Week 1 Flashcards
What is anatomy?
the structure of body parts and their relationship to one another.
What is physiology?
the function of the body and how each body part works
What are the 6 levels of structural organisation?
- Chemical level
- Cellular level
- Tissue Level
- Organ level
- Organ System level
- Organism level
what is the chemical level?
atoms form molecules
what is the cellular level?
Cells are made of molecules
What is the tissue level?
tissues consist of similar cells
What is the organ level?
organs are made up of different cells
what is the organ system level?
Consist of 2 or more organs working together
What is the organism level
Human organism is made up of many organisms
what is the integumentary system
- Forms the external body covering i.e skin
- Skin, sweat glands, oil glands, hair & nails
- protects deep tissues from injury
- synthesises vitamin D
What are the functions of the integumentary system?
Protection as chemical barrier, physical barrier and biological barrier
how is the integumentary system a chemical barrier?
- skin has a lower pH and cooler temperature to the body which stops bacterial growth
- melanin protects against UV damage
How is the integumentary system a physical barrier?
- skin continuity provides a tighter barrier, prevents loss of water and water soluble products
How is the integumentary system a biological barrier?
-Langerhans’ cells (white blood cells) of epidermis act as first line of defence against bacteria
What are the two distinct regions of skin?
Epidermis
Dermis
what is the epidermis?
is the outer surface coat of epithelial cells
what is the dermis?
is the deeper connective tissue layer making up the bulk of skin
How does the epidermis gain nutrients?
through diffusion
what are the 2 layers of the dermis
papillary layer (superficial) reticular layer (deep)
How is the skin attached?
it’s attached by undulating borderline and rests on the subcutaneous tissues called the hypodermis
What cells are in the epidermis
the epidermis is keratinised stratified squamous epithelium and consists of four cells keratinocytes, melanocytes, Langerhans’s cells, Merkel cells
what are keratinocytes?
- most common cell in epidermis
- produce keratin: a protect fibrous protein
- at the surface become dry & scaly
what are melanocytes
- produce melanin
- specialised epithelial cells synthesise the pigment melanin
- found in deepest layer of epidermis
- melanin is created and transported to the keratinocytes
- melanin protects against UV light
what are Langerhan’s cells?
- immune protection
- produced in the bone marrow and move to epidermis
Phagocytes that help activate the immune system - type of epidermal dendritic cells
What are Merkel cells?
- essential for touch & sensation
- small no. at epidermal -dermal junction
- Associated with sensory nerve fibre and act as touch receptors (tactile cells)
What causes the different skin colours?
Melanin, Carotene, Haemoglobin
What is melanin?
- located in epidermis
- freckles and moles are an accumulation of melanin
- ranges in colour from black to reddish yellow
- melanocytes are stimulated by sunlight to produce melanin
What is carotene?
- yellow/orange pigment in the stratum corneum and hypodermis
- most obvious in palms and soles
What is haemoglobin?
- Oxygenation of haemoglobin contributes to pinkish colour in Caucasians
what are the appendages of the skin?
Sweat glands, sebaceous glands, nails, hair, hair follicles
what are sweat glands?
Sweat glands are all over the body except for lips, nipples and external genitalia
what are the 2 types of sweat glands?
eccrine and apocrine
what is the eccrine sweat gland?
produce sweat and are abundant on palms, soles, forehead
what is the apocrine sweat glands?
are found in axillary/anogenital regions and secrete sweat mixed with fat and organic molecules
- ducts empty into hair follicles
- body odour occurs from bacteria on organic molecules secreted in sweat
what are sebaceous glands
oil glands
What is the function of sebaceous glands?
found all over the body except for soles and palms
- secrete a substance called sebum
- sebum softens and lubricates the skin, prevents brittle hair, reduces water loss, kills bacteria
- sebum secretion is controlled by hormones
- acne is due to bacterial infection and inflammation of these glands
What is the musculoskeletal system made of?
Bone, Cartilage, ligaments
what is the function of the musculoskeletal system?
- protect and support organs
- provides framework for muscles
- blood cell information
- stores minerals
- manipulation of environment, locomotion and facial expression
- maintains posture
- produces heat
What is the lymphatic/ immune system?
- composed of red bone marrow, thymus, spleen, lymph nodes, lymphatic vessels
what is the function of the lymphatic/immune system?
- picks up fluid leaked from blood vessels and returns it to blood
- disposes of debris in the lymphatic stream
- houses the white blood cells involved in the immune response
what is the Respiratory system
consists of the nasal cavity, pharynx, trachea, bronchi & lungs
what is the function of the respiratory system?
- supplies blood with oxygen and removes carbon dioxide
- regulates acid-base balance
What is the urinary system
composed of kidneys, ureters, urinary bladder and urethra
what does the urinary system do
- eliminates nitrogenous waste from the body
- regulates water, electrolytes, pH of the blood
what is homeostasis
- the ability to maintain a relatively stable internal environment in an ever changing outside world
- internal environment of the body is in a dynamic state of equilibrium
- chemical, thermal, neural and hormonal factors interact to maintain homeostasis
Negative Feedback
- the output decreases the original stimulus
What is an example of negative feedback
Blood sugar regulation (insulin lowers blood glucose when levels are high and glycogen raises blood glucose when levels are low)
Positive Feedback
output increase or exaggerates the original stimulus
e.g. regulation of blood clotting
What is homeostatic imbalance?
Disturbance of homeostasis or the body’s normal equilibrium
