HUMAN RESPONSES TO THE ENVIRONMENTTwo systems to be studied:

1.Nervous system2.Endocrine system

Introduction• To survive all organisms have to react to

changes in their external and internal environment

• External environment: Environment outside the body for example of factors that might change are temperature, light, etc in their natural environment or habitat.

• Internal environment: Environment inside the body e.g. concentration of CO2, O2, H2O around cells/tissues/organs inside the body.

Introduction (cont.)• Human response to these changes in the

environment occurs to maintain stability/balance within the organism.

• Organisms sense changes in the environment as a stimulus.

• These impulses are send to the brain which interpret the information and sends a different message back to the part of the body telling it how to react.

Homeostasis • The body works hard to keep its internal

environment as constant as possible. • All the organs and systems of the body work

together to create this stable internal condition. • The process of maintaining a constant cell

environment in the body is called homeostasis.• The endocrine and nervous systems, as our co-ordinating systems, play a very important part in regulating homeostasis. • Examples: Blood pressure, glucose levels in the

blood, ect.

Human Nervous system - What to learn:

• Structure of 3 types of neurons, nerve bundles, transmission of an impulse (Making of drawings)

• CNS, Peripheral, Autonomic (sympathetic & parasympathetic), disorders

• Difference between reflex arc and reflex action• Structure (making of drawings) and functioning

of a simple arc, Significance of a reflex arc • Sense organs (Ear and Eye) - Drawings

Co-ordination in Humans

Nervous co-ordination Chemical co-ordination

Central nervous system

Peripheral and autonomic

nervous systems

Sense receptors

and organs

Endocrine system

Feedback mechanisms

Over- & under-

secretion

Human nervous system – is a complex system

Cross-section of the human brain showing the different parts

Functions of certain parts of the brain

Cerebellum• Co-ordinates movements of your voluntary

muscles• Maintains your balance by controlling muscle tension

Functions of certain parts of the brain

Hypothalamus• Controls your blood pressure• Controls your body temperature• Regulates your levels of thirst and hunger• Regulates emotions such as anger and

pleasure• Regulates your sleep patterns

(Control centre for homeostasis)

Functions of certain parts of the brain

Cerebrum • Controls all voluntary muscle actions • Receives and interpret sensations of sight, hearing, taste, smell, touch and speech• Responsible for higher thought processes such as memory, reasoning, judgement and intelligence• Responsible for behaviour and emotions

Functions of certain parts of the brain

Medulla oblongata (same structure as the spinal cord)

• Controls important involuntary actions such as heartbeat and breathing• Enables each half of your brain to control the opposite side of your body• Transmit nerve impulses between the spinal cord and the brain

Functions of certain parts of the brainSpinal cord • Links the brain with all the organs of the body (except those in the head & neck)• Carries sensory information to the brain for interpretation• Carriers then motor information from the brain to the effectors (muscles and glands)• It’s a centre for the reflex action, which enables the body to respond very quickly to harmful stimuli using the reflex arc

A typical nerve cell – A NEURON

Dendrites

Cell membrane

Cell body

Nissl body

Axon

Node of Ranvier

Myelin sheath

Neurilemma

Portion of axon cut out to show great length

Motor end-plates in effector muscle

Structure of a multipolar neuron (motor neuron)

Nucleus of Schwann cell

Schwann cell

Impulse direction

NERVE BUNDLE

Reflex Arch

Reflex Arch

REFLEX ARC

SPINAL CORD

DISORDERS

DISORDERS

INJURED NERVE AGING BRAIN

LEARNER ACTIVITIES• Label brain, spinal cord and neuron diagrams• Practical using sheep brain, slides• Table of parts and function of all the above• Describe reflex action using a diagram as a

guide and give significance• Group work : effect of drugs on CNS-

presentation• Write short notes on Alzheimer’s Disease and

Attention Deficit Disorder

EYE

• Structure of eye and function of parts.- 1 lesson

• Formation of an image ,Binocular vision -1 lesson

• Accomodation-,Pupillary mechanism -1 lesson• Disorders – homework – 1 lesson

LEARNER ACTIVITIES• PRACTICAL – demonstrate blind spot, dissect

eye of sheep, pig etc• Label diagram of human eye.• List functions of parts of eye• Using diagrams describe in writing formation

of an image,accomodation, binocular vision,pupillary mechanism

• Homework- notes on long and short sightedness, astigmatism,cataracts

EAR

• Structure and functions of parts of ear,adaptations of parts of ear – 1 lesson

• Hearing and balance – 1 lesson• Hearing defects(infections and deafness)-1

lesson• Link deafness and speech disorders,Sign

language,Attitudes to deaf and blind,Rights of deaf and blind – 1 lesson

LEARNER ACTIVITIES

• Label diagram of ear• Write notes on adaptions of parts of an

ear(homework and feedback)• Describe hearing and balance functioning of

ear in writing ( open book after explanation by teacher)

• Cause and treatment of disorders – homework• Discussion on attitudes,sign language,rights of

blind and deaf

DIAGRAMS OF EAR

INNER EAR

FAR SIGHTEDNESS

HUMAN ENDOCRINE SYSTEM• Definition of chemical

coordination,differences between endo and axo crine glands,characteristics of hormones (30 minutes)

• Location and functions of hormones,negative feedback ( 1.5 lessons)

• Disorders: diabetes,hypo/hyper thyroidism,growth disorders, infertility (homework/feedback – 1 lesson)

HUMAN ENDOCRINE SYSTEM

GLANDS

GLANDS

GLANDS

GONADS

RELATIONSHIP BETWEEN GLANDS/ORGANS

REGULATION BETWEEN NERVOUS/ENDOCRINE SYSTEM

NEGATIVE FEEDBACK

ASSESSMENT DIAGRAMS

DISORDERS

TYPE 1 DIABETES

INSULIN PRODUCTION AND DIABETES

MENSTRUAL CYCLE

PITUITARY & OVARIAN HORMONES

REGULATION BETWEEN NERVOUS &ENDOCRINE SYSTEMS

SWEAT GLANDS

HORMONE ACTIONSTIMULATES SWEAT GLANDS

Sweat glands

VASODILATION AND VASOCONSTRICTION

PALM SWEATING

VASODILATION AND VASOCONSTRICTION

GRAPH FOR ASSESSMENT

GRAPH FOR ASSESSMENT

HOMEOSTASIS

NEGATIVE FEEDBACK –COLD EXPOSURE