SHORT QUESTIONS:
- What do you mean by feedback system?
A response within a system (molecule, cell, organism, or population) that influences the continued activity or productivity of that system.
- Why the nervous coordination is faster than chemical coordination?
It is an advance type of coordination exhibited by most of the animals, which is a consequence of specially designed cell, Neurons. The neurons upon stimulation generate electrochemical signals. Since the signaling is in electric form so it is very rapid.
- Which of the two coordination types is better and why?
There are two types of coordination
- Chemical coordination
- Nervous coordination
Both are inter-related and interact with each other to develop proper response. Due to certain limitations of the use of electrical impulses, chemical coordination is also required. Nervous coordination is limited to only those regions which are connected by nerves while chemical coordination can take place throughout the body because hormones travel through blood.
- How reflex action works by a reflex-arc?
Some of reflex action is directly regulated by brain while others by spinal cord. The shortest path of a reflex action, such as knee-jerk involves two neurons, a sensory neuron and a motor neuron. The pathway of a reflex action is termed as reflex arc.
- Why driving license is not issued to a color blind person?
Color blindness is a deficiency of vision in which one cannot distinguish certain colors such as blue and yellow or red and green. The vision may be normal in a color blind person, yet the most common problem is driving because of their inability to distinguish red and green traffic lights.
- Why thyroid glands swell up and give the name of the disease?
It’s a butterfly shaped gland located on trachea in the base of neck. It regulates the physical growth and mental development in children. In case of its deficiency, physical and mental retardation occur in children. If the intake of iodine in diet is low in adult, the thyroid gradually enlarges in size. This abnormal condition is termed as “goiter”.
- What is the role of Islet’s of Langerhans cells?
Pancreas consists of patches of cells called “Islet’s of Langerhans” which are involved in regulating glucose metabolism through their hormones insulin and glucagon. · Diabetes mellitus is a disorder in which pancreas produces
- What is “emergency hormone” and why it is named so?
Cortisol is one of the important hormones secreted by adrenal cortex in response to illness or inflammation of any tissue. It stimulates glucose production. Adrenal medulla responds to emergency conditions to produce so called “flight or fight response”. It secretes adrenaline or emergency hormone resulting in an increase in blood glucose level by breaking down of glycogen.
- What are the possible reasons of paralysis?
It is characterized by partial or complete loss of controlled movement caused by the inability to contract one or more muscles. It may be accompanied by loss of sensation. The most common cause is either bleeding (hemorrhage) or blood clot in the specific part of brain.
- What is Epilepsy?
It is a brain disorder in which there is temporary alteration in one or more function or recurrent seizures. It is due to the abnormal electrical activity in brain. Stimulus like sudden flash light on eyes is also associated cause of the epilepsy.
- Differentiate between Chemical and Nervous Coordination.
| NERVOUS COORDINATION | CHEMICAL COORDINATION |
| Activity of Neurons | Activity of special secretory cells |
| Signal type is electro-chemical | Signal type is purely chemical |
| Rapid in action | Slower in action |
| Response is shorter duration | Response is longer duration |
| Advance type of coordination | Primitive type of coordination |
| Exclusively related to animals | Related to all organisms |
| Involves neurotransmitters | Involves other signaling molecules such as hormones. |
C. EXTENSIVE RESPONSE QUESTIONS:
1. Discuss the detailed structure of human brain?
Human Brain
It is the major command and control center of our body. It is wrapped in three protective membranes called meninges. Inside the brain, there are empty cavities or ventricles filled with a cerebro spinal fluid (CSF). Human brain consists of following important parts: Cerebrum, hippocampus, amygdala, thalamus, hypothalamus, mid-brain, cerebellum, and medulla oblongata.
CEREBRUM:
- It is the largest part of the brain where important decisions are made.
- It is considered to be the seat of intelligence, all conscious activities and memory.
- Its outer part, cortex or gray matter is grayish in color and consists of cell bodies of neurons.
- Cerebrum consists of two hemispheres, i.e. Right and left cerebral hemispheres. The right cerebral hemisphere regulates the left side of the body while the left cerebral hemisphere to the right side of the body.
THALAMUS:
Thalamus lies inside in the brain just above the hypothalamus. It guides the stimuli towards appropriate part of the cortex.
HYPOTHALAMUS:
Hypothalamus regulates life maintaining functions like blood pressure, body temperature, hunger, thirst, etc. It plays vital role in maintaining homeostasis of the body.
HIPPOCAMPUS:
It is related with long-term memory.
AMYGDALA:
It’s a deep seated small area involved in emotions (pain, pleasure, etc.)
Mid brain: In human it is relatively smaller and involved in integration of visual and olfactory (smell) stimuli. It is also collaborator of spinal cord with fore-brain.
CEREBELLUM:
- It is highly convoluted structure located on the dorsal side just below the cerebrum.
- It controls the precision in movement of the muscles for balance and maintains the position of the body in relation to gravity.
- Activities like writing, drawing, painting, dancing, crafting have become possible due to its elaborate structure in human.
MEDULLA OBLONGATA:
It lies just above the spinal cord. It is the control center for automatic activities like breathing, heart-beat, blood pressure, coughing, swallowing, hiccupping, digesting food, etc. Such activities are termed as Reflexes.
PONS:
It lies on the ventral side of medulla oblongata. It helps in controlling the facial muscles as well as helps in sleep and wakening.
2. Write a note on human eye or ear.
EAR
Ear is an organ of hearing and balance. It consists of three parts:
- outer ear, 2) middle ear and 3) inner ear.
OUTER EAR
The outer ear consists of pinna, ear canal and tympanic membrane or ear drum. The pinna composed of folds of skin and cartilage. Ear canal has hair and produces wax to trap dust and small foreign bodies. The outer ear collects and transmits sound waves.
MIDDLE EAR
The middle ear consists of a small cavity containing three small moveable bones (malleus, incus and stapes). The middle ear is connected to inner nasal cavity through a small tube, the Eustachian tube. The middle ear receives sound waves from air outside and transmits it into the fluid in the inner ear.
INNER EAR
The inner ear consists of a front membranous cochlea and a rear, three semicircular canals deep inside the skull bones. The cochlea is associated with hearing while semicircular canals are associated with balance. Both cochlea and semicircular canals are fluid filled and contain sensory hair cells. These cells transform sound waves into nerve impulse.
EYE
It is the organ of sight. It works on the principle of a simple camera which collects light reflected from any object in front and diverts it to a layer of sensory cells or retina.
RETINA
The light captured by retina is converted into nerve impulses and reported to the brain. Each eye lies in a bony socket for protection.
PUPIL
A tough outer coat, sclera (white part of eye) covers each eye. In front, the sclera becomes transparent termed as cornea. At its back lies coloured part or iris with a central hole, called pupil. The pupil appears blackish.
CILIARY BODY:
Behind the iris is a crystalline convex lens suspended by a ring of circular muscles known as ciliary body.
VITREOUS HUMOR:
The contraction of ciliary muscles causes changes in the shape of the lens to adjust focus. Behind the lens, there is a main cavity of eye ball filled with a clear gel, vitreous humor.
RODS AND CONS
The innermost layer of eye is retina on which the image is formed by cornea and lens. It has sensory cells, rods and cones which upon stimulation convert light signals into nerve impulses and report them to the brain.
PUPIL REFLEX:
The pupil adjusts itself depending upon the intensity of light. In case of bright light, it protects the retina by constricting itself so less amount of light falls on retina. Vice versa, in dim light condition, the pupil dilates to allow more light to fall on retina.
3. Why does the intelligence level of persons differ from each other, even though the components of brain are same?
Human intelligence is the intellectual capability of humans, which is marked by complex cognitive feats and high levels of motivation and self-awareness.[1] High intelligence is associated with better outcomes in life.[2]
As a construct and measured by intelligence tests, intelligence is considered to be one of the most useful concepts used in psychology, because it correlates with many relevant variables, for instance the probability of suffering an accident, salary, and more.[6]
EDUCATION
According to a 2018 metastudy of educational effects on intelligence, education appears to be the “most consistent, robust, and durable method” known for raising intelligence.
MYOPIA
A number of studies have shown a correlation between IQ and myopia. Some suggest that the reason for the correlation is environmental, whereby people with a higher IQ are more likely to damage their eyesight with prolonged reading, or the other way around whereby people who read more are more likely to reach a higher IQ, while others contend that a genetic link exists.
AGING
There is evidence that aging causes a decline in cognitive functions. In one cross-sectional study, various cognitive functions measured declines by about 0.8 in z-score from age 20 to age 50, the cognitive functions included speed of processing, working memory, and long-term memory.
GENES
A number of single-nucleotide polymorphisms in human DNA are correlated with intelligence.
MOTIVATION
Motivation is a factor that influences the results of the IQ test. People with higher motivation tend to obtain higher IQ scores.
4. What is endocrine system? Discuss the gland involved in regulation of blood glucose and how?
ENDOCRINE SYSTEM
Endocrine system consists of ductless glands which secrete hormones directly into the blood.
They act like chemical signals or chemical messengers for target organs either stimulating or inhibiting their function.
The pancreas maintains the body’s blood glucose (sugar) balance.
PANCREAS:
- Pancreas is about 6 inches long, leaf-like in structure located in the abdominal cavity in between stomach and small intestine.
- It is both exocrine as well as endocrine gland in nature.
- The endocrine part consists of patches of cells called “Islets of Langerhan’s”. It is involved in regulating glucose metabolism.
- In response to high level of glucose, it secretes Insulin which helps in decreasing the blood glucose levels.
- On the other hand, low level of blood glucose, it secretes glucagon which increases the glucose level up to normal.
- The regulation of blood glucose through insulin and glucagon is a type of negative feed-back in which opposite effect is observed in relation to stimulus.
5. What is diabetes mellitus? Explain some ways of its management?
DIABETES MELLITUS:
It’s a disorder in which pancreas produces insufficient or no insulin. As a result, the level of glucose in blood becomes very high. The excess amount of glucose is excreted in urine so the frequency of passing urine increases many times.
WAYS TO MANAGE DIABETES MELLITUS
Balanced Diet
Exercise
Medication
Blood Glucose Monitoring
DIETARY MANAGEMENT OF DIABETES
- Dietary Management and appropriate amount of physical activity play important roles in diabetic control.
- Balanced diet with a variety of foods.
- “3 Low, 1 High” principle, i.e low fat, low sodium (or salt), low sugars and high fibre.
- Reduce intake of saturated fat, Tran’s fat and sodium can lower the risk of developing heart diseases and hypertension.
- Controlling intake of energy for the purpose of weight reduction or maintenance.