Definitions Book 3

Question 1

Sensory receptor

Answer 1

A specialised structure that can detect a specific stimus and convert stimulus energy to a changing membrane potential to be transmitted to CNS as action potentials for sensory perception and interpretation

Question 2

Sensory amplification

Answer 2

During conversion of stimulus energy to action potentials, sensory signals can by strengths by sensory amplification

Question 3

Sensory adaptation

Answer 3

If the stimulation is continuous, many receptors show a decrease in responsiveness

Question 4

Chemoreceptor

Answer 4

Sensory receptors which respond to chemical stimuli

Question 5

Thermoreceptors

Answer 5

Specialised temperature sensitive receptors which detect the heat and cold on the body surface and in internal environment of body

Question 6

Photoreceptor

Answer 6

Sensitive to light

Question 7

Mechanoreceptors

Answer 7

Respond to stimuli arising from mechanical energy deformation such as pressure, touch, stretch, sound and motion

Question 8

Pain receptors

Answer 8

Detect stimuli that reflect harmful conditions that could arise from extreme pressure, temperature and certain chemicals that could damage tissues

Question 9

Endocrine glands

Answer 9

Ductless glands consisting of specialised cells which secrete hormones (chemical messengers) that diffuse directly into the bloodstream and reach specific target organs/tissues

Question 10

Hormone

Answer 10

Specific type of signalling molecule secreted by an endocrine gland/cells which travel the bloodstream and act on specific target cells elsewhere in the body, changing the target cells functioning

Question 11

Target cells

Answer 11

Only cells which have matching receptors for that hormone, and are receptive to chemical signal although the hormone reaches all body cells

Question 12

Trophic hormones

Answer 12

Some hormones secreted by anterior pituitary redirect chemical signals from hypothalamus to other endocrine glands. These are trophic hormones

Question 13

Monocular vision

Answer 13

Seeing the visual field with only one eye

Question 14

Binocular vision

Answer 14

Seeing the visual field with two eyes with greater overlapping fields of view

Question 15

Homeostasis

Answer 15

A steady state condition where the body’s intern environment remains relatively constant within narrow physiological limits despite significant changes in the external environment

Question 16

Internal environment

Answer 16

Immediate surroundings of body cells which provides the cells the medium in which they have to live

Question 17

Response

Answer 17

A physiological activity that helps return the variable towards the set point level

Question 18

Zygote

Answer 18

The 2 haploid pronuclei of the mature ovum and sperm fuse to produce a diploid, single cell known as a zygote

Question 19

Fertilisation

Answer 19

Fusion of haploid pronuclei of sperms and ovum

Question 20

Cleavage

Answer 20

Series of mitotic divisions that occur 24 hrs after fertilisation

Question 21

Implantation

Answer 21

7 days after fertilisation, the blastocyst attaches to endometrium of mothers uterus

Question 22

Placenta

Answer 22

Embryonic trophoblast and the mother’s endometrium intermingles to form placenta

Question 23

Umbilical cord

Answer 23

Flexible cord like structure containing blood vessels and attaches embyro/fetus to the placenta during gestation

Question 24

Pregnancy/gestation

Answer 24

Condition of carrying one or more developing offspring inside a female’s uterus

Question 25

Labour

Answer 25

A series of strong rhythmic uterine contractions that push the fetus and placenta out the body

Question 26

Lactation

Answer 26

Secretion and ejection of mothers milk from mammary glands

Question 27

Contraception

Answer 27

Deliberately preventing pregnancy

Question 28

Abortion

Answer 28

Premature termination of a pregnancy in progress

Question 29

Infertility

Answer 29

Inability to conceive offspring

Question 30

Hydrostatic Skelton

Answer 30

A fluid filled cavity enclosed within body wall

Question 31

Exoskeleton

Answer 31

Rigid outer covering of the body of animal which acts as the skeleton

Question 32

Endoskeleton

Answer 32

Hard skeleton buried in soft tissues of the animal

Question 33

Fontanelles

Answer 33

Soft membranous regions of the cranium which allow slight compressions at birth, facilitating parturition

Question 34

Sutures

Answer 34

Immovable joints present between skull bones to provide more protection

Question 35

Sinuses

Answer 35

Several air filled cavities lined by ciliated mucous membranes present in skull