phys homeostasis and thermoregulation

what is physiology?

it describes how living things work with an emphasis on integrating all levels and organs to understand normal function

what is anatomy?

it describe sthe structure of living things including an understanding of separate components and structural connections between the different components

how are anatomy and physiology related?

through structure function relationships as certain physiological process can only be explained in the context of underlying anatomy (certain structures perform certain roles)

what is homeostasis?

continuous physiological processes that establishes a stable internal environment

what three components help ensure that internal variables remain within a healthy range in homeostasis, and can you explain the role of each component?

1. receptor/ sensor - monitors the variables

2. integrating/ control center - processes information and initiates responses

3. effector- is a cell or organ that creates the response

what does it mean by long distance and local regulation mechanisms in homeostasis?

1. local regulation- when a cell or organ adjusts itself without involving the endocrine or nervous system

2. long distance regulation- nervous or endocrine response used to adjust affected cell or organ and has a more wide spread affect

what is a feedback loop?

it involves the response freding back a response to regulate the input received from receptors

what are the two types of feedback loops?

negative feedback- response opposes the initial stimulus and stabilizes the regulated variable

positive feedback- response reinforces the initial stimulus and temporarily dysregulates the regulated variable which ends with an event

what is an integumentary system?

the organ system that covers the outer layer of the body (skin hair nails etc)

true or false is the integumentary system the largest system in the human body?

true as it makes up 16% of our body weight

what two sections make up the integumentary system?

-cutaneous memory (skin)

-accessory structures

what are some of the functions of the cutaneous membrane in the integumentary system?

• physical protection from environmental hazards

• storage of lipids'

• coordination’s of immune responses and cancers in skin

what are the functions of accessory structures in the integumentary system of the human body?

• sensory info

• excretion

• thermoregulation

• synthesis of D3

what two sections make up the cutaneous layer of the integumentary system?

epidermis and dermis

what is the role of the dermis?

in the reticular layer it has receptors for pain, touch etc. it also contains blood vessels for thermoregulation whereas the papillary layer nourishes and supports the epidermis

what is the role of the epidermis?

protect the dermis, prevent water loss, sensory receptors, protect from pathogens

what are the three main accessory structures and what is the function of each one?

nails- protection and aid in dexterity

exocrine glands- assist in thermoregulation through sweat and waste excretion

hair follicle- protect skull and traps foreign material

what are the two types of sweat glands?

merocrine/eccrine and apocrine

what are merocrine/ eccrine sweat glands?

tubular coiled sweat glands the secrete sweat directly to the surface of the skin (is widespread and responsible for the perspiration of chemicals, salts, water and deters bacterial growth)

what are apocrine glands?

coiled and tubercular glands that secretes sticky odorous sweat into hair follicles (found at distinct locations and only start working around puberty)

what is the normal body temp range?

36.7-37.2 degrees celcius

what is teh thermoregulatory center (control center) in the brain?

the hypothalamus

what is the effectors for thermoregulation in increasing and decreasing tempreture?

increasing- decreased blood flow to skin, decreased sweating causing shivering

decreasing- increased blood flow to skin, increased sweating

can you explain the following thermoreceptors?

peripheral- skin thermoreceptors detecting the temp in the surrounding environment

central- (organs, skeletal muscle and hypothalamus which reads internal body temperature and is the control center for repsonses)

-warm and cold receptors - respond to colder and warmer temperatures specifically

• phasic thermoreceptors - they become more reactive with chnages in temperature but relax as the stimulus stays the same

what are the 4 ways of heat rransfer?

convection, conduction, radiation and evaporation

what factors can contribute to differences in thermoregulation?

• Acclimatization- gradual adjustment to external enviornment

• brow adipose tissue/fat- important in newborns

• body size- larger surface area allows more room for heat to escape

• body composition- fat is a good insulator

• different setpoints

what is the purpose of the sebaceous gland in the accessory structures of the integumentary system?

sebaceous glands produce an oil that forms a protective layer over the skin and moisturises the skin

what does ‘physio’ and ‘ology’ mean?

nature and the study of

where can shell and core temps be taken from?

• core: oral, esophageal, rectal

• shell- tympanic, clavicle, armpit

in hot environments do blood vessels vasodilate or vasoconstrict?

vasodilate