ALLIED HEALTH UNIT 4 SAC 3

Nervous system, the senses and the endocrine system

function of the nervous system

• responds to changes inside and outside the body (maintain homeostasis)

label structure of a neuron

describe soma

is the central part that holds the nucleus

describe dendrites

acts as the primary recieving site for signals

describe axon

conducts electrical impulses

describe myelin sheath

insulating layer that wraps around the axon of a nucleus

describe nodes of ranvier

specialised gaps in the myelin sheath

describe axon terminals

specialised ending of an axon where it transmits signals

describe schwann cells

specialised glial cells of PNS

how are nerve impulses transmitted across the synaptic gap

role of neurotransmitters

• are endogenous chemicals that allow neurons to communicate with each other

• enables the brain to provide a variety of functions

role of receptors

converting stimuli from the environment into electrical signals that can be transmitted along nerve cells

label synapse between two neurons

describe the features of the synapse between two neurons

involves a presynaptic neuron, a postsynaptic neuron, and a synaptic cleft

label the brain

function of frontal lobe

involved in personality, characteristics, decision-making, and movement. also speech ability

function of parietal lobe

involved in identify objects, understanding spatial relationships, interpreting pain and understanding spoken language

function of temporal lobe

involved in short term memory, speech, musical rhythm

function of occipital lobe

involved with vision

function of the cerebellum

coordinate voluntary muslce movement

maintain posture, balance and equilibrum

function of the cerebellum in coordinating voluntary movement, posture, balance

identify parts of the brain stem

function of pons

involved in tear production, chewing, blinking, focusing, vision, balance and facial expression

function of medulla

regulates bodily activities incluyding HR, blood flow, O2 levels

function of oblongata

regulating essential autonomic functions and relaying nerve signals

describe CNS

• central brain system (brain and spinal cord)

• the bodys processing center

Describe PNS

• peripheral nervous system

• the network of nerves that extends outside of brain and spinal cord

describe somatic nervous system

responsible for voluntary movement and sensory information processing

describe ANS

• autonomic nervous system

• regulates involuntary bodily functions without conscious thought including breathing, heart rate

describe sypathetic division

• the "fight-or-flight" branch

• prepares the body for intense physical activity and stress by increasing heart rate, rerouting blood to muscles, and suppressing non-essential functions

describe parasympathetic

• responsible for the rest and digest response

describe general role of the sense in detecting changes in internal and external environmentDescribe

• to act as biological monitoring systems, converting stimuli from the internal and external environment into electrical signals (nerve impulses) that the brain interprets to create perceptions, guide responses, and maintain homeostasis

identify the tongues taste buds

describe the basic taste sensations

(salty, sweet, sour, bitter, unami)

outline the role of chemoreceptors in detecting dissolved chemicals

describe the function of olfactory receptors in nasal cavity

• certain chemical substances become dissolved in the thin layer of fluid covering the surface of mucous membrane and comes into contact with hairs

• activates olfactory bulb which creates nerve signal to olfactory neuron

how is smell information transmitted to the brain

from odorant molecules in the air to the olfactory sensory neurons which convert into electrical signals. These signals then travel along the olfactory nerves through the cribriform plate to the olfactory bulb, the first relay station in the brain

label the main structures of the eye

function of the cornea

to protect the eye and to focus light entering the eye

function of the sclera

acts as a protective outer layer and provides structural support for the eyeball

function of the iris

controls the amount of light entering the eye

function of the pupil

regulates the amount of light entering

function of the lens

focuses light on retina, enables clear vision

function of the retina

converts light into electrical signals that the brain can interpret as visual images

function of the macula

provides sharp, central vision, enabling us to see fine details, reconise faces and read

function of the optic nerve

transmit visual information from the retina to the brain

function of the aqueous humour

keeps your eye inflated and provides nourishment

function of the vitreous humour

maintains eye shape and contributes to image clarity

function of the choroid

nourish the outer retina by supplying it with oxygen and essential nutrients

• stimulates sensory receptors

function of the ciliary body

producing aqueous humour, helping to focus, and maintaining the lens's position

contracts and relaxes ligaments

explain the process of vision

role of rods and cones

• photoreceptor cells in the retina that convert light into neural signals for vision

explain how the eye adjusts for near and far vision

label main structures of the ear

function of the pinna

collect and funnel sound waves into the ear canal

function of the external auditory canal

channel sound waves from the outer ear to the eardrum

function of the tympanic membrane

a sound receiver and transmitter

function of the ossicles

transmit and amplify sound vibrations from the eardrum to the inner ear

function of the malleus

transmit sound vibrations from the eardrum to the incus

function of the incus

to receive sound vibrations from the malleus and transmit them to the stapes

function of the stapes

transmitting sound vibrations from the incus to the inner ear

function of the tympanic cavity

houses and transmits sound vibrations via the ossicles

function of the eustachian tube

to equalize air pressure between the middle ear and the atmosphere

function of the cochlea

to convert sound waves into neural impulses that the brain interprets as sound

function semicircular canals

detect and sense rotational or angular movements of the head

function of the round window

to decompress the fluid-filled cochlea, acting as a pressure release valve for the inner ear's fluid system

function of the vestibulocochlear nerve

hearing and balance

how are sound waves collected by the pinna and travel through the ear canal to vibrate the tympanic membrane

how vibrations are amplified by the ossicles and transmitted to the fluid-filled cochlea

role of hair cells in converting mechanical vibrations into electrical impulses

convert mechanical vibrations from sound waves into electrical signals from mechanotransduction

transmission of auditory information via the auditory nerve to the brain for interpretation

outline role of th esemicircular canals and vestibule in maintaining balance and equilibrium

function of the endocrine system

regulate physiological processes through release of hormones

• metabolism-how body converts food into energy

• growth and development-crucial

• reproduction - controls processes

• homestasis- helps maintain a stable internal environment

• response to stress

• mood and emotions

• immune- helps defend the body from infections

explain how the endocrine system works in conjunction with the nervous system to coordinate and control body activities

describe the stimulus (hormone control)

changes in internal/external environment

drop in blood glucose levels

decribe the receptor (hormone control)

detects change

pancreas

describe the control centre (hormone control)

hypothalamus, putitary glands

describe the effector (hormone control)

target organ or tissue

describe response (hormone control)

change to restore homestasis

liver cells respond to insulin by taking up glucose

describe feedback (hormone control)

often negative feedback to regulate hormone levels

blood glucose levels return to normal

label the glands

hypothalamus hormones

• antidiuretic hormone - regulates water balance by increaseing water reabosorption in the kidneys helping maintain blood pressure by constriciting blood vessels

• dopamine - acts on areas of the brain to give you feelings of pleasure and motivation

pituitary gland hormones

Growth hormone - stimulates growth bones and tissues, protein synthesis, cell regeneration

thyroid stimulating hormone - stimulate the thyroid gland to produce and release thyroid hormones, T3 and T4. regulating metablois, heart rate and body temperature

pineal gland hormone

melatonin - is essential for regulating sleep-wake cycles and circadian rhythm

thyroid gland hormones

thyroxine - increase metablic rate and supports growth and development

calcitonin - lowers blood calcium levels by inhibiting osteoclast and decreasing calcium reabsorption by the kidney

parathyroid gland hormones

adrenal glands hormones

• epinephrine - initiates the "fight-or-flight" response to prepare the body for intense physical exertion

• cortisol - acts as the bodys primary stress response system regulating metabolism, BP, and immune function

pancreas hormone

• insulin - lowers blood glucose by promoting uptake of glucose into cells and stimulating glycogen stoarge in the liver

• glucagon - raises blood glucose by stimulating break down of glycogen in glucose in the liver

ovaries gland hormones

osteogen - regulates the female reproduction system, stimulates secondary sex characteristics maintaning the menstrual cycle and pregnancy, promotes healthy cholestrole levels (overall female health)

progesterone - preparing the uterus for pregnancy by thickening it lining to support a fertilised egg

testes gland hormones

testosterone - to regulate sex drive, bone strength and muscle mass and to promote sperm production

inhibin b - to inhibit the secretion of follicles stimulating hormone from pituitary gland creating a negative feedback loop in the hypothalamic pituitary gonadal access to regulate reproductive functions