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Neuroglial cells are non-nervous supporting cells that fill in the inter-neuronal space and are capable of regeneration and division.

Formation of antibodies

Cardiac Muscle tissue

Medullated nerve has covering of Fat.

Blood & Lymph

Synapse is called the functional junction between two neuron.

Neuron is the structural and functional unit of nervous system.

Cardiac muscle

Actin & Myosin

Striped or Striated Muscles-

They are attached to the bones with the help of tendons/ aponeurosis, hence also called as skeletal muscles. They are voluntary in function, hence also called as voluntary muscles.

The muscle fibre is long, thread-like, unbranched & multinucleated. The muscle fibre, being muscle cell, is bounded by a sarcolemma. It’s cytoplasm is called as sarcoplasm. The muscle fibre consists of myofibrils which are situated parallel to each other. The myofibrils are made up of actin and myosin contractile proteins. The muscle fibre has alternate light and dark bands. The light band is called as I – band (Isotropic band) where dark band is called as A – band (Anisotropic band). There is a Z – line in the centre of I – band. The structure between two Z – lines is called as sarcomere which is a functional unit of muscle. During muscle contraction, the myosin filaments remain stationary while the actin filaments slide over the myosin.

Unstriped or Unstriated Muscles-

They are found in visceral organs such as alimentary canal, blood vessels, trachea, diaphragm, urinary bladder etc. They are also called as involuntary muscles. The muscle cell is spindle shaped, uninucleated & without light & dark bands. The muscle cell has many myofibrils made up of actin & myosin. They contract with rhythm under the control of autonomous nervous system.

They provide conductibility to body & body parts & facilitate movements & locomotion.

Neurolemma of axon

The gaps (constrictions) in the axon are called as Nodes of Ranvier.

Transitional cells change their shape depending on the degree of distention (stretch) needed. As the tissue stretches, the transitional cells start changing shape from round and globular to thin and flat.

1. Cell junctions: The epithelial cells are connected to each other laterally as well as to the basement membrane by junctional complexes called cell junctions. 

2. The different types of cell junctions are as follows: 

a. Gap Junctions (GJs): These are intercellular connections that allow the passage of ions and small molecules between cells as well as exchange of chemical messages between cells. 

b. Adherens Junctions (AJs): They are involved in various signalling pathways and transcriptional regulations. 

c. Desmosomes (Ds): They provide mechanical strength to epithelial tissue, cardiac muscles and meninges. 

d. Hemidesmosomes (HDs): They allow the cells to strongly adhere to the underlying basement membrane. These junctions help maintain tissue homeostasis by signalling. 

e. Tight junctions (TJs): These junctions maintain cell polarity, prevent lateral diffusion of proteins and junctions.

Calcified cartilage is a type of cartilage that becomes rigid due to deposition of salts in the matrix. This reduces the flexibility of joints in old age and cartilage becomes rigid.

Bones support and protect different organs and help in movement.

1. Nervous and muscular tissues are responsible for this action 

2. Nervous tissue recognizes the stimuli whereas muscular tissue allows responding to the stimuli.

1. The centre of long bones (diaphysis) contains bone marrow, which is a site of production of blood cells (red blood cells).

2. Any severe injury to the bone marrow can affect rate of haematopoiesis (formation of blood cells). 

3. A low count of erythrocytes (red blood cells) is characterised as anaemia. Hence, an injury to Priya’s long bone might have resulted in anaemia.

(d) Salivary gland

Location: It is found in inner lining of buccal cavity of frog, nasal cavity, trachea, oviduct of vertebrates, etc. 

Structure: 

1. Cells of this tissue are cuboidal or columnar. 

2. Free ends of cells are broad while narrow ends rest on a basement membrane. 

3. The free ends of the cell show hair-like cilia. 

4. The nucleus is oval and placed at basal end of the cell.

Function: To create a movement of materials that comes in contact with the epithelium, in a specific direction. This aids in functions like prevention of entry of foreign particles in the trachea, pushing of the ovum through the oviduct, etc.

Muscles of the cardiac tissue show characteristics of both striated and nonstriated muscle fibres. 

Structure: 

1. Sarcolemma is not distinct. 

2. Uninucleate muscle fibres appear to be multinucleate. 

3. Adjacent muscle fibres join together to give branched appearance.

4. Transverse thickenings of the sarcolemma called intercalated discs form points of adhesion of muscle fibres. 

5. These junctions allow cardiac muscles to contract as a unit to aid quick transfer of stimulus. 

Location: They are found in the wall of the heart or myocardium.

Function: Cardiac muscles bring about contraction and relaxation of heart, which helps in circulation of blood throughout the body.

1. Cell junctions: The epithelial cells are connected to each other laterally as well as to the basement membrane by junctional complexes called cell junctions. 

2. The different types of cell junctions are as follows:

a. Gap Junctions (GJs): These are intercellular connections that allow the passage of ions and small molecules between cells as well as exchange of chemical messages between cells. 

b. Adherens Junctions (AJs): They are involved in various signalling pathways and transcriptional regulations. 

c. Desmosomes (Ds): They provide mechanical strength to epithelial tissue, cardiac muscles and meninges. 

d. Hemidesmosomes (HDs): They allow the cells to strongly adhere to the underlying basement membrane. These junctions help maintain tissue homeostasis by signalling. 

e. Tight junctions (TJs): These junctions maintain cell polarity, prevent lateral diffusion of proteins and ions.

No, a neuron is not capable of regeneration because it lacks a centriole.

1. A nerve impulse is transmitted from one neuron to another through junctions called synapses. 

2. A synapse is formed by the membranes of a pre-synaptic neuron and a postsynaptic neuron, which may or may not be separated by a gap called synaptic cleft. 

3. There are two types of synapses, namely, electrical synapses and chemical synapses. 

4. Electrical synapses:

The membranes of pre- and post-synaptic neurons are in very close proximity. Thus, electrical current can flow directly from one neuron into the other across these synapses. Impulse transmission across an electrical synapse is faster.

5. Chemical synapse: 

The membranes of the pre- and post-synaptic neurons are separated by a fluid- filled space called synaptic cleft. 6. Chemicals called neurotransmitters are involved in the transmission of impulses at these synapses. 

7. The axon terminals contain vesicles filled with these neurotransmitters. 

8. When an impulse arrives at the axon terminal, it stimulates the movement of the synaptic vesicles towards the membrane where they fuse with the plasma membrane and release their neurotransmitters into the synaptic cleft. 

9. The released neurotransmitters bind to their specific receptors, present on the post-synaptic membrane. 

10. This binding opens ion channels and allows the entry of ions which can generate a new potential in the postsynaptic neuron.

Epithelial tissue rests on a basement membrane which acts as a scaffolding on which epithelium can grow and regenerate after injuries.

Smooth muscles (Involuntary muscles) are responsible for shrinking of eye pupil.

1. Cell junctions: 

The epithelial cells are connected to each other laterally as well as to the basement membrane by junctional complexes called cell junctions. 

2. The different types of cell junctions are as follows: 

a. Gap Junctions (GJs): 

These are intercellular connections that allow the passage of ions and small molecules between cells as well as exchange of chemical messages between cells. 

b. Adherens Junctions (AJs): 

They are involved in various signalling pathways and transcriptional regulations.

c. Desmosomes (Ds): 

They provide mechanical strength to epithelial tissue, cardiac muscles and meninges. 

d. Hemidesmosomes (HDs): 

They allow the cells to strongly adhere to the underlying basement membrane. These junctions help maintain tissue homeostasis by signalling. 

e. Tight junctions (TJs): 

These junctions maintain cell polarity, prevent lateral diffusion of proteins and ions.

Arrangement of lamillae in the Mammalian bones.

The mammalian cardiac muscles are modified and are capable of generating an impulse on their own. Hence, the mammalian heart known as a myogenic heart.

Based on the presence of matrix there are two types of bones present in the human body: 

1. Spongy bones: Haversian system is absent in these bones. Rectangular matrix is arranged in the form of trabeculae. It contains red bone marrow. 

2. Compact bones: Matrix of these bones shows haversian system without any space between the lamellae.

Ossein is present in the bone matrix.

There are over 650 named skeletal muscles in the human body.

Sarcomere is the functional unit of skeletal muscles.

1. The given diagram represents the myofibril of a muscular tissue.

2. ‘X’ is the sarcomere. It is a repeating unit of contraction within the myofibril.

(c) chondrin

(b) histology

(b) Hemidesmosomes

Pancreas is a gland which is both exocrine and endocrine.

Types: Depending on the mode of secretion, multicellular glands can be further classified as duct bearing glands (exocrine glands) ad ductless glands (endocrine glands). 

a. Exocrine glands: These glands pour their secretions at a specific site. e.g. salivary gland, sweat gland, etc. 

b. Endocrine glands: These glands release their secretions directly into the blood stream, e.g. thyroid gland, pituitary gland, etc.

1. Exocrine glands: These glands pour their secretions at a specific site. e.g. salivary gland, sweat gland, etc. 

2. Endocrine glands: These glands release their secretions directly into the blood stream, e.g. thyroid gland, pituitary gland, etc.

Number of organs combine together to form an organ-system, e.g. Respiratory system.

The different types of epithelial tissues are as follows: 

1. Simple epithelium: Epithelial tissue made up of single layer of cells is known as simple epithelium. Simple epithelium is further classified into: 

a. Squamous Epithelium 

b. Cuboidal Epithelium 

c. Columnar Epithelium 

d. Ciliated Epithelium 

e. Glandular Epithelium 

f. Sensory epithelium 

g. Germinal epithelium 

2. Compound epithelium: Epithelium composed of several layers is called compound epithelium. Compound epithelium is further classified into: 

a. Stratified epithelium 

b. Transitional epithelium

There are 3 different types of epithelial tissue: squamous, cuboidal, and columnar.

1. Each spinal nerve consists of many axons and contains layers of protective connective tissue coverings. 

2. Axons are enclosed in a fatty sheath called myelin sheath.

3. Individual axons within a nerve are wrapped in an endoneurium (innermost layer). 

4. Groups of axons with their endoneurium are arranged in bundles called fascicles. 

5. Each fascicle is wrapped in perineurium (middle layer). 

6. The outermost covering over the entire nerve is the epineurium. The epineurium extends between fascicles. 

7. Many blood vessels nourish the nerve and are present within the perineurium and epineurium.

They are special muscle which are found only in the heart. The muscle fiber of cardiac muscle is elongated, thread like and branched. They have light and dark bands but they are involuntary in function. They have special intercalated discs. They never under go muscle fatigue. They have hemoglobin & always perform aerobic respiration.

Areolar tissue acts as packing material, helps in healing process and connects different organs or layers of tissues.

Muscles of the cardiac tissue show characteristics of both striated and nonstriated muscle fibres. 

Structure: 

1. Sarcolemma is not distinct. 

2. Uninucleate muscle fibres appear to be multinucleate. 

3. Adjacent muscle fibres join together to give branched appearance. 

4. Transverse thickenings of the sarcolemma called intercalated discs form points of adhesion of muscle fibres. These junctions allow cardiac muscles to contract as a unit to aid quick transfer of stimulus. 

Location: They are found in the wall of the heart or myocardium.

Function: Cardiac muscles bring about contraction and relaxation of heart, which helps in circulation of blood throughout the body.

Sarcomere is the functional unit of skeletal muscles.