To study the integumentary and special senses using specimens, models
Aim
To study the integumentary and special senses using specimens, models
SKIN
Requirement: Human skin chart model.
Theory :
Structure
Skin has multipale layer of cells which are divided into two part . The skin has a surface area of about 1.5 to 2 mm in adults and it contains glands, hair and nails.
There are two main layers: Epidermis and Dermis
Between the skin and underlying structures, there is a layer of subcutaneous fat.
Epidermis
This consist of the following-
- Stratum corneum – the horny layer
- Stratum lucidum – the transport layer
- Stratum grenulosum – the granular layer
- Stratum Malpighian – the prickle–celled layer
- Malpighian cells are branched, broad & thick. Melanoblast granules of pigment are found in the deepest layer.
- The epidermis is the most superficial layer of the skin and is composed of stratified keratinized squamous epithelium which varies in thickness in different parts of the body.
- It is thickest on the palms of the hands and soles of the feet.
- There are no blood vessels or nerve endings in the epidermis, but its deeper layers are bathed in interstitial fluid from the dermis, which provides oxygen and nutrients, and is drained away as lymph.
The skin showing the main layers of the epidermis
- desquamation (shedding) of the keratinized cells from the surface
- effective keratinisation of the cells approaching the surface, continual cell divison in the deeper layers with newly formed cells being pushed to the surface
- Hairs, secretions from sebaceous glands and ducts of sweat glands pass through the epidermis to reach the surface.
- The surface of the epidermis is ridged by projections of cells in the dermis called the papillae. The pattern of ridges is different in every individual and the impression made by them is the ‘fingerprint’.
Dermis
The layer is below the epidermis. It has multiple layers & contains a large number of different structures:-
- Melanophore cells: contain the pigment melanin.
- Vessels: there is an arterial & venous capillary network carrying blood and lymphatic vessels convey lymph.
- Elastic fibre:- minute fibres help to keep up the texture of the skin.
The dermis is tough and elastic. It is formed from connective tissue and the matrix contains collagen fibres interlaced with elastic fibres. Rupture of elastic fibres occurs when the skin is overstretched, resulting in permanent striae, or stretch marks, that may be found in pregnancy and obesity. Collagen fibres bind water and give the skin its tensile strength, but as this ability declines with age, wrinkles develop. Fibroblasts, macrophages and mast cells are the main cells found in the dermis. Underlying its deepest layer there is areolar tissue and varying amounts of adipose tissue (fat).
EAR
Requirement: Human Ear Model
Theory
The ear is the organ of hearing and maintenance of body equilibrium. It is controlled by the brain through the eighth cranial nerve called the vestibulocochlear nerve.
Structure
The ear is divided into three distinct parts:
Outer ear
Middle ear (tympanic cavity)
Inner ear
Outer ear
The outer ear consists of the auricle (pinna) and the external acoustic meatus.
a) The auricle (pinna)
- It consist of pinna which helps to collect the sound wave and the external auditory which convey the sound wave from the pinna to the tympanic membrane.
- The article is the expanded portion projecting from the side of the head. It is composed of fibrielastic cartilage covered with skin.
- It is deeply grooved and ridged and the most prominent outer ridge is the helix. The lobule (earlobe) is the soft pliable part at the lower extremity, composed of fibrous and adipose tissue richly supplied with blood.
b) External acoustic meatus (auditory canal)
- This is a slightly ‘S’-shaped tube about 2.5 cm long extending from the auricle to the tympanic membrane(eardrum). Hair and wax are present near its outer part to arrest particles. This canal conveys sound waves to the drum.
- The lateral third is cartilaginous and the remainder is a canal in the temporal bone. The meatus is lined with skin containing hairs continuous with that of the auricle.
- There are numerous sebaceous and ceruminous glands in the skin of the lateral third.
c) Ceruminous Glands
- Are modified sweat glands that secrete cerumen(wax) , a sticky material containing Iysozyme and immunoglobulins. Foreign materials, e.g. dust, insects and microbes, are prevented from reaching the tympanic membrane by wax, hairs and the curvature of the meatus. Movements of the temporomandibular joint during chewing and speaking ‘massage’ the cartilaginous meatus, moving the wax towards the exterior.
- The tympanic membrane (eardrum) completely separates the external acoustic meatus from the middle ear. It is oval-shaped with a slightly broader edge upwards and is formed by three types of tissue: the outer covering of hairless skin, the middle layer of fibrous tissue and the inner lining of mucous membrane continuous with that of the middle ear.
EYE
Requirement: Human Eye Model
Theory:
- Eyelids and eyelashes keep dust out of the eyes; conjunctiva lines the eyelids and covers the white of the eye.
- Lacrimal glands produce tears, which flow across the eyeball to two lacrimal ducts, to the lacrimal sac to the nasolacrimal duct to the nasal cavity. Tears wash the anterior eyeball and contain lysozyme to inhibit bacterial growth.
- The eyeball is protected by the bony orbit(socket).
- The six extrinsic muscles move the eyeball; innervated by the 3 rd, 4 th, and 6 th cranial nerves.
- Sclera- the outermost layer of the eyeball; made of fibrous connective tissue; an anterior portion is a transparent cornea, the first light-refracting structure.
- Choroid layer- middle layer of the eyeball; dark blue pigment absorbs light to prevent glare within the eyeball.
- The ciliary body(muscle) and suspensory ligaments- change the shape of the lens, which is made of a transparent, elastic protein which refracts light.
- Iris-two sets of smooth muscle fibres regulate the diameter of the pupil, that is, how much light strikes the retina.
- Retina – the innermost layer of the eyeball; contains rods and cones.
- Rods – detect light; abundant toward the periphery of the retina.
- Cones- detect colour; abundant in the centre of the retina.
- Fovea- in the centre of the macula lutea; contains only cones; area of best colour vision.
- Optic disc- no rods or cones; optic nerve passes through eyeball.
- The posterior cavity contains vitreous humour (semi-solid) that keeps the retina in place.
- The anterior cavity contains aqueous humour that nourishes the lens and cornea; made by capillaries of the ciliary body, flows through the pupil, and is reabsorbed to blood at the canal of Schemm.
Physiolgoy of Vision :
- Refraction (bending and focusing) pathway of light: cornea, aqueous humour, lens, vitreous humour.
- The lens is adjustable, the ciliary muscle relaxes for distant vision, and the lens is thin. The ciliary muscle contracts for near vision, and the elastic lens thickens and has greater refractive power.
- Light strikes the retina and stimulates chemical reactions in the rods and cones.
- In rods: rhodopsin breaks down to scotopsin and retinal (from vitamin A), and an electrical impulse is generated. In cones; specific wavelengths of light are absorbed (red, blue, green); chemical reactions generate nerve impulses.
- Ganglion neurons from the rods and cones form the optic nerve, which passes through the eyeball at the optic disc.
- Optic chiasma- Site of the crossover of medial fibres of both optic nerves, permitting binocular vision.
- Visual areas in occipital lobes –each area receives impulses from both eyes; both areas create one image from the two slightly different images of each eye; both areas right the upside-down retinal image.
BP207P Human Anatomy and Physiology II Practical
To study the integumentary and special senses using specimens, models, etc.,
To study the nervous system using specimens, models, etc.,
To study the endocrine system using specimens, models, etc
To demonstrate the general neurological examination
To demonstrate the function of olfactory nerve
To examine the different types of taste.
To demonstrate the visual acuity
To demonstrate the reflex activity
Recording of body temperature
Determination of tidal volume and vital capacity.
Study of digestive, respiratory, cardiovascular systems, urinary and reproductive systems with the help of models, charts and specimens.
Recording of the basal mass index.
Study of family planning devices and pregnancy diagnosis test.
Demonstration of total blood count by cell analyzer
Permanent slides of vital organs and gonads
First Year B Pharm Notes, Syllabus, Books, PDF Subjectwise/Topicwise
Suggested readings
Recommended readings:
Performance Monitoring and Updates in AI-Enabled Medical Devices: FDA’s Guiding Principles
Lifecycle Management in AI-Enabled Medical Devices: FDA’s Comprehensive Framework
Data Management in AI-Enabled Medical Devices: Key to Safety and Effectiveness
