salivary gland; Ligament\n(d) Osteoblasts; Osteoclast

Here's the odd one out for each set:\n\n**(a) Areolar tissue; Blood; Neuron; Tendon**\n* **Odd one out: Neuron**\n* **Reason:** Areolar tissue, Blood, and Tendon are all types of connective tissue. Neuron is a cell of nervous tissue.\n\n**(b) RBC; WBC; Platelets; Cartilage**\n* **Odd one out: Cartilage**\n* **Reason:** RBC (Red Blood Corpuscles), WBC (White Blood Corpuscles), and Platelets are all components of blood (a fluid connective tissue). Cartilage is a type of specialized connective tissue, but not a cellular component of blood.\n\n**(c) Exocrine; Endocrine; Salivary gland; Ligament**\n* **Odd one out: Ligament**\n* **Reason:** Exocrine, Endocrine, and Salivary gland are all related to glands and their secretions (epithelial tissue derivatives). Ligament is a type of dense regular connective tissue.\n\n**(d) Osteoblasts; Osteoclasts; Chondrocytes; Adipocytes**\n* **Odd one out: Adipocytes**\n* **Reason:** Osteoblasts (bone-forming cells), Osteoclasts (bone-resorbing cells), and Chondrocytes (cartilage cells) are all cells associated with skeletal connective tissues (bone and cartilage). Adipocytes are fat-storing cells found in adipose tissue.

Q: Q4. Match the following:\n(a) Squamous epithelium (i) Lining of stomach and intestine\n(b) Cuboidal epithelium (ii) Walls of blood vessels\n(c) Columnar epithelium (iii) Ducts of gland

Here is the correct matching:\n\n(a) Squamous epithelium - (ii) Walls of blood vessels\n(b) Cuboidal epithelium - (iii) Ducts of glands\n(c) Columnar epithelium - (i) Lining of stomach and intestine\n(d) Ciliated epithelium - (iv) Bronchioles\n(e) Compound epithelium - (v) Moist surface of buccal cavity

Q: Q7. Mark the odd one out of the following: (a) Areolar tissue; Adipose tissue; Dense regular tissue; Blood; Neurons. (b) RBC; WBC; Platelets; Cartilage. (c) Exocrine; Endocrine; Saliva

(a) **Neurons**\n * Areolar tissue, Adipose tissue, Dense regular tissue, and Blood are all types of connective tissues. Neurons, on the other hand, are the fundamental units of nervous tissue.\n\n(b) **Cartilage**\n * RBC (Red Blood Cells), WBC (White Blood Cells), and Platelets are all cellular components of blood. Cartilage is a type of specialized connective tissue.\n\n(c) **Ligament**\n * Exocrine, Endocrine, and Salivary gland are all related to glandular structures and their secretions. Ligament is a type of dense regular connective tissue that connects bones to bones.\n\n(d) **Adipocytes**\n * Osteoblasts (bone-forming cells), Osteoclasts (bone-resorbing cells), and Chondrocytes (cartilage cells) are all cells associated with skeletal connective tissues (bone and cartilage). Adipocytes are fat-storing cells found in adipose tissue.

Q: Q10. Give the functions of the following: (a) Adipose tissue (b) Compound epithelium (c) Cardiac muscle (d) Neuroglia

The functions of the given tissues/structures are:\n\n**(a) Adipose tissue**\n1. **Energy Storage:** Primarily stores fat, serving as a reserve energy source for the body.\n2. **Insulation:** Acts as a thermal insulator, preventing heat loss from the body.\n3. **Cushioning/Protection:** Provides cushioning and protection to vital organs (e.g., kidneys, eyeballs) against mechanical shocks and injuries.\n\n**(b) Compound epithelium**\n1. **Protection:** Its primary function is to provide protection against mechanical and chemical stresses, abrasion, and invasion by microorganisms. It covers dry surfaces (like skin) and moist surfaces (like the buccal cavity).\n2. **Limited Role in Secretion/Absorption:** Due to its multi-layered nature, its role in secretion and absorption is limited compared to simple epithelium.\n\n**(c) Cardiac muscle**\n1. **Pumping Blood:** Its sole and vital function is to contract rhythmically and continuously to pump blood throughout the circulatory system, maintaining blood flow to all parts of the body.\n2. **Involuntary Movement:** It performs involuntary movements, meaning its contractions are not under conscious control.\n\n**(d) Neuroglia (Glial cells)**\n1. **Support and Protection:** They provide structural support to neurons within the nervous system.\n2. **Nourishment:** They supply nutrients to neurons and remove waste products.\n3. **Insulation:** Some neuroglial cells (e.g., Schwann cells, oligodendrocytes) form myelin sheaths around axons, providing electrical insulation and speeding up nerve impulse transmission.\n4. **Phagocytosis:** Certain glial cells (e.g., microglia) act as phagocytes, removing cellular debris and pathogens.\n5. **Maintain Homeostasis:** They help maintain the chemical environment around neurons, regulating ion concentrations and neurotransmitter levels.

Question 1

Q1. State the main function of each of the following:
(a) Areolar tissue
(b) Adipose tissue
(c) Dense regular connective tissue
(d) Loose connective tissue
(e) Specialised connect

Accepted Answer

Here are the main functions of the specified tissues:

**(a) Areolar tissue:**
It serves as a supporting framework for epithelia. It fills space inside organs, supports internal organs, and helps in the repair of tissues. It is the most widely distributed connective tissue in the body.

**(b) Adipose tissue:**
Its primary function is to store fat. It acts as an energy reserve, insulates the body against heat loss, and cushions organs against mechanical shock.

**(c) Dense regular connective tissue:**
This tissue provides great tensile strength in a single direction. Examples include tendons (which attach skeletal muscles to bones) and ligaments (which attach one bone to another bone). Tendons help in movement, while ligaments provide stability to joints.

**(d) Loose connective tissue:**
This is a general category that includes areolar tissue and adipose tissue. Its main functions are to provide support, elasticity, and to bind organs together. It also serves as a reservoir for water and salts and plays a role in defense against pathogens.

**(e) Specialised connective tissue (Cartilage and Bone):**
*   **Cartilage:** Provides support and flexibility to various parts of the body (e.g., tip of nose, outer ear joints, between adjacent bones of the vertebral column, limbs and hands in embryos). It also reduces friction at joints.
*   **Bone:** Forms the structural framework of the body, provides support and protection to softer tissues and organs. It also serves as a site for muscle attachment, allowing movement. Bones are also involved in mineral storage (calcium and phosphate) and hematopoiesis (production of blood cells in bone marrow).

Question 2

Q2. Distinguish between:
(a) Simple epithelium and Compound epithelium
(b) Cardiac muscle and Striated muscle
(c) Dense regular and Dense irregular connective tissues
(d) Adipose a

Accepted Answer

Here are the distinctions between the given pairs:

**(b) Cardiac muscle and Striated muscle**
*Note: 'Striated muscle' generally refers to skeletal muscle, which is also striated. Cardiac muscle is also striated but has distinct features.*

Question 3

Q3. Mark the odd one out:
(a) Areolar tissue; Blood; Neuron; Tendon
(b) RBC; WBC; Platelets; Cartilage
(c) Exocrine; Endocrine; Salivary gland; Ligament
(d) Osteoblasts; Osteoclast

Accepted Answer

Here's the odd one out for each set:

**(a) Areolar tissue; Blood; Neuron; Tendon**
*   **Odd one out: Neuron**
*   **Reason:** Areolar tissue, Blood, and Tendon are all types of connective tissue. Neuron is a cell of nervous tissue.

**(b) RBC; WBC; Platelets; Cartilage**
*   **Odd one out: Cartilage**
*   **Reason:** RBC (Red Blood Corpuscles), WBC (White Blood Corpuscles), and Platelets are all components of blood (a fluid connective tissue). Cartilage is a type of specialized connective tissue, but not a cellular component of blood.

**(c) Exocrine; Endocrine; Salivary gland; Ligament**
*   **Odd one out: Ligament**
*   **Reason:** Exocrine, Endocrine, and Salivary gland are all related to glands and their secretions (epithelial tissue derivatives). Ligament is a type of dense regular connective tissue.

**(d) Osteoblasts; Osteoclasts; Chondrocytes; Adipocytes**
*   **Odd one out: Adipocytes**
*   **Reason:** Osteoblasts (bone-forming cells), Osteoclasts (bone-resorbing cells), and Chondrocytes (cartilage cells) are all cells associated with skeletal connective tissues (bone and cartilage). Adipocytes are fat-storing cells found in adipose tissue.

Question 4

Q4. Match the following:
(a) Squamous epithelium (i) Lining of stomach and intestine
(b) Cuboidal epithelium (ii) Walls of blood vessels
(c) Columnar epithelium (iii) Ducts of gland

Accepted Answer

Here is the correct matching:

(a) Squamous epithelium - (ii) Walls of blood vessels
(b) Cuboidal epithelium - (iii) Ducts of glands
(c) Columnar epithelium - (i) Lining of stomach and intestine
(d) Ciliated epithelium - (iv) Bronchioles
(e) Compound epithelium - (v) Moist surface of buccal cavity

Question 5

Q5. Write short notes on the following:
(a) Compound epithelium
(b) Cardiac muscle
(c) Adipose tissue
(d) Ciliated epithelium
(e) Smooth muscle

Accepted Answer

Here are short notes on the specified tissues and structures:

### (a) Compound Epithelium
**Definition:** Compound epithelium consists of two or more layers of cells. Unlike simple epithelium, it does not have all cells resting directly on the basement membrane.
**Structure:** The cells in the outermost layer vary in shape (squamous, cuboidal, or columnar), while the cells in the deeper layers are typically cuboidal or columnar.
**Function:** Its primary function is to provide protection against mechanical and chemical stresses. It has limited roles in secretion and absorption.
**Location:** It covers the moist surfaces of the buccal cavity, pharynx, inner lining of salivary gland ducts, and pancreatic ducts. Stratified squamous epithelium (a type of compound epithelium) forms the epidermis of the skin.
**NEET Relevance:** High. Questions on its protective function and specific locations are frequent.

### (b) Cardiac Muscle
**Definition:** Cardiac muscle is a specialized contractile tissue found exclusively in the wall of the heart.
**Structure:** Cardiac muscle cells (cardiomyocytes) are cylindrical, branched, and uninucleated (sometimes binucleated), with the nucleus centrally located. They are striated, but the striations are less prominent than in skeletal muscle. A unique feature is the presence of **intercalated discs** at the fusion points of adjacent cells, which act as communication junctions and allow rapid electrical impulse transmission.
**Function:** Cardiac muscle is involuntary, meaning its activity is not under conscious control. It is responsible for the rhythmic contractions and relaxations of the heart, pumping blood throughout the body. It is fatigue-resistant.
**Location:** Exclusively in the myocardium (middle layer) of the heart wall.
**NEET Relevance:** High. Its involuntary nature, presence of intercalated discs, and location are key points for MCQs.

### (c) Adipose Tissue
**Definition:** Adipose tissue is a type of loose connective tissue specialized for the storage of fat.
**Structure:** It is composed mainly of **adipocytes** (fat cells). Each adipocyte contains a large fat globule that pushes the nucleus and cytoplasm to the periphery, giving the cell a signet-ring appearance. The matrix is scanty.
**Function:**
1.  **Energy Storage:** It serves as the body's primary energy reserve.
2.  **Insulation:** It acts as an insulator, preventing heat loss from the body.
3.  **Cushioning:** It cushions vital organs (like kidneys, eyeballs, heart) against mechanical shocks and trauma.
**Location:** Found beneath the skin (subcutaneous fat), around internal organs, and in the yellow bone marrow.
**Types:** White adipose tissue (most common in adults) and brown adipose tissue (more common in infants, involved in non-shivering thermogenesis).
**NEET Relevance:** High. Its function as an energy reserve, insulator, and cushioning agent, along with its location, are frequently tested.

### (d) Ciliated Epithelium
**Definition:** Ciliated epithelium is a type of simple columnar or cuboidal epithelium characterized by the presence of cilia on its free surface.
**Structure:** The cells are typically columnar or cuboidal, and their free surface bears numerous, fine, hair-like projections called cilia.
**Function:** The rhythmic, coordinated beating of cilia helps to move particles or mucus in a specific direction over the epithelial surface.
**Location:**
1.  **Respiratory Tract:** Lines the inner surface of hollow organs like bronchioles and fallopian tubes. In the respiratory tract, it helps to move mucus (trapping dust particles and microbes) towards the pharynx to be swallowed or expelled.
2.  **Fallopian Tubes:** In the oviducts (fallopian tubes), it helps in the movement of the ovum towards the uterus.
**NEET Relevance:** Medium. Its specific function of moving substances and its locations are important for MCQs.

### (e) Smooth Muscle
**Definition:** Smooth muscle is a type of involuntary muscle tissue, also known as non-striated muscle.
**Structure:** Smooth muscle cells are spindle-shaped (fusiform), uninucleated (single, centrally located nucleus), and lack striations (hence 'smooth'). They are held together by cell junctions and bundled together in a connective tissue sheath.
**Function:** Smooth muscles are involuntary, meaning their contractions are not under conscious control. They are responsible for slow, prolonged contractions and movements in internal organs. Examples include:
1.  **Peristalsis:** Movement of food through the digestive tract.
2.  **Vasoconstriction/Vasodilation:** Regulation of blood flow by changing the diameter of blood vessels.
3.  **Urination:** Contraction of the urinary bladder.
4.  **Uterine Contractions:** During childbirth.
**Location:** Found in the walls of visceral organs such as the stomach, intestine, blood vessels, uterus, urinary bladder, and iris of the eye.
**NEET Relevance:** High. Its involuntary nature, lack of striations, spindle shape, and locations are frequently asked in NEET.

Question 6

Q6. Differentiate between (a) Simple epithelium and Compound epithelium. (b) Cardiac muscle and Striated muscle. (c) Dense regular and Dense irregular connective tissues. (d) Adipose a

Accepted Answer

Differentiation between the given pairs is as follows:

**(a) Simple epithelium and Compound epithelium**

**(b) Cardiac muscle and Striated muscle**

**(c) Dense regular and Dense irregular connective tissues**

**(d) Adipose and Blood tissue**

**(e) Simple gland and Compound gland**

Question 7

Q7. Mark the odd one out of the following: (a) Areolar tissue; Adipose tissue; Dense regular tissue; Blood; Neurons. (b) RBC; WBC; Platelets; Cartilage. (c) Exocrine; Endocrine; Saliva

Accepted Answer

(a) **Neurons**
    *   Areolar tissue, Adipose tissue, Dense regular tissue, and Blood are all types of connective tissues. Neurons, on the other hand, are the fundamental units of nervous tissue.

(b) **Cartilage**
    *   RBC (Red Blood Cells), WBC (White Blood Cells), and Platelets are all cellular components of blood. Cartilage is a type of specialized connective tissue.

(c) **Ligament**
    *   Exocrine, Endocrine, and Salivary gland are all related to glandular structures and their secretions. Ligament is a type of dense regular connective tissue that connects bones to bones.

(d) **Adipocytes**
    *   Osteoblasts (bone-forming cells), Osteoclasts (bone-resorbing cells), and Chondrocytes (cartilage cells) are all cells associated with skeletal connective tissues (bone and cartilage). Adipocytes are fat-storing cells found in adipose tissue.

Question 8

Q8. Match the following:
(a) Adipose tissue – (i) Glandular epithelium
(b) Stratified epithelium – (ii) Fat storage
(c) Hair follicle – (iii) Compound epithelium
(d) Cardiac muscle

Accepted Answer

The correct matches are:

(a) Adipose tissue – **(ii) Fat storage**
(b) Stratified epithelium – **(iii) Compound epithelium**
(c) Hair follicle – **(i) Glandular epithelium** (Hair follicles are associated with sebaceous glands, which are glandular epithelium)
(d) Cardiac muscle – **(vi) Involuntary, branched, striated**
(e) Ciliated epithelium – **(v) Movement of particles**
(f) Glandular epithelium – **(i) Glandular epithelium** (This is a direct match, but in the context of the question, 'Hair follicle' is a more specific association for (i) as glandular epithelium is a broader category. However, if (i) is used for (c), then (f) would be a general description. Let's re-evaluate the best fit for (i). Hair follicles are epidermal invaginations, and sebaceous glands associated with them are glandular epithelium. So (c) to (i) is a good fit. (f) Glandular epithelium is a type of epithelium specialized for secretion, which is its primary characteristic. If (i) is used for (c), then (f) doesn't have a unique match. Let's assume (i) is meant to be used once. The question has 6 items to match with 6 options. Let's re-check the options and matches carefully.

Corrected Matching:
(a) Adipose tissue – **(ii) Fat storage**
(b) Stratified epithelium – **(iii) Compound epithelium**
(c) Hair follicle – **(i) Glandular epithelium** (Hair follicles are associated with sebaceous glands, which are glandular epithelium)
(d) Cardiac muscle – **(vi) Involuntary, branched, striated**
(e) Ciliated epithelium – **(v) Movement of particles**
(f) Glandular epithelium – **(i) Glandular epithelium** (This creates a conflict as (i) is used twice. Let's assume the question intends for (f) to be matched with its own definition, or there's a slight ambiguity. Given the options, (c) Hair follicle is best associated with glandular epithelium due to sebaceous glands. (f) Glandular epithelium is a type of epithelium, and its function is secretion, which is not an option. Let's assume the question implies a direct definition for (f) if (i) is not taken by (c). However, if we must use each option only once, then (f) Glandular epithelium is a type of epithelium, and (i) Glandular epithelium is its direct name. This means (c) would need another match. Let's re-evaluate (c). Hair follicle is an epidermal derivative. It contains cells that produce hair and is associated with sebaceous glands (glandular epithelium). So (c) is strongly linked to (i). If (f) is also linked to (i), there's an issue. Let's assume (f) is a general category, and (i) is a specific example or characteristic. The most direct match for (f) is its own name. If (i) is used for (f), then (c) needs another match. There is no other suitable match for (c). Therefore, the question likely intends for (c) to match (i) due to the sebaceous glands.

Let's consider the possibility that (i) is a characteristic, not a type. 'Glandular epithelium' is a type of epithelium. So, (f) Glandular epithelium is directly (i) Glandular epithelium. This means (c) Hair follicle needs another match. There is no other suitable match for (c). This implies there might be a slight error in the question's options or the expectation of how to match.

However, in typical NCERT context, 'Hair follicle' is often associated with the sebaceous glands, which are glandular epithelium. And 'Glandular epithelium' is a type of epithelium. Let's stick to the most direct and unique associations.

**Final Corrected Matches (assuming each option (i)-(vi) is used once):**
(a) Adipose tissue – **(ii) Fat storage**
(b) Stratified epithelium – **(iii) Compound epithelium**
(c) Hair follicle – **(i) Glandular epithelium** (due to sebaceous glands associated with it)
(d) Cardiac muscle – **(vi) Involuntary, branched, striated**
(e) Ciliated epithelium – **(v) Movement of particles**
(f) Glandular epithelium – **(iv) Involuntary smooth muscle** (This is incorrect. Glandular epithelium is not involuntary smooth muscle. There seems to be an error in the question's options or the number of options vs. items. If we strictly follow the options, (iv) is left for (f), which is biologically incorrect. Let's assume (f) is a general term and (i) is its specific type. If (i) is used for (c), then (f) has no match. If (f) matches (i), then (c) has no match.

Let's re-evaluate the options and matches, assuming the question is well-posed and each item on the left matches exactly one item on the right.

1.  **(a) Adipose tissue** is for **(ii) Fat storage**. (Clear)
2.  **(b) Stratified epithelium** is another name for **(iii) Compound epithelium**. (Clear)
3.  **(d) Cardiac muscle** is **(vi) Involuntary, branched, striated**. (Clear)
4.  **(e) Ciliated epithelium** is for **(v) Movement of particles**. (Clear)

This leaves:
**(c) Hair follicle** and **(f) Glandular epithelium** on the left.
**(i) Glandular epithelium** and **(iv) Involuntary smooth muscle** on the right.

*   **(f) Glandular epithelium** is directly **(i) Glandular epithelium**. This is the most direct match.
*   This leaves **(c) Hair follicle** to be matched with **(iv) Involuntary smooth muscle**. This is incorrect. Hair follicles contain arrector pili muscles, which are involuntary smooth muscles. So, this match is plausible! The arrector pili muscle is associated with the hair follicle and is indeed involuntary smooth muscle.

Therefore, the final correct matches are:
(a) Adipose tissue – **(ii) Fat storage**
(b) Stratified epithelium – **(iii) Compound epithelium**
(c) Hair follicle – **(iv) Involuntary smooth muscle** (due to arrector pili muscle)
(d) Cardiac muscle – **(vi) Involuntary, branched, striated**
(e) Ciliated epithelium – **(v) Movement of particles**
(f) Glandular epithelium – **(i) Glandular epithelium**

Question 9

Q9. Write short notes on the following. (a) Areolar tissue (b) Adipose tissue (c) Dense regular connective tissue (d) Smooth muscle (e) Cardiac muscle

Accepted Answer

Here are short notes on the specified tissues:

**(a) Areolar tissue**
*   **Description:** Areolar tissue is a type of loose connective tissue. It is the most widely distributed connective tissue in the body.
*   **Structure:** It consists of a semi-fluid ground substance containing various cells (fibroblasts, macrophages, mast cells) and fibers (collagen and elastin) loosely arranged. Fibroblasts are the primary cells that produce and secrete fibers.
*   **Location:** It is found beneath the skin, often supporting epithelia, and surrounds nerves and blood vessels, filling spaces between organs.
*   **Function:** It serves as a support framework for epithelia, helps in the repair of tissues, and acts as a reservoir of water and salts for surrounding tissues. Macrophages and mast cells provide defense against pathogens.

**(b) Adipose tissue**
*   **Description:** Adipose tissue is another type of loose connective tissue specialized for fat storage. It is found predominantly beneath the skin.
*   **Structure:** It is composed mainly of adipocytes (fat cells), which are large, spherical cells filled with a single, large fat globule, pushing the nucleus and cytoplasm to the periphery. It also contains a network of blood vessels.
*   **Location:** It is located primarily beneath the skin (subcutaneous fat), around internal organs (e.g., kidneys, heart), and in the yellow bone marrow.
*   **Function:** Its main functions include storing fats (energy reserve), providing insulation against heat loss, and cushioning internal organs against mechanical shock.

**(c) Dense regular connective tissue**
*   **Description:** Dense regular connective tissue is a type of dense connective tissue characterized by a highly organized arrangement of its fibers.
*   **Structure:** It consists mainly of collagen fibers arranged in parallel bundles, with fibroblasts present in rows between these bundles. This parallel arrangement provides great tensile strength in a single direction.
*   **Location:** It forms structures like tendons and ligaments.
    *   **Tendons:** Connect skeletal muscles to bones.
    *   **Ligaments:** Connect bone to bone.
*   **Function:** It provides strong, flexible connections between structures, resisting pulling forces in the direction of the fiber orientation.

**(d) Smooth muscle**
*   **Description:** Smooth muscle, also known as non-striated or involuntary muscle, is a type of muscle tissue that lacks striations.
*   **Structure:** Its cells are spindle-shaped (fusiform), uninucleate (single nucleus), and do not have striations. They are typically arranged in sheets or layers.
*   **Location:** It is found in the walls of internal organs such as the stomach, intestine, blood vessels, urinary bladder, uterus, and iris of the eye.
*   **Function:** It performs involuntary movements, such as the peristaltic movements of the digestive tract, constriction and dilation of blood vessels, and regulation of pupil size. Its contractions are slow and prolonged.

**(e) Cardiac muscle**
*   **Description:** Cardiac muscle is a specialized type of muscle tissue found exclusively in the heart.
*   **Structure:** Its cells are branched, cylindrical, and typically uninucleate (though some can be binucleate). They exhibit prominent striations, similar to skeletal muscle. A unique feature is the presence of intercalated discs, which are specialized cell junctions that allow rapid communication and coordinated contraction.
*   **Location:** Exclusively in the wall of the heart.
*   **Function:** It is responsible for the rhythmic, involuntary contractions of the heart, pumping blood throughout the body. It is highly resistant to fatigue and contracts continuously throughout life.

Question 10

Q10. Give the functions of the following: (a) Adipose tissue (b) Compound epithelium (c) Cardiac muscle (d) Neuroglia

Accepted Answer

The functions of the given tissues/structures are:

**(a) Adipose tissue**
1.  **Energy Storage:** Primarily stores fat, serving as a reserve energy source for the body.
2.  **Insulation:** Acts as a thermal insulator, preventing heat loss from the body.
3.  **Cushioning/Protection:** Provides cushioning and protection to vital organs (e.g., kidneys, eyeballs) against mechanical shocks and injuries.

**(b) Compound epithelium**
1.  **Protection:** Its primary function is to provide protection against mechanical and chemical stresses, abrasion, and invasion by microorganisms. It covers dry surfaces (like skin) and moist surfaces (like the buccal cavity).
2.  **Limited Role in Secretion/Absorption:** Due to its multi-layered nature, its role in secretion and absorption is limited compared to simple epithelium.

**(c) Cardiac muscle**
1.  **Pumping Blood:** Its sole and vital function is to contract rhythmically and continuously to pump blood throughout the circulatory system, maintaining blood flow to all parts of the body.
2.  **Involuntary Movement:** It performs involuntary movements, meaning its contractions are not under conscious control.

**(d) Neuroglia (Glial cells)**
1.  **Support and Protection:** They provide structural support to neurons within the nervous system.
2.  **Nourishment:** They supply nutrients to neurons and remove waste products.
3.  **Insulation:** Some neuroglial cells (e.g., Schwann cells, oligodendrocytes) form myelin sheaths around axons, providing electrical insulation and speeding up nerve impulse transmission.
4.  **Phagocytosis:** Certain glial cells (e.g., microglia) act as phagocytes, removing cellular debris and pathogens.
5.  **Maintain Homeostasis:** They help maintain the chemical environment around neurons, regulating ion concentrations and neurotransmitter levels.

Chapter 7: Structural Organisation in Animals